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 ( 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. • Heating at 75–80 °C for 180 min optimizes flavor, nutrition, and safety. • Heating at 70 °C for 240 min reduces nucleotides and weakens umami. • Free and essential amino acids increased with heating temperature. • Heating at 100 °C for 20 min reduces volatiles, yielding a relatively monotonous flavor profile.