Changes in in vitro protein digestion of retort‐pouched pork belly during 120‐day storage

Summary To investigate the effect of long-term storage on in vitro protein digestion of the retort-pouched pork belly. The products were stored at 25 °C for 0, 30, 60 and 120 days and digested with pepsin and trypsin at each time point. SDS-PAGE and LC-MS-MS were applied to separate and identify proteins and their digested products. In vitro protein digestibility decreased from 47.7% after 60-day storage to 25.4% after 120-day storage for the samples digested by pepsin, and from 63.9% to 45.7% for the samples digested by pepsin and trypsin at corresponding time points. LC-MS-MS demonstrated changes in peptide composition and abundance with storage time. Long-term storage could deteriorate nutritive values of meat products by reducing digestible protein content.