Application of Pca and Slda Methods for the Classification and Differentiation of Cooked Pork From Chinese Indigenous Pig Breeds and A Hybrid Pig Breed

In order to differentiate and characterize the cooked pork samples from three Chinese indigenous pig breeds (Anqingliubai, Wannanhua Pig, and Dingyuan Pig) and a typical hybrid pig breed Yorkshire×Large White×Duroc, the volatile flavor composition was determined for 32 monovarietal samples from these four pig varieties. A headspace solid-phase microextraction gas chromatography–mass spectrometry (headspace–solid-phase microextraction–gas chromatography–mass spectrometry) procedure was used to identify the volatile flavor compounds and detect the concentration of these compounds. One way analysis of variance, principal component analysis, and stepwise linear discriminant analysis were used to process data and to develop discriminant models. Principal component analysis described the correlation between samples (objects) and volatile flavor compounds (variables). The results of the principal component analysis show that the most important contributions to the differentiation of Anqingliubai cooked pork samples are undecanal and 2-undecenal. Hexadecanal and 2-decene-1-ol are the major contributions in Yorkshire×Large White×Duroc cooked pork samples. Benzaldehyde, hexanal, dodecanal, 1-octen-3-ol, and 1-octanolare strongly associated to Wannanhua pig cooked pork samples. Dingyuan pig cooked pork samples are most correlated with heptanal, octanal, 14-octadecenal, (E)-2-octenal, N-hexadcanoic acid, (E)-13-octadecenic acid 3-hydroxy-2-butanone, 2-ethylfuran and 2-butanone. Stepwise linear discriminant analysis was used for differentiation of cooked pork samples according to the varieties, resulting in a correct classification of 100%.