Academic literature on the topic 'Enzymatic antioxidant capacity'
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Journal articles on the topic "Enzymatic antioxidant capacity"
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Živković, Jelena, Slavica Sunarić, Nataša Trutić, Marko Denić, Gordana Kocić, and Tatjana Jovanović. "Antioxidants and Antioxidant Capacity of Human Milk / Antioksidansi i antioksidativni kapacitet humanog mleka." Acta Facultatis Medicae Naissensis 32, no. 2 (June 1, 2015): 115–25. http://dx.doi.org/10.1515/afmnai-2015-0012.
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SUMMARY Milk contains plenty of enzymatic and non-enzymatic antioxidant components that probably account for the vital antioxidant protection of the infants at early stages of life against the development of complications induced by oxygen free radicals. Indigenous milk enzymes play a key role in regulating lactogenesis, including active involution of mammary gland. Moreover, they are essential constituents of antioxidation and the innate immune system of milk. Among antioxidant enzymes, superoxide dismutase, catalase and selenium-containing glutathione peroxidase have been demonstrated in human milk. Mainly, the enzyme content of colostrum is higher than that in corresponding mature milk. Beside lipophilic antioxidant in human milk, tocopherols, carotenoids and vitamin A are of great interest. Those components demonstrate the highest levels in colostrum and decline during early lactation, despite the fact that total lipids increase. The complete list of active antioxidant components in human milk is not yet known. This review reports the main findings of enzymatic and non-enzymatic antioxidants, as well as antioxidant capacity of human milk. Synergism of action of several antioxidants helps to eliminate free radicals in newborns. Bearing in mind that milk contains a number of antioxidants, many reactions are possible and it is difficult to define the exact contribution and function of each antioxidant. Besides qualitative and quantitative analysis of human milk antioxidants, the measurement of total antioxidant capacity could be a useful tool for examination of this dynamic, complex fluid
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Matyas, Melinda, Monica G. Hasmasanu, and Gabriela Zaharie. "Antioxidant Capacity of Preterm Neonates Assessed by Hydrogen Donor Value." Medicina 55, no. 11 (October 30, 2019): 720. http://dx.doi.org/10.3390/medicina55110720.
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Background and objectives: Premature newborns have a number of oxidative stress-inducing disorders. Antioxidant defense is deficient in premature newborns. Hydrogen donors can be used to evaluate the non-enzymatic antioxidant defense. By measuring hydrogen donors, a group of antioxidants can be assessed: tocopherol, ascorbic acid, and glutathione. These represent the most relevant group of non-enzymatic antioxidants. The main aim of this study was to evaluate the non-enzymatic antioxidant defense capacity of premature newborns by measuring hydrogen donors. Materials and Methods: We evaluated the non-enzymatic antioxidant capacity by hydrogen donor measurement in 24 premature newborns with various oxidative stress-inducing disorders and in 14 premature newborns without oxidative stress-inducing conditions. Statistical analysis was performed using the Statistica program (v. 8, StatSoft, Round Rock, TX, USA). Differences between groups were tested with Wilcoxon matched test for quantitative paired data or Mann–Whitney test for quantitative independent data. The Z test for proportions was used to compare qualitative data among subgroups. Results: Hydrogen donors in the study group had a significantly lower value on the first day of life compared to the value of the control group. Also, the hydrogen donor value in the study group was significantly lower on the first day compared to the third day of life (p < 0.05). Neonates with mild respiratory distress (14 cases) had increased hydrogen donor values on their third day of life compared to the first day of life. Conclusions: The antioxidant capacity is influenced by oxidative stress-inducing disorders. Respiratory distress influenced the hydrogen donor value and antioxidant defense. Antioxidant defense gradually improves after birth according to gestational age.
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Takele, A., and J. Farrant. "Enzymatic antioxidant defence mechanisms of maize and sorghum after exposure to and recovery from pre- and post-flowering dehydration." Acta Agronomica Hungarica 57, no. 4 (December 1, 2009): 445–59. http://dx.doi.org/10.1556/aagr.57.2009.4.7.
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Drought stress is often the most limiting factor for maize and sorghum production in the semi-arid areas. This study evaluates the enzymatic antioxidant protection mechanism response of maize (cv Melkassa-2) and sorghum (cv. Macia) after exposure to and recovery from pre- and post-flowering dehydration.The response of enzymatic antioxidant protection systems revealed that in both test crops dehydration during both the pre- and post-flowering stages resulted in increased activities of enzymatic antioxidant protection mechanisms (SOD, GR, CAT and APX). There were, however, differences between the species in the type and extent of enhanced developmentally-induced and dehydration-induced antioxidant activities. Differences were also noticed in the relative water contents at which changes in enzymatic antioxidant activities occurred. Under dehydration conditions, sorghum was generally found to have relatively higher enzymatic antioxidant activities, providing it better protection against oxidative stress by minimizing the level of lipid peroxidation.Lipid peroxidation, measured as MDA content, was increased in both species during pre- and post-flowering dehydration, but the increase was greater in maize than in sorghum during both developmental stages. Sorghum appeared to be able to reduce MDA on rehydration, but maize contained only 85% less MDA after rehydration as compared to the control following pre-flowering rehydration. During post-flowering rehydration, neither species was able to decrease the MDA content to the control level.The results indicated that tolerance to drought in sorghum is well associated with the consistent enhanced capacity of the enzymatic antioxidant system under both pre- and post-flowering dehydration conditions, and that the sensitivity of maize to drought is linearly correlated to the decreased capacity of the antioxidant system. It may be concluded that, since differences were observed between the species in the response of enzymatic antioxidants to pre- and post-flowering dehydration/rehydration, with sorghum exhibiting comparatively higher overall activities of enzymatic antioxidants and a lower level of MDA than maize during both pre- and post-flowering dehydration, selection based on these criteria may help in the development of genotypes tolerant to dehydration.
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Ankamah, Emmanuel, J. Sebag, Eugene Ng, and John M. Nolan. "Vitreous Antioxidants, Degeneration, and Vitreo-Retinopathy: Exploring the Links." Antioxidants 9, no. 1 (December 20, 2019): 7. http://dx.doi.org/10.3390/antiox9010007.
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The transparent vitreous body, which occupies about 80% of the eye’s volume, is laden with numerous enzymatic and non-enzymatic antioxidants that could protect the eye from oxidative stress and disease. Aging is associated with degeneration of vitreous structure as well as a reduction in its antioxidant capacity. A growing body of evidence suggests these age-related changes may be the precursor of numerous oxidative stress-induced vitreo-retinopathies, including vision degrading myodesopsia, the clinically significant entoptic phenomena that can result from advanced vitreous degeneration. Adequate intravitreal antioxidant levels may be protective against vitreous degeneration, possibly preventing and even improving vision degrading myodesopsia as well as mitigating various other vitreo-retinopathies. The present article is, therefore, a review of the different antioxidant molecules within vitreous and the inter-relationships between vitreous antioxidant capacity and degeneration.
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Fan, Silin, Tiantian Xiong, Qiumei Lei, Qinqin Tan, Jiahui Cai, Zunyang Song, Meiyan Yang, Weixin Chen, Xueping Li, and Xiaoyang Zhu. "Melatonin Treatment Improves Postharvest Preservation and Resistance of Guava Fruit (Psidium guajava L.)." Foods 11, no. 3 (January 19, 2022): 262. http://dx.doi.org/10.3390/foods11030262.
