Letteratura scientifica selezionata sul tema "Cocoa"

The purpose of this activity is to improve the productivity of the farmers in the success of cocoa fruit through the use of appropriate technology for the separation of coco seeds / squeezer machine, with the application of this technology is expected to assist farmers in the production process so that the quality results of cocoa produced will be more optimal. Cocoa bean separator machine serves to accelerate the process of separation of salut which during this process is still manually and takes a long time. This salute separator machine as much as possible the process is easy and the results are really on target. The main objective of making cocoa depulper is to assist cocoa farmers in the process of harvesting and improving the quality of crops so that the needs of cocoa farmers can be fulfilled. Keywords: cocoa, salute, depulper, rotary system

Improving cocoa quality through encouraging farmers to do fermentation is one of the ways to increase the added value of cocoa. However, majority ofIndonesian farmers are reluctance to do fermentation. This research aimed to study factors causing farmers reluctant to do fermentation, weight differencebetween fermented and unfermented cocoa, cocoa processing time difference between fermented and unfermented cocoa, quality difference between fermentedand unfermented coco refers to cocoa bean standard (SNI): 01-2323-2008/Amd-2010, and feasible added value incentive of fermented cocoa beans. The data collectionwere conducted through household farmers’ survey, focus group discussion and experimental research. The experimental research was conducted to understandthe weight and processing time differences; and to asess the quality, including moisture content, bean count, pH and fermentation index. Analysis of the datawere conducted by methods of Fishbone Ishikawa and logit multiplier linear analysis. The research results showed that the main factors causing farmers reluctant todo fermentation were insuitable of selling price of fermented cocoa, the existence of village collectors in buying unfermented cocoa, the lack of cooperation amongfarmers in farmer group (Subak Abian) and the lack of farmers’ skills on cocoa bean fermentation. This study also found that the weight depreciation differencebetween fermented and unfermented cocoa was 0.5-3.75%, and the processing time difference between fermented and unfermented cocoa was 12-24 hours. Qualityof fermented cocoa beans was higher than that of unfermented cocoa beans and it can fulfill the standard of SNI: 01-2323-2008/Amd-2010. It was found that thefeasible added value incentive of fermented cocoa benas was 2,126-3,426 IDR/kg. Keywords: cocoa, fermentation, unfermented, quality, incentive

The study aimed to explore the influence of fermentation and non-fermentation on cocoa processing (Theobroma cacao L.) on physical properties, chemical properties, fatty acid profiles and sensory properties of cococa butter. The study was conducted using an experimental method with two treatments and three replications. Analysis of cocoa butter consisted of yield, color, moisture content, free fatty acids, iod numbers, peroxide numbers, determination of fatty acid profile using GC-MS, and analysis of sensory properties. The results showed that the yield was between 20.82-21.00%. The color of fermented cocoa butter has a value of L* 17.88, a*8.70, and b*7.99 while for nonfermented cocoa butter has a value of L* 14.88, a* 8.96, and b* 6.78, water content between 0.10-0.12%, free fatty acids 0.51-0.56%, iod numbers 26.40-26.50 g I2/100g, peroxide numbers between 0.40-0.70 meq peroxide/kg fat, 190.23-191.40 mg KOH/g fat. The fatty acid profile using GC-MS showed that the dominant fatty acid constituents contained in fermented and nonfermented cocoa fats are oleic acid (29.39-29.57%), heptadecanoic acid (25.85-26.77%), and palmitic acid (21.49-21.83%). Based on sensory analysis of cocoa butter with fermented treatment is preferred because it has a more attractive color, taste, and aroma compared to nonfermented cocoa butter.

Cocoa (Theobroma cacao L.) is an important agricultural export of South Pacific countries, providing livelihoods for an estimated 310,000 people. The wet tropical coast of Far North Queensland has also started producing cocoa for a local boutique chocolate making industry. Although the volumes of cocoa produced are small by global standards, Pacific island and north Australian cocoa is well placed to compete in the high-value, low-volume markets—based on fine flavour, unusual genetic resources and novel ‘single origin’ branding. A member of the Malvaceae family, cocoa has its origins in Central and South America. First domesticated over 2000 years ago, cocoas’ global dispersal was mediated by humans and cultivation is now widespread across the humid tropics. The use of molecular markers to characterize the diversity of genetic resources available and identify superior genetic material is vital to the continued improvement and selection of clones. This work used single nucleotide polymorphism (SNP) markers to identify the parentage of Pacific island cocoa selections in relation to the 10 distinct cocoa families formerly identified from the original Central and South American populations. On farm collections from Pacific island countries has revealed distinct geographic cocoa populations. Specific populations show strong Criollo parentage, a source of fine flavour qualities, while others exhibit a high component of Amelonado parentage. Small populations showed a higher percentage of IMC, Parinari, National or Scavina parentage. Production and quality data linked to these populations assists to identify superior parentage to enable local programs to rapidly bring these into commercial production thereby improving cocoa productivity and quality in the Pacific.

