Littérature scientifique sur le sujet « Postharvest »
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Articles de revues sur le sujet "Postharvest"
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Amilia, Winda, Andrew Setiawan Rusdianto, and Sayidati Zulaikhah. "Edible Coatings to Reduce Postharvest Loss of Harumanis Mango (Mangifera indica L.)." Journal La Lifesci 1, no. 3 (July 22, 2020): 1–7. http://dx.doi.org/10.37899/journallalifesci.v1i3.105.
Texte intégralRésumé :
Harumanis is type of mango in Indonesia that meets the needs of export or local markets. Harumanis mango have not been able to fully boost the rate of export of this Indonesian fresh fruit due to poor postharvest technology. This condition has an adverse impact as it increases postharvest loss. Thus, in these conditions there must be postharvet handling of harumanis mango, one of which is edible coating made from chitosan with the addition of starch. The difference in the value of amylose and amylopectin from starch resulted in differen results. The aim of this research was to determine the effect of addition of starch types in chitosan edible coating on the postharvest loss of harumanis mango based onthe physico-chemical tests. The experiment used completely randomized design with two factor. The parameters observed were physical test including weight loss, texture, and color. Chemical test including respiration rate, vitamin C, and total soluble solids. The result showed that the addition of starch on chitosan edible coating significantly affected postharvest loss to the results of physical and chemical tests. The best treatment was the addition of starh to edible coating with chitosan because it can provide physical and chemical defense during storage at room temperature.
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Martins, Carlos Roberto, Alexandre Hoffmann, Cesar Valmor Rombaldi, Roseli de Mello Farias, and Adenir Vieira Teodoro. "Apple biological and physiological disorders in the orchard and in postharvest according to production system." Revista Brasileira de Fruticultura 35, no. 1 (March 2013): 1–8. http://dx.doi.org/10.1590/s0100-29452013000100001.
Texte intégralRésumé :
The study aimed to evaluate the incidence of biological and physiological disorders in the field and postharvested apples cvs. Gala, Fuji and Catarina grown in four production systems: conventional, organic transition, integrated and organic. Apples were evaluated for damages related to biological and physiological disorders in the orchard and after harvest. The greatest damages were attributed to pests, especially Anastrepha fraterculus in the organic system and Grapholita molesta in the organic transition. Apples produced in organic orchards had higher damage levels caused by postharvest physiological disorders than those grown in other production systems. For apples becoming from organic orchards most of the damage was due to lenticels breakdown and degeneration ('Gala'), and bitter pit ('Fuji' and 'Catarina'). The incidence of postharvest rot was not influenced by apple production system.
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Maynard, Donald N. "Postharvest Biology." HortScience 40, no. 7 (December 2005): 1936. http://dx.doi.org/10.21273/hortsci.40.7.1936.
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Pedreschi, R., M. Hertog, and B. M. Nicolaï. "POSTHARVEST PROTEOMICS." Acta Horticulturae, no. 877 (November 2010): 75–80. http://dx.doi.org/10.17660/actahortic.2010.877.4.
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Nicolaï, B. M., R. Pedreschi, A. Geeraerd, T. Vandendriessche, and M. L. A. T. M. Hertog. "POSTHARVEST METABOLOMICS." Acta Horticulturae, no. 880 (November 2010): 369–76. http://dx.doi.org/10.17660/actahortic.2010.880.44.
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Gathambiri, CW, WO Owino, S. Imathiu, and JN Mbaka. "Postharvest losses of bulb onion (Allium cepa L.) in selected sub-counties of Kenya." African Journal of Food, Agriculture, Nutrition and Development 21, no. 02 (March 24, 2021): 17529–44. http://dx.doi.org/10.18697/ajfand.97.20145.
Texte intégralRésumé :
Inappropriate postharvest practices such as unsuitable harvesting methods and inadequate curing in bulb onion lead to losses. Postharvest losses in bulb onion contribute to food and nutrition insecurity. Although Kenya has suitable environmental conditions for bulb onion production, its productivity is low, which is attributed to pre-and postharvest factors. Information on bulb onion postharvest losses and their causes in the country is scanty which limits the development of postharvest losses reduction strategies. Therefore, this study was carried out in three major bulb onion growing sub-counties of Kenya namely Mt.Elgon, Buuriand KajiadoEastto determine postharvest practices, causes, and factors influencing postharvest losses of bulb onion. A multi-stage sampling design was used to select the study areas and a total of 166respondents were randomly selected. Face-to-face interviews were conducted using a structured questionnaire to collect information on postharvest handling practices, postharvest loss levels, and their causes at farm level. Data were subjected to descriptive and logistic regression analysis using Statistical Package for Social Scientists(SPSS) software version 2.0. Results indicated that 68% of the respondents were males and with an average age of40 years in the three sites. Forty-eight percent of the respondents used leaves toppling, and 25% used drying of upper leaves as maturity indices. About 42% of the respondents used machete (panga) as a harvesting tool which significantly (P<0.05) influenced postharvest losses. Seventy seven percent of the respondents indicated that up to 30% of postharvest losses occurred at farm level. Forty percent of the respondents indicated that bulb onion rots caused 10 % loss at farm level. The level of education and mode of transport (bicycles and donkeys) significantly (P<0.05) influenced postharvest losses. It was concluded that the postharvest losses at farm levelwas30%andwere mainly caused by rotting. Socio-economic characteristics and postharvest handling practices influenced bulb onion losses at farm level. Development of postharvest losses reduction strategies on bulb onions focusing on alleviating rotting through appropriate postharvest handling practices at farm level was recommended.
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Kutyauripo, Innocent, Blessing Masamha, and Peter Maringe. "Exploring climate change adaptation strategies in maize (Zea mays) postharvest management practices among smallholder farmers." Outlook on Agriculture 50, no. 2 (April 8, 2021): 148–57. http://dx.doi.org/10.1177/00307270211001666.
Texte intégralRésumé :
Climate change has negative effects on postharvest management of cereals. However, much emphasis is placed on climate change adaptation (CCA) in crop production whilst not adequately addressing the CCA in postharvest management of maize. A cross-sectional survey was conducted among smallholder farmers. Key informant interviews, observations and structured interviews on 280 household heads were done. Binary logistic regression was used to analyse determinants of use of postharvest CCA practices whilst multinomial logistic regression was used to analyse determinants of use of postharvest storage facilities. Farmers used grain protectants (40.4%) and minimised the duration of the harvesting process (34.3%) as their major CCA practices in maize postharvest management. There was a significant difference in postharvest maize loss quantities ( p ≤ 0.05) between users and non-users of CCA practices. The choice and use of climate-resilient postharvest strategies were significantly influenced by location, cultivated land, access to radio and membership to farmer club. Choice of a postharvest storage facility was significantly influenced by training and membership to farmers’ club. Smallholder farmers are using some conventional maize postharvest management practices like grain protectants to adapt to the effects of climate change. The use of maize postharvest CCA strategies significantly reduced postharvest losses.
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Ansah, Isaac Gershon Kodwo, and Bright K. D. Tetteh. "Determinants of Yam Postharvest Management in the Zabzugu District of Northern Ghana." Advances in Agriculture 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/9274017.
Texte intégralRésumé :
Postharvest loss reduction has received attention in many policy documents across nations to ensure global food security, particularly in developing countries. Many researchers have examined various options for reducing postharvest losses. We contribute our quota to this scientific discourse by using a different approach. We argue that the human element of managing postharvest loss is central and therefore poses the question of what are the characteristics of the farmer who manages postharvest losses better. We examine this question by using a cross section of yam farmers in the Zabzugu district in Northern Ghana and generate a proportional variable called postharvest management, which measures how effective a farmer works to reduce storage losses. We then use a fractional logistic regression model to examine the determinants of postharvest management. A significant result is that subsistence farmers manage postharvest losses better than commercial farmers. Characteristically, the farmer who effectively manages postharvest losses is a young, subsistence farmer, living in or close to a district capital with fewer household members, has attained formal education, and produces more yam. Efforts to reduce postharvest losses require the provision of access roads to remote towns or providing effective storage techniques and training on postharvest management practices.
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Stieve, Susan M., and Dennis P. Stimart. "051 GENETIC ANALYSIS OF POSTHARVEST LONGEVITY IN ANTIRRHINUM MAJUS L." HortScience 29, no. 5 (May 1994): 435c—435. http://dx.doi.org/10.21273/hortsci.29.5.435c.
Texte intégralRésumé :
Selecting for increased postharvest longevity through use of natural variation is being investigated in Antirrhinum majus (snapdragon) in order to decrease postharvest chemical treatments for cut flowers. The postharvest longevity of eighteen white commercial inbreds was evaluated. Twelve stems of each inbred were cut to 40 cm and placed in distilled water. Stems were discarded when 50% of spike florets wilted or browned. Postharvest longevity ranged from 3.0 (Inbred 1) to 16.3 (Inbred 18) days. Crossing Inbred 18 × Inbred 1 yields commercially used Hybrid 1 (6.6 days postharvest). The F2 population averaged 9.1 days postharvest (range 1 to 21 days). F3 plants indicate short life postharvest may be conferred by a recessive gene in this germplasm. Populations for generation means analysis as well as hybrids between short, medium and long-lived inbreds were generated and evaluated for postharvest longevity.
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Çelikel, Fisun Gürsel. "Organik Bahçe Ürünlerinin Hasat Sonrası Kalitelerinin Korunması." Turkish Journal of Agriculture - Food Science and Technology 6, no. 2 (March 3, 2018): 175. http://dx.doi.org/10.24925/turjaf.v6i2.175-182.1532.