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Guava fruit has a short postharvest shelf life at room temperature. Melatonin is widely used for preservation of various postharvest fruit and vegetables. In this study, an optimal melatonin treatment (600 μmol·L−1, 2 h) was identified, which effectively delayed fruit softening and reduced the incidence of anthracnose on guava fruit. Melatonin effectively enhanced the antioxidant capacity and reduced the oxidative damage to the fruit by reducing the contents of superoxide anions, hydrogen peroxide and malondialdehyde; improving the overall antioxidant capacity and enhancing the enzymatic antioxidants and non-enzymatic antioxidants. Melatonin significantly enhanced the activities of catalase, superoxide dismutase, ascorbate peroxidase and glutathione reductase. The contents of total flavonoids and ascorbic acid were maintained by melatonin. This treatment also enhanced the defense-related enzymatic activities of chitinase and phenylpropanoid pathway enzymes, including phenylalanine ammonia lyase and 4-coumaric acid-CoA-ligase. The activities of lipase, lipoxygenase and phospholipase D related to lipid metabolism were repressed by melatonin. These results showed that exogenous melatonin can maintain the quality of guava fruit and enhance its resistance to disease by improving the antioxidant and defense systems of the fruit.
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Fang, Tian, Xiaoqian Zhang, Shanshan Hu, Yanyan Yu, Xue Sun, and Nianjun Xu. "Enzymatic Degradation of Gracilariopsis lemaneiformis Polysaccharide and the Antioxidant Activity of Its Degradation Products." Marine Drugs 19, no. 5 (May 12, 2021): 270. http://dx.doi.org/10.3390/md19050270.
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Gracilariopsis lemaneiformis polysaccharides (GLP) were degraded using pectinase, glucoamylase, cellulase, xylanase, and β-dextranase into low-molecular-weight polysaccharides, namely, GPP, GGP, GCP, GXP, and GDP, respectively, and their antioxidant capacities were investigated. The degraded GLP showed higher antioxidant activities than natural GLP, and GDP exhibited the highest antioxidant activity. After the optimization of degradation conditions through single-factor and orthogonal optimization experiments, four polysaccharide fractions (GDP1, GDP2, GDP3, and GDP4) with high antioxidant abilities (hydroxyl radical scavenging activity, DPPH radical scavenging activity, reduction capacity, and total antioxidant capacity) were obtained. Their cytoprotective activities against H2O2-induced oxidative damage in human fetal lung fibroblast 1 (HFL1) cells were examined. Results suggested that GDP pretreatment can significantly improve cell viability, reduce reactive oxygen species and malonaldehyde levels, improve antioxidant enzyme activity and mitochondria membrane potential, and alleviate oxidative damage in HFL1 cells. Thus, the enzyme degradation of GLP with β-dextranase can significantly improve its antioxidant activity, and GDP might be a suitable source of natural antioxidants.
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Salami, Maryam, Ali Akbar Moosavi-Movahedi, Faezeh Moosavi-Movahedi, Mohammad Reza Ehsani, Reza Yousefi, Mohammad Farhadi, Amir Niasari-Naslaji, Ali Akbar Saboury, Jean-Marc Chobert, and Thomas Haertlé. "Biological activity of camel milk casein following enzymatic digestion." Journal of Dairy Research 78, no. 4 (September 13, 2011): 471–78. http://dx.doi.org/10.1017/s0022029911000628.
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The aim of this study was to investigate the effects of enzymatic hydrolysis with digestive enzymes of camel whole casein and beta-casein (β-CN) on their antioxidant and Angiotensin Converting Enzyme (ACE)-inhibitory properties. Peptides in each hydrolysate were fractionated with ultra-filtration membranes. The antioxidant activity was determined using a Trolox equivalent antioxidant capacity (TEAC) scale. After enzymatic hydrolysis, both antioxidant and ACE-inhibitory activities of camel whole casein and camel β-CN were enhanced. Camel whole casein and β-CN showed significant ACE-inhibitory activities after hydrolysis with pepsin alone and after pepsinolysis followed by trypsinolysis and chymotrypsinolysis. Camel β-CN showed high antioxidant activity after hydrolysis with chymotrypsin. The results of this study suggest that when camel milk is consumed and digested, the produced peptides start to act as natural antioxidants and ACE-inhibitors.
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Nam, Yea-eun, Yunsoo Kim, Hye Jin Kim, Minji Jung, and Oran Kwon. "Single and Repeated Supplementation of SOD Differently Improve Antioxidant Capacity Against Exercise Challenges." Current Developments in Nutrition 6, Supplement_1 (June 2022): 322. http://dx.doi.org/10.1093/cdn/nzac053.063.
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Abstract Objectives Oxidative stress, commonly exposed in our daily life, produces free radicals. Excessively produced free radicals damage body components and eventually promote degenerative diseases. It has been reported that the reinforcement of superoxide dismutase (SOD), the first barrier of the antioxidant system, protects our body from oxidative stress by enhancing the subsequent redox cycle. The use of SOD, an enzymatic antioxidant rather than a simple antioxidant, is still insufficient to evaluate its safety and efficacy. Therefore, the purpose of this study is to evaluate the long-term consumption safety for enzymatic antioxidants and the effect of SOD supplementation on exercise-induced oxidative stress. Methods This study was designed as a randomized, double-blind, placebo-controlled in 80 healthy adults. The subjects consumed SOD (250 IU/capsule) daily for 8 weeks and induced oxidative stress via acute aerobic exercise at the beginning and end of the experimental period. The exercise challenge was performed on a treadmill for 30 minutes at an intensity of 60% of each subject's maximal oxygen consumption (VO2 max). Blood and urine samples have collected a total of three times, after overnight fasting, immediately after exercise, and after a 30-minute rest, which was used to evaluate the safety of long-term enzymatic antioxidant supplementation, as well as functional indicators of antioxidant systems and oxidative stress. Results Endogenous antioxidant defense systems, oxidative damage, and even antioxidant balance indicators were compared by considering the interaction between the group and status over time. A single intake of SOD significantly reduced the level of oxidative damage and inflammation indicators (P < 0.05) as it sequentially activated antioxidant enzymes (P < 0.10). Furthermore, long-term intake of SOD showed a stabilized defense response against the same oxidative stress load and improved balance between antioxidant enzymes immediately after exercise (P < 0.05) without any side effects. Conclusions These findings suggest that single and repeated supplementation of SOD may differently improve the antioxidant defense system without side effects. Funding Sources This work was supported by the BK21 Fostering Outstanding Universities for Research funded by the Ministry of Education (Korea) and the National Research Foundation of Korea.
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Praud, Delphine, Maria Parpinel, Mauro Serafini, Rino Bellocco, Alessandra Tavani, Pagona Lagiou, Carlo La Vecchia, and Marta Rossi. "Non-enzymatic antioxidant capacity and risk of gastric cancer." Cancer Epidemiology 39, no. 3 (June 2015): 340–45. http://dx.doi.org/10.1016/j.canep.2015.04.003.
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Lee, Kyung Hee, Myeounghoon Cha, and Bae Hwan Lee. "Neuroprotective Effect of Antioxidants in the Brain." International Journal of Molecular Sciences 21, no. 19 (September 28, 2020): 7152. http://dx.doi.org/10.3390/ijms21197152.