Remote sensing approaches are often used to monitor land cover change. However, the small physical size (about 1–2 hectare area) of smallholder orchards and the cultivation of cocoa (Theobroma cocoa L.) under shade trees make the use of many popular satellite sensors inefficient to distinguish cocoa orchards from forest areas. Nevertheless, high-resolution satellite imagery combined with novel signal extraction methods facilitates the differentiation of coconut palms (Cocos nucifera L.) from forests. Cocoa grows well under established coconut shade, and underplanting provides a viable opportunity to intensify production and meet demand and government targets. In this study, we combined grey-level co-occurrence matrix (GLCM) textural features and vegetation indices from Sentinel datasets to evaluate the sustainability of cocoa expansion given land suitability for agriculture and soil capability classes. Additionally, it sheds light on underexploited areas with agricultural potential. The mapping of areas where cocoa smallholder orchards already exist or can be grown involved three main components. Firstly, the use of the fine-resolution C-band synthetic aperture radar and multispectral instruments from Sentinel-1 and Sentinel-2 satellites, respectively. Secondly, the processing of imagery (Sentinel-1 and Sentinel-2) for feature extraction using 22 variables. Lastly, fitting a random forest (RF) model to detect and distinguish potential cocoa orchards from non-cocoa areas. The RF classification scheme differentiated cocoa (for consistency, the coconut–cocoa areas in this manuscript will be referred to as cocoa regions or orchards) and non-cocoa regions with 97 percent overall accuracy and over 90 percent producer’s and user’s accuracies for the cocoa regions when trained on a combination of spectral indices and GLCM textural feature sets. The top five variables that contributed the most to the model were the red band (B4), red edge curve index (RECI), blue band (B2), near-infrared (NIR) entropy, and enhanced vegetation index (EVI), indicating the importance of vegetation indices and entropy values. By comparing the classified map created in this study with the soil and land capability legacy information of Bougainville, we observed that potential cocoa regions are already rated as highly suitable. This implies that cocoa expansion has reached one of many intersecting limits, including land suitability, political, social, economic, educational, health, labour, and infrastructure. Understanding how these interactions limit cocoa productivity at present will inform further sustainable growth. The tool provides inexpensive and rapid monitoring of land use, suitable for a sustainable planning framework that supports responsible agricultural land use management. The study developed a heuristic tool for monitoring land cover changes for cocoa production, informing sustainable development that balances the needs and aspirations of the government and farming communities with the protection of the environment.

One of the main reasons of the confectionery product organoleptic parameters is microorganism activity. Growth most of them can be prevented or inhibited by the control of initial content. The influence of microorganisms with lypolityc activity to the cocoa-containing confectionery production quality was determined and the mathematic correlations were established, according which can be predicted changing of production characteristics on the basis of them initial content. Quantity of the mesophyll aerobic and optionally anaerobic microorganisms (QMA&OAM) were determined in accordance with GOST 33536-2015. Some microorganism colonies were separated by the thinning stroke inoculating on the solid nutrient agar. Testing cultures have been grown by the surface cultivation method on solid mediums and on liquid nutrient mediums (submerged cultivation). For the microorganisms studying was used microscopical method, biochemical characteristics were estimated by the standard methods. The conclusion about genus and species of the cultures was prepared on the basis of identification by mean the 16S rRNA analysis. The cocoa-containing product models were created which shown the organoleptic spoilage processes. For the basis was chosen mixture of the cocoa powder, sugar powder, and fats of the lauric types and four formulas A,B,C and D of the confectionery and coca-containing glazes analogues with minimum and maximum content of the total evaporated residue cocoa which is the regulated merit rate of the coca-containing confectionery products. Based upon the experimental results was determined dependence of the cocoa-containing confectionery products acidity change which can be used for prediction of them quality changes.

