Apple fruits of 18 cultivars from 7 different main growing areas in China were collected for cloudy juice processing and the amino acid components and contents of fresh cloudy apple juices were measured. By descriptive and stepwise linear discriminant analysis (SLDA), the results showed that the amino acid contents of cloudy apple juices differed from varieties and origins. In general, the variation coefficients of alanine, leucine, serine, valine and isoleucine were relatively high, which were 191.38%, 96.91%, 67.82%, 53.60% and 57.97% respectively. The variation coefficient of aspartic acid, threonine, glutamic acid, glycine, lysine, and total amino acid were relatively low, which were 43.92%, 45.70%, 28.37%, 35.16%, 47.47% and 39.40% respectively. Moreover, cloudy apple juice form Huajin contained the highest amount of aspartic acid, serine, alanine and total amino acids, which were 235.6 mg/100 g, 12.6 mg/100 g, 10.5 mg/100 g and 289.4 mg/100 g, respectively. Thus, with its highest contents in the above four amino acids, cloudy apple juice of Huajin located at the edge of the figure, showing the great difference with other varieties. Besides, the amino acid components and contents of apple juices were greatly affected by origins, and the samples from different areas were dispersed in the figure. Compared to other origins, cloudy apple juices from Xinjiang showed significant lower contents in threonine, serine, glutamic acid and valine, which were 1 mg/100 g, 2.4 mg/100 g, 7.1 mg/100 g, 1 mg/100 g respectively. Cloudy apple juices with different varieties from Shandong Province and cloudy apple juice of Fuji from different origins showed significantly different in amino acid constitution, which obtained 77.8% and 81.8% discriminant accuracy respectively based on SLDA. The above results show that cloudy apple juices could be differentiated for varieties and origins based on amino acid contents by SLDA. © 2019, Editorial Office of Journal of CIFST. All right reserved.