Texte intégralRésumé :
Not only cultural treatments in orchard but also postharvest handling affect the taste, shelf life and nutritional quality of organic fruits and vegetables. Organic crops are mostly harvested at ripe stage or close to ripen, thus, their shelf life is shorter and they are more perishable. Postharvest physiology and requests of crops should be considered during postharvest handling in order to maintain their high quality and prevent postharvest losses. The main aim in postharvest concept is to slow down the metabolism of fresh crops continue to live after harvest. The most important factor is temperature. The fruits and vegetables should be protected from high temperatures and cooled immediately after harvest. The cold chain should be kept until consumer. In addition, diseases can be prevented by controlling environment. Sanitation is another rule to consider. All these rules are important for all growers; however they are of special importance for organic horticulture which allows limited postharvest technologies. In this review, the allowed postharvest treatments of certificated organic fruits and vegetables are given. Preharvest factors, harvest, postharvest factors, cooling methods, cold storage, sanitation methods and products, ethylene and its control, and other specific postharvest subjects are discussed.
Thèses sur le sujet "Postharvest"
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Peck, Leslie Kathryn. "Pre- and Postharvest Practices for Optimizing the Postharvest Quality of Cut Sunflower, Dahlia, and Delphinium." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/73589.
Texte intégralRésumé :
The primary objective of this research was to identify practices by which specialty cut flower growers can extend the vase life of cut delphinium, sunflower, and dahlia. Experiments investigated the effects of nitrogen fertilization rate on delphinium 'Guardian Mix' and the effects of deficit irrigation on delphinium 'Guardian Blue.' 'Guardian Mix' plants produced marketable cut stems at nitrogen rates as low as 50 mg/L. Deficit irrigation did not change vase life, stomatal conductance, or transpiration rates of delphinium 'Guardian Blue.' Studies tested the effects of foliar calcium applications or benzyladenine application on sunflower 'Moulin Rouge' and 'Procut Lemon.' Calcium did not change the vase life, stomatal conductance, or transpiration rates of either sunflower cultivar. Benzyladenine applied as a preharvest spray or a postharvest dip did not alter vase life of sunflower 'Moulin Rouge' or 'Procut Lemon.' Transpiration rate and conductance rates of sunflowers significantly decreased in the first three days after harvest. In both sunflower experiments, vase life of 'Moulin Rouge' was shorter than vase life of 'Procut Lemon.' Benzyladenine was also applied to dahlia 'Park Princess' and 'Karma Yin Yang' cut flowers. Benzyladenine did not change dahlia vase life. Dahlia 'Park Princess,' 'Bride to Be,' 'Cherish,' and 'Lollipop' cut flowers were not sensitive to exogenous ethylene. Further experiments tested the effect of flower stage at harvest, vase water temperature, or preharvest fungicide application on dahlia 'Park Princess' and 'Karma Yin Yang' cut flowers. Vase life of 'Park Princess' flowers was extended when flowers were harvested before fully open, but 'Park Princess' flowers harvested at budbreak failed to open completely after harvest. 'Karma Yin Yang' cut flower vase life did not differ when flowers were harvested at different stages. Placing cut dahlias in hot vase water had varied effects, but did not extend vase life of either cultivar. Fungicide applications extended vase life of 'Park Princess' flowers. However, the use of fungicide is not necessary to prevent postharvest fungal infection in cut dahlias. The results of all experiments indicate that optimal handling practices vary between cut flower taxa and that factors determining cut flower vase life are complex.<br>Master of Science
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Daniel, Chanel Karousha. "The effect of garlic extracts on the control of postharvest pathogens and postharvest decay of apples." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86544.
Texte intégralRésumé :
Thesis (MSc)--Stellenbosch University, 2014.<br>ENGLISH ABSTRACT: Apples are an important export commodity for the South African market, and
postharvest losses that occur as a result of decay due to infection with pathogenic fungi such
as Botrytis cinerea Pers., Penicillium expansum (Link) Thom. and Neofabraea alba (E.J.
Guthrie) are of major concern for all parties concerned with fruit production and distribution.
Decay control of these fungi is primarily managed through the use of synthetic
fungicides; however, pathogen development of resistance to these fungicides and recent
worldwide concern over healthier living and a greener environment has called for the
discriminate use of synthetic chemicals. This has opened up an avenue for the development
of safer and more environmentally friendly alternatives to control postharvest decays. The
use of plant extracts and essential oils are favoured as natural sources of antimicrobials whilst
still being safe for human consumption and having no negative impact on the environment.
Allium sativum (garlic) is one such plant species that is well documented for its value
in improving human health and is readily available for consumption not just as a flavour
component of food but also to be taken as a daily herbal diet supplement. Given the
antimicrobial effectiveness of garlic against human pathogens and ailments, its value as an
antifungal agent against postharvest pathogens causing grey mould, blue mould and bull’s
eye rot of apples was investigated in vitro and in vivo within this study. Furthermore, an
attempt was made to elucidate the chemical components of garlic extracts by gas
chromatography-mass spectrometry (GC-MS). All experiments in this study were carried out with garlic extracts prepared from fresh
garlic bulbs. For the in vitro experiments, two extract preparations of garlic, one containing
ethanol (Extract 1) and one where ethanol had been removed by evaporation (Extract 2), was
tested for antifungal action within an amended media experimental design. Both extract
preparations were each subjected to two dilution series (0-80% garlic extract) with water and
ethanol as diluents. Both extract preparations were successful at retarding pathogen mycelial
growth and spore germination; however, concentrations of Extract 2 (ethanol evaporated) and
diluted with distilled water provided markedly better inhibition of B. cinerea and
P. expansum than the ethanolic dilutions of extract 2. Both extract preparations yielded
similar inhibitory results when tested against N. alba. Due to the results achieved in the
amended media experiments, the use of a crude garlic extract without ethanol and diluted in water was considered to be the best option for further tests throughout the remainder of the
study. In vitro volatile effects of crude garlic extracts at concentrations between 0 and 40%
garlic extract were subsequently tested. Garlic volatiles were effective in inhibiting pathogen
mycelial growth and spore germination of all three pathogens, at lower concentrations
compared to the amended media experiments. In vitro volatile exposure with garlic extracts
was more effective at inhibiting N. alba than direct application of the extracts.
Curative and protective application of garlic extracts and clove oil for increased
fungal inhibition through synergism was tested by direct and volatile exposure to the
pathogens in vivo on three economically important apple cultivars; ‘Granny Smith’, ‘Golden
Delicious’, and ‘Pink Lady’. Direct exposure of artificially wounded and inoculated fruit to
the garlic extract and clove oil revealed that garlic extracts applied curatively but not
protectively effectively controlled decay caused by B. cinerea and P. expansum on all apple
cultivars. Both curative and protective applications were ineffective in controlling N. alba. In
vivo volatile exposure to the garlic extracts and clove oil did not inhibit decay on any of the
cultivars and was not effective against any of the three pathogens investigated.
A full chemical profile analysis was done by GC-MS analysis of garlic extract
samples. The compounds diallyl disulphide, allyl methyl trisulphide, allyl methyl disulphide
and dimethyl trisulphide were detected in relatively high amounts. This result suggests that
the abundance of sulphur and sulphur related compounds detected may be responsible for the
antifungal action noted in the experimental studies. In conclusion, garlic was shown to have antifungal activity against B. cinerea,
P. expansum and N. alba. The pathogens used in this study were not compared with each
other, but undoubtedly each pathogens reacts differently to exposure to the garlic extracts. It
would therefore be advisable to investigate the effects of the extracts on each of the
pathogens in a more in-depth study. More investigations into the application of the garlic
extracts is required before it may be recommended for use; however, results for the use of
garlic extracts against these postharvest pathogens and the postharvest decay they cause are
promising.<br>AFRIKAANSE OPSOMMING: Appels is ‘n belangrike uitvoerproduk vir die Suid-Afrikaanse vrugtebedryf, maar
noemenswaardige na-oes verliese word weens bederf deur patogeniese swamme soos Botrytis
cinerea Pers., Penicillium expansum (Link) Thom. en Neofabraea alba (E.J. Guthrie) ervaar.
Dit raak alle partye betrokke met die produksie en verspreiding van hierdie vrugsoort.
Hierdie swamme word hoofsaaklik met behulp van kunsmatige swamdoders beheer,
alhoewel weerstand-ontwikkeling en wêreldwye bewusmaking van ‘n gesonder leefstyl en
omgewing die gebruik van kunsmatige middels streng aanspreek en die ontwikkeling van
veiliger en meer omgewingsvriendelike alternatiewe middels verlang. Plant-ekstrakte en
essensiële olies kan dien as sulke middels en is natuurlike bronne van anti-mikrobiese
aktiwiteit, is veilig vir menslike verbruik en het ook geen negatiewe invloed op die
omgewing nie. Allium sativum (knoffel) is so ‘n plantspesie wat as alternatiewe middel
gebruik kan word. Dit is bekend vir sy waarde in die verbetering van menslike gesondheid, is
maklik bekombaar en word nie net as ‘n geurmiddel vir voedsel gebruik nie, maar ook as ‘n
daaglikse krui-aanvulling. Gegewe die anti-mikrobiese doeltreffendheid van knoffel teenoor
menslike patogene en kwale, is die werking (in vitro en in vivo) teen na-oes patogene wat
grys skimmel, blou skimmel en teikenvrot in appels veroorsaak, in hierdie studie ondersoek.
