Effect of tea polyphenol and nisin on the quality of tortoise (Trachemys scripta elegans) meat during chilled storage

The effect of tea polyphenol (TP) and nisin on the quality of tortoise (Trachemys scripta elegans) meat was evaluated over 15 days of storage at 4 degrees C. The tortoise meat was analyzed periodically for sensory, microbial (total viable counts), and physicochemical (e.g., water loss, pH, color, thiobarbituric acid reactive substances [TBARS], and total volatile base nitrogen [TVB-N]) characteristics. TP or nisin treatment exerted significant effects on improving the sensory attributes and color of the tortoise meat, inhibiting bacterial growth, retarding weight loss, and delaying the increase of pH and TVB-N values. Thereby, the shelf-life of the meat has been extended 3-6 days. No significant differences were observed between TP- and nisin-treated groups for all indices studied except TBARS. Practical applicationsTortoise meat has become one of delicious foods on the feast because of its high nutrition value and good taste. However, once the tortoises were sacrificed, the meat is prone to decay due to the contamination of microorganisms. Therefore, the processing and preservation of tortoise meat has important practical significance. The results revealed that either TP or nisin could be used as a potential preservative to extend the shelf-life of tortoise meat during chilled storage.