Abstract: In order to explore the effect of ultra-high pressure (UHP) treatment on the quality and flavor of prefabricated Spanish mackerel fish cake, the samples not treated (control) or treated with different pressures (200, 300 and 400 MPa for 20 min) and stored at 4 ℃ for up to 12 days were analyzed for changes in physicochemical indexes and sensory properties, and the effect of UHP treatment on their volatile components was analyzed by headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that in terms of texture characteristics, UHP treatment significantly affected the hardness, cohesiveness, and chewiness (P < 0.05), and the texture of the 300 MPa/20 min group was superior to that of the other groups and was closer to that of commercially available fish cake products. With respect to storage stability, the inhibition rate of total bacterial count increased with increasing pressure (the total bacterial count in the 400 MPa/20 min group was 2.8 (lg(CFU/g)) after 12 days of storage, while that of the control group reached up to 5.3 (lg(CFU/g))). Compared with the control group, UHP treatment significantly delayed the accumulation of total volatile basic nitrogen (TVB-N) while having less effect on the color parameters (L*, a*, b*, and whiteness) of the product. Regarding sensory quality, the sensory scores of all treatment groups were significantly better than that of the control group (P < 0.05). With regard to flavor characteristics, 53 volatile components (total amount of 112.22 mg/kg) were detected in the 300 MPa/20 min group, which significantly more than those detected in the other groups. The contents of key flavor substances such as α-terpineol (4.65 mg/kg), 2-zinol (6.02 mg/kg), and citral (18.87 mg/kg) were the highest in the 300 MPa/20 min group. In summary, 300 MPa/20 min was the optimal treatment condition, which can effectively inhibit microorganisms while maintaining good quality and flavor.

Key words: prefabricated Spanish mackerel fish cake; ultra-high pressure treatment; storage; quality; volatile components