Cocoa, the main derivative of the seeds of Theobroma cacao L., has been recognized to have several effects on human health including antioxidant and neuro- and cardio-protective effects, among others. These effects have been attributed mainly to its bioactive compounds. In this context, the aim of this work is to evaluate the nutritional composition, bioactive compounds (i.e., phenolic compounds, procyanidins and methylxanthines) and the antioxidant activity of seven different cocoas (alkalized and non-alkalized) from different origins (Peru, Venezuela, Ivory Coast, Dominican Republic, and West Africa). It represents the first stage of a larger project aiming to find high polyphenol cocoa-based nutritional strategies and related biomarkers that may potentiate brain plasticity and cognitive function. Cocoa powders were extracted by ultrasound-assisted technology, and the total phenolic content (TPC) was measured by Folin–Ciocalteu. Methylxanthines (caffeine and theobromine) and procyanidin contents were determined by HPLC-FLD-DAD, and the antioxidant activity was assessed through DPPH, ABTS and FRAP assays. Non-alkalized cocoas showed higher phenolic and procyanidin contents and higher antioxidant activity compared to the alkalized ones. A strongly significant (p < 0.05) positive correlation between the antioxidant activity and the TPC, especially with the total procyanidin content, but not with methylxanthines was found. In conclusion, the non-alkalized cocoas, especially the one from Peru, were the best candidates in terms of bioactive compounds. The cocoa from Peru had a TPC of 57.4 ± 14.4 mg of gallic acid equivalent/g d.w., 28,575.06 ± 62.37 µg of catechin equivalents/g d.w., and 39.15 ± 2.12 mg/g of methylxanthines. Further studies should be undertaken to evaluate its effect on brain plasticity and cognitive function.

Survey, monitoring and documentation of entomofauna of cocoa was carried out in three cocoa growing states viz., Tamil Nadu, Kerala and Andhra Pradesh during 2014-2015. Results revealed that a total number of 23 species of insect pests and 13 species of natural enemies were documented and identified. Among the insect pests, 14, 2 and 7 species were sucking pests, borers and defoliators, respectively. Among the natural enemies, 7 species of predators and 6 species of parasitoids were documented and identified on different insect pests of cocoa. Among the insect pests, sucking pests were found to be predominant and maximum number of entomofauna were recorded in major coco growing areas of Tamil Nadu. From the results it was concluded that the list of entomofauna documented can enhance the knowledge on diversity of the entomofauna associated with cocoa in three different cocoa growing states. Sucking pests were found to be predominant and caused huge yield loss in Tamil Nadu and Kerala. While in Andhra Pradesh pod borer and bark eating caterpillar were found to be predominant causing severe yield loss. This information provides a base for development of location specific Integrated Pest Management module.

Plant physiological status during the growing season (specific leaf area (SLA), resorption of N and P)leads to knowing the best plant nutrition management (amount and time) based on the plating pattern. Furthermore, proline and glucose content in root tissues may provide a better technique to represent plant stress conditions. This study aimed to evaluate the SLA, the level of reabsorption of N and P from the leaf, and root proline and glucose content of cocoa plants in different seasons and planting patterns. This study was performed in the fields of Plana village, Somagede, Banyumas, 14 Central Java, Indonesia, and was conducted in December 2015 (rainy season) and October 2016 (dry season) on 7 years-old cocoa plants (Theobroma cacao). Three different planting patterns were observed; (1) only cocoa plants, (2) cocoa and coconut pattern, and (3) cocoa with shading trees. The results showed that different seasons and planting patterns affected each observed parameter differently. Cocoas’ SLA was not significantly different in all areas for both 2015 and 2016. N resorption during the growing season did not change in 2015 and 2016 in all planting patterns, whereas P resorption had a significant change in 2016 in all planting patterns. The proline content was significantly different in June 2015, October 2015, and March 2016 in all planting patterns. The glucose content in roots showed insignificant differences in 2015 and 2016 in all planting patterns. These results also showed that SLA and glucose did respond to season and plating patterns. These parameters are suggested as poor indicators of physiological status. Furthermore, sowing cocoa plants with other types of plants can be used to help farmers and stakeholders in managing cocoa cultivation in efficient and sustainable ways.

