CHITOSAN AND LEMON PEEL EXTRACT COATING ON QUALITY AND SHELF LIFE OF YELLOWFIN TUNA (THUNNUS ALBACARES) MEAT STORED UNDER REFRIGERATED CONDITION
Sarasan Sabu, T Ashita, S Stephy
Abstract
The present study investigated the effect of chitosan combined with lemon peel extract coating on the quality and shelf life of refrigerated yellowfin tuna meat using physicochemical, microbial and sensory assessments. Fresh yellowfin tuna meat as chunks were divided into five lots and coated with lemon peel extract (LPE) and chitosan (CH) at different concentrations viz., control, C (0%), LPE 1%, CH 1%, LPE+CH 1% and LPE+CH 2% (w/v). Sensory, biochemical and microbial quality of the samples were observed for 12 days during 4°C refrigerated storage. Sensory evaluation revealed that shelf life of yellowfin tuna under the study was 6 days for control, 8 days each for LPE (1%) and CH (1%), 10 and 12 days for LPE+CH (1%) and LPE+CH (2%) respectively. Significantly higher pH, total volatile basic nitrogen (TVB-N), tri-methyl amino nitrogen (TMA-N), peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) values were recorded in control samples than coated samples (p<0.05). Significant reduction in microbial counts were recorded in CH+LPE treated samples (p<0.05) compared to the LPE or CH coating alone, in the later stages of storage. Coated samples with combination of LPE+CH 1% and 2% indicated better storage qualities compared to other treatments. The present study revealed that LPE along with chitosan edible coating enhanced the shelf life of yellowfin tuna meat.