标题：Classification of Various Milk Products Manufactured in Thrace Region of Turkey Based on their Nitrate and Nitrite Contents Using Chemometric Methods
摘要：In this study the amounts of nitrate and nitrite in white cheese (n=28), kashar cheese (n=19), produced cheese (n=1), yoghurt (n=16), raw milk (n= 5) and pasteurized-sterilized milk (n=7) manufactured in Thrace region, which has an important region in production of milk products of Turkey, were determined. The results were used to classify the samples according to the geographical origin using chemometric methods, namely Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA). The levels of nitrates and nitrites in food are accepted as an important parameter of environmental pollution. It was observed that 11.11% of white cheese, 21.05% of kashar cheese, 18.75% of yoghurt and 25% of drinking milk samples did not contain nitrates. On the other hand, no significant amount of nitrites were found in 51.85%of white cheese, 31.58% of kashar cheese, 6.25% of yoghurt and all of the drinking milk samples. In addition, PCA results showed that the first principal component (PC1) and the second principal component (PC2) explained 83.04% and 16.96% of the total variance, respectively for the entire milk product samples originated from Thrace region. Based on the HCA results, the milk product samples were separated and classified into three main groups according to their geographical origins.