Il cacao (Theobroma cacao L.) è un’importante coltura a livello mondiale. La sua produzione è alla base dell’economia della maggior parte dei paesi produttori e dei profitti di molte industrie dolciarie. Attualmente, circa il 70% delle fave di cacao nel mondo è raccolto in Africa. Il Ghana è il secondo paese produttore dopo la Costa d’Avorio. La maggior parte del cacao proviene da piccoli agricoltori che spesso usano sistemi di coltivazione obsoleti e poco organizzati. La crescente domanda di cacao nel mercato mondiale ha aumentato l’attenzione su una produzione sostenibile attraverso una serie di miglioramenti per la coltivazione e i processi post-raccolta. Questa tesi fa parte di un progetto che ha come obiettivo a lungo termine quello di incrementare la produzione di cacao di alta qualità da parte di piccoli coltivatori in Africa occidentale. Per questo lavoro sono state esaminate fave di cacao prodotte da 30 piccoli agricoltori di sei regioni del Ghana. I campioni sono stati analizzati e comparati sotto forma di fave di cacao intere, in polvere e liquore di cacao. I risultati hanno rilevato alcuni difetti nel processo di fermentazione evidenziati dai bassi livelli dell’ indice di fermentazione e dalla presenza di Ocratossina A. Dai risultati si evince anche che le fave di cacao prodotte in Ghana hanno grandi dimensioni, alto contenuto di grassi e presentano note aromatiche fruttate.

The underlying resistance mechanisms to cocoa pod borer (CPB) in cocoa were investigated. Experiments performed under field conditions in Malaysia showed that female CPB preferred to lay eggs on pods of clones with a rough pod surface compared to clones with a smooth pod surface. This appeared to be related to a higher density of trichomes on rough pods. The production of volatile compounds by cocoa pod trichomes is thought to stimulate females CPB to lay more eggs. Cocoa pods develop a lignified sclerotic layer and the thickness of this sclerotic layer determines the hardness of the pod, but pod hardness also depends on the composition of sclereid cells in the sclerotic layer. The sclerotic layers are soft in young pods and gradually increase in thickness and hardness as the pod grows. The quality of the pod as a food source affected the life-history traits of the CPB. However, the concentration of nitrogen and polyphenols in the pod walls did not appear to be a factor limiting the growth and development of CPB larvae. Therefore, the importance of other food quality components such as lipids, proteins, amino acids and carbohydrates (including water) warrants further investigation. The variation in CPB attack between clones under natural field conditions appeared to be influenced by plant and insect variables, and modified by environmental conditions. Any changes in the plant variables affect the spatial and temporal distribution of CPB and then, subsequently influence the expression of resistance. Clones with good resistant traits also face severe infestation in the absence of favourable pod size, particularly during low pod production or the presence of non-bearing cocoa trees within rows or blocks. The basis for characterising resistant clones was proposed. A resistance index based on eight variables, low number of CPB eggs recorded on the surface of the pod, low number of entry holes observed on the pod, harder sclerotic layer, smoother pod surface, high larval mortality in the pre-sclerotic layer, low larval penetration through the sclerotic layer, low number of exit holes, and low pod damage index was derived and is proposed as a basis for screening and selecting resistant clones to CPB. The lowest average rank for these variables reflects the highest overall resistance level to CPB. Among the eight variables, the percentage larval penetration appeared to be a prominent key to the damage severity of the cocoa pod.

