Alterations in the sequence and bioactivity of food-derived oligopeptides during simulated gastrointestinal digestion and absorption: a review.

Food-derived oligopeptides (FOPs) exhibit various bioactivities. However, little was known about their sequence changes in the gastrointestinal tract and the effect of changes on bioactivities. FOPs' sequence features, changes and effects on bioactivities have been summarised. The sequence length of FOPs decreases with increased exposure of hydrophobic and basic amino acids at the terminal during simulated gastrointestinal digestion. A decrease in bioactivities after simulated intestinal absorption has correlated with a decrease of Leu, Ile, Arg, Tyr, Gln and Pro. The sequence of FOPs that pass readily through the intestinal epithelium corresponds to transport modes, and FOPs whose sequences remain unchanged after transport are the most bioactive. These include mainly dipeptides to tetrapeptides, consisting of numerous hydrophobic and basic amino acids, found mostly at the end of the peptide chain, especially at the C-terminal. This review aims to provide a foundation for applications of FOPs in nutritional supplements and functional foods.

Properties of texturized protein and performance of different protein sources in the extrusion process: A review.

The need for protein is increasing due to the rapid growth of the global population. However, conventional animal meat production has caused severe environmental, land usage, and other issues. Meat substitutes can provide consumers with a high-quality alternative to protein. Texturized protein (TP) is a critical ingredient in meat substitutes and is mainly obtained through extrusion processing. Therefore, this review first discussed the essential physical properties of TP, including appearance and structure, water-holding capacity (WHC) and oil-holding capacity (OHC), texture, and sensory properties. The performance of plant and novel source proteins in extrusion processing is also summarized. The properties of the desired TP should be considered first before extrusion processing. Under different extrusion parameters, proteins from the same source can exhibit varying properties. Although the novel source proteins can adversely affect TP quality, their high yield and environmental protection are worthy of further study. This paper aims to review the impact of proteins from different sources on the properties of TP during the extrusion process and discuss practical research methods for TP.