Establishment of a quality evaluation system for Antarctic krill meal using multivariate statistics

Antarctic krill (Euphausia superba) meal has been widely recognized as the most important marine product of protein with highly nutritional values and huge resources. It is also mainly used in the field of aquacultural feed and oil extraction of an Antarctic krill. Therefore, the quality of Antarctic krill meal is crucial to its application. However, the quality evaluation on the Antarctic krill meal varies in different conditions, even conflicts in the related information expression. In this study, a feasible quality evaluation system was established to assess the Antarctic krill meal using the principal component analysis. 15 quality indicators of an Antarctic krill meal were classified, including the moisture, protein, lipid, ash, salt, phospholipid, astaxanthin, tocopherol, acid value, histamine, TVB-N, pyrrole, fluorine, lysine, and methionine. A SPSS 24.0 software was used to carry out the probability distribution, analytical hierarchy process, K-means cluster, and discriminant analysis. A factor analysis was performed to select the primary quality indicators from 15 quality indices of an Antarctic krill meal. The probability distribution and analytical hierarchy process were used to grade and determine the weights of the quality indicators. The K-means cluster and discriminant analysis were employed to establish the discriminant model of a quality evaluation for the Antarctic krill meal. The results demonstrated that the quality indicators of an Antarctic krill meal were dispersed with the coefficient of variation from 8.89% to 84.46%. Six quality indicators of an Antarctic krill meal (protein, lipid, salt, lysine, tocopherol, and TVB-N) were in the highly significant correlation with the quality of Antarctic krill meal, further to serve as the indicators of quality evaluation for the Antarctic krill meal. Five grades were divided in the six quality indicators, including the lower, low, medium, high, and higher level, indicating normal or near normal distributions. The principal component analysis showed that the cumulative variance contribution rate of six principal components were 92.263%. The importance of 6 principal components and the comprehensive evaluation model were selected to establish the quality grading standards and scoring system for the Antarctic krill meal. The results showed that a highly accurate quality evaluation was achieved in the various Antarctic krill meal, whether the modeling samples or experimental ones. Therefore, the scores from the prediction model can be utilized to fully distinguish the quality indicators, such as protein, lipid, salt, lysine, tocopherol, and TVB-N in the tested samples. Combining the grade and score of quality indicators, it was found that the quality of an Antarctic krill meal was a comprehensive effects of different components in the Antarctic krill meal. The prediction model can also be used to accurately distinguish and evaluate the difference in the quality of Antarctic krill meal. This finding can provide a basic information support to establish the evaluation system, further to realize the comprehensive detection in the quality of Antarctic krill meal. The facile evaluation can also be extended to the scientific quality evaluation of fish meal. © 2020, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.