Particle stabilisation of emulsions has generated significant interest in recent years due to the enhanced stability of these emulsions over surfactant or protein stabilised emulsions. Once the particle is at the interface, it is considered to be permanently adsorbed as a high energy input is required to disrupt the particle layers to cause coalescence. The range of food grade particles capable of stabilising emulsions has increased over the last two decades however most food grade particles require a degree of chemical modification. This research introduces the use of cocoa particles as a natural particulate emulsifier stabilising both oil-in-water (o/w) and water-in-oil (w/o) emulsions. The ability of cocoa particles to stabilise o/w emulsions was studied as a function of particle concentration, type, size and continuous phase pH. All emulsions were stable to coalescence for an extended storage period. An overlap in size distribution was found between the emulsion droplets and cocoa particle size, which brought into question the interfacial structure. The role of soluble molecules originating from the cocoa particles and cocoa particle fines in stabilising emulsion droplets were investigated. The fine fraction of cocoa particles was found to be adsorbed at the interface confirming the fact that cocoa particles act as particulate emulsifiers. The origin of the interfacial properties of cocoa particles was investigated using a high fat cocoa powder and cocoa fibre. Cocoa particles were subjected to multiple extraction and hydrolysis protocols, resulting in particles which could and could not stabilise emulsions. The chemical composition and surface properties of the treated particles were investigated to isolate a key component responsible for the interfacial properties of the cocoa particles. The interfacial properties are now known not to lie with the lipid, polyphenol, protein or starch fractions of the cocoa particles. However, no specific component responsible could be identified. The investigations did offer two potential hypotheses as to why cocoa particles stabilise emulsions; the surface roughness and the lignin present in cocoa particles, both of which need further investigation. The enhanced stability of emulsions stabilised by cocoa particles was exploited in an attempt to nutritionally enhance food products. The first application involved the in-vitro digestion of the cocoa particle stabilised emulsions, which showed that the adsorption of cocoa particles at the interface slowed digestion. The benefit of slowing digestion is that undigested material reaches the intestine and activates the ileal brake, which is thought to reduce food intake. In a second study, cocoa particle stabilisation was used to nutritionally improve chocolate by incorporating water into chocolate, using a water-in-cocoa butter emulsion stabilised by cocoa particles. The emulsion chocolates had the gloss and snap expected from chocolate and the emulsion was considered stable due to the homogeneous structure and lack of sugar bloom chocolate. This indicated the potential use of cocoa PSEs in calorie reduced chocolate. This research has highlighted the use of cocoa particles to stabilise food emulsions and the potential advantages of using these particles.

Cocoa has been useful in several ways, especially to countries that produce it and consumers all over the world. Its benefits range from improving economies to satisfying millions all over the world who desire one cocoa product or the other. The production of cocoa however is not without its own attendant problems. Aging tree stock, spread of diseases, and production capacity problems are, but a few of many challenges that seed gardens that produce cocoa face. This study investigated the pollination process on selected seed gardens in Ghana, the second largest world producer of cocoa. The purpose of this study was to investigate the artificial pollination process of cocoa on seed gardens in Ghana, and explore ways by which the Lean principle of Value Stream Mapping could be applied in improving the process. The process of pollination was observed on eighteen seed gardens, and a current value stream map depicting the existing process developed to give an indication of the current state of affairs. Subsequently, a future value stream map based on the current map was developed to show aspects of the process that could be improved to enhance the operations of the seed gardens. The future value stream map revealed that operational procedures relating to cleaning and preparation of trees, choosing male and female trees for pollination, harvesting of pollen, and manually pollinating practices presented various avenues for improving the pollination process and hence seed production output.

Climate-smart agriculture (CSA) has emerged as a concept to address the multiple challenges and interdependencies of agriculture and climate change. Within CSA debates, equity and agroecology are especially contested. In Ghana, the concept of climate-smart cocoa (CSC) has emerged to simultaneously respond to high rates of deforestation, climate change pressures and low productivity of cocoa – Ghana’s principal agricultural export. Since CSC in Ghana is a nascent concept, it has received very little academic or critical appraisal. By applying a meta-discourse framework, this study aimed at gaining insights into local CSC discourses in Ghana and how these reflect global environmental meta-discourses. The adoption of certain discourses can reveal insights into subsequent policies and their implications for already marginalised cocoa smallholders. My findings are based on 37 qualitative interviews with cocoa smallholders, extension officers as well as governmental, non-governmental and private sector representatives of Ghana’s cocoa sector. Overall, my results suggest that an ecological modernisation discourse was the most pronounced meta-discourse reflected within CSC. A sustainable intensification discourse was the most common CSC practice to achieve a win-win between environment and development aspirations. Agroecological practices within CSC were mainly adopted to serve ecological modernisation discourses and are thus diametrically opposed to those promoted by more radical meta-discourses. Issues of contextual equity, especially regarding tree tenure, were ubiquitous, and discussed by a large majority of cocoa stakeholders. I caution that an overly simplistic win-win approach risks side-lining contextual equity issues and complexities regarding shade cover and agrochemical input. Community Resource Management Area Mechanisms (CREMAs) and other local governance mechanisms represent promising ways to balance trade-offs within the dominant CSC discourse by giving cocoa smallholders a stronger voice. However, given the dominance of large agricultural actors – such as foreign chocolate companies – within the current political economy of Ghana’s cocoa sector, this study cautions not to overestimate the potential of these local governance structures.

