Physicochemical properties and volatile flavor compounds of five kinds of red-fleshed kiwifruit wines

To investigate the physicochemical properties, volatile flavor compounds and phenolics compound contents in red-fleshed kiwifruit wine, selecting five commercially available red-fleshed kiwifruit wines as research objects, the physicochemical indexes, total phenols and total flavonoids were detected by conventional methods, the volatile flavor compounds were detected by headspace solid-phase microextraction (HS-SPME), solid-phase extraction (SPE), and liquid-liquid extraction (LLE) in combination with gas chromatography-mass spectrometry (GC-MS). Additionally, the content of volatile phenolic compounds and their odor activity values (OAV) were analyzed. The results showed that the pH values of the red-fleshed kiwifruit wines were 3.46-3.81, soluble solids contents were 9.00-14.90 °Bx, total acidity were 4.41-14.89 g/L, reducing sugars were 6.05-9.04 g/L, total phenol contents were 51.39-296.48 mg/L, and total flavonoid contents were 257.84-897.23 mg/L. A total of 118 volatile flavor compounds were identified using the three pretreatment methods. HS-SPME extracted the highest number of volatile flavor compounds (86), SPE had the highest extraction efficiency for volatile phenols, and LLE had significant extraction losses. 7 volatile phenolics compounds were identified by SPE combined with GC-MS, among which 2,6-dimethoxyphenol, eugenol, and guaiacol had higher average contents of 25.99 μg/L, 18.97 μg/L, and 17.64 μg/L, respectively. The OAV of eugenol was the highest, ranging from 1 to 9, which was the key volatile phenolics compound in kiwifruit wine.