Abstract: The protein subunits from 36 peanut varieties grown in Xinjiang were analyzed by sodium dodecyl sulphate polyacrylamide gel electrophoresis and the quality characteristics of peanut protein isolates were also explored. The data obtained were subjected to correlation and cluster analysis. The results showed that there was a large genetic variability in the proportion of protein components among peanut varieties. The protein subunits were significantly different among peanut varieties, with the largest difference being observed in the 35.5 kDa subunit of arachin. Six (16.67%) of the 36 peanut varieties such as ‘Jihua 10’ were found to lack the 35.5 kDa subunit. The quality characteristics of peanut protein isolates varied among germplasm materials. The coefficient variations of water-holding capacity, solubility and other indicators but not of protein purity were greater than 10%, indicating considerable differences in protein quality characteristics among varieties. Correlation analysis showed that there was a significantly negative correlation between arachin and conarachin (r = ?1.000, P < 0.01), and protein solubility was significantly negatively correlated with gel hardness (r = ?0.498, P < 0.01). Cluster analysis showed that the 36 peanut varieties (lines) could be divided into five classes at the level of D2 = 5. Among them, the protein solubility of class II and the protein gel hardness and cohesiveness of class IV were better, making them worthy of popularization.

Key words: Xinjiang-grown peanut, peanut protein, subunit composition, quality characteristics