Digestive properties of β-CN and α-La in different milk protein ingredients

Abstract

The digestion behavior of proteins not only differs between protein types but also between ion saturation and protein profile. This study aimed to investigate the digestive properties of α-La and β-CN in different dairy protein ingredients, including β-CN concentrate (βCC), micellar casein concentrate (MCC), α-La concentrate (α-LaC), and whey protein concentrate (WPC80), using an in-vitro infant static digestion model. α-La digested much faster in WPC than in α-LaC in the gastric phase, whereas β-CN digested faster in βCC than in MCC during gastric digestion. In the intestinal phase, α-La released more amino acids than β-CN. The released essential amino acids index (EAAIS) was higher in α-LaC than WPC80 and higher in βCC than MCC. This study facilitates better understanding of the effect of protein profile, protein structure, and calcium binding on the digestion behavior of β-CN and α-La, which provide reference for selection of dairy ingredient for infant formula.