Abstract: To explore an effective method to preserve the quality of grass carp during cold storage, the effect of chitosan coating incorporated with food preservatives on the flesh quality of grass carp was evaluated by determining quality changes in fish fillet samples treated with 10 mg/mL chitosan + 5 mg/mL tea polyphenols + 2 000 U/mL lysozyme and those treated with sterilize water (control) in terms of freshness (K-value), adenosine triphosphate (ATP)-related compounds content, juice loss rate, texture and volatile components during cold storage. The results showed that K-value, hypoxanthine, juice loss rate, adhesiveness and volatile components increased to different extents with increasing storage time, especially for the preservative-treated group. Inosinic acid and hardness values in the control group kept on declining with storage time, whereas those in the preservative-treated group initially rose and then dropped at a significantly lower rate than that observed for the control group. This study indicated that the chitosan coating incorporated with food preservatives could effectively maintain the flesh quality and delay the quality deterioration of grass carp.

Key words: grass carp; chitosan; composite preservative; K-value; electronic nose