Correlation of Mullet (Mugil cephalus) Fillet Color Changes with Chemical and Sensory Attributes during Storage at 0°C

The main objective of this study was to assess the freshness of striped mullet (Mugil cephalus) fillets stored at 0 degrees C by evaluating color changes using a machine vision system and correlating this to chemical and sensory attributes. The mean L*, a*, b* values from the entire area of the fillet surface were calculated by image analysis. These values for the skin side of fillets did not show a significant change during storage. The increase in a* value and the decrease in b* value were significant at Day 6 for the meat side of fillets. According to peroxide value (PV) (0.98 +/- 0.071 mmol CPO/kg fish) and thiobarbituric acid reactive substances (TBARS) (6.38 +/- 1.06 mg MDA/kg fish) values, mullet fillets were not acceptable for consumption at Day 6. However, according to sensory evaluation, fillets were rejected at Day 4, with an overall quality score of 5.12 +/- 3.80 out of 15. Chemical analysis, particularly TBARS and PV, significantly correlated with color changes in the meat side of mullet fillet. The a* and b* values for the meat side are good indicators of the quality deterioration in mullet fillets stored at 0 degrees C. Machine vision can be used as an alternative and promising method to evaluate the freshness of mullet fillets.