Bepaling van die chemiese samestelling van die knoffel-ekstrak is ook met behulp van gaschromatografie
massa spektrometrie (GK-MS) onderneem.Vars knoffelbolle is vir elke
eksperiment in hierdie studie gebruik met die voorbereiding van die knoffel-ekstrak. Vir die
in vitro eksperiment is twee knoffel-ekstrakte voorberei, naamlik: ‘n ekstrak wat etanol bevat
(Ekstrak 1) en een waarvan die etanol verwyder is met verdamping (Ekstrak 2). Die ekstrakte
is getoets vir werking teen fungi in kultuur-medium.. Albei ekstrakte is verdun tot twee
konsentrasie reekse (0-80%) met water en etanol as verdunningsmiddels. Albei ekstrakte het
suksesvolle werking getoon teenoor die patogene ten opsigte van vertraging van miseliumgroei
en spoor-ontkieming, alhoewel konsentrasies van Ekstrak 2, verdun met gesuiwerede
water, patogene B. cinerea en P. expansum beter onderdruk het as Ekstrak 2 verdunnings
met etanol.. Beide ekstrakte en hul afsonderlike verdunnings met etanol en water het
soortgelyke resultate gelewer met onderdrukking van N. alba.
Volgens resultate wat verkry is van die kultuur-medium eksperimente, is Ekstrak 2
verdun met gesuiwerde water beskou as die geskikste vir verdere toetse in hierdie studie. Die vlugtige effek van Ekstrak 2 is in vitro getoets by konsentrasies tussen 0 tot 40%. Die
vlugtige stowwe van knoffel het al drie patogene se groei en spoor-ontkieming effektief
onderdrukby laer konsentrasies as wat gebruik is in die kultuur-medium eksperiment. Dus is
in vitro blootstelling van N. alba aan die vlugtige stowwe meer effektief as direkte toediening
van die ekstrakte.
Die voorkomende en beskermende effek van die knoffel-ekstrak, asook naeltjie-olie,
is in vivo ondersoek om te bepaal of die stowwe saam sterker onderdrukking van die
patogene kon bewerkstellig. Direkte en vlugtige blootstelling is op drie ekonomies-belangrike
appel-kultivars getoets, naamlik: ‘Granny Smith’, ‘Golden Delicious’ en ‘Pink Lady’. Direkte
blootstelling met die knoffel-ekstrak en naeltjie-olie aan gewonde en ge-inokuleerde vrugte
het aangedui dat B. cinerea- en P. Expansum-bederf net beheer kon word indien knoffel
voorkomend toegedien is vir al die ondersoekte appel-variëteite. Voorkomende en
beskermende toediening was onsuksesvolle om N. alba te beheer. In vivo blootstelling van
die drie patogene aan die knoffel-ekstrak en naeltjie-olie se vlugtige stowwe kon nie enige
van die patogene effektief onderdruk nie en was onsuksesvol in bederf-beheer.
‘n Volledige chemiese profiel is saamgestel deur GK-MS ontleding van die knoffelekstrakte.
Hoë vlakke van verbindings dialliel disulfied, alliel-metiel-tri-sulfied, alliel-metieldisulfied
en dimetiel-trisulfied is bespeur. Die aantal vrye sulfied en sulfied-verwante
verbindings in die ekstrak kan moontlik ‘n verduideliking bied vir die anti-swam werking
waargeneem gedurende hierdie studie. Ten slotte: knoffel toon ‘n anti-swam werking teenoor B. cinerea, P. expansum en N.
alba. Die patogene in hierdie studie is nie met mekaar vergelyk nie, omdat elkeen uniek en
uiteenlopend op knoffel reageer het. Alhoewel die huidige studie alreeds belowende resultate
gelewer het, moet die ekstrak se effek op elke patogeen onderskeidelik nog in diepte
ondersoek word, asook die wyse van die toediening in die na-oes praktyk voordat hierdie
middel aanbeveel kan word vir gebruik.
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Auret, Erika Elizabeth. "Control strategies for citrus postharvest diseases." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-06192006-084845.
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Shah, Hafiz Muhammad Shoaib. "Postharvest quality management of Rubus berries." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2025. https://ro.ecu.edu.au/theses/2912.
Texte intégralRésumé :
Rubus berries are a highly sought after, nutritious, and delicate fruit which are consumed around the globe either as fresh, processed, or frozen since. The fruit is fragile and prone to higher postharvest losses due to incidence of decay, higher moisture loss, cell wall degradation and postharvest oxidative damage, leading to reduced levels of bioactive compounds such as phenolics, flavonoids, ascorbic acid, and anthocyanins. This project aimed to evaluate different pre- and postharvest interventions for their ability to extend the storage life and quality management of Rubus berries during low temperature storage at 2 ºC and 85 ± 2 % relative humidity (RH). The effects of preharvest melatonin (MLT) spray application on postharvest quality of blackberries and raspberries were investigated during cold storage. Following harvest, raspberries were cold stored for 10 days with 5-day storage intervals while blackberries were cold stored for 12 days with 4-day storage intervals. The results indicated that preharvest MLT application significantly reduced red drupelet reversion (RDR) in blackberries. Preharvest MLT treatment suppressed moisture loss, decay incidence, degradation of anthocyanins, flavonoids and phenolics, production of reactive oxygen species (ROS) and lipid peroxidation, while upregulating ascorbate-glutathione cycle, catalase, and superoxide dismutase activities in Rubus berries as compared to control fruit. The effects of preharvest methyl jasmonate (MeJA) on RDR, phenolic biosynthesis, lipid peroxidation, ROS metabolism and antioxidant capacity of blackberries were also investigated. MeJA-treated blackberries exhibited higher endogenous phenolic biosynthesis, with higher phenylalanine ammonia lyase (PAL) activity. Anthocyanin degradation was suppressed, resulting in a reduction of RDR in MeJA-treated blackberries than in control fruit. MeJA application improved ROS neutralisation by increasing the activity of antioxidant enzymes, ascorbic acid, and glutathione levels during 12-day cold storage. As compared to control fruit, preharvest MeJA application reduced fruit softening in raspberries, maintained higher levels of insoluble pectin and cellulose, and reduced the activity of cell wall hydrolysing enzymes including cellulase, pectin methyl esterase and polygalacturonase during 10-days storage at 2 ºC. Higher levels of phenolics were observed in raspberries treated with MeJA as compared to control fruit. The efficacy of polyimide based multilayer modified atmosphere packaging (MAP) was evaluated to determine its role in preserving levels of bioactive compounds and postharvest quality of Rubus berries. MAP alleviated fruit decay incidence and maintained higher soluble solids concentrations, ascorbic acid, total antioxidants, and glutathione in both raspberries and blackberries, than in control fruit. Higher activity of phenolic biosynthetic enzymes including PAL and shikimate dehydrogenase were also noted in Rubus berries stored in modified atmosphere (MA) conditions. The degradation of fruit colour was also delayed due to higher anthocyanin and flavonoid levels in MA-packed Rubus berries. The effect of different relative humidity (RH) levels (75, 85, 95 %) during cold storage at 2°C on moisture loss and postharvest quality of Rubus berries during 10- days cold storage was evaluated. The results indicated that an RH level of 95 % suppressed moisture loss from Rubus berries, while higher fruit decay was observed at the same RH in raspberries as compared to fruit stored at 85 % RH. Fruit subjected to 85 % and 95 % RH had higher titratable acidity, ascorbic acid, total phenolics and flavonoids after 10 days cold storage than those stored at 75 % RH. Higher glutathione content, monomeric anthocyanin pigment and total anthocyanins were noted both in blackberries and raspberries during cold storage at 85 % RH. Fruit quality of Rubus berries deteriorated more rapidly during storage at 75 % RH, while storage at 95 % RH level caused higher fruit decay in raspberries. In conclusion, the oxidative damage in Rubus berries during cold storage was mitigated by preharvest MLT and MeJA application as well as by using MAP storage, which was associated with higher phenolics biosynthesis, delayed moisture loss and decay incidence, and upregulation of the ascorbate-glutathione cycle, as well as delayed lipid peroxidation and ROS accumulation. The storage life of blackberries could be extended with preharvest application of MLT (100 µmol L-1 ) and MeJA (1 mmol L-1 ), two weeks before anticipated harvest. Preharvest application of MLT (100 µmol L-1 ) and MeJA (2 mmol L-1 ) three days before tentative harvest maturity extended the postharvest storage life and quality. Fruit senescence was lower, and postharvest quality was higher in Rubus berries stored in polyamide-based MAP than in control. Cold storage of raspberries and blackberries for 10 days at 85 and 95 % RH levels could maintain relatively better postharvest quality. Although the storage life of Rubus berries could be extended by applying different pre and postharvest interventions, the efficacy of each intervention depends on fruit quality at treatment, harvest maturity, storage duration and conditions (relative humidity), and plant species.
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Pangaribuan, Darwin H. "Postharvest physiology of fresh-cut tomato slices /." [St. Lucia, Qld.], 2005. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19021.pdf.
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Hewage, Kalehe Sarananda. "Factors influencing postharvest longevity of Embul bananas." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307677.
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Galli, Federica. "RIPENING AND POSTHARVEST MANAGEMENT OF PAWPAW FRUIT." UKnowledge, 2007. http://uknowledge.uky.edu/gradschool_diss/507.
