관능평가 및 이화학적 분석을 이용한 바닷가재(Nephropidae) 및 꽃게(Portunus trituberculatus)의 품질 평가

Abstract

Lobster(Nephropidae) and swimming crab(Portunus trituberculatus) are widely used as a side dish in the world. However, their safeties are low because of rotten problems related to freshness during import process or storage. The objective of this study is to provide chemical data in order to support subjective discrimination guideline against sensory evaluation occurred during storage of lobsters and swimming crabs. The samples used in this study were whole and meat of lobster, whole and cut body of swimming crab. Color difference, drip loss, pH, K-value, total volatile basic nitrogen(TVB-N), trimethylamine(TMA), dimethylamine (DMA), ammonia, volatile nitrogen compounds and volatile sulfur compounds were measured. Their freshness was judged into 5 grades, so 5 point is the freshest one and 1 point is the least. As freshness was decreased, the pH values tended to increase to the highest values of pH 7.8 and pH 8.2 for lobster and swimming crab, respectively. TMA, DMA, and ammonia were measured with the maximum values of 6.63±0.26 mg%, 5.48±0.15 mg% and 2.65±0.01 mg% in the lobster, respectively. Swimming crab had their maximum values of 4.60±0.12 mg%, 4.42±0.16 mg% and 2.29±0.01 mg%, respectively. Volatile sulfur compounds such as hydrogen sulfide, methyl mercaptan, dimethyl sulfide and dimethyl disulfide were analyzed. The amount of volatile sulfur compounds in the lobsters and swimming crabs were so low not to be measured in the 5-4 point range, and their values were increased when sensory scores were 3 to 1 point. These results can provide the basic information to support the scientific data for sensory evaluation used in the freshness of lobsters and swimming crabs.