Kiwifruit harvested at different times in 1989 was stored at 4° for various durations, and white wines were produced from fruits with various maturities.
The addition of cellulose powder to the crushed fruit at pressing did not influence the quality of wine made from the fruit although it reduced the pressing time of fruit to obtain juice and juice yield was increased. However, enzymatic treatment of the juice appreciably improved the appearance, aroma, and flavor of the wine made from it (must).
General composition and free amino acid and organic acid compositions of the wines hardly differed with the hardiness of the fruits used; by contrast, sensory evaluation gave different results depending on fruit hardness. The highest quality wine was obtained using the fruit with an intermediate degree of hardness of 1.3 to 1.6 kg/cm².
Whereas the titratable acidity and the pH of kiwifruit juices were hardly changed during the storage of the fruits, the contents of total phenols, total sugars (degree Brix), total reducing sugars, total individual monosaccharides, and total organic acids were increased, and the compositions of organic acids and free amino acids were considerably changed. There were significant differences in juice components between the fruit that ripened on vines and that which ripened during storage after harvesting for the same time. The latter was found to be better raw material for wine must than the former.