Abstract:

Three appearance indexes (dry weight of 100 berries, berry shape index and fresh-to-dry ratio) and the contents
of seven nutrients in 10 different varieties of goji berries (Lycium barbarum L.) were determined. Based on our analytical
results, cluster analysis and comprehensive quality evaluations were carried out. The results indicated that the quality indexes
of different varieties of goji berries were varied over a relatively narrow range. Cluster analysis showed that 10 varieties of
goji berries could be divided into 4 classes: 1. Bianguo goji; 2 including 0901, Ningqi No.7 and Ningqi No.4; 3. Mengqi
No.1; and 4 including five other varieties. For principal component analysis, four principal components were extracted,
and their cumulative variance contribution rate was up to 85.87%, which reflected mostly the quality characteristics of goji
berries. The results of principal component analysis indicated that 0901, Bianguo goji, Ningqi No.7 and Ningqi No.4 had
better overall quality among the goji varieties tested.

Key words: Lycium barbarum L., cluster analysis, principal component analysis, quality evaluation