Texte intégralRésumé :
Pawpaw (Asimina triloba (L.) Dunal) has significant potential as a new fruit crop. During ripening, loss of firmness is extremely rapid, and this trait may be the biggest obstacle to the development of a broader market as handling without injury is difficult. Cold storage of pawpaw seems limited to 4 weeks at 4 C. A study of several cultivars with commercial appeal showed that ripening traits such as ethylene production, respiration and loss of firmness were similar in all genotypes, and that no cultivar showed superior responses to cold storage. Cold storage for longer than 4 weeks caused the development of cold injury symptoms such as black discoloration, rapid loss of firmness, impaired respiration, tissue acidification, decrease in antioxidant content, decrease in volatile ester production and development of off-flavor volatile compounds. Overall cold storage injury symptoms observed in pawpaw may be due to oxidative damage linked to the failure of the two major antioxidant systems that could protect against such damage: phenolics and the ascorbateglutamate system. With the aim of enhancing pawpaw low temperature tolerance and prolonging cold storage length, different techniques such as hot air exposure and hot water dips of fruit prior to beginning cold storage, and intermittent warming periods during cold storage, were evaluated. Despite positive results with these techniques for other commodities, all the strategies failed to appreciably alter fruit ripening, loss of firmness or maintain fruit quality during and/or after cold storage.
8
Van, Hoorn A. T. (Aaltje Trientje). "Optimisation of blueberry postharvest handling and storage." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/20906.
Texte intégralRésumé :
Thesis (MScAgric)--University of Stellenbosch, 2004.<br>ENGLISH ABSTRACT: By world standards South Africa’s contribution to fresh blueberry production is very
small, a mere 0.25 %. This seemingly insignificant and unimpressive statistic is,
however, by no means indicative of the impending impressive potential the South African
blueberry industry holds. South Africa is encountering a rapid growth phase off a very
small base and the current 100-150 ton export crop is expected to increase to a range of
500 to 600 tons or more in the next five years. Consequently, export by sea must be
considered as a logistic alternative. Seafreight success relies on controlled atmosphere
storage which in turn relies on berries of exceptional quality. To achieve this,
fundamental differences between blueberry cultivars must be examined and blueberry
handling and storage regimes must be assessed and optimised.
This study investigates the storage potential of certain rabbiteye blueberries relative to
controlled atmospheres and short pre-cooling delays. Quality assessments were based on
external colour, soluble solids, titratible acidity, firmness and decay development.
Furthermore, the respiration and ethylene production rates as well as moisture loss, of
various cultivars were determined to characterize fundamental differences amongst
cultivars and to gain insight into their postharvest behaviour. Lastly the effect of infection
on pigment levels of blueberry flesh and peel was examined for the purpose of laboratory
experience.
Controlled atmosphere storage had the greatest impact on berry firmness and percentage
decay. No off flavours were detected during sensory analysis at the CA levels tested. CAstored
berries were firmer and incidence of decay was reduced significantly. Significant
decay reduction was challenged by the market tolerance of no more than 2 %. Decay
suppression and storage extension was insufficient (for the set period), particularly after
the shelf life period. Cultivar and seasonal differences as well as picking maturity and
inoculum pressure determine blueberry CA storability. CA may be a valuable technology,
however advances must first be made in ensuring optimal blueberry quality to warrant
export by sea. Short pre-cooling delays (0, 2, 4, 6 h) at 20 ºC had no effect on colour (L, C, H), total
soluble solids, titratable acidity and firmness of blueberry cultivars, ‘Centurion’,
‘Premier’ and ‘Tifblue’. Results for percentage decay indicate that prompt cooling
becomes more critical as the duration of storage increases, particularly when market
specification of no more than 2 % decay must be met. Berries subjected to longer delays
appear to be more susceptible to decay. Differences exist among cultivars and knowledge
gained from this research can be used to adapt handling and cooling regimes. Information
generated will benefit cultivar selection for marketing (local vs. export), storage (short vs.
long term) and logistics (air vs. seafreight).
Rabbiteye blueberry cultivars differ considerably in terms of their respiration rate,
ethylene production and moisture loss. These quality parameters were evaluated for
various cultivars at 15 ºC. ‘Climax’ appears to have the highest respiration rate, ethylene
production and moisture loss, whilst ‘Premier’ has the lowest respiration rate and
ethylene production was too low to be detected by gas chromatography. The lowest
moisture loss proportionality constant was found for ‘Tifblue’ and ‘Centurion’.
A change in blueberry flesh colour from white to dark red was noted in infected berries.
Artificial inoculation with Botrytis cinerea showed a similar result. The colour change
was evaluated by comparing anthocyanin pigment levels (determined by
spectrophotometry and HPLC) of the peel and flesh. Anthocyanin content of infected
flesh doubled, whilst that of infected peel was less than 50 % of the control. Pigment
leakage has been reported in blueberries. It would appear that cell disruption, induced by
infection may facilitate migration of anthocyanin from the peel to the flesh.
The storage potential of blueberries depends on cultivar, maturity at harvest, climatic
conditions as well as the inoculum pressure. Under favourable conditions storage life of
blueberries can be manipulated effectively. Further cultivar specific research that targets
relevant quality issues should be investigated. Reliable techniques should be developed to
quantify blueberry firmness changes. Research on inoculum levels may give insight into the reduction of decay pressure and decay suppressing alternatives such as antibacterial
pads can be examined. Peel integrity relative to decay susceptibility can also be
researched on a cellular level.<br>AFRIKAANSE OPSOMMING: Suid-Afrika se bydrae tot wêreld bloubessie produksie is baie klein, ‘n skrale 0.25 %.
Hierdie onindrukwekkende statistiek weerspieel egter glad nie die indrukwekkende
potensiaal van die Suid-Afrikaanse bloubessie bedryf nie. Die bedryf ondervind tans ‘n
dramatiese groei met ‘n klein begin vanaf die huidige 100-150 ton opbrengs tot wat
volgens verwagting binne die volgende vyf jaar sal styg tot in die orde van 500-600 ton.
Na aanleiding van die verwagte toename in produksie, sal seevrag verskeping oorweeg
moet word as alternatief vir uitvoer eerder as lugvrag. Die sukses van seevrag lê in die
gebruik van beheerde atmosfeer opberging (BA), waarvan die sukses op sy beurt bepaal
word deur bessies van hoogstaande kwaliteit. Om steeds aan die verwagtings van die
oorsese mark te voldoen moet grondliggende verskille tussen bloubessie kultivars
ondersoek word en daaropvolgend moet hantering en opbergingstelsels aangepas en
geoptimeer word.
Die navorsing bestudeer die opbergingspotensiaal van verskeie rabbiteye bloubessies
relatief tot beheerde atmosfere en kort vertragings in verkoeling. Kwaliteit, gebasseer op
eksterne kleur, oplosbare deeltjies, titreerbare sure, fermheid en persentasie bederf, is
ondersoek. Die respirasie en etileenproduksie tempos sowel as vogverlies van verskeie
kultivars was verder bepaal om die fundamentele verskille tussen kultivars te bepaal,
sowel as insig te verwerf in na-oes gedrag. Die effek van infeksie op pigment vlakke van
bloubessie vlees en skil was ondersoek vir die doel van laboratorium ondervinding.
Beheerde atmosfeer opberging het die grootste effek getoon op bessie fermheid en
persentasie bederf. Na aanleiding van sensoriese toetse is daar geen wansmaake
aangeteken ten op sigte van die BA vlakke wat getoets is nie. Bessies onderworpe aan
beheerde atmosfeeriese toestande was fermer en bederfonderdrukking was beduidend.
Die markverdraagsaamheid ten opsigte van bessiebederf, is egter 2 %. Hiervolgens was
onderdrukking van verval asook opbergingsvermoë, onvoldoende (spesifiek na die rakleeftyd). Kultivar en seisoenale verskille asook plukrypheid en inokulum druk, bepaal
ook die sukses van BA opberging. BA word beskou as ‘n waardevolle tegnologie vir
verlenging van opberging. Dit blyk egter dat daar eers ‘n vooruitgang gemaak moet word
in die versekering van optimale bessie kwaliteit voordat verskeping oorweeg kan word.
Kort vertragings (0, 2, 4, 6 uur by 20 ºC) in verkoeling, het geen invloed gehad op kleur,
(L, C, H), totale oplosbare vastestowwe, titreerbare suur en fermheid van bloubessie
kultivars ‘Centurion’, ‘Premier’ en ‘Tifblue’ nie. Bederfresultate dui daarop dat
onmiddelike verkoeling krities is, veral by verlengde opberging, om aan die 2 % bederf
drempelwaarde te voldoen. Bessies onderhewig aan langer vertragings voor verkoeling,
blyk meer vatbaar te wees vir bederf. Verskille bestaan tussen kultivars en kennis
ingewin tydens hierdie navorsing kan toegepas word om hanteringsprosedures en
verkoeling aan te pas. Ingeligte besluitneming kan dus ten opsigte van kultivarspesifieke
bemarking (plaaslik en uitvoer), opberging (kort- en langtermyn) en vervoer (lug- en
seevrag) gemaak word.
Rabbiteye bloubessie kultivars verskil aansienlik ten opsigte van hul respirasietempo,
etileenproduksie en vogverlies. Laasgenoemde kwaliteitsbepalers is by verskillende
kultivars ondersoek by 15 ºC. ‘Climax’ het die hoogste respirasietempo, etileenproduksie
en vogverlies getoon, terwyl ‘Premier’ die laagste respirasietempo gehad het, en die
etileenproduksie te laag was om met die gaschromatograaf te bepaal. Die laagste
vogverlies proporsionaliteitskonstante is waargeneem tussen ‘Tifblue’ en ‘Centurion’.