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The brain is vulnerable to excessive oxidative insults because of its abundant lipid content, high energy requirements, and weak antioxidant capacity. Reactive oxygen species (ROS) increase susceptibility to neuronal damage and functional deficits, via oxidative changes in the brain in neurodegenerative diseases. Overabundance and abnormal levels of ROS and/or overload of metals are regulated by cellular defense mechanisms, intracellular signaling, and physiological functions of antioxidants in the brain. Single and/or complex antioxidant compounds targeting oxidative stress, redox metals, and neuronal cell death have been evaluated in multiple preclinical and clinical trials as a complementary therapeutic strategy for combating oxidative stress associated with neurodegenerative diseases. Herein, we present a general analysis and overview of various antioxidants and suggest potential courses of antioxidant treatments for the neuroprotection of the brain from oxidative injury. This review focuses on enzymatic and non-enzymatic antioxidant mechanisms in the brain and examines the relative advantages and methodological concerns when assessing antioxidant compounds for the treatment of neurodegenerative disorders.
Dissertations / Theses on the topic "Enzymatic antioxidant capacity"
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Valencia, Yemina Karen Diaz. "Características de grãos e amido de diferentes cultivares de quinoa (Chenopodium quinoa Willd.)." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11141/tde-10052016-175319/.
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Os grãos de quinoa possuem excelente balanço nutricional além das propriedades funcionais, comparativamente superior à dos cereais. A quinoa é cultivada em diversos países e, devido às suas características, têm aumentado o interesse de pesquisadores e consumidores. A quinoa contém pericarpo branco, no entanto, existem grãos com pericarpo vermelho e preto, e todos os tipos são utilizados como alimento em diferentes preparações. Com o objetivo de avaliar as características de grãos de quinoa, amostras de cor branca, preta e vermelha foram analisadas quanto às propriedades físico-químicas e funcionais dos grãos e do amido extraído das diferentes amostras. O amido, extraído pelo método alcalino, foi submetido as análises de teor de amilose, difração de raios X, microscopia eletrônica de varredura (MEV), propriedades térmicas (por DSC-Differential Scanning Calorimeter) e propriedades de pasta (por RVA- Rapid Visco Analyser), além de suscetibilidade à hidrólise enzimática e cor. A composição físico-química dos grãos de quinoa apresentou como principais diferenças o teor de cinzas, fibras e amido. O teor de amilose variou de 13,6% a 21,3%, entre as amostras de amido; os padrões de cristalinidade dos amidos foram de tipo A, típico dos cereais; e, a cristalinidade relativa variou de 25,4 a 29,6 %; as micrografias obtidas por MEV apresentaram as formas poliédricas dos grânulos de amido. Os viscoamilogramas, obtidos para os diferentes amidos, mostraram um comportamento semelhante entre as amostras brancas e pretas. As propriedades térmicas de retrogradação das amostras de quinoa vermelha apresentaram uma menor taxa de retrogradação que variou de 7,5 a 8,5 %; as cultivares brancas apresentaram as maiores taxas de retrogradação de 19,0 a 25,4 %. A hidrólise enzimática dos grânulos de amido, analisada em equivalentes de maltose, variou de 7,2 a 8,7 mg/mL, com uma velocidade maior para a cultivar BSyB, em 60 minutos. O amido extraído das amostras brancas de quinoa apresentou valor de luminosidade de 99,0 e os amidos extraídos das amostras de cor vermelha e preta apresentaram em torno de 97,0. As análises realizadas neste estudo ampliam o conhecimento das características da quinoa de cor branca, vermelha e preta, além de mostrar que a cultivar brasileira (BSyB) apresenta características diferenciadas em vários parâmetros. Devido as suas propriedades todas as amostras analisadas possuem potencial para futuras aplicações tecnológicas.The quinoa grain have excellent nutritional balance beyond functional properties, comparatively higher than that of cereals. Quinoa is cultivated in many countries and due to its characteristics; this has increased the interest of researchers and consumers. Quinoa contains white pericarp, however, there are red and black grain pericarp and all of kinds are used as food in different preparations. In order to evaluate the quinoa grain characteristics, samples of white, black and red color were analyzed for physical-chemical and functional properties of the grains and starch extracted from different samples, aiming a future technology use. Starch from quinoa grains was extracted by the alkaline method and analyzed for amylose content, X-ray diffraction, scanning electron microscopy (SEM), thermal properties (by Differential Scanning Calorimeter, DSC) and properties folder (by Rapid Visco Analyser, RVA), susceptibility to enzymatic hydrolysis and color. The physicochemical composition of quinoa grains presents major differences as the ash content, fiber and starch. The amylose content ranged from 13.6% to 21.3% among starch samples; patterns crystallinity of starches of type A were typical cereal; and the relative crystallinity ranged from 25.4 to 29.6%; SEM micrographs obtained showed the polyhedral forms of starch granules. The viscoamilogramas obtained for the different starches, show a similar behavior between the white and black samples. The thermal properties of retrogradation of red quinoa samples showed less retrogradation rate ranged from 7.5 to 8.5%; white cultivars showed the highest rates of downgrading from 19.0 to 25.4%. The enzymatic hydrolysis of the starch granules analyzed to maltose equivalents, ranged from 7.2 to 8.7 mg / ml, at a higher speed for cultivating BsyB in 60 minutes. The starch extracted from samples of white quinoa showed 99.0 brightness value and starches extracted from samples of red and black color had around 97.0. The analyzes performed in this study extend the knowledge of quinoa characteristics of white, red and black, in addition to showing that the Brazilian cultivar (BsyB) has different characteristics on various parameters. Because of their properties, all samples have the potential for future technological applications.
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Almeida, Francisca Diva Lima. "Employment of emerging technologies on orange juice processing added of prebiotic fructo-oligosaccharide and orange juice produced via enzymatic synthesis." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16471.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorConselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
The aim of this research was to use emerging technologies on the processing of the prebiotic orange juice added of fructo-oligosaccharides (FOS) and in prebiotic orange juice produced by enzymatic synthesis. The first stage of the study was evaluated the effect of atmospheric pressure cold plasma (ACP) and high pressure processing (HPP) on the prebiotic orange juice added 7% commercial FOS. The orange juice was directly and indirectly exposed to plasma discharge at 70 kV with processing times of 15, 30, 45 and 60 seconds. For high pressure processing, the juice containing the same concentration of FOS was treated at 450 bars for 5 minutes. After the treatments, the fructo-oligosaccharides were qualified and quantified by Thin Layer Chromatography (TLC), using densitometer. The organic acids, color analysis and pH values were also evaluated. Both processes did not degrade the FOS. The organic acids and the color of the treated samples were also preserved. On the second stage of the study, the effect of plasma and ozone treatments on prebiotic orange juice produced by enzymatic synthesis were evaluated. The orange juice was directly and indirectly exposed to plasma discharge at 70 kV with processing times of 15, 30, 45 and 60 seconds. For ozone processing, different loads (0.057, 0.128 and 0.230 mg/ O3.mL of juice) were evaluated. After the treatments, the oligosaccharides were quantified by HPLC. The juice pH, color, total phenolic content and total antioxidant activity were also determined. Both processes promoted a partial degradation of the oligosaccharides in the juice. However, the juice maintained an enough amount of oligosaccharides to be classified as a prebiotic food. The other parameters analyzed were preserved. Thus, atmospheric cold plasma and ozone are suitable non-thermal alternatives for prebiotic orange juice treatment.
