Abstract:
To investigate the effects of freezing methods on the quality of frozen prepared abalone, steamed abalone was treated using −18 ℃ refrigerator freezing (RF
−18 ℃), −35 ℃ refrigerator freezing (RF
−35 ℃), −80 ℃ refrigerator freezing (RF
−80 ℃), liquid nitrogen freezing (LNF
−80 ℃), and immersion freezing (IF
−30 ℃). The freezing rates, physicochemical properties, and volatile components of abalone stored at −18 ℃ for 30 days were measured. The results showed that the times taken by abalone to pass through the maximum ice crystal zone were 81 min (RF
−18 ℃), 39 min (RF
−35 ℃), 31 min (RF
−80 ℃), 5 min (LNF
−80 ℃), and 13 min (IF
−30 ℃), respectively. Both LNF
−80 ℃ and IF
−30 ℃ groups effectively shortened the entire freezing period and were more efficient than RF in inhibiting the formation of TBARS and TVB-N. Abalone treated with LNF
−80 °C and IF
−30 °C exhibited a more compact microstructure. During frozen storage, the contents of nonanal and hexanal in abalone increased, leading to a stronger fishy odor. However, rapid freezing could delay the oxidation of lipids and proteins, thereby slowing down the deterioration of quality. Both LNF
−80 ℃ and IF
−30 ℃ effectively maintained the quality of abalone during the freezing process. However, from the perspective of energy consumption and equipment investment, IF
−30 ℃ demonstrated higher cost-effectiveness. The findings of this study provide important theoretical and practical references for the selection of freezing technologies in the abalone processing and prepared dishes industries.