KEEPING-QUALITY ASSESSMENT OF PASTEURIZED MILK BY MULTIVARIATE-ANALYSIS OF DYNAMIC HEADSPACE GAS-CHROMATOGRAPHIC DATA .2. FLAVOR CLASSIFICATION BY LINEAR DISCRIMINANT-ANALYSIS

The flavor quality of pasteurized milk was classified by applying line ar discriminant analysis (LDA) to volatiles as determined by dynamic h easpace capillary gas chromatography (DH-GC). LDA was able to classify milk into good, marginal, and poor quality or into fruity, rancid, an d normal flavor groups at a greater than 80% success rate. The zone of good or normal flavor groups could be visualized in two-dimensional c anonical plots; thus, any sample deviating from this zone could be con sidered a defective product. In addition, LDA of gas chromatographic d ata allowed the association of milk volatiles that contributed most si gnificantly to the discrimination among flavor quality groups. Spoilag e-associated volatiles were identified by using DH-GC-MS. The analytic al system established has potential for application in the dairy indus try for early detection of spoilage or for tracing defects associated with consumer complaints.