Effect of drying methods and antioxidants on the flavor and lipid oxidation of silver carp slices

Silver carp slices were dried using hot air, microwave, and microwave-vacuum (MV). The drying kinetics, lipid oxidation, flavor, and content of fat, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and earthy-musty off-odour compounds were compared among the dried slices. Furthermore, the effect of vitamin C (Vc) and tea polyphenols (TP) on the microwave-dried fish slices was investigated. The Exponential models gave good fit for the drying data. Compared with hot air drying, microwave and MV drying reduced the drying time drastically. Drying removed part of the fishy off-odour, produced grilled flavor and "Oxidated oil" off-odour. Hot air dried fish slices had better grilled flavor. The TP restrict the formation of fishy and "Oxidated oil" off-odours effectively. Microwave drying removed a large part of "Earthy-musty" off-odour, and marinating with Vc or TP help to remove this off-odour. The slices dried with microwave or MV had less thiobarbituric acid reactive substance (TBARS). The TBARS decreased with power intensity during microwave drying but increased with the vacuum during MV drying. All drying processes largely decreased the contents of fat, EPA and DHA (P < 0.05). Microwave drying retained more fat (P < 0.05). The Vc and TP protected the EPA and DHA effectively.