‘n Verandering is waargeneem in bloubessie vrugvleeskleur van wit tot donkerrooi by
besmette bessies. ‘n Soortgelyke resultaat is verkry met kunsmatige inokulering met
Botrytis cinerea. Die kleurverskil is geëvalueer deur vergelyking te tref met die
antosianienpigment vlakke tussen die skil en die vlees (bepaal deur spektrofotometrie en
HPLC). Antosianieninhoud van besmette vrugvlees het verdubbel, terwyl die van
besmette vrugskil minder as 50 % van die kontrole groep was. Pigmentlekkasie is al
vermeld by bloubessies. Dit wil voorkom of selskade veroorsaak deur infeksie beweging
van antosianien vanaf die skil na die vlees kan aanhelp. Die opbergingspotensiaal van bloubessies hang af van kultivar, rypheid by oes,
omgewings toestande sowel as inokulum druk. Onder gunstige toestande kan bloubessies
se opbergingsvermoë effektief gemanipuleer word. Verder kultivar-spesifieke navorsing
wat relevante kwaliteits kwessies aanspreek, kan gedoen word. Verder kan betroubare
tegnieke in die meting van bloubessie fermheid veranderinge ondersoek word. Navorsing
ten opsigte van inokulum vlakke mag insig gee in terme van bederf-druk vermindering en
die gebruik van bederf-onderdrukking alternatiewe soos anti-bakteriese lappies. Skil
integriteit relatief tot bederf-vatbaarheid kan ook op sellulere vlak ondersoek word.
9
Lerud, Ryan M. "Sensors and Portable Instruments for Postharvest Agriculture." PDXScholar, 2019. https://pdxscholar.library.pdx.edu/open_access_etds/4994.
Texte intégralRésumé :
The sensing needs for the fresh produce industry can be split into two primary stages: during maturation in the field, also referred to as Precision Farming, and during storage and transport of the produce, or Postharvest Storage. This work seeks to improve the accuracy and reliability of commercially available electrochemical and spectroscopic sensors tailored to the sensing needs of the fresh produce industry. For electrochemical sensing, this study proposes the use of an inline filter to remove polar organic compounds, which can interfere with the readings of a platinum-based electrochemical sensor. A 50% improvement in measurement accuracy was achieved when monitoring the storage headspace of a container of apples. For portable spectroscopy instruments, this study suggests improvements for the alignment of the optical bench and the spectral collect protocol. Methods to reduce the influence of environmental noise, such as variability of background light (sunlight in the field) and thermal effects on hardware performance, are presented. This study also presents the first report of the calibration transfer of spectral regressions developed with Karl Norris's Derivative Quotient Method. The motivation for this aspect of research was to develop methods to collect stable and accurate data in the field, which can be used to improve the quality of fresh produce reaching the customer and reduce premature food spoilage.
10
Meyer, Celeste. "Carbohydrates and leaf blackening of Protea cut flowers." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53320.
Texte intégralRésumé :
Thesis (MScAgric)--Stellenbosch University, 2003.<br>ENGLISH ABSTRACT: Protea cut flowers are exported worldwide but the vase life of some species and cultivars
is considerably shortened by post-harvest leaf blackening. Research has established
carbohydrate depletion to be positively correlated with this disorder. Consequently, a
study had been made of the carbohydrate status of various species and cultivars, as well
as the effect of supplemental glucose (pre and post-storage) on leaf blackening.
Glucose, fructose, sucrose and starch concentrations of various Protea species and
cultivars held in water were measured at harvest, and again at leaf blackening initiation.
All measured carbohydrates declined significantly in 'Carnival', 'Pink Ice' and 'Sheila'.
In 'Cardinal' all carbohydrate concentrations decreased significantly, except the sucrose
concentration in the inflorescence. 'Susara' and 'Ivy' had very high initial carbohydrate
concentrations in the leaves which decreased significantly. The very high initial
carbohydrate concentrations in the inflorescence of 'Ivy' declined significantly. 'Brenda'
differed from the other cultivars and species in that glucose concentrations increased over
time. Carbohydrate concentrations of most of the tested proteas declined significantly
from harvest to the initiation of leaf blackening. This highlighted the dependence of the
leaves and inflorescence on the carbohydrate reserves, further substantiating the
carbohydrate depletion theory. The inflorescences were characterized by high fructose
and glucose concentrations and low sucrose concentrations when compared to the leaves. It was hypothesized that glucose pulsing and cold storage at 1°C for three weeks would
significantly reduce leaf blackening. 'Brenda', 'Cardinal', 'Carnival', 'Pink Ice',
'Susara ' and 'Sylvia' had significantly less leaf blackening with glucose treatments of 4
and 10%. Leaf blackening of 'Sheila', P. cynaroides and P. grandiceps was not
significantly reduced by glucose pulsing. P. magnifica showed a small, but significant,
reduction in leaf blackening in response to the 3, 6 and 9% treatments after 10 days only,
but despite this, leaf blackening was unacceptably high. 'Pink Ice' harvested at the soft
tip stage had less leaf blackening than those harvested open or closed. Toxicity
symptoms on the leaves, and in some instances flowers, were observed at higher glucose
concentrations (8 and 10%) onP. grandiceps, P. cynaroides, 'Cardinal' and 'Sheila'. All
glucose treatments resulted in toxicity symptoms on P. magnifica. A decrease in nonstructural
carbohydrates post-harvest apparently occurs in all proteas but it appears that
only members of the Ligulatae respond to glucose.
Glucose pulsing followed by cold storage at 1°C for three weeks in combination with
post-storage glucose vase solutions, significantly reduced leaf blackening of some Protea
cultivars. Glucose (1 and 2%), with hypochlorite, significantly delayed leaf blackening
in 'Cardinal' and 'Sylvia' after seven days. Leaf blackening of 'Brenda', 'Carnival',
'Pink Ice' and 'Susara' was not significantly reduced by the glucose vase solutions.
Other disinfectants, in combination with the sugar treatments, need to be evaluated since
the hypochlorite treatment had a dehydrating effect on all the cultivars and resulted in
increased leaf blackening. Carbohydrate supplementation of protea flowers with glucose, pre and post-storage, will
help meet the post-harvest carbohydrate requirements of certain Protea cultivars and
species to an extent. Glucose treatments must be seen in conjunction with maintaining
the cold chain and when combined with cold chain maintenance, can extend the storage
and vase life.<br>AFRIKAANSE OPSOMMING: Protea snyblomme word wêreldwyd uitgevoer alhoewel die vaasleeftyd van sommige
spesies en kultivars beduidend verkort word deur na-oes loof verbruining. Navorsing het
koolhidraatverbruik positief gekorreleer met hierdie probleem. Gevolglik is 'n studie
gemaak van die koolhidraatstatus van verskeie spesies en kultivars asook die effek van
addisionele glukose (voor en na opberging) op loofverbruining.
Glukose, fruktose, sukrose en stysel konsentrasies van verskeie Protea spesies en
kultivars wat in water gehou is, is bepaal met oes en weer met die eerste tekens van
loofverbruining. Al die gemete koolhidraatkonsentrasies het beduidend afgeneem in
'Carnival', 'Pink Ice' en 'Sheila'. In 'Cardinal' het al die koolhidraatkonsentrasies
beduidend afgeneem, behalwe vir die sukrosekonsentrasie in die blom. 'Susara' en 'Ivy'
het baie hoë begin koolhidraatkonsentrasies in die blare wat beduidend afneem. Die baie
hoë inisiële koolhidraatkonsentrasies in die blom van 'Ivy' neem beduidend af met tyd.
'Brenda' verskil van die ander kultivars en spesies deurdat die glukosekonsentrasies
toeneem met tyd. Koolhidraatkonsentrasies van die meeste getoetste proteas neem
beduidend af vanaf oes totdat die eerste tekens van loofverbruining verskyn. Dit het die
afhanklikheid van die blare en blom op die koolhidraatreserwes beklemtoon en daardeur
verder die koolhidraatteorie ondersteun. Die blomme is gekarakteriseer deur hoë
fruktose- en glukosekonsentrasies en lae sukrosekonsentrasies wanneer dit met die blare
vergelyk is.Die hipotese is gestel dat die voorsiening van glukose, vir 'n aantal ure, gekombineerd
met koue opberging by 1°C vir drie weke loofverbruining beduidend sal verminder.
'Brenda', 'Cardinal', 'Carnival', 'Pink lee', 'Susara' en 'Sylvia' het beduidend minder
loofverbruining met glukose behandelings tussen 4 en 10%. Loofverbruining van
'Sheila', P. cynaroides en P. grandiceps is nie beduidend verminder deur glukose
behandelings nie. P. magnifica het 'n klein, maar beduidende verlaging in
loofverbruining getoon met die 3, 6 en 9% behandelings na 10 dae, maar ten spyte
hiervan was loofverbruining onaanvaarbaar hoog. 'Pink lee' is geoes by die sagte punt
stadium en het minder loofverbruining gehad as blomme wat oop of toe geoes is.
Toksisiteitsimptome op die blare, en in sommige gevalle blomme, is waargeneem met
hoër glukose konsentrasies (8 en 10%) op P. grandiceps, P. cynaroides, 'Cardinal' en
'Sheila'. Alle glukosebehandelings het toksisiteitsimptome tot gevolg gehad op P.
magnifica. 'n Afname in nie-strukturele koolhidrate na oes kom waarskynlik voor in alle
proteas maar dit wil voorkom of slegs lede van die Ligulatae positief reageer op glukose.