The aim of this thesis is to analyse the impact of the “meso model” on Ghana’s cocoa sector in general and the practices and opportunities for smallholder cocoa farmers in particular. Additionally, Ghana’s efforts to embrace globalisation are examined. The theoretical framework of this thesis is the neo-structuralism paradigm out of which an analytical framework was distilled to assess the impact of the 1993 reforms. The qualitative methodology was mainly used to collect data but some quantitative techniques were also used to enhance the collection and analysis of the data. Ghana was adjudged the “Star Pupil” of Africa by the International Monetary Fund (IMF) and the World Bank after implementing bold economic reforms in 1983 and the cocoa sector reforms in 1993. But ironically Ghana stood up to the IMF and the Bank by refusing to dismantle its cocoa marketing board (COCOBOD) as was recommended by them under the Washington Consensus and rather adopted a” meso model” of partial liberalisation of the cocoa sector after skilful negotiations. The thesis makes a significant, original contribution to knowledge in the field of economic development through the following key findings: Firstly, the output of cocoa farmers in general is a function of not only the price paid to them but also the overall environment created for production. Secondly, the” meso model” Ghana adopted challenges the “One Size Fits All” Washington Consensus development model because it enhanced cocoa farmers’ output and income, and Ghana’s cocoa export and foreign revenue enabling it to attain economic growth and development. Thirdly, the use of mobile phones by cocoa farmers contributes to the reduction in their transport cost and transforms their mode of operations. Finally, Ghana’s efforts to embrace globalisation and to integrate into the global economy have been impressive albeit urban bias.

