Milk Protein and Enzymes Symposium: Don’t Have a Cow-Plant Proteins, Bovine Protein Expression, and Milk Humanization

摘要

Studies have linked food structure and texture to kinetics of nutrientdelivery. Changes in some nutrient release rates, such as for proteinand lipids, could induce different physiological effects (e.g., satietyeffect, reduction of postprandial lipemia). Examples will be presented toshowcase the contribution of dairy food structure, as found in yogurt andcheese, on nutrient release rates. The impact of the casein:whey proteinratio or fiber addition on digestion kinetics of protein, and subsequently,satiety, was examined in one study. A static in vitro digestion model wasused on experimental yogurts differing in the casein-to-whey proteinratio (C:W) or dietary fiber content. Healthy men (20) consumed the 5isocaloric/isoproteinemic yogurt snacks previously studied. Ad libitumfood intake was monitored 2.5 h post-snack consumption. A human clinicaltrial revealed that yogurt formulation with increased whey proteincontent significantly reduced subsequent energy intake compared withthe control, and increased satiety. This result was linked to a slower invitro disintegration rate. Soluble protein release for yogurt increased inwhey protein whereas no difference was observed for yogurts with fiber.A second study allowed for the discrimination of the effects of cheeseattributes on lipid release and absorption. Nine commercial cheeseswere digested in vitro and 2 were selected for an in vivo study. Healthywomen/men (43) ingested 33 g of fat from cheddar, cream cheese orbutter, incorporated in a standardized meal. Plasma concentrations oftriglycerides (TG) were measured before the meal and at 2, 4, 6 and 8h. At the end of the in vitro gastric digestion, cheddar and cream cheeseshowed different disintegration, attributed to the texture and manufacturingprocesses. The in vivo study revealed that cream cheese, but notcheddar, induced a more important increase in TG concentrations thanthe butter (Δ vs baseline: +44% vs +24%, P = 0.002) at 2 h. These studiesdemonstrate that the dairy food matrix per se modulates nutritionalproperties. Studies published on this topic will be included to put intoperspective the role of the dairy food matrix on nutrient release, thephysiological effects, and how this can be compared with other foods.