Glukosebehandeling gevolg deur koue opberging by 1°C vir drie weke in kombinasie met
na-stoor glukose vaasoplossings het loofverbruining van sommige Protea kultivars
beduidend verminder. Glukose (l en 2%), saam met hipoehloriet, het loofverbruining
beduidend verminder in 'Cardinal' en 'Sylvia' na sewe dae. Loofverbruining van
'Brenda', 'Carnival', 'Pink lee' en 'Susara' is nie beduidend verminder deur die glukose
vaasoplossings nie. Ander ontsmettingsmiddels in kombinasie met die
suikerbehandelings moet geëvalueer word aangesien die hipoehlorietbehandeling 'n dehidrerende effek op al die kultivars gehad het en 'n toename in loofverbruining tot
gevolg gehad het.
Byvoeging van glukose by proteablomme, voor en na opberging, sal tot 'n mate help om
in die na-oes koolhidraatbehoeftes van sekere Protea kultivars en spesies te voorsien.
Glukosebehandelings moet saam met die beheer van die koueketting gesien word en
wanneer gekombineerd met koueketting beheer kan dit opberg en vaasleeftyd verleng.
Livres sur le sujet "Postharvest"
1
Pringle, B., C. Bishop, and R. Clayton, eds. Potatoes postharvest. Wallingford: CABI, 2009. http://dx.doi.org/10.1079/9780851995021.0000.
Texte intégral
2
Spadaro, Davide, Samir Droby, and Maria Lodovica Gullino, eds. Postharvest Pathology. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-56530-5.
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3
International Congress of Plant Pathology (9th : 2008 : Turin, Italy), ed. Postharvest pathology. Dordrecht: Springer, 2010.
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5
International Postharvest Science Conference (1996 Taupo, N.Z.). Postharvest 96. Edited by Ferguson I. B, Bieleski R. L. 1931-, Laing William A, Clark C. J, International Society for Horticultural Science., and New Zealand Society for Horticultural Science. Leuven, Belgium: ISHS, 1998.
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6
E, Paull Robert, and Kays Stanley J, eds. Postharvest biology. 2nd ed. Athens, GA: Exon Press, 2004.
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7
Paliyath, Gopinadhan, Jayasankar Subramanian, Loong-Tak Lim, K. S. Subramanian, Avtar K. Handa, and Autar K. Mattoo, eds. Postharvest Biology and Nanotechnology. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2018. http://dx.doi.org/10.1002/9781119289470.
Texte intégral
8
J, Weichmann, ed. Postharvest physiology of vegetables. New York: M. Dekker, 1987.
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9
Bautista-Baños, Silvia. Postharvest decay: Control strategies. Amsterdam: Elsevier/AP, Academic Press is an imprint of Elsevier, 2014.
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10
Dasgupta, M. K. Postharvest pathology of perishables. New Delhi: Oxford & IBH Publishing, 1989.
Trouver le texte intégralChapitres de livres sur le sujet "Postharvest"
1
Mencarelli, Fabio, and Andrea Vannini. "Postharvest Handling." In The Chestnut Handbook, 255–74. Title: The chestnut handbook : crop and forest management / [edited by] Gabriele Beccaro, Alberto Alma, Giancarlo Bounous, José Gomes-Laranjo. Description: Boca Raton : CRC Press, 2020.: CRC Press, 2019. http://dx.doi.org/10.1201/9780429445606-9.
Texte intégral
2
Mitra, Sisir. "Postharvest Management." In Botany, Production and Uses, 236–54. GB: CABI, 2024. http://dx.doi.org/10.1079/9781800623156.0013.
Texte intégral
3
Dole, John M., and James E. Faust. "Postharvest management." In Cut flowers and foliages, 342–68. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789247602.0008.
Texte intégralRésumé :
Abstract This chapter focuses on the main issues that need to be considered at every step in the postharvest handling system of cut flowers, i.e. temperature, water, sanitation, carbohydrates, disease and ethylene. Their impacts on the vase life and quality of various species are discussed as well as the importance of optimizing the postharvest life of cut flowers and foliage by proper cultivar selection before planting and the use of appropriate production systems.
4
Ravichandra, N. G. "Postharvest Diseases." In Postharvest Plant Pathology, 47–150. London: CRC Press, 2021. http://dx.doi.org/10.1201/9781003246084-2.
Texte intégral
5
Morgan, Lynette. "Harvest and postharvest factors." In Hydroponics and protected cultivation: a practical guide, 268–90. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789244830.0014.
Texte intégralRésumé :
Abstract This chapter discusses harvest and postharvest factors. Harvesting involves the gathering or removal of a mature crop, with minimum damage and losses, from where it has been grown and transporting it on either for direct consumption or into the postharvest handling chain for further storage and distribution. Determination of harvest maturity, hand harvesting, robotic harvesting of greenhouse crops, postharvest handling, grading and storage, fresh-cut salad processing, shelf-life evaluation, packaging, postharvest cooling, postharvest handling damage, GAP - Good Agricultural practices in Postharvest Handling, postharvest storage, postharvest disorders, food safety and hygiene, ready-to-eat, minimally processed produce, certification and food safety systems, and postharvest developments are also discussed.
6
Morgan, Lynette. "Harvest and postharvest factors." In Hydroponics and protected cultivation: a practical guide, 268–90. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789244830.0268.
Texte intégralRésumé :
Abstract This chapter discusses harvest and postharvest factors. Harvesting involves the gathering or removal of a mature crop, with minimum damage and losses, from where it has been grown and transporting it on either for direct consumption or into the postharvest handling chain for further storage and distribution. Determination of harvest maturity, hand harvesting, robotic harvesting of greenhouse crops, postharvest handling, grading and storage, fresh-cut salad processing, shelf-life evaluation, packaging, postharvest cooling, postharvest handling damage, GAP - Good Agricultural practices in Postharvest Handling, postharvest storage, postharvest disorders, food safety and hygiene, ready-to-eat, minimally processed produce, certification and food safety systems, and postharvest developments are also discussed.
7
Levin, Elena, Samir Droby, Michael Wisniewski, and Christopher Dardick. "Role of Effector Proteins in the Virulence of Penicillium expansum on Apple Fruit." In Postharvest Pathology, 1–19. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-56530-5_1.
Texte intégral
8
Adaskaveg, James E., Helga Förster, Daniel Chen, and Kevin A. Nguyen. "Integration of Postharvest Fungicides and Fruit Sanitation Treatments to Optimize Decay Control and Address Food Safety Concerns." In Postharvest Pathology, 153–61. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-56530-5_10.
Texte intégral
9
Palou, Lluís, and María B. Pérez-Gago. "GRAS Salts as Alternative Low-Toxicity Chemicals for Postharvest Preservation of Fresh Horticultural Products." In Postharvest Pathology, 163–79. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-56530-5_11.
Texte intégral
10
Ippolito, Antonio, Annamaria Mincuzzi, Antony Surano, Khamis Youssef, and Simona Marianna Sanzani. "Electrolyzed Water as a Potential Agent for Controlling Postharvest Decay of Fruits and Vegetables." In Postharvest Pathology, 181–202. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-56530-5_12.
Texte intégralActes de conférences sur le sujet "Postharvest"
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Ambrose, Othniel E., Anastasia Azuka, Temitayo Emmanuel Fabunmi, Babatunde Segun Adejumobi, Moses Oluwafemi Onibonoje, and Kayode Stephen Aderomose. "Development of an IoT-based Postharvest Monitoring and Control System." In 2024 IEEE 5th International Conference on Electro-Computing Technologies for Humanity (NIGERCON), 1–6. IEEE, 2024. https://doi.org/10.1109/nigercon62786.2024.10926976.
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Hanson, Linda E., Young Cho, and Subashini Nagendran. "Postharvest Rhizopus rot on sugar beet." In American Society of Sugarbeet Technologist. ASSBT, 2011. http://dx.doi.org/10.5274/assbt.2011.106.
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"Postharvest Strawberry Bruise Detection Using Deep Learning." In 2021 ASABE Annual International Virtual Meeting, July 12-16, 2021. American Society of Agricultural and Biological Engineers, 2021. http://dx.doi.org/10.13031/aim.202100458.
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"Integrated management for postharvest diseases in Taiwan." In Dragon Fruit Regional Network Initiation Workshop. Food and Fertilizer Technology Center for the Asian and Pacific Region, 2018. http://dx.doi.org/10.56669/udol6399.
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"Postharvest handling management of pitaya (Hylocereus spp.)." In Dragon Fruit Regional Network Initiation Workshop. Food and Fertilizer Technology Center for the Asian and Pacific Region, 2018. http://dx.doi.org/10.56669/xuir1436.
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Stevanović, Snežana. "Effect of storage in controlled atmosphere on apple fruits quality." In 35th International Congress on Process Industry. SMEITS, 2022. http://dx.doi.org/10.24094/ptk.022.055.
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Food market is increasingly interested in fresh, unprocessed food products containing no added chemicals. Increasing quantities of food are exported as fresh commodity; therefore, there is a demand for modern postharvest technologies. Fresh fruits continue with metabolic activities after harvest, resulting in continuous loss of fruit compounds, water and gaseous exchanges with surrounding environment through respiration and transpiration. This contributes significantly to postharvest quality loss because of resultant mass, firmness and freshness loss, as well as short shelf life which are the critical parameters determining the competitiveness of fresh produce in the market. One of the successful postharvest technologies used to reduce losses is the modification of the atmosphere, i.e. storage with a controlled atmosphere. The objective of this study was to evaluate the effect of storage in controlled atmosphere on quality changes of apple fruits. The regular air storage was used as a control. Soluble solids content, starch, pectin matter, total solid and acids, pH value and firmness were analyzed in fresh and stored apple fruits. The obtained results demonstrated significantly lower changes in analyzed quality parameters of apples stored in controlled atmosphere compared with air stored apples. After 4 months of storage in chamber under regular air, apples had significantly lower firmness than apples stored in controlled atmosphere. In addition, total loss was significantly higher in apples stored under regular air than in controlled atmosphere.
