Abstract
This study investigated the effects of low-temperature vacuum cooking (sous vide, 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, b (⁎) shows a decrease, whereas the a (⁎) value exhibits a trend of initial decrease followed by an increase (p < 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.