Les athlètes utilisent les suppléments nutritionnels avec pour objectif d'améliorer leur performance sportive. La performance sportive dépend de facteurs physiques, mais également de facteurs cognitifs. Les suppléments nutritionnels riches en flavanols issu du cacao (CF) peuvent stimuler la fonction vasculaire, réduire le stress oxydant et améliorer la fonction cognitive. L'objectif de cette thèse est donc d’analyser les effets d'une consommation aigue, ou pendant une semaine, de CF, sur la performance physique et cognitive chez des athlètes, chez des sujets actifs et chez des personnes ayant un diabète de type 1 (DT1). De plus, l’objectif est d’investiguer les effets des CF en altitude simulé, où l’hypoxie limite la performance cognitive et physique.La consommation aigue de 900 mg CF (dont 196 mg d'épicatéchine) suscite une augmentation de l’oxygénation cérébrale, mais pas de la concentration de BDNF sérique et n'a pas d’effet sur la fonction cognitive chez des sportifs sains. L’effet bénéfique des CF sur l’oxygénation cérébrale au repos est dépassé par l’ampleur de l’augmentation de la perfusion et de l’oxygénation cérébrale à l’exercice physique et n'est donc plus visible en post-exercice.En hypoxie (altitude simulée de 4000 m), la consommation aigue de 530 mg CF (dont 100 mg d'épicatéchine) augmente la réponse hémodynamique du cortex préfrontal durant une tâche cognitive, mais n’affecte pas l’activité neuronale. Les CF améliorent la pensée abstraite en normoxie, mais n’améliorent aucun autre domaine des fonctions cognitives. Seule la précision lors du test de Stroop est diminuée par l’hypoxie. De plus, la réponse hémodynamique du cortex préfrontale et l’activité neuronale ne diffèrent pas en hypoxie vs. en normoxie.Le diabète de type 1 (DT1) est associé avec une dysfonction endothéliale, qui constitue un des facteurs de déclin cognitif lié au diabète. Dans une 3ième étude, la fonction cognitive n’est pas altérée chez les patients DT1, en comparaison des sujets sains, alors que l'activation cérébrale diffère entre ces 2 groupes. Cette différence d'activation cérébrale pourrait alors jouer un rôle compensatoire chez les patients DT1. La consommation aigue de CF peut améliorer les fonctions exécutives chez des patients DT1 et des sujets sains, et peut augmenter le signal BOLD dans les régions du cerveau activées par les tâches cognitives.Ainsi, la consommation aigue de CF augmente la vasoréactivité cérébrale. Ces changements sont associés avec une meilleure fonction cognitive chez des patients DT1, alors que ce n’est pas le cas chez des sujets entraînés, ni au niveau de la mer, ni en hypoxie. Malgré ces effets bénéfiques des CF, l’exercice physique semble rester un moyen beaucoup plus efficace pour stimuler la vasoreactivité cérébrale et les fonctions cognitives.Nous nous sommes aussi intéressés aux effets de CF sur la capacité antioxydante, le stress oxydant et la production de NO pendant l’exercice, ainsi que sur les implications pour la performance physique et la récupération, chez des athlètes. La consommation aigue de 903 mg CF augmente la capacité antioxydante au repos et pendant l’exercice, mais sans réduire le stress oxydant et la production de NO. La consommation pendant une semaine de 530 mg CF (dont 100 mg d'épicatéchine) atténue la peroxydation lipidique induite par l’exercice, mais n’influence pas la capacité antioxydante. Les CF ne modifient pas la production et la biodisponibilité du NO pendant un exercice en normoxie et en hypoxie (altitude simulée de 3000 m). La consommation de CF pendant une semaine peut augmenter la fonction endothéliale de repos, et peut réduire les effets nuisibles de l'hypoxie sur l’oxygénation préfrontale au repos et pendant l’exercice modéré. Par contre, cet effet disparait pendant l’exercice intense. La consommation aigue, et pendant une semaine, de CF n’augmente pas la performance physique, ni en normoxie, ni en hypoxie
Sports performance depends on physical factors, but also on cognitive functioning. Nutritional supplements as potential ergogenic aids can impact muscle, but also the brain. Cocoa flavanols (CF) have antioxidant capacities, can stimulate vascular function, and potentially enhance cognitive function. CF intake might thus improve exercise performance and recovery by reducing oxidative stress, increasing NO availability and/or boosting cognitive function. It is the purpose of this PhD to identify the effects of CF on physical and cognitive performance in healthy athletes at sea level and altitude, as well as in patients with type 1 diabetes. Our systematic review showed that CF can reduce exercise-induced oxidative stress, but without improving exercise performance. Combining CF intake and exercise training improves cardiovascular risk factors and vascular function in healthy and overweight participants, but evidence on the synergistic effects of CF and exercise training on oxidative stress, inflammation and fat and glucose metabolism is lacking.In a randomized, placebo-controlled, double blind cross-over study, we showed that 900 mg CF intake increased prefrontal oxygenation in athletes, but without affecting executive function. BDNF was not affected by CF intake. The effects of high-intensity exercise largely overruled the effects of CF intake: large beneficial effects of exercise on prefrontal oxygenation and cognitive function were observed and CF supplementation did not enlarge these effects. In a 2nd study, the effect of acute CF intake (530 mg CF) on performance on a demanding cognitive test was assessed in normoxia and hypoxia (simulated altitude 4000 m). Electroencephalogram and fNIRS were used to analyse neuronal activity and hemodynamic changes. Acute CF intake improved the neurovascular response, but did not affect neuronal activity and cognitive performance in normoxia and hypoxia. Most cognitive functions, the cerebrovascular response and neuronal activity, were not altered in hypoxia in healthy subjects. In a 3rd study, we found that acute intake of 900 mg CF enhanced cognitive performance on the Flanker test in patients with type 1 diabetes, and their healthy matched controls. CF intake increased the BOLD response in brain areas activated during this specific task. While cognitive performance was not deteriorated in patients with type 1 diabetes, a different brain activation pattern during the cognitive task was observed, compared to healthy controls and this brain activation pattern was altered by CF intake. To conclude, acute CF intake improves prefrontal oxygenation and cerebrovascular responsiveness. This can be associated with better cognitive function in patients with type 1 diabetes, but does not result in improved executive function in healthy persons. Compared to exercise, the magnitude of the CF-induced neurovascular changes is small.Two studies were conducted examining the effects of CF on exercise-induced oxidative stress, NO availability and its implications for exercise performance, in well-trained cyclists. We found that acute CF (900 mg) improved the exercise-induced increase in total antioxidant capacity, but did not reduce the exercise-induced increase in lipid peroxidation. One week CF intake (530 mg CF) improved vascular function at rest, and prefrontal oxygenation at rest and during low-intensity exercise, but did not influence muscular oxygenation. One week CF intake partially restored the hypoxia-induced decline in prefrontal oxygenation during rest and low-intensity exercise, but not during high-intensity exercise. One week CF intake reduced exercise-induced lipid peroxidation, but did not alter total antioxidant capacity. Both acute and 1-week CF intake did not improve exercise performance and recovery and do not change NO production during exercise (in normoxia and hypoxia) in well-trained athletes

