Comprehensive Quality Evaluation of Red Jujube Vinegars Made from Different Varieties Based on Principal Component Analysis

In order to determine good jujube varieties for the production of vinegar, databases of soluble solids, total acid, transmittance, color, total phenols, total flavonoids, antioxidant properties and volatile flavor components were constructed for jujube vinegars made from four different varieties, Ruoqiang grey jujube from Xinjiang, Zanhuang jujube from Hebei, Tanzao jujube from Shanxi, and Tongxin round jujube from Ningxia. By comparing quality indexes and combining the results of principal component analysis (PCA) and sensory evaluation, it was concluded that Tanzao jujube vinegar was significantly superior to the other three jujube vinegars in terms of total acid content, total flavonoid content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging capacity, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cationic radical scavenging capacity, hydroxyl radical scavenging capacity, and volatile flavor components, and scored highest in both PCA and sensory evaluation. Therefore, Tanzao jujube was the most suitable raw material for jujube vinegar production. The results of this research provide a reference for raw material selection for and nutritional quality optimization of jujube vinegar.