Effects of combination heating on texture of fish mince.

摘要

This is a range finding study on the effects of microwave/convection combination heating on the textural quality of mince fish using a modified household microwave/convection combination oven. The scope of the study consists of evaluating three independent variables—microwave/convective exposure time combination, heating mode sequence combination, and lengths of heating time—on the changes of four TPA textural parameters (hardness, springiness, cohesiveness, and resilience) of mince fish. Also studied are the relationship between temperature, weight loss, and water holding capacity (WHC) on texture change, as well as chemical analysis of fish proteins on changes occurring on the fish mince at the molecular level.; Changing exposure time combination from 9 minutes convection and 1-minute microwave heating to 8 minutes convection and 2 minutes microwave heating for a total heating time of 10 minutes resulted in a 42%, 4%, 6% and 5% increase in hardness, springiness, cohesiveness, and resilience, respectively. The change in textural parameters corresponds to a 150% increase in final product temperature, 20% decrease in the WHC, and 31% cooking loss. Sequence combination treatment showed mixed effects where sequence combination C/M showed the greatest change in hardness (120%) and resilience (21%). Sequence combination M/C/M/C and C/M showed the greatest change in springiness (8%). Sequence M/C/M/C also showed the greatest change in cohesiveness (44%).; For the 20 minute heating time, changing exposure combination from 19 minutes convection and 1 minute microwave heating to 18 minutes convection and 2 minutes microwave heating resulted in an average of 8%, 2%, 2%, and 3% change in hardness, springiness, cohesiveness, and resilience, respectively. This corresponds to an average increase of 77% in the fmal temperature, 17% decrease in WHC, 31% cooking loss. Sequence combinations also caused mixed effects on the texture parameters of fish mince. Sequence WC showed the greatest change in hardness (53%) and springiness (12%). Sequence M/C/M showed greatest change in cohesiveness (45%) while sequence combination M/C/M/C showed the greatest change in resilience (14%).; Heat-treated fish mince resulted in significantly lower soluble protein content. Electrophoretic studies showed the presence of cross-linking with greater change in temperature.