In vitro digestion mimicking conditions in adults and elderly reveals digestive characteristics of pork from different cooking ways.

This study aimed to investigate the impact of three cooking ways (sous vide (SV), frying (FR) and roasting (RO)) on pork protein digestion characteristics under conditions simulating healthy adult (control, C) and elderly individuals with achlorhydria (EA). Changes in degree of hydrolysis (DH), SDS-PAGE profiles, zeta potential, particle size and secondary structure during digestion were evaluated. Our results revealed the EA condition markedly affected the protein digestion process of pork with different cooking ways. The DH values of SV (25.62%), FR (21.38%) and RO (19.40%) under the EA condition were significantly lower than those of under the control condition (38.32%, 33.00% and 30.86%, respectively). Moreover, differences were also observed among three cooking ways under the EA condition. For a given cooking way, the differences between control and EA conditions gradually diminished from the gastric to the intestinal phase. Under a certain digestion condition, SV maintained the highest degree of digestion throughout the process, particularly under the EA condition. Therefore, we conclude that pork cooked by sous vide is more recommendable for the elderly considering protein digestibility.

Simultaneous Determination of Amphenicols and Metabolites in Animal-Derived Foods Using Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry.

Amphenicols are widely used to prevent and treat animal diseases. However, amphenicol residues accumulate in livestock and poultry and harm consumers. We hypothesized that one can combine solid-phase extraction (SPE) with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to simultaneously determine amphenicols and metabolites in pork, beef, lamb, chicken, and their products and meet government regulations for maximum residue limits. We extracted crude samples with ethyl acetate and ammonia water (98:2, v/v), purified the samples with a CNW Si SPE column, defatted the samples with acetonitrile-saturated n-hexane, and then determined the resulting analytes by UHPLC-MS/MS. The limit of detection of the analytes in livestock and poultry meat was 0.03-1.50 µg/kg, and the limit of quantification was 0.05-5.00 µg/kg. Measured chloramphenicol, thiamphenicol, and florfenicol concentrations were linear over the range 0.50-50 µg/kg; and the florfenicol amine concentration was linear over the range 5.00-200 µg/kg (all with correlation coefficients >0.9990). The recovery of the spiked samples was between 72% and 120%. The intraday relative standard deviation (RSD) ranged from 1% to 9%, and the interday RSD ranged from 1% to 12%. Based on the above results, the current method is sensitive, accurate, and reproducible with the detection limits being well below the maximum residue limits as per Chinese standard GB 31650-2019, and thus, our research hypothesis could be confirmed.