Influence of aqueous green tea extract on microbiological activity and biogenic amines formation on minced mutton

The increased demand for meat and meat products necessitates safe preservation in order to meet their desired quality. Natural preservatives have become the safer alternative to artificial preservatives. These preservatives come mainly from plant sources without negative side effects as unlike artificial ones. This study aimed to examine the effect of green tea extract (GTE) on extending the shelf life of fresh mutton under various storage conditions. Lamb leg samples were stored for 0, 3, 6, 9 and 12 days at a temperature of 5℃ and frozen storage at -20°C for 30, 60 and 90 days of storage. Minced meat samples were treated with various levels of aqueous extract of green tea leaves to increase the shelf life of fresh mutton. The aqueous extracts were sprayed on minced meat samples at concentrations of 0, 0.5, 1, 1.5 and 2% (GTE1, GTE2, GTE3, GTE4 and GTE5, respectively). The results revealed that the extraction of green tea was instrumental in significantly inhibiting Escherichia coli growth in GTE2, GTE4, and GTE5 for up to 4 days in chilled samples. There was no significant effect on frozen samples stored for 30 days. The biogenic amines differed among samples treated with different extracts, with GTE1 having the highest as compared to GTE2, GTE3, GTE4, and GTE5 for samples stored at 5°C for all storage periods. On day 30, cadaverine was not noticed in the mutton but subsequently appeared at an increasing rate in GTE1 as compared to other treated groups after 60 and 90 days of frozen storage. Green tea extract has the potential to act as a natural antibacterial and antioxidant in the preservation of mutton.