O objetivo desta pesquisa foi empregar tecnologias emergentes no processamento de suco prebiÃtico de laranja adicionado de fruto-oligossacarÃdeos (FOS) e em suco prebiÃtico de laranja produzido via sÃntese enzimÃtica. A primeira etapa da pesquisa consistiu em avaliar o efeito da aplicaÃÃo das tecnologias de plasma e de alta pressÃo, como mÃtodos de conservaÃÃo, em suco de laranja adicionado de 7% de FOS comercial. O suco foi exposto direta e indiretamente ao processamento por plasma em diferentes tempos: 15 30, 45 e 60 s. Para o processamento com alta pressÃo, o suco foi tratado a uma pressÃo de 450 bars por 5 minutos. ApÃs os tratamentos, a concentraÃÃo de fruto-oligossacarÃdeos foi quantificada pela tÃcnica de cromatografia em camada delgada (CCD), utilizando o equipamento densitÃmetro. DeterminaÃÃes de cor, pH e concentraÃÃo de Ãcidos orgÃnicos foram tambÃm realizadas. Ambos os processos nÃo degradaram os FOS presentes no suco. Ãcidos orgÃnicos e a cor das amostras tratadas tambÃm foram preservados. Na segunda etapa da pesquisa, foi avaliado o efeito da aplicaÃÃo dos tratamentos de plasma e ozÃnio em suco prebiÃtico de laranja produzido via sÃntese enzimÃtica. O suco foi exposto direta e indiretamente ao processamento por plasma, a 70 kV, em diferentes tempos: 15 30, 45 e 60 s. Para o processamento com ozÃnio, diferentes cargas (0,057, 0,128 e 0,230 mg/ O3.mL de suco) foram avaliadas. ApÃs os tratamentos, a concentraÃÃo de oligossacarÃdeos foi determinada pela tÃcnica de HPLC. Os valores de pH, cor, conteÃdo de fenÃlicos totais e atividade antioxidante total tambÃm foram determinados. Ambos os processos promoveram uma degradaÃÃo parcial dos oligossacarÃdeos no suco. Contudo, o suco manteve uma quantidade suficiente de oligossacarÃdeos para ser classificado como um alimento prebiÃtico. Os demais parÃmetros analisados foram preservados. Diante disso, sugere-se que os tratamentos de plasma, alta pressÃo e ozÃnio sÃo alternativas nÃo tÃrmicas adequadas para o tratamento de suco de laranja prebiÃtico.
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Celant, Viviane Marcela. "Características bioativas e respostas fisiológicas de amoras-pretas durante maturação e armazenamento." Universidade Estadual do Oeste do Paraná, 2013. http://tede.unioeste.br:8080/tede/handle/tede/1444.
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Previous issue date: 2013-08-30Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The blackberry (Rubus spp.) has high nutritional quality, is rich in vitamin C, carbohydrates, minerals, vitamins A and B, as well as being a source of functional compounds. The blackberry is an excellent source of natural antioxidants, such as anthocyanins and polyphenols. It is a non-climacteric fruit and, due to their physical fragility and high rates of respiration and perspiration, its fruits are highly perishable, this fator becomes limiting your marketing fresh. The objective of this work was to evaluate the bioactive characteristics, physiological and biochemical characteristics of blackberry cultivars during maturation and storage in different packaging. Therefore, three experiments were conducted. The first consisted of evaluating the content of phenolic compounds, flavonoids and anthocyanins, antioxidant capacity and chemical characteristics of aqueous and etanol extracts of the fruits of blackberry cultivars Brazos, Tupy, Arapaho, Choctaw and Guarani. The results showed that 80% ethanol was more efficient in extracting anthocyanins in all cultivars and total flavonoid content was higher in 'Guarani'. The efficiency of sequestration of TEAC and DPPH radical was dependent on the solvent used in the extraction, with higher antioxidant capacity in aqueous and TEAC highest antioxidant capacity in DPPH etanol extracts. Regardless of the extraction solvent, 'Arapaho' had the highest antioxidant capacity. The second experiment evaluated the same parameters of experiment 1, but only in the ethanol extract of the fruit of 'Brazos' and 'Tupy' on maturation of immature, intermediate and mature. 'Brazos' and 'Tupy' showed total phenolic content higher in the immature stage. Antioxidant activity by ABTS method was higher in ripe fruits. The DPPH antioxidant activity was higher in 'Brazos' when immature, 'Tupy' showed similar values to the ABTS assay. Increases in the content of ascorbic acid as the fruit ripening of 'Brazos' and 'Tupy'. In the third experiment also evaluated the same parameters of other experiments, only in etanol solvent, together with the enzymatic activity of fruits of blackberry 'Tupy' , packaged in polyethylene terephthalate and polyvinyl chloride film, and stored for 1 , 4 and 8 days in a refrigerated environment. The weight loss was lower in fruits stored in PET packaging. There were some increases in the content of ascorbic acid in fruits from the 1st to the 4th day in both packages. The DPPH and ABTS antioxidant activity of fruit wrapped in PET was superior to fruits with PVC. Phenolic compounds increased with storage in both packaging used, with the highest levels found in fruits stored in PVC at the end of storage. The anthocyanin contentes were also higher on the 8th day of storage, especially in fruits kept in the PET packaging. At the end of the 8 days of storage the peroxidase activity was higher in fruits stored in PVC, and the activity of phenylalanine ammonia - lyase was higher in fruits packed in PET for all storage periods
A amora-preta (Rubus spp.) apresenta alta qualidade nutricional, é rica em vitamina C, carboidratos, minerais, vitaminas do complexo B e A, além de ser fonte de compostos funcionais. A amora-preta é excelente fonte de antioxidantes naturais, como antocianinas e polifenóis. É um fruto não climatérico e, devido à sua fragilidade física e altas taxas de respiração e transpiração, seus frutos são extremamente perecíveis, fator este que torna limitante a sua comercialização in natura. Assim, o objetivo deste trabalho foi avaliar as características bioativas, respostas fisiológicas e bioquímicas de cultivares de amora-preta durante a maturação e armazenamento em diferentes embalagens. Para tanto, três experimentos foram conduzidos. O primeiro constou da avaliação dos conteúdos de compostos fenólicos, flavonoides e antocianinas totais, da capacidade antioxidante e das características químicas dos extratos aquoso e etanólico dos frutos das cultivares de amora-preta Brazos, Tupy, Arapaho, Choctaw e Guarani. Os resultados mostraram que etanol 80% foi mais eficiente na extração de antocianinas totais para todas as cultivares e o conteúdo de flavonoides totais foi superior em Guarani . A eficiência de sequestro dos radicais TEAC e DPPH foi dependente do solvente utilizado na extração, com maior capacidade antioxidante TEAC nos extratos aquosos e maior capacidade antioxidante DPPH nos extratos etanólicos. Independente do solvente de extração, Arapaho apresentou a maior capacidade antioxidante. No segundo experimento foram avaliados os mesmos parâmetros do experimento 1, porém apenas em extrato etanólico dos frutos de Brazos e Tupy nos estádios de maturação imaturos, intermediários e maduros. Brazos e Tupy apresentaram conteúdos de compostos fenólicos totais mais elevados no estádio imaturo. A atividade antioxidante avaliada pelo método ABTS foi maior em frutos maduros. A atividade antioxidante DPPH foi maior em Brazos quando imaturos, Tupy apresentou valores similares ao ensaio ABTS. Ocorreram aumentos no conteúdo de ácido ascórbico conforme a maturação dos frutos de Brazos e Tupy . No terceiro experimento também foram avaliados os mesmos parâmetros dos demais experimentos, apenas em solvente etanólico, juntamente com a atividade enzimática de frutos de amora-preta Tupy , embalados em embalagens de politereftalato de etileno e filme de policloreto de vinila e armazenados por 1, 4 e 8 dias em ambiente refrigerado. A perda de massa fresca foi menor em frutos armazenados em embalagem PET. Foram verificados acréscimos no conteúdo de ácido ascórbico nos frutos entre o 1° ao 4° dia em ambas as embalagens. A atividade antioxidante DPPH e ABTS dos frutos embalados com PET foi superior aos frutos com PVC. Compostos fenólicos aumentaram significativamente com o armazenamento em ambas as embalagens utilizadas, sendo os maiores teores encontrados para frutos mantidos em PVC ao final do armazenamento. Os teores de antocianinas também foram superiores no 8° dia do armazenamento, principalmente em frutos mantidos em embalagem do tipo PET. Ao final dos 8 dias de armazenamento a atividade de peroxidase foi maior para frutos mantidos em PVC, e a atividade de fenilalanina amônia-liase apresentou-se maior nos frutos embalados em PET para todos os períodos de armazenamento.
