Peptidomic Analysis of Potential Bioactive Peptides in Mare Milk Under Different Heat Treatment Conditions

Active peptides in mare milk have unique biological activities, but how the bioactive protein in mare's milk changes under the influence of temperature has not been fully studied. Therefore, in this study, the differential expression of bioactive peptides potentially present in horse milk under different heat treatment conditions was investigated for the first time using peptidomic and bioinformatic techniques. We collected a total of 15 samples. In this study, we divided the samples into five groups, specifically, 65 °C, 30 min; 72 °C, 15 min; 83 °C; 10 min; 95 °C, 5 min; and an untreated group as a control, which involved four different temperature treatments, in order to understand changes in bioactive peptides and to identify the sequence of bioactive peptides. In the experiment, a total of 2341 active peptides were identified. The amino acid composition of the potential active peptides remained stable across different temperatures, but their abundance varied with temperature. In all, 23 peptides from 20 different proteins were identified, with the highest number of active peptides identified at 72 °C. Through database searches, we found that a majority of these peptides were within β-lactoglobulin and immunoglobulin domain proteins, which are known for their potential biological activities. These findings provide a theoretical foundation for the development of peptides with different bioactivities as potential functional foods.