Effects of distribution density on Turpan seedless white grape in air-curing barn drying

In order to explore the effects of distribution density on qualityof raisins which are seedless white grape dried in air-curing barn. The distribution density of Turpan seedless white grape was 1:0.5,1:0.75,1:1 in air-curing barn,respectively. The appearance,degree of uniformity,breakage rate,drying rate,total sugar content,V_C content were analyzed against different distribution density. The results showed that when distribution density was 1:0.5,the raisins could meet the requirements of first grade the appearance and degree of uniformity was 83% and 85%,breakage rate was 11.5%,drying time was 26 d,total sugar content and V_C content was 701.9 mg/g and 7.05 mg/100 g,respectively;when distribution density was 1:0.75,the raisins could meet the requirements of first grade the appearance and degree of uniformity was 85% and 86%,breakage rate was 12.0%,drying time was 26 d,total sugar content and V_C content was 702.4 mg/g and 7.34 mg/100 g,respectively;when distribution density was 1:1,the raisins could meet the requirements of first grade the appearance and degree of uniformity was 80% and 85%,breakage rate was 17.3%,drying time was 28 d,total sugar content and V_C content was 691.5 mg/g and 7.21 mg/100 g,respectively. The drying rate of distribution density was 1:1(p<0.05)that lower than others,while the content of sugar and V_C was the highest in raisins which distribution density was 1:0.75. According to the comprehensive analysis of six indexes of non-nuclear white raisins’ products,1:075 was the best density of hanging stings.