Effect of low-temperature vacuum cooking (sous vide, SV) on the nutritional and flavor quality of small yellow croaker (Larimichthys polyactis) soup

This study investigated the effects of low-temperature vacuum cooking (<i>sous vide</i>, SV) on the nutritional and flavor quality of small yellow croaker soup (SYCS) Initially increasing the temperature and extending the duration can improve sensory scores, but heating at 90 °C for 300 min significantly degrades sensory quality. Regarding color parameters, <i>b</i> ^<i>⁎</i> shows a decrease, whereas the <i>a</i> ^<i>⁎</i> value exhibits a trend of initial decrease followed by an increase (<i>p <</i> 0.05). Temperature and extended time cause soluble proteins to increase initially and then decrease, evidenced by increased total volatile bases nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARS) values, indicating lipid oxidation and protein breakdown. The most balanced and intense umami perception, along with high nucleotide content, was achieved at 80 °C for 180 min. Although short-time treatment at 100 °C 20 min best preserved amino acids and polyunsaturated fatty acids (PUFAs), the concurrent release of bitter compounds likely compromised its overall sensory umami. Volatile organic compounds (VOCs) analysis revealed temperature-dependent flavor profiles, 70 °C 240 min enhanced roasted notes, while 80 °C imparted a fresh aroma. GC-IMS elucidated formation mechanisms, indicating that flavor derives from degradation and co-oxidation of key components. These findings offer a foundational reference for understanding and regulating quality attributes in small yellow croaker soup, with implications that may extend to other aquatic products following further validation.