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Changying Li, Gerard Krewer, and Stanley J Kays. "Blueberry Postharvest Disease Detection Using an Electronic Nose." In 2009 Reno, Nevada, June 21 - June 24, 2009. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2009. http://dx.doi.org/10.13031/2013.27360.
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Shir, Ofer M., Boris Yazmir, Assaf Israeli, and Dan Gamrasni. "Algorithmically-guided postharvest protocols by experimental combinatorial optimization." In GECCO '22: Genetic and Evolutionary Computation Conference. New York, NY, USA: ACM, 2022. http://dx.doi.org/10.1145/3520304.3533976.
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Stasenko, Nikita, Maxim Savinov, Valeriy Burlutskiy, Maria Pukalchik, and Andrey Somov. "Deep Learning for Postharvest Decay Prediction in Apples." In IECON 2021 - 47th Annual Conference of the IEEE Industrial Electronics Society. IEEE, 2021. http://dx.doi.org/10.1109/iecon48115.2021.9589498.
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"Postharvest handling of orchid cut flowers in Thailand." In Development and adoption of green technologies for sustainable agriculture and enhancement of rural entrepreneurship. Food and Fertilizer Technology Center for the Asian and Pacific Region, 2009. https://doi.org/10.56669/vasn7548.
Texte intégralRapports d'organisations sur le sujet "Postharvest"
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Prusky, Dov, Martin Dickman, and Robert Fluhr. Effect of pH Modulation and ROS Production by Postharvest Pathogens on Postharvest Disease Development. United States Department of Agriculture, July 2012. http://dx.doi.org/10.32747/2012.7613876.bard.
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Lerud, Ryan. Sensors and Portable Instruments for Postharvest Agriculture. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.6870.
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Cherry, Joe, Yosef Mizrahi, Avtar Handa, and Varda Kagan-Zur. Regulation of Tomato Ripening and Postharvest Storage. United States Department of Agriculture, February 1993. http://dx.doi.org/10.32747/1993.7603825.bard.
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Yalch, Teale, Jo Lofthouse, and Stella Nordhagen. Creating alliances and fostering innovations to reduce postharvest food loss: Experiences from GAIN’s Postharvest Loss Alliances for Nutrition. Global Alliance for Improved Nutrition (GAIN), September 2020. http://dx.doi.org/10.36072/wp.9.
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Meir, Shimon, Michael S. Reid, Cai-Zhong Jiang, Amnon Lers, and Sonia Philosoph-Hadas. Molecular Studies of Postharvest Leaf and Flower Senescence. United States Department of Agriculture, January 2011. http://dx.doi.org/10.32747/2011.7592657.bard.
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Original objectives: To understand the regulation of abscission by exploring the nature of changes of auxin-related gene expression in tomato (Lycopersicon esculatumMill) abscission zones (AZs) following organ removal, and by analyzing the function of these genes. Our specific goals were: 1) To complete the microarray analyses in tomato flower and leaf AZs, for identifying genes whose expression changes early in response to auxin depletion; 2) To examine, using virus-induced gene silencing (VIGS), the effect of silencing target genes on ethylene sensitivity and abscission competence of the leaf and flower AZs; 3) To isolate and characterize promoters from AZ-specific genes to be used in functional analysis; 4) To generate stable transgenic tomato plants with selected genes silenced with RNAi, under the control of an AZ-specific promoter, for further characterization of their abscission phenotypes. Background: Abscission, the separation of organs from the parent plant, results in postharvest quality loss in many ornamentals and other fresh produce. The process is initiated by changes in the auxin gradient across the AZ, and is triggered by ethylene. Although changes in gene expression have been correlated with the ethylene-mediated execution of abscission, there is almost no information on the initiation of the abscission process, as the AZ becomes sensitized to ethylene. The present project was focused on elucidating these early molecular regulatory events, in order to gain a better control of the abscission process for agricultural manipulations. Major conclusions, solutions, achievements: Microarray analyses, using the Affymetrix Tomato GeneChip®, revealed changes in expression, occurring early in abscission, of many genes with possible regulatory functions. These included a range of auxin- and ethylene-related transcription factors (TFs), other TFs that are transiently induced just after flower removal, and a set of novel AZ-specific genes. We also identified four different defense-related genes, including: Cysteine-type endopeptidase, α- DOX1, WIN2, and SDF2, that are newly-associated with the late stage of the abscission process. This supports the activation of different defense responses and strategies at the late abscission stages, which may enable efficient protection of the exposed tissue toward different environmental stresses. To facilitate functional studies we implemented an efficient VIGS system in tomato, and isolated two abscission-specific promoters (pTAPG1 and pTAPG4) for gene silencing in stable transformation. Using the VIGS system we could demonstrate the importance of TAPGs in abscission of tomato leaf petioles, and evaluated the importance of more than 45 genes in abscission. Among them we identified few critical genes involved in leaf and flower abscission. These included: PTRP-F1, PRP, TKN4, KNOTTED-like homeobox TF, KD1, and KNOX-like homeodomain protein genes, the silencing of which caused a striking retardation of pedicel abscission, and ERF1, ERF4, Clavata-like3 protein, Sucrose transporter protein, and IAA10 genes, the silencing of which delayed petiole abscission. The importance of PRPand KD1 genes in abscission was confirmed also by antisense–silencing using pTAPG4. Experiments testing the effects of RNAi silencing of few other genes are still in progress, The analysis of the microarray results of flower and leaf AZs allowed us to establish a clear sequence of events occurring during acquisition of tissue sensitivity to ethylene, and to confirm our hypothesis that acquisition of ethylene sensitivity in the AZ is associated with altered expression of auxin-regulated genes in both AZs. Implication, both scientific and agricultural: Our studies had provided new insights into the regulation of the abscission process, and shaded light on the molecular mechanisms that drive the acquisition of abscission competence in the AZ. We pointed out some critical genes involved in regulation of abscission, and further expanded our knowledge of auxin-ethylene cross talk during the abscission process. This permits the development of novel techniques for manipulating abscission, and thereby improving the postharvest performance of ornamentals and other crops.
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Meir, Shimon, Michael Reid, Cai-Zhong Jiang, Amnon Lers, and Sonia Philosoph-Hadas. Molecular Studies of Postharvest Leaf and Flower Abscission. United States Department of Agriculture, 2005. http://dx.doi.org/10.32747/2005.7696523.bard.
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Original objectives: Understanding the regulation of abscission competence by exploring the nature and function of auxin-related gene expression changes in the leaf and pedicelAZs of tomato (as a model system), was the main goal of the previously submitted proposal. We proposed to achieve this goal by using microarray GeneChip analysis, to identify potential target genes for functional analysis by virus-induced gene silencing (VIGS). To increase the potential of accomplishing the objectives of the previously submitted proposal, we were asked by BARD to show feasibility for the use of these two modern techniques in our abscission system. Thus, the following new objectives were outlined for the one-year feasibility study: 1.to demonstrate the feasibility of the VIGS system in tomato to perform functional analysis of known abscission-related genes; 2. to demonstrate that by using microarray analysis we can identify target genes for further VIGS functional analysis. Background to the topic: It is a generally accepted model that auxin flux through the abscission zone (AZ) prevents organ abscission by rendering the AZ insensitive to ethylene. However, the molecular mechanisms responsible for acquisition of abscission competence and the way in which the auxin gradient modulates it are still unknown. Understanding this basic stage of the abscission process may provide us with future tools to control abscission for agricultural applications. Based on our previous study, performed to investigate the molecular changes occurring in leaf and stem AZs of MirabillisJalapaL., we have expanded our research to tomato, using genomic approaches that include modern techniques for gene discovery and functional gene characterization. In our one-year feasibility study, the US team has established a useful system for VIGS in tomato, using vectors based on the tobacco rattle virus (TRV), a Lcreporter gene for silencing (involved in regulation of anthocyanin biosynthesis), and the gene of interest. In parallel, the Israeli team has used the newly released Affymetrix Tomato GeneChip to measure gene expression in AZ and non-AZ tissues at various time points after flower removal, when increased sensitivity to ethylene is acquired prior to abscission (at 0-8 h), and during pedicelabscission (at 14 h). In addition, gene expression was measured in the pedicel AZ pretreated with the ethylene action inhibitor, 1-methylcyclopropene (1-MCP) before flower removal, to block any direct effects of ethylene. Major conclusions, solutions and achievements: 1) The feasibility study unequivocally established that VIGS is an ideal tool for testing the function of genes with putative roles in abscission; 2) The newly released Affymetrix Tomato GeneChip was found to be an excellent tool to identify AZ genes possibly involved in regulation and execution of abscission. The VIGS-based study allowed us to show that TAPG, a polygalacturonase specifically associated with the tomato AZ, is a key enzyme in the abscission process. Using the newly released Affymetrix Tomato GeneChip we have identified potential abscission regulatory genes as well as new AZ-specific genes, the expression of which was modified after flower removal. These include: members of the Aux/IAAgene family, ethylene signal transduction-related genes, early and late expressed transcription factors, genes which encode post-translational regulators whose expression was modified specifically in the AZ, and many additional novel AZ-specific genes which were previously not associated with abscission. This microarray analysis allowed us to select an initial set of target genes for further functional analysis by VIGS. Implications: Our success in achieving the two objectives of this feasibility study provides us with a solid basis for further research outlined in the original proposal. This will significantly increase the probability of success of a full 3-year project. Additionally, our feasibility study yielded highly innovative results, as they represent the first direct demonstration of the functional involvement of a TAPG in abscission, and the first microarray analysis of the abscission process. Using these approaches we could identify a large number of genes involved in abscission regulation, initiation and execution, and in auxin-ethylene cross-talk, which are of great importance, and could enable their potential functional analysis by VIGS.
