Nutritional Components, Antioxidant Activity and Volatile Flavor Substances in Different Parts of Meigancai from Jinyun

The flavor and quality characteristics of different parts (Jinyao, Fengjian, Sanduan, Yingeng, Huakai, and Wuduan) of Meigancai (preserved mustard greens) from Jinyun were systematically evaluated in terms of their basic physicochemical properties, nutritional composition, antioxidant capacity, and volatile flavor profiles. The results showed that the moisture content (10.61%–16.30%), total acid content (33.56–46.81 g/kg), and reducing sugar content (24.72–135.79 mg/g) of all parts were within acceptable ranges. Significant differences were observed among different parts in terms of antioxidant activity, free amino acid composition, and volatile flavor compounds. Among the six parts, Wuduan exhibited the strongest antioxidant capacity, accompanied by the highest levels of total flavonoids and vitamin C. The total free amino acid content ranged from 10.88 to 30.40 g/kg. Yingeng showed clear advantages in protein content, total free amino acids, and taste activity values (TAV), indicating superior nutritional quality and favorable taste characteristics. A total of 76 volatile compounds were identified across all parts by gas chromatography-ion mobility spectrometry (GC-IMS) and 131 compounds by gas chromatography-mass spectrometry (GC-MS). Notably, Wuduan was characterized by both a greater diversity and higher relative abundance of volatile compounds, contributing to a more complex and layered flavor profile. Overall, this study establishes a multidimensional quality evaluation framework for Jinyun Meigancai and elucidates quality differences among its various parts, providing a theoretical basis for raw material selection, consumption guidance, and high-value utilization of Jinyun Meigancai.