Characterization of the color, physicochemical properties, organic acids, and aroma profiles of kiwifruit wines by different fermentation patterns and fining stages

The high contents of pectins, proteins, and polyphenols in the raw materials pose a challenge to the fining of fruit wines. This research investigated the impacts of juice, mash, and mash with peel fermentations on the color, organic acids, and aroma of kiwifruit wines, and further explored the effects of adding gelatin and bentonite before and during fermentations on the quality of the wines. The findings revealed that while the chroma and hue of the three fermentation patterns did not exhibit significant differences, but the contents of esters, aldehydes, and terpenes were higher in the juice and mash fermentations. The contents of total volatiles, acids, and ketones were the highest in the mash fermentation. Besides, total acidity, alcohol, chroma, hue, clarity, varieties and contents of volatiles were significantly affected by the fining stages. Clarity during fermentation fining increased from 79.72% of the control to 84.91%-88.29%. There was a minor difference in the content of the major volatiles between the control and the later stage of fermentation bentonite (LFB) fining, and the esters content of LFB fining increased by 51.87%. It indicated that mash fermentation and LFB fining were a concise and effective way to improve the clarity and flavor of kiwifruit wine.