Effect of Chitosan-Ascorbate and Calcium Lactate on the Fermentation and Quality Characteristics of Squid Sikhae

Chitosan-Ascorbate 및 Calcium Lactate가 오징어 식해의 숙성과 품질 특성에 미치는 영향

Effects of chitosan-ascorbate(CA) and calcium lactate(CL) on fermentation and quality of squid sikhae were investigated CA and LA were added at $0.5\%$ (designated CA1 and CL1) and $1.0\%$(CA2 and CL2) concentrations, respectively and fermented for 12 days at $10^{\circ}C$. pH of CA-added sikhae was higher than that of control, while acidity of the former was lower than that of the latter. During 12 days of fermentation, CA-added sikhae showed higher protease activity than control by $2.3\~2.6$ times and CL-added sikhae by $2.8\~3.6$ times. At 12 days of fermentation, CA-added sikhae revealed higher protease activity than control by $1.2\~1.4$ times and CL-added sikhae by $1.5\~1.9$ times. CA-added sikhae also showed higher amino-nitrogen content than control by $1.4\~1.7$ times and CL-added sikhae by $1.9\~3.5$ times. In comparison of CA1 with CA2, CA2 showed all higher pH, protease and amylase activity, and amino-nitrogen content than CA1. In analysis of electrophoresis, molecular weights of major proteins in ~w squid were $116.9\~119.0$, 96.5 and 59.3kDa. However, after fermentation for 12 days, a protein band of 119.0kDa disappeared but a new protein band with below 14 kDa appeared in sikhae, especially CA-added sikhae. In sensory evaluation, the intensity of sour taste was the highest for control and the lowest for CA2. Softness of squid was the highest for control and the lowest for CA2. Overall acceptability was the best for CA2. In conclusion, these results suggest use of $1\%$ CA in sikhae preparation as addition of CA(CA2) increased the protease and amylase activity, nitrogen content of amino form, sensory acceptability as well as shelf-life of sikhae.