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Nascimento, Edilza Silva do. "Obtenção de hidrolisado proteico de sementes de quiabo Abelmoschus esculentus (L.) Moench e sua capacidade antioxidante." Universidade Federal da Paraíba, 2015. http://tede.biblioteca.ufpb.br:8080/handle/tede/7907.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
The reactive oxygen species (ROS) are generated through reactions physiologically normal in the human organism during the respiratory process and perform various functions such as signage and providing defense against infections. However, in excessive amounts the ROS cause cellular damage and are involved in the initiation or progression of degenerative chronic diseases. In contrast, the antioxidant agents play a vital role for reduce the processes oxidative in the organism. Among them are hydrolyzed peptides from protein sources and, that demonstrate antioxidant activity. However, it is necessary the hydrolytic process for release of small fragments of amino peptide with the capacity to reduce the ROS. However, the conditions of hydrolysis employed such as type of enzyme, enzyme concentration, pH, time and temperature can influence the formation of peptides with antioxidant properties. Thus, this study aimed to obtain hydrolyzed from okra seed proteins using Alcalase® hydrolytic enzyme in different conditions and evaluate the antioxidant capacity of the hydrolysates produced. Using a Central Composite Rotatable Design (CCRD), was evaluated the influence of independent variables: enzyme concentration (EC) and hydrolysis time (T), on the dependent variables: degree of hydrolysis (DH), protein recovery efficiency (PRE), total antioxidant capacity (TAC) and scavenging of radicals radicais 2.2’-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) e 2.2-diphenyl-1-picrilidrazil (DPPH). The results showed that the increase in EC and T influenced positively on DH and TAC and only increased T influenced on the PRE, the ability of eliminating radical ABTS and DPPH were not influenced by the independent variables. It was verified that the increased TAC is directly into proportional to the increase in DH. The electrophoretic profile revealed that okra seed protein concentrate (OSPC), presents protein bands with relative masses above 38 kDa and less than 8.5 kDa. It was also found, the efficiency of the process of hydrolysis by Alcalase®, evidenced by the disappearance of most of the protein bands and the appearance of peptides of molecular mass < 3.5 kDa in hydrolysates with a higher DH. The OSPC showed lower TAC and ability of the ABTS and DPPH radical scavenger in comparison to the hydrolysates obtained. The best operating conditions of the independent variables (EC and T) obtained in the optimization study, using the methodology CCRD was possible to obtain a hydrolyzate considered optimal, the enzyme concentration was 2% and time of hydrolysis of 300 min, in this condition the hydrolyzed resulted in increased DH (19.32%), TAC (51.54%) and significant results for DPPH (52.60%) and ABTS (73.04%). The hydrolyzed great presented a considerable content of amino acids with ability to donate protons and electrons, especially acids (32.90 g/100 g of protein), hydrophobic (38.58 g/100 g of protein) and aromatic (9.43 g/100 g of protein). The results show that the protein hydrolyzate of okra seed emerges as a promising bioactive compound, with antioxid capacity. However, other studies are needed to assess the effects that the hydrolysate can produce in vivo, in order to verify the effectiveness of antioxidant activity in the human organism.
As espécies reativas de oxigênio (EROs) são geradas através de reações fisiologicamente normais no organismo humano durante o processo respiratório e exercem diversas funções como sinalização e fornecimento de defesa contra infecções. No entanto, em quantidades excessivas as EROs causam dano celular e estão envolvidas na iniciação ou progresso de doenças crônicas degenerativas. Em contrapartida, os agentes antioxidantes desempenham um papel vital para reduzir os processos oxidativos no organismo. Dentre os quais destacam-se hidrolisados e peptídeos oriundos de fontes proteícas, que demonstram atividade antioxidante. Porém, se faz necessário o processo hidrolítico para que ocorra a liberação dos pequenos fragmentos de peptídeos com capacidade em reduzir as EROs. Todavia, as condições de hidrólise empregadas tais como tipo de enzima, concentração enzimática, pH, tempo e temperatura podem influenciar a formação de peptídeos com propriedades antioxidantes. Desta forma, esse estudo objetivou obter hidrolisado a partir das proteínas de sementes de quiabo com uso da enzima Alcalase® em diferentes condições hidrolíticas e avaliar a capacidade antioxidante dos hidrolisados produzidos. Utilizando um delineamento composto central rotacional (DCCR), foi avaliada a influência das variáveis independentes: concentração enzimática (CE) e tempo de hidrólise (T), sobre as variáveis dependentes: grau de hidrólise (GH), rendimento da recuperação de proteínas (RRP), capacidade antioxidante total (TAC) e sequestro dos radicais 2,2’-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) e 2,2-diphenyl-1-picrilidrazil (DPPH). Os resultados mostraram que o aumento da CE e T influenciaram positivamente sobre o GH e TAC e apenas o aumento do T influenciou no RRP, a capacidade de eliminação dos radicais ABTS e DPPH não foram influenciadas pelas variáveis independentes. Foi verificado que o aumento da TAC é diretamente proporcional ao aumento do GH. O perfil eletroforético revelou que o concentrado proteico de sementes de quiabo (CPSQ) apresenta bandas proteícas com massas relativas acima de 38 kDa e menor que 8,5 kDa. Foi constatado ainda a eficiência do processo de hidrólise pela Alcalase®, através do desaparecimento da maioria das bandas proteicas e aparecimento de peptídeos de massa molecular < 3,5 kDa nos hidrolisados com maior GH. O CPSQ apresentou menor TAC e capacidade sequestrante dos radicais ABTS e DPPH em comparação aos hidrolisados obtidos. Operando-se as melhores condições das variáveis independentes (CE e T) obtidas no estudo de otimização, a partir da metodologia do DCCR foi possível obter um hidrolisado considerado ótimo, cuja concentração enzimática foi de 2% e tempo de hidrólise de 300 min, nesta condição o hidrolisado resultou em maior GH (19,32%), TAC (51,54%) e resultados expressivos para DPPH (52,60%) e ABTS (73,04%). O hidrolisado ótimo apresentou um teor considerável de aminoácidos com capacidade em doar prótons e elétrons, destacando-se os ácidos (32,90 g/100g de proteína), hidrofóbicos (38,58 g/100g de proteína) e aromáticos (9,43 g/ 100g de proteína). Os resultados evidenciam que o hidrolisado proteico de sementes de quiabo surge como um composto bioativo promissor, com capacidade antioxidante. No entanto, outros estudos são necessários para avaliar os efeitos que o hidrolisado pode produzir in vivo, no intuito de constatar a efetividade da atividade antioxidante no organismo humano.
