荔枝干品质评价指标体系的建立

Establishment of Quality Evaluation Index System for Dehydrated Litchi

通过对荔枝干的品质指标进行分析,确定不同品质指标对荔枝干品质的影响,为荔枝干品质评价指标的筛选提供理论依据,并优选出具有干制优势的荔枝品种。通过测定33个品种的荔枝汁液外流率、果实质量、可食率、色泽、破壳率、总糖、总酸、蛋白质、糖酸比等11个品质指标,对其进行主成分分析和聚类分析,结果发现:荔枝干多个品质指标间存在相对独立性或密切相关性;经主成分分析,6个主成分的累计贡献率达88.80%,可反映荔枝干品质的绝大部分信息;聚类分析结果表明,11个主要品质指标可聚为6类,最终将品质指标简化为糖酸比、可食率、果皮色泽L*值、汁液外流率、果实质量和蛋白质含量6个指标。建立了荔枝加工品质评价体系模型,并优选出品质较好的加工品种:"鸡嘴"、"糯米糍"和"仙进俸"。

Qualities of dehydrated litchi were analyzed to determine the influences of various potential processing characteristics on quality of dehydrated litchi, and provide the theoretical basis for the selection of evaluation index on processing quality. Thus, cultivars suitable for processing were selected according to the evaluation model. The processing quality indices of 33 dehydrated litchi cultivars, which include single fruit weight, edible ratio, color, total sugar, total acid, were analyzed and determined. The principal component analysis and cluster analysis were performed on these indices and cuhivars. Relative independence or high relativity were found among these quality indices of dehydrated litchi. The principle component analysis showed that the accumulated contribution rate of 6 principle components was 88.80%, which reflected almost all the needed information of the quality on dehydrated litchi; Meanwhile, The cluster analysis showed that the 11 major quality indices were clustered into 6 categories. Therefore, the quality indices were simplified to 6 indexes as follows： sugar to acid ratio, edible ratio, L of skin, extractable juice percentage, single fruit weight and proteins content. Consequently,model of evaluation on litchi processing was established, and cuhivars which exhibited good qualities such as ＇Jizui＇, ＇Nuomici＇ and ＇Xianjinfeng＇ were selected using this index system.