Stability of Blueberry Anthocyanins with Different Oligopeptides under Acidic Conditions

Abstract:

The ability of seven oligopeptides (wheat, rice, corn, mung bean, pea, rice bran, and fish collagen peptides) to stabilize blueberry anthocyanins in an acidic system (pH value 4.0) was investigated. The most effective oligopeptides were identified through the analysis of their effects on blueberry anthocyanin color, anthocyanin retention, total phenolic content, and anthocyanin retention after gastrointestinal digestion, heating (95 ℃ , 30 min), and storage (37 ℃ , light, 7 d). The interaction mechanisms were further analyzed using infrared spectroscopy, fluorescence spectroscopy, and scanning electron microscopy. Compared with the control group, wheat peptides demonstrate notable effectiveness in maintaining the color of blueberry anthocyanins after heat treatment and improving storage stability. The ΔE value of the blueberry anthocyanin solution with wheat peptides was reduced by 64.27% after 7 d of storage, and the retention rate of the anthocyanins was 71.60%. Moreover, the retention of blueberry anthocyanosides after gastrointestinal digestion was notably improved by the wheat peptides, as the retention rate increased by 20.39% and 92.46% after gastric and intestinal digestion, respectively. In addition, mutual binding between wheat oligopeptide and mallow pigment-3-Ogalactoside (M3G) occurred, thereby resulting in the formation of the wheat oligopeptide-M3G complex. The results show that the addition of oligopeptides under acidic conditions improved the stability of blueberry anthocyanins, with wheat peptides exhibiting the most pronounced effect in enhancing the stability of blueberry anthocyanins.