Effects of Adding Salt and Sugar on the Quality and IMP‐Related Enzyme Activity of Grass Carp (Ctebopharyngodon idellus) Fillets During 0C Storage. Issue 2 (3rd June 2016) - Qin, Na
Abstract: The effects of adding small amounts of salt and sugar on the quality and IMP (inosine mono‐phosphate)‐related enzyme activity of grass carp ( Ctenopharyngodon idellus ) fillets were evaluated by quantifying pH, total volatile base nitrogen (TVB‐N), color, sensory scores, ATP‐related compounds, AMP deaminase and acid phosphatase (ACP) activity. Fish samples were left untreated (CK), or were dry‐cured with 1.0% salt (T1) or 1.0% salt and 1.0% sugar (T2). Curing treatments decreased TVB‐N accumulation, accelerated the conversion of ATP to IMP, and improved the level of IMP in grass carp. No significant differences ( P > 0.05) were observed among CK, T1, and T2 for color. Among the nucleotide ratios ( K, Ki, H, P, Fr, and G values), the K and H values were superior to the Ki, P, G, and Fr values as freshness indicators. IMP content showed a significant ( P < 0.01) correlation with the sum of its precursor substance. Practical Applications: Grass carp is one of the most important farmed species of freshwater fish worldwide. However, grass carp fillets are usually more perishable than most other foodstuffs because of their high levels of moisture and nutrients. Salting can prolong fish shelf life and enhance the flavor of fish. Moreover, ready‐to‐use, high‐quality, safe food products have become popular. Therefore, it is an attractive tendency to process salted and prepared products to meet human consumption. Inosine monophosphate (IMP) contributes to the umami taste of fish products and umami taste is generally the most important sensory property affecting consumer acceptance. Thus, the present study investigates how low concentration of salt and sugar affects quality and IMP‐related enzyme activity of grass carp. Salt and sugar can be used as not only safe ingredients for preservation, but flavor enhancer of fish. Additionally, using K or H value to monitor freshness changes of grass carp is feasible.