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Boško, Borković. "Fitohemijska analiza i antioksidantni kapacitet plodova trešnje inficiranih gljivom Monilinia laxa Aderh. i Ruhl." Phd thesis, Univerzitet u Novom Sadu, Poljoprivredni fakultet u Novom Sadu, 2019. https://www.cris.uns.ac.rs/record.jsf?recordId=107893&source=NDLTD&language=en.
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Mrka trulež, čiji je prouzrokovač Monilinia laxa, spada u najčešče i najznačajnije bolesti ploda koštičavih voćaka, naročito trešnje. Cilj ovog rada je bio da se utvrde razlike u reakciji devet sorti plodova trešnje (različitih pomoloških osobina) prema mrkoj truleži, uzorkovanih sa oglednog dobra Departmana za voćarstvo i vinogradarstvo, Poljoprivredni fakultet Novi Sad na Rimskim Šančevima (koordinate: 45°20´N, 19°51´E). S obzirom da se u prirodnim uslovima plod trešnje može zaraziti od strane više patogena, biohemijski parametri su analizirani i na veštački inokulisanim plodovima. Ispitivane sorte su pokazale značajne razlike u pojavi oboljenja na plodu, kako u uslovima veštačke inokulacije, tako i u prirodnoj infekciji. U oba slučaja kod sorti su zabeležene različite ocene intenziteta zaraze, zavisno od sortimenta. Biohemijskom analizom plodova zabeležene su značajne razlike u sadržaju rastvorljivih proteina (SP), aktivnosti supereksid dismutaze (SOD), aktivnosti gvajakol peroksidaze (GPx), aktivnost pirogalol peroksidaze (PPx), lipidnoj peroksidaciji (LP). Utvrđene su značajne razlike u sadržaju šećera, organskih kiselinih i sekundarnih metabolita (fenoli, tanini, proantocijanidini, flavonoidi, antocijanini). Takođe rezultati su pokazali razlike u antioksidantnoj aktivnost (DPPH, FRAP, ABTS i TRC testovi). Na sadržaj sekundarnih biomolekula kao i na antioksidantnu aktivnost uticali su sorta, intenzitet zaraze ploda, kao i interakcija između ova dva faktora. Većina ispitivanih sorti je pokazala visok sadržaj polifenolnih komponenti, dok je u uslovima infekcije,
Fitohemijska analiza i antioksidantni kapacitet plodova trešnje inficiranih gljivom Monilinia laxa Aderh i Ruhl, B. Borković
sadržaj ovih parametara bio značajno niži. Na osnovu dobijenih razultata, sadržaj sekundarnih metabolita se može koristiti kao jedan od parametara u oceni otpornosti sorti trešnje prema mrkoj truleži. Datum
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Singh, Sukhvinder Pal. "Postharvest oxidative stress in plums : mechanism and implications for storage and fruit quality." Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/551.
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Postharvest life and susceptibility to chilling injury (CI) in Japanese plums (Prunus salicina Lindl.) are greatly influenced by preharvest and postharvest factors. The phenomenon of postharvest oxidative stress has been implicated in affecting fruit quality, potential storability and susceptibility to development of physiological disorders during storage of fruits. Therefore, the investigations were carried out to understand the role of various factors, such as cultivar, harvest maturity, storage conditions (temperature and atmosphere composition), duration of storage and postharvest treatments, in the development of oxidative stress in Japanese plums, in relation to fruit quality and CI. The degree of lipid peroxidation and membrane integrity was measured by determining the activity of lipoxygenase enzyme, concentration of thiobarbituric acid–reactive substances, and amount of electrolyte leakage. The activities of antioxidant enzymes, superoxide dismutase, catalase, and peroxidase, were determined as a direct measure of the enzymatic antioxidant capacity. The activities of enzymes (ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, glutathione reductase, and glutathione–S–transferase) involved in the oxidation and regeneration of ascorbate (AA) and glutathione (GSH) were also determined to underpin the dynamics of the AA–GSH cycle. The concentrations of AA, dehydroascorbate (DHA), GSH, and oxidized glutathione (GSSG) were determined to compute the AA:DHA and GSH:GSSG ratios as the indicators of redox potential of fruit tissue. The total phenolics concentration and total antioxidant capacity were also determined as a part of the non–enzymatic antioxidants.The experimental data suggest that postharvest oxidative stress developed during fruit ripening in Japanese plums, but the rate was dependent on the climacteric behaviour of fruit. The climacteric cultivars, ‘Blackamber’ and ‘Amber Jewel’, showed a faster decline in the ability of antioxidative system to encounter the oxidative stress during fruit ripening as compared to ‘Angeleno’, a suppressed–climacteric cultivar. The delay in harvesting of ‘Amber Jewel’ plums by one week slightly improved fruit quality and the initial status of antioxidants than the commercial harvest. However, the fruit harvested at commercial maturity had better retention of antioxidative system during cold storage at 0°C for 3–4 weeks compared to the fruit from the delayed harvest. The changes in enzymatic and non–enzymatic antioxidants as a function of storage duration appear to be more prominent in providing protection against oxidative injury expressed as CI than their at–harvest status. The response of the antioxidative system in ‘Amber Jewel’ plums at 5°C was significantly better than at 0°C. But, the storage temperature of 5°C was not sufficiently low to inhibit the process of fruit ripening, resulting in limited storage life of 2 weeks. The multiple–point time course analysis of lipid peroxidation and changes in enzymatic and non–enzymatic antioxidants of ‘Blackamber’ plums revealed that the third week of storage is the critical point beyond which the capacity of antioxidative system to cope with the increasing oxidative stress from CI and fruit ripening began to decline, resulting in increased incidence and severity of CI during the extended periods of storage. Controlled atmospheres (CA) were found beneficial to reduce the levels of oxidative stress in ‘Blackamber’ plums.CA containing 1% O[subscript]2 + 3% CO[subscript]2 were effective in mitigating the oxidative stress during the 5 weeks of cold storage at 0–1°C, plus 6 days of shelf life at 21±1°C. The efficacy of CA (1% or 2.5% O[subscript]2 + 3% CO[subscript]2) in alleviating CI in ‘Blackamber’ plums could be further enhanced by the pre–storage treatment of fruit with 1–methylcyclopropene (1–MCP, 0.6 μL L[superscript]–[superscript]1). The combination of CA and 1–MCP exhibited synergistic effects on the alleviation of oxidative stress, resulting in enhanced storage life up to 8 weeks, plus 6 days of shelf–life. The role of nitric oxide (NO) as an antioxidant was also investigated in order to retard fruit ripening, delay the onset of senescence and development of oxidative stress in the Japanese plums. Postharvest NO fumigation (10 or 20 μL L[superscript]–[superscript]1) delayed the fruit ripening and maintained quality for 9–12 days in ‘Amber Jewel’ and ‘Blackamber’ plums at 21±1°C. NO fumigation was also beneficial to reduce the symptoms of CI during cold storage of ‘Amber Jewel’ and ‘Blackamber’ plums for 5–6 weeks at 0°C, plus 5 days of shelf–life at 21±1°C. The positive effects of NO fumigation on the enzymatic and non–enzymatic antioxidants in addition to reduced rates of lipid peroxidation were associated with the enhanced chilling tolerance in Japanese plums. The response of ‘Amber Jewel’ to postharvest NO fumigation was significantly better than ‘Blackamber’.In conclusion, the development of oxidative stress in Japanese plums was influenced by cultivar, harvest maturity, cold storage (temperature, duration and atmosphere composition), and postharvest treatments with NO and 1–MCP. The mitigation of oxidative stress by manipulation of postharvest storage conditions and treatments can be achieved to maintain fruit quality and reduce the incidence and severity of CI in Japanese plums.
