Effects of Carboxymethyl Chitosan on the Biochemical and Microbial Quality of Dried Anchovy

Abstract

Carboxymethyl chitosan (CMCH) is one of the water soluble derivatives of chitosan that can be used as an edible coating for food products. However, its use in fish and fish products is not well established. So, in the present study, the effects of CMCH as an edible coating for preserving the quality of dried anchovy were evaluated. Anchovies were dipped in 0.5 and 1% ( w / v ) solutions of CMCH for 5 min, drained and dried under sun. Control samples were prepared by dipping in potable water and drying under sun. TVB-N and TMA-N of the treated samples were significantly (p < 0.05) lower than control over 135 days storage period. At the end of 135 days, TVB-N and TMA-N levels were 121.95, 115.63 and 106.72 mg % and 47.13, 38.24 and 35.43 mg % for control, 0.5 % CMCH treated and 1 % CMCH treated samples, respectively. Microbial growth and fungal growth were lower in 1 % CMCH treated sample. Aerobic plate count at the end of 135 days reached 4.89, 4.80 and 4.70 log10 cfu g-1 respectively, for control, 0.5 % CMCH and 1 % CMCH treated anchovies. Fungal count in control reached 1.93 log10 cfu g-1 whereas that of 1 % CMCH treated anchovy was 1.50 log10 cfu g-1 at the end of 135th day. CMCH treatment has also controlled lipid oxidation during storage of dried anchovy as the TBARS of control was higher (2.91 mg MDA per Kg) than 0.5% CMCH (2.17 mg MDA per Kg) and 1% CMCH treated (1.92 mg MDA per Kg) anchovy on 135th day. In brief, the edible coating of CMCH has effectively controlled the spoilage changes in dried anchovy during storage.