Anti-Diabetic and Anti-Obesity Activities of Cocoa (Theobroma cacao) via Physiological Enzyme Inhibition

dc.contributor.authorRyan, Caroline Maryen
dc.contributor.committeechairNeilson, Andrew P.en
dc.contributor.committeememberLambert, Joshua D.en
dc.contributor.committeememberO'Keefe, Sean F.en
dc.contributor.committeememberStewart, Amanda C.en
dc.contributor.departmentFood Science and Technologyen
dc.date.accessioned2017-02-13T15:28:34Zen
dc.date.available2017-02-13T15:28:34Zen
dc.date.issued2016-06-01en
dc.description.abstractFermentation and roasting of cocoa (Theobroma cacao) decrease levels of polyphenolic flavanol compounds. However, it is largely unknown how these changes in polyphenol levels caused by processing affect cocoa's anti-diabetic and anti-obesity bioactivities, such as inhibition of certain enzymes in the body. Polyphenol profiles, protein-binding abilities, presence of compounds termed oxidative polymers, and abilities to inhibit α-glucosidase, pancreatic α-amylase, lipase, and dipeptidyl peptidase-IV (DPP4) in vitro were compared between unfermented bean (UB), fermented bean (FB), unfermented liquor (UL), and fermented liquor (FL) cocoa extracts. Overall, there were significant decreases (p<0.05) in total polyphenols, flavanols, and anthocyanins between the two sets of unfermented and fermented cocoa extracts (CEs). All CEs effectively inhibited α-glucosidase (lowest IC50 = 90.0 ug/mL for UL) and moderately inhibited α-amylase (lowest IC50=183 ug/mL for FL), lipase (lowest IC25=65.5 ug/mL for FB), and DPP4 (lowest IC25=1585 ug/mL for FB) in dose-dependent manners. Fermentation and roasting of the samples affected inhibition of each enzyme differently (both processes enhanced α-amylase inhibition). Improved α-glucosidase and α-amylase inhibitions were correlated with presence of different classifications of oxidative polymers, suggesting that these compounds could be contributing to the bioactivities observed. Some α-glucosidase inhibition might be due to non-specific protein-binding. Improved DPP4 inhibition was strongly correlated to increased CE degree of polymerization. In conclusion, potential enzyme inhibition activities of cocoa were not necessarily negatively affected by the large polyphenol losses that occur during fermentation and roasting. Additionally, it is possible that more complex compounds could be present in cocoa that contribute to its potential anti-diabetic and anti-obesity bioactivities.en
dc.description.degreeMaster of Science in Life Sciencesen
dc.format.mediumETDen
dc.identifier.othervt_gsexam:7415en
dc.identifier.urihttp://hdl.handle.net/10919/75003en
dc.publisherVirginia Techen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectCocoaen
dc.subjectflavanolsen
dc.subjectprocyanidinsen
dc.subjectdiabetesen
dc.subjectObesityen
dc.subjectα-glucosidaseen
dc.subjectα-amylaseen
dc.subjectlipaseen
dc.subjectdipeptidyl peptidase-IVen
dc.titleAnti-Diabetic and Anti-Obesity Activities of Cocoa (Theobroma cacao) via Physiological Enzyme Inhibitionen
dc.typeThesisen
thesis.degree.disciplineFood Science and Technologyen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Science in Life Sciencesen

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