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Lai, Yi-Chen, and 賴怡蓁. "Studies on the Antioxidant Capacity of Abalone Enzymatic Hydrolysates." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/mn4y6a.
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碩士國立臺灣海洋大學
食品科學系
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The objectives of this research were to study the antioxidant activity of abalone hydrolysates. The abalone meat was hydrolyzed by autolysis, Prozyme 6 and Protamex. The pH value of the hydrolysates increased first and then decreases during hydrolysis. Both ammonia and peptide contents of the hydrolysates were increased with the hydrolysis time. However, the soluble protein content started to decrease after 10 hours of hydrolysis. The hydrolysates of Protamex contained highest soluble protein after 5 hours of hydrolysis. Highest peptide content will be reached after 24 hours of hydrolysis with Prozyme 6. The total free amino acids (FAA) of all hydrolysates increased with the hydrolysis time. Hydrolyzing with enzyme is better than hydrolyzing by autolysis in regard of total FFA content. Hydrolyzing with Prozyme 6 will obtain higher total FAA content. The dominant FAA in hydrolysates of abalone muscle was taurine. Carnosine (car) and anserine (Ans) were not detected in the autolytic hydrolysate. However, they were found in the enzymatic hydrolysates. These hydrolysates were capable of chelating ferrous. At the same hydrolyzing time, autolytic hydrolysate could chelate more ferrous than enzymatic hydrolysates. Hydrolysate of Prozyme 6 have better reducing power and scavenging DPPH radical ability. Based on the previous results, hydrolyzing with enzyme different amino acid composition and the resulting peptide, antioxidant activity is not the same.Sensory evaluation of different hydrolysates shows that non-hydrolyzed muscle have the highest acceptance. Prolonged hydrolyzing will increase the bitterness of the hydrolysates, therefore lower the acceptance.
Book chapters on the topic "Enzymatic antioxidant capacity"
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Benzie, Iris F. F., and Malegaddi Devaki. "The ferric reducing/antioxidant power (FRAP) assay for non-enzymatic antioxidant capacity: concepts, procedures, limitations and applications." In Measurement of Antioxidant Activity & Capacity, 77–106. Chichester, UK: John Wiley & Sons, Ltd, 2017. http://dx.doi.org/10.1002/9781119135388.ch5.
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Busto, María D., Mónica Cavia-Saiz, Natividad Ortega, and Pilar Muñiz. "Enzymatic Debittering on Antioxidant Capacity of Grapefruit Juice." In Processing and Impact on Antioxidants in Beverages, 195–202. Elsevier, 2014. http://dx.doi.org/10.1016/b978-0-12-404738-9.00020-9.
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Alberto De La Riva De La Riva, Gustavo, Luis Adrián Saldaña Trujillo, and Juan Carlos González-Hernández. "Assessment on Oxidative Stress in Animals: From Experimental Models to Animal Production." In Importance of Oxidative Stress and Antioxidant System in Health and Disease [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.109043.
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Oxygen is a key element involved in a variety of vital physiological reactions in aerobic organisms, including those produced in the electron transport chain, hydroxylation, and oxygenation. Reactive oxygen species and reactive oxygen nitrogen species (ROS/RONS) are naturally formed as by-products from these previously mentioned processes and reactions involving the O2 molecules. Under healthy conditions, the harmful effects of ROS/RONS in the organisms are controlled by antioxidants, molecules of enzymatic or non-enzymatic nature, able to prevent, retard, or eliminate oxidative damage. Nevertheless, when ROS/RONS production exceeds the antioxidant capacity of one organism, oxidative stress emerges, leading to the apparition of many diseases, some of which can depict significant losses in the field of animal production. Thereby, looking for increasing animal productivity, procedures to mitigate the effects of oxidative stress on living organisms are tested in laboratory animal models, and the obtained results are used to develop strategies that avoid oxidative stress in farm animals either invertebrates (mollusks and crustacean species) or vertebrates (fish, birds, and mammals). In this chapter, oxidative stress will be addressed from the field of animal health and welfare and its impact on animal production, presenting some strategies, studies conducted, and recent perspectives to mitigate the effects of oxidative stress and improve the productivity indicators in farm animals.
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Mukuwa Greanious Alfred, Mavondo-Nyajena, Ncube Nesisa, Sibanda Alfred, Dube Delton, Chikuse Francis Farai, and Makoni Paul. "Phytotherapeutics Attenuation of Oxidative Stress, Inflammation and Lipid Peroxidation in Severe and Chronic Diseases." In Lipid Peroxidation [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99832.
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Lipid peroxidation is an end process of cellular injury driven by oxidative stress (OS) and inflammation through several molecular changes. Metabolism-generated reactive oxygen species avidly attack the polyunsaturated fatty acids in lipid cell membranes, initiating a self-propagating chain-reaction. Cell membrane destruction, lipids and the end-products of lipid peroxidation reactions are hostile to the viability of cells, even tissues causing and exacerbating Diabetes Mellitus (DM), neurodegenerative disorders (NDDs), cardiovascular diseases (CVDs) and Rheumatoid Arthritis (RA). Current treatment regimens have untoward side effects in the long-term necessitating phytochemical use as these are part of natural food sources. Enzymatic and non-enzymatic antioxidant defense mechanisms may be over run causing lipid peroxidation to take place. In disease states, oxidative stress may increase with subsequent production of increased free radicals which may over run the antioxidant capacity of the body with resultant oxidative damage on polyunsaturated fatty acids in the cell fluid membranes with cellular and tissue damage. Phytochemicals, have been shown to ameliorate diseases through attenuation of oxidative stress, inflammation, lipid peroxidation, causing tissue regeneration by regulating signaling systems and neuroprotective processes. Involvement of polyphenolic and non-phenolic phytochemical in the attenuation of OS, inflammation and lipid peroxidation remain areas of critical importance in combating DM, CVDA, NDD and RA.
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Chebil, Latifa, Ghada Ben Rhouma, Leila Chekir-Ghedira, and Mohamed Ghoul. "Enzymatic Polymerization of Rutin and Esculin and Evaluation of the Antioxidant Capacity of Polyrutin and Polyesculin." In Biotechnology. InTech, 2015. http://dx.doi.org/10.5772/60413.
Full textConference papers on the topic "Enzymatic antioxidant capacity"
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Peng, Han, and Fereidoon Shahidi. "Antioxidant activity of EGC (epigallocatechin) ester derivatives in food and biological model system." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/qchb4629.
