Shelf life extension of ‘’Gyros'’ pork meat using plant extracts with antioxidant and antimicrobial activities

Abstract

The aim of the present study was to estimate the shelf life of ‘’Gyros'’ pork meat (GPM), during storage under refrigeration. Raw (R) (control sample), marinated (M), and treated samples with green coffee (GC), turmeric (T) and ginger (G) extracts with ethanol solution of grape origin were subjected to microbiological, physicochemical, and sensory analyses. Results showed that TVC and Pseudomonads in R, M, and G treated samples reached 7 log CFU/g on day 4, whereas Enterobacteriaceae remained <6 log CFU/g throughout storage. T and GC samples had TVC and Pseudomonads populations <7 log CFU/g on day 6 and day 8, respectively, and Enterobacteriaceae populations <6 log CFU/g. Furthermore, the ethanolic extracts of GC and T showed antibacterial activity against Salmonella Typhimurium and Staphylococcus aureus. The ethanolic extracts exhibited also high antioxidant activity against DPPH free radical, indicating lower TBARS and mercaptans content values, whereas delayed the decrease in heme iron during refrigerated storage compared to the R samples. Sensory analysis showed that treated samples had a special and acceptable taste. Based on the obtained results, the shelf life of R, M and G treated GPM was 4 days, while samples treated with T and GC had an increased shelf life by 2 and 4 days, respectively.