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Prusky, Dov, and Jeffrey Rollins. Modulation of pathogenicity of postharvest pathogens by environmental pH. United States Department of Agriculture, December 2006. http://dx.doi.org/10.32747/2006.7587237.bard.
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Until recently, environmental pH was not considered a factor in determining pathogen compatibility. Our hypothesis was that the environmental pH at the infection site, which is dynamically controlled by activities of both the host and the pathogen, regulates the expression of genes necessary for disease development in Colletotrichum gloeosporioides and Sclerotinia sclerotiorum. This form of regulation ensures that genes are expressed at optimal conditions for their encoded activities.Pectate lyase encoded by pelB, has been demonstrated to play a key role in virulence of C. gloeosporioides in avocado fruit. Polyglacturonase synergism with oxalic acid production is considered to be an essential pathogenicity determinant in the interactions of S. sclerotiorum with its numerous hosts. A common regulatory feature of these virulence and pathogenicity factors is their dependence upon environmental pH conditions within the host niche to create optimal conditions for expression and secretion. In this proposal we have examined, 1) the mechanisms employed by these fungi to establish a suitable pH environment, 2) the molecular levels at which genes and gene products are regulated in response to environmental pH, and 3) the molecular basis and functional importance of pH-responsive gene regulation during pathogenicity. The specific objectives of the proposal were: 1. Characterize the mechanism of local pH modulation and the effect of ambient pH on the expression and secretion of virulence factors. 2. Provide evidence that a conserved molecular pathway for pH-responsive gene expression exists in C. gloeosporioides by cloning a pacC gene homologue. 3. Determine the role of pacC in pathogenicity by gene disruption and activating mutations. Major conclusions 1. We determined the importance of nitrogen source and external pH in the secretion of the virulence factor pectate lyase with respect to the ambient pH transcriptional regulator pacC. It was concluded that nitrogen source availability and ambient pH are two independent signals for the transcriptional regulation of genes required for the disease process of C. gloeosporioides and possibly of other pathogens. 2. We also determined that availability of ammonia regulate independently the alkalinization process and pelB expression, pecate lyase secretion and virulence of C. gloeosporioides. 3. Gene disruption of pacC reduced virulence of C. gloeosporioides however did not reduced fully pelB expression. It was concluded that pelB expression is regulated by several factors including pH, nitrogen and carbon sources. 4. Gene disruption of pacC reduced virulence of S. slcerotiourum Creation of a dominant activating
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Lers, Amnon, Majid R. Foolad, and Haya Friedman. genetic basis for postharvest chilling tolerance in tomato fruit. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7600014.bard.
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ABSTRACT Postharvest losses of fresh produce are estimated globally to be around 30%. Reducing these losses is considered a major solution to ensure global food security. Storage at low temperatures is an efficient practice to prolong postharvest performance of crops with minimal negative impact on produce quality or human health and the environment. However, many fresh produce commodities are susceptible to chilling temperatures, and the application of cold storage is limited as it would cause physiological chilling injury (CI) leading to reduced produce quality. Further, the primary CI becomes a preferred site for pathogens leading to decay and massive produce losses. Thus, chilling sensitive crops should be stored at higher minimal temperatures, which curtails their marketing life and in some cases necessitates the use of other storage strategies. Development of new knowledge about the biological basis for chilling tolerance in fruits and vegetables should allow development of both new varieties more tolerant to cold, and more efficient postharvest storage treatments and storage conditions. In order to improve the agricultural performance of modern crop varieties, including tomato, there is great potential in introgression of marker-defined genomic regions from wild species onto the background of elite breeding lines. To exploit this potential for improving tomato fruit chilling tolerance during postharvest storage, we have used in this research a recombinant inbred line (RIL) population derived from a cross between the red-fruited tomato wild species SolanumpimpinellifoliumL. accession LA2093 and an advanced Solanum lycopersicumL. tomato breeding line NCEBR-1, developed in the laboratory of the US co-PI. The original specific objectives were: 1) Screening of RIL population resulting from the cross NCEBR1 X LA2093 for fruit chilling response during postharvest storage and estimation of its heritability; 2) Perform a transcriptopmic and bioinformatics analysis for the two parental lines following exposure to chilling storage. During the course of the project, we learned that we could measure greater differences in chilling responses among specific RILs compared to that observed between the two parental lines, and thus we decided not to perform transcriptomic analysis and instead invest our efforts more on characterization of the RILs. Performing the transcriptomic analysis for several RILs, which significantly differ in their chilling tolerance/sensitivity, at a later stage could result with more significant insights. The RIL population, (172 lines), was used in field experiment in which fruits were examined for chilling sensitivity by determining CI severity. Following the field experiments, including 4 harvest days and CI measurements, two extreme tails of the response distribution, each consisting of 11 RILs exhibiting either high sensitivity or tolerance to chilling stress, were identified and were further examined for chilling response in greenhouse experiments. Across the RILs, we found significant (P < 0.01) correlation between field and greenhouse grown plants in fruit CI. Two groups of 5 RILs, whose fruits exhibited reproducible chilling tolerant/sensitive phenotypes in both field and greenhouse experiments, were selected for further analyses. Numerous genetic, physiological, biochemical and molecular variations were investigated in response to postharvest chilling stress in the selected RILs. We confirmed the differential response of the parental lines of the RIL population to chilling stress, and examined the extent of variation in the RIL population in response to chilling treatment. We determined parameters which would be useful for further characterization of chilling response in the RIL population. These included chlorophyll fluorescence Fv/Fm, water loss, total non-enzymatic potential of antioxidant activity, ascorbate and proline content, and expression of LeCBF1 gene, known to be associated with cold acclimation. These parameters could be used in continuation studies for the identification and genetic mapping of loci contributing to chilling tolerance in this population, and identifying genetic markers associated with chilling tolerance in tomato. Once genetic markers associated with chilling tolerance are identified, the trait could be transferred to different genetic background via marker-assisted selection (MAS) and breeding. The collaborative research established in this program has resulted in new information and insights in this area of research and the collaboration will be continued to obtain further insights into the genetic, molecular biology and physiology of postharvest chilling tolerance in tomato fruit. The US Co-PI, developed the RIL population that was used for screening and measurement of the relevant chilling stress responses and conducted statistical analyses of the data. Because we were not able to grow the RIL population under field conditions in two successive generations, we could not estimate heritability of response to chilling temperatures. However, we plan to continue the research, grow the RIL progeny in the field again, and determine heritability of chilling tolerance in a near future. The IS and US investigators interacted regularly and plan to continue and expand on this study, since combing the expertise of the Co-PI in genetics and breeding with that of the PI in postharvest physiology and molecular biology will have great impact on this line of research, given the significant findings of this one-year feasibility project.
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Schripsema, Auke, and Rene Oostewechel. HAED-Jo: postharvest systems fact-finding mission : four-day mission. Wageningen: Wageningen Food & Biobased Research, 2018. http://dx.doi.org/10.18174/453843.
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Bostock, Richard M., Dov Prusky, and Martin Dickman. Redox Climate in Quiescence and Pathogenicity of Postharvest Fungal Pathogens. United States Department of Agriculture, May 2003. http://dx.doi.org/10.32747/2003.7586466.bard.
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Monilinia fructicola causes brown rot blossom blight and fruit rot in stone fruits. Immature fruit are highly resistant to brown rot but can become infected. These infections typically remain superficial and quiescent until they become active upon maturation of the fruit. High levels of chlorogenic acid (CGA) and related compounds occur in the peel of immature fruit but these levels decline during ripening. CGA inhibits cutinase expression, a putative virulence factor, with little or no effect on spore germination or hyphal growth. To better understand the regulation of cutinase expression by fruit phenolics, we examined the effect of CGA, caffeic acid (CA) and related compounds on the redox potential of the growth medium and intracellular glutathione (GSH) levels. The presence of CA in the medium initially lowered the electrochemical redox potential of the medium, increased GSH levels and inhibited cutinase expression. Conidia germinated in the presence of CA, CGA, or GSH produced fewer appressoria and had elongated germ tubes compared to the controls. These results suggest that host redox compounds can regulate fungal infectivity. In order to genetically manipulate this fungus, a transformation system using Agrobacterium was developed. The binary transformation vector, pPTGFPH, was constructed from the plasmid pCT74, carrying green fluorescent protein (GFP) driven by the ToxA promoter of Pyrenophora tritici-repentis and hygromycin B phosphotransferase (hph) under control of the trpC promoter of from Aspergillus nidulans, and the binary vector pCB403.2, carrying neomycin phosphotransferase (nptII) between the T-DNA borders. Macroconidia of M. fructicola were coincubated with A. tumefaciens strain LBA 4404(pPTGFPH) on media containing acetosyringone for two days. Hygromycin- and G418-resistant M. fructicola transformants were selected while inhibiting A. tumefaciens with cefotaxime. Transformants expressing GFP fluoresced brightly, and were formed with high efficiency and frequency of T-DNA integration frequency. The use of these transformants for in situ studies on stone fruit tissues is discussed.