Process optimization and analysis of non- volatile flavor compounds of deep- frying coated Aristichthys nobilis

Fuzzy mathematic evaluation model was used to optimize the process of frying Aristichthys nobilis steaks with a view to determine the optimal values of curing time,frying temperature and frying time. The correlation coefficients for physicochemical indexes and sensory evaluation were analysed. Non- volatile flavor compounds were identified by high performance liquid chromatography( HPLC). The results showed that optimum condition was as follows: curing time 20 min,frying temperature 180 ℃ and frying time 5 min.Under this condition,the content of total free amino acid was 408.53 mg /100 g and the content of total flavor nucleotides was 73.06 mg /100 g. The water content,a*and b*were the key factors to the sensory evaluation of frying steaks.Compared to the raw,different frying conditions had significant effects on the content of the free amino acid and flavor nucleotides( p <0.05). Glu,Gly,His and Ala were the highest content in the free amino acid.In addition,Glu and His contributed to the flavor significantly.In most samples,the content of 5'- IMP was highest,but the 5'- AMP was not found under all kinds of conditions.Otherwise,5'- IMP and 5'- GMP were more than the threshold and made a contribution to the taste.Therefore,under the condition of curing time 20 min,frying temperature 180 ℃ and frying time 5 min,the steaks had the optimum quality.