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Objective: Antioxidants retard oxidative processes in food and pharmaceuticals as well as in the body. However, potential adverse effects of synthetic antioxidants and insufficient efficacy of current natural/natural-derived antioxidant substitutes necessitate developing novel antioxidants. Thus, EGC, as one of the most widely distributed dietary flavanols, serves as an efficient natural antioxidant with numerous health effects, but it is relatively poorly soluble in lipophilic media. In this study, novel lipophilic EGC derivatives prepared via enzymatic esterification will be evaluated in controlling oxidation in food and biological systems.
Methods: EGC esters were prepared under optimized reaction conditions, including enzyme type, substrate ratio (Acyl acceptor/acyl donor), and reaction time. The purified products were then tested for their antioxidant ability using β-carotene bleaching, LDL (low-density lipoprotein) oxidation, and DNA scission assays.
Results: In the β-carotene bleaching assay, the oxidation inhibition of EGC and its esters was observed for about 80 min at 50℃ by maintain the yellow colour and then decreased gradually with time. Meanwhile, EGC monoesters (except EGC acetate and stearate) showed a significantly higher inhibition rate than EGC. In the LDL oxidation assay, a similar downtrend of antioxidant ability was observed. However, EGC exhibited higher antioxidant capacity compared to EGC monoesters. In the DNA scission test, the EGC acylated with short-chain fatty acids (C2-C6) showed the higher DNA stability than EGC or other EGC monoesters.
Conclusion: Overall, EGC monoesters displayed significant antioxidant activity in all three assays. The results in biological/food systems were in agreement with our previous chemical antioxidant tests. Moreover, the antioxidant ability of EGC as a natural antioxidant was retained or even enhanced after modification. Thus, acylated EGCs could serve as viable alternatives to traditional synthetic antioxidants.
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Durand, Erwann, Nastassia Kaugarenia, Nathalie Barouh, Pierre Villeneuve, and Romain Kapel. "Antioxidant chelating peptides production from Rapeseed meal proteins proteolysis." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/whcd7145.
Full textAbstract:
The oxidative chemical degradation produced by reactive species (free radicals, oxygen, etc.) is responsible for the deterioration of most of the formulated products. One of the main properties of an antioxidant lies in its capacity to limit the chemical propagation of oxidation by reducing free radicals. Another strategy to prevent oxidation is binding transition metals, since they are ubiquitous and deeply involved in the initiation and propagation of lipids oxidation. Naturally occurring phospholipids, polyphenols, proteins, or peptides that can bind metal ions could be more valued than synthetic molecules, for human wellbeing, but also to align with consumer preferences. Yet, EDTA salts and sodium citrate remain the most common metal chelators in foods. In this study, we went to investigate a strategy to develop naturally produced antioxidants peptides from edible plant biomass, such as rapeseed. Several enzymatic hydrolyses of total rapeseed protein isolate with various proteases have been performed, and the produced peptides were screened for their antioxidant capacity. Peptides generated with Prolyve® allowed for particularly high Fe2+ chelation capacity (EC50 = 247 ± 27 µg). Accordingly, the enzymatic processing step with Prolyve® was modeled and optimized to minimize reaction costs and maximize peptide recovery. Then, lipid oxidation was studied in the presence or in the absence of chelating peptides, in micellar, bulk, and oil-in-water emulsion systems, and compared with EDTA salts and sodium citrate. Results clearly emphasized a very interesting potential from the peptides sample to prevent lipid oxidation by chelation of transition metals in emulsified models.This result is particularly important to develop the potential of applications of rapeseed meal in various food formulations. In addition, this study emphasized an approach aiming at developing food chelator peptides from plant proteins, having multifunctional properties, and through sustainable processing.
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Rohfritsch, Zhen, Greta Canelli, Philippe Pollien, and Rachid Bel-Rhlid. "Wheat and Rice Bran as Natural Additives for the Protection of Fish Oil from Oxidation." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/xpsc2867.
Full textAbstract:
Fortification of food products with omega-3 polyunsaturated fatty acids (ω-3 PUFAs) is difficult due to their high oxidative susceptibility. The use of synthetic antioxidants in food products to extend shelf life is challenged by the growing demand for natural ingredients from consumers. In this study, the stabilization effect of wheat and rice bran on fish oil oxidation was investigated. Five, 10, and 20g of fish oil were added to respectively 95, 90, and 80g of cereal brans. The obtained powders were homogenized and stored for accelerated oxidation study at 38 °C for up to 30 days (to avoid dramatic changes of the oxidation reaction pathways compared to those at room temperature). Secondary oxidation products were analyzed by both Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry and Liquid Chromatography-High Resolution Mass Spectroscopy. Wheat bran showed a better protection effect on fish oil oxidation. That could be explained by its phytochemical and physical stabilization effect. Heat and enzymatic treatments did not improve the antioxidant capacity of wheat or rice bran. Fine wheat bran water extract protected the fish oil from oxidation to the same extent as the whole wheat bran.
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Reinoso, Zain Sanchez, Jacinthe Thibodeau, Laila Ben Said, Ismail Fliss, Laurent Bazinet, and Sergey Mikhaylin. "Bioactive Peptide Production from Slaughterhouse Blood Proteins: Impact of Pulsed Electric Fields and Ph on Enzyme Inactivation, Antimicrobial and Antioxidant Activities of Peptic Hydrolysates from Bovine and Porcine Hemoglobins." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/fsht2150.
Full textAbstract:
Slaughterhouse blood is a valuable by-product since multiple bioactive compounds can be derived out of it. Its solid fraction consists mainly of hemoglobin, which is a good source of antimicrobial and antioxidant peptides that can be released by peptic hydrolysis. Nevertheless, this method has limitations such as low yield, expensive cost of enzyme process, and non-eco-friendly production (high energy consumption and chemical reagents requested). Amount the alternative green technologies for protein valorization, pulsed electric field (PEF) stands out since it allows modifying the physicochemical properties of proteins, promoting the enzymatic hydrolysis, enzyme inactivation, and bioactivity enhancement. Thus, this study aimed to evaluate the effect of PEF on the pepsin inactivation and biological activities (antimicrobial and antioxidant) in hemoglobin hydrolysates. Bovine and porcine hemoglobins were hydrolyzed with pepsin for 3 h (37°C, pH 3.0) and treated with PEF (73 pulses, 23.8kV/cm, 90Hz) to inactivate the enzyme. The hydrolysis degree was evaluated, which did not show significant changes after PEF-inactivation of pepsin, whereas the peptide population analysis by RP-UPLC-MS/MS showed some changes in PEF-treated hydrolysates over time, which suggested a residual pepsin activity. Additionally, the impact of pH (3, 7, and 10) on bioactivity was studied. PEF-treatments did not show a significant impact on antimicrobial (antibacterial, antifungal, and anti-yeast activities) and antioxidant activities (DPPH and ORAC). However, higher pH fostered stronger anti-yeast activity (R. mucilaginosa) and DPPH‐scavenging capacity, whereas pH 7 fostered the antifungal activity (M. racemosus). Even though some changes were observed in the peptide population, no negative effects of PEF were found for biological activities. Thus, the utilization of hemoglobin from the meat industry combined with PEF-treatment fits the circular economy concept since derived peptides can be recycled to protect meat and other products against microbial growth and oxidation.