Cocoa beans (Theobroma cacao) are a highly concentrated source of dietary flavanols- bioactive compounds associated with the health protective properties of cocoa. Cocoa beans undergo processing steps, such as fermentation, roasting, winnowing, grinding, pressing, etc., to produce a final product with specific desirable sensory attributes. It is well established that these processing steps, specifically fermentation and roasting, result in dramatic degradation of cocoa's native flavanols, but it is possible that these processing steps may generate compounds with novel activities, potentially preserving or enhancing bioactivity. Raw unfermented cocoa beans were processed by way of a partial factorial approach to produce cocoa powders from the same batch of raw beans using various combinations of fermentation [unfermented, cool fermented (maximum 46°C), hot fermented (maximum 60°C))] and roasting [unroasted, cool roasted (120°C), hot roasted (170°C)]. To simulate cocoa fermentation in a highly controlled environment, a pilot-scale fermentation model system was employed to eliminate many external unknowns and ensure that the differences between our cocoa powders were due to our various treatments, rather than unknown factors occurring during fermentation and roasting. Low and high molecular weight fractions (8-10 kDa cutoff) were produced from cocoa powder extracts (CPE) of each treatment to quantify Maillard reaction products (MRP). A HILIC-UPLC MS/MS method was developed to more efficiently and sensitively quantify cocoa flavanols with high degrees of polymerization (DP) produced during processing. Overall, cocoa processing significantly (p<0.05) decreased the total phenolic and total flavanol concentrations of CPEs. Hot roasting had the greatest impact on native flavanol degradation yet produced CPEs with the highest mean degree of polymerization (mDP). All CPEs dose-dependently inhibited α-glucosidase enzyme activity, with cool fermented/cool roasted cocoa powder exhibiting the best inhibition (IC50 of 62.2 µg/mL). Increasing flavanol mDP was correlated with decreasing IC50 values, suggesting that the complex flavanols produced during processing enhance cocoa's bioactivity (or their production is associated with other products that enhance bioactivity). Alternatively, high molecular weight CPE fractions were correlated with increasing IC50 values, suggesting that MRPs interfere with enzyme inhibition or are associated with other products (polyphenols, macronutrients, etc.) that interfere with enzyme inhibition. Overall, the data presented within this work indicate that the components of processed cocoa powders are promising inhibitors of α-glucosidase, despite a significant reduction in native flavanol composition induced by processing, and moreover that fermentation and roasting conditions can positively influence the bioactivity of cocoa despite losses of native flavanols.
Master of Science in Life Sciences
According to the Centers for Disease Control and Prevention, obesity-related chronic conditions such as cardiovascular disease and type 2 diabetes mellitus (T2D) are the leading cause of preventable and/or premature death, with 51% of the American population predicted to be obese by 2030. Cocoa (Theobroma cacao) is a highly concentrated source of polyphenols, and these compounds have been shown to interact with and inhibit digestive enzymes responsible for carbohydrate breakdown. By inhibiting the activity of these digestive enzymes, it is possible to slow down carbohydrate absorption after a meal and ultimately reduce large spikes in blood glucose levels, being a promising strategy in the prevention and maintenance of T2D. Cocoa beans undergo processing steps to produce a final product, such as cocoa powder, and it is known that these processing steps reduce the levels of beneficial polyphenols. Yet, how this processing-induced degradation effects the health protective activities of cocoa is still widely unknown and is the focus of this work. Through highly controlled cocoa bean processing, cocoa powders of different processing conditions were produced and used to assess how various processing parameters impacted digestive enzyme activity. Overall, processing steps did reduce levels of native polyphenols. However, these losses did not demonstrate a reduction in enzyme inhibition and certain processing conditions actually enhanced digestive enzyme inhibition. This research shows promise for the potential use of processed cocoa powder as an effective strategy in the prevention and maintenance of T2D and further work must be done to understand the mechanisms behind this relationship.

Flavanol-rich dark chocolate (DC) and green tea extract capsules (GT) were assessed for effects on markers of vascular health. Commercially available dark chocolate was analysed for flavanol and methylxanthine levels using HPLC. There was considerable variation between brands of high cocoa solid content, and epicatechin (EC) levels did not correlate with calculated % non-fat cocoa solids. EC-rich DC also had considerably high methylxanthine levels. EC-rich DC was used to assess acute endothelial fitness. EndoPAT index (PAT) was determined in fingertips (3 subjects). PAT was not affected by dark chocolate ingestion, but systolic blood pressure (SBP) increased significantly by 5.2±4.9 mmHg (p