Oligopeptides derived from rice protein hydrolysates: absorption, bioactivity, preparation, debittering, and application

Rice protein, a high-quality protein, contains all of its essential amino acids, and its amino acid composition is consistent with the ideal pattern recommended by the Food and Agriculture Organization/World Health Organization. Rice protein-derived products as feed additives have rather low added value. Rice protein hydrolysates (RPHs) are valuable products that can be generated from underutilized rice protein. In the RPH, oligopeptide-enriched RPH and its oligopeptides have been proposed as superior candidates for improving absorption and bioavailability and have potential broad application. Thus, this review outlines the absorption behavior, bioactivity, and preparation of rice oligopeptides. The structure-bitterness relationships and debittering of these materials are discussed in detail, as are their safety and allergenicity. Additionally, the applications of rice oligopeptides in the food and pharmaceutical industries as functional ingredients are also highlighted.