The Effect Of Individual Milk Proteins On Bioaccessibility Of Green Tea Flavan-3-Ols

Moser, Sydney Elizabeth. M.S., Purdue University, December 2013. The Effect of Individual Milk Proteins on Stability of Green Tea Flavan-3-ols. Major Professor: Mario G. Ferruzzi. While information regarding the impact of flavan-3-ol-protein interactions on food quality attributes (flavor, texture, and physical stability) exists, insight into the potential consequence of these interactions on bioavailability of health-promoting flavan3-ols remains unclear. The ability of nonspecific protein interactions in flavan-3-ol rich foods and beverages to alter digestive stability and/or digestive release (bioaccessibility) of flavan-3-ols has been previously proposed but unconfirmed. The primary objective of this study was to characterize effects of individual milk proteins and the milk matrix on in vitro bioaccessibility of green tea flavan-3-ols from model beverage systems. As a secondary objective, the impact of protein gastrointestinal digestion on protein-flavan-3ol binding was assessed using fluorometry. Protein solutions containing sodium-caseinate (S-CSN), α-lactalbumin (α-LA), β-lactoglobulin (β-LG) (0.356 mg/100 mL, 0.01 mg/100 mL, 0.035 mg/100 mL, respectively), or non-fat dry milk (NFDM, 0.1 mg/mL) were prepared in Jenness Koops buffer containing milk salts or dd water and formulated at dosages of 10, 20, and 40% (v/v) into model green tea beverages containing 60 mg/100 mL total flavan-3-ols. Samples were then subjected to in vitro digestion simulating