Harvest Date and Post Harvest Alkaline Treatment Effects on Quantity and Quality of Kashmar, Iran, Green Raisin

The yield and quality features of raisin are affected by various factors especially har-vest date and dipping solutions. Combinations of different harvest date (four harvest dates) and post harvest alkaline emulsion (three alkaline solutions) were tested in Vitis vi-nifera L. cv ‘Paycamy’ green raisin production in Kashmar, Khorasan Province of Iran. Such raisin quantitative and qualitative characteristics as: yield, drying ratio (fresh: rai-sin yield), raisin wastes, sugar content, price, color, homogeneity of color, raisin size, alka-line solution residues and surface texture of raisin (shrinkage) were assessed. Harvest date results showed that grape °Brix and raisin sugar content increased from ۱۵.۵ to ۲۱ and ۵۳% to ۶۲% respectively. In addition, fourth harvest yield increased raisin yield up to ۳۰% as compared to the first harvest. The amount of wastes resulted from decayed berry in the fourth harvest was higher than those for the other harvest dates, but such qualita-tive traits as color, size and texture softness improved through further fruit ripening. In-teraction effect of alkaline solution and harvest date on price and raisin size (number of raisins per ۱۰۰ g) were significant (P< ۰.۰۱). Alkaline solution affected raisin waste, the differences among post harvest treatments being significant. The color of raisin was not affected by alkaline solution but it was steadily improved with each succeeding harvest date.

Keywords:

Grape (Vitis vinifera L. cv. Paycamy) , Green raisin , Harvest time , Post harvest treatments , Raisin quality