Project description:Previous studies have evaluated pork quality by omics methods. However, proteomics coupled with metabolomics to investigate pork freshness by using pork exudates has not been reported. This study determined the changes in profiles of peptides and metabolites in exudates from pork stored at different temperatures (25, 10, 4, and -2 ℃). Multivariate statistical analysis revealed similar changes in profiles in exudates collected from pork stored at -2 and 4 ℃, and additional changes following storage at higher temperatures. We identified peptides from 7 proteins and 30 metabolites differing in abundance between fresh and spoiled pork. Significant correlations be-tween pork quality and most of the peptides from these 7 proteins and 30 metabolites were found. The present study provides insight into changes in peptide and metabolite profiles of exudates from pork during storage at different temperatures and our analysis suggest that such changes can be used as markers for pork spoilage.
Project description:Lactococcus piscium strain MKFS47 is a psychrotrophic spoilage lactic acid bacterium, isolated from the cold-stored modified atmosphere packaged broiler filet strips with the first signs of spoilage. For the experiment L. piscium MKFS47 was grown in MRS broth without acetate with 2% glucose, samples were taken at 3h, 5h and 11h in three replicates. The extracted RNA was sequenced using SOLiD 5500XL. RNA-seq reads were mapped against L. piscium MKFS47 genome and were counted per gene using Lifescope software. The experiment was conducted to identify the time-course differential expression of the L. piscium MKFS47 genes.
Project description:This study applied peptidomics to investigate potential biomarkers for evaluating pork-meat freshness. Meat samples stored at -2, 4, 10, and 25 °C were collected at specific time points to evaluate meat freshness indicators (color, total viable count, pH, and total volatile basic nitrogen). The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) profile was analyzed, and substantial protein degradation (myosin heavy chain, paramyosin, troponin) was detected at the end of storage, regardless of the temperature. Peptidomics analysis was performed using a UHPLC-LTQ-Orbitrap mass spectrometer, and the potential peptide marker MVHMASKE was filtered via multivariate analysis and quantified by parallel reaction monitoring combined with external standard quantitation. In addition, the relationship between peptide content and change in meat freshness was verified using real-life samples and the content of MVHMASKE showed an obvious decline during storage, presenting a period of pork meat from fresh to spoilage. This study provides favorable evidences to evaluate pork meat freshness by mass spectrometry-based pep-tidomics.
Project description:Aiming to reduce food spoilage, the present study developed novel highly active food-grade preservatives affecting a wide range of bacteria. For this purpose, storage proteins were extracted from food plants. After enzymatic hydrolysis by the digestive protease chymotrypsin, the peptide profiles were analyzed by ultrahigh-performance micro-liquid chromatography–triple quadrupole time-of-flight tandem mass spectrometry. Virtual screening identified 21 potential antimicrobial peptides in chickpea legumin. Among those, the peptides Leg1 (RIKTVTSFDLPALRFLKL) and Leg2 (RIKTVTSFDLPALRWLKL) exhibited antimicrobial activity against 16 different bacteria, including pathogens, spoilage-causing bacteria and two antibiotic-resistant strains. Minimum inhibitory concentrations (MIC) down to 15.6 µM indicated 10–1,000-fold higher activity of the novel antimicrobial peptides compared to conventional food preservatives. Moreover, Leg1 and Leg2 showed bactericidal activity in bacterial suspension and during the storage of raw pork meat.