Grapes are good source of dietary sugars, organic acids and provide good amount of minerals like iron and phosphorus and some vitamins. Among the grape processed products raisins are one of the most important processed products obtained from grapes. The mature, clean and uniform size green grape berries (Thompson seedless) were taken. The berries were treated by using different methods viz. Preyal dip, Australian dip and soda dip. Drying was done at 50 and 60oC to study the effect of drying temperature on quality of raisin. The grape berries were dried from 78 per cent ( per cent, .) to per cent ( per cent, .). The total drying time of 60 to 96 hrs, 40 to 51 hrs, 60 to 78 hrs, and 60 to 80 hrs was required for control sample, Australian cold dip, soda dip, preyal dip methods respectively. The drying rate varied between to g/. for all treatments. The average score for color, appearance, texture and taste of the raisins ranged between to , to and respectively. The overall acceptability of the raisins made by using Australian cold dip, preyal dip, soda dip and control methods was found as and when grapes were dried at 50oC. The minimum overall acceptability of the raisins made by using Australian cold dip, preyal dip, soda dip and control methods was found as , , and when grapes were dried at 60oC. The better quality raisins could be prepared from the grapes using Australian cold dip method at drying temperature 50oC. Drying characteristics and organoleptic properties of raisins prepared by different methods the Australian cold dip method was found to be suitable for preparation of raisins. | Effect of various pretreatments on raisin making from grapes (Vitis vinifera L.)
