Determination of Fatty Acids in Raw, Pasteurized, and Sterilized Milk in Four Manufacturing Units in Isfahan and Markazi Provinces, Iran

Although there is general information in the scientific literature regarding the concentration of fatty acids in milk, detailed information on the fatty acid pattern of thermally processed milk distributed in the Iranian market has rarely been released. This study was conducted in order to compare the raw milk fatty acid pattern and its modification as a result of commercial thermal processing during a 3-month study in the summer, 2015.
In this cross-sectional study, 72 samples including raw, pasteurized, and sterilized milk were randomly collected from 4 manufacturing units in Isfahan and Markazi Provinces, Iran, during 3 sampling times in the summer with 1 month intervals. The fatty acids pattern was determined using gas chromatography (GC) method. Data were analyzed in SPSS using two-way ANOVA test and LSD post hoc test.
Findings: The results showed that the concentrations of both saturated and unsaturated fatty acids in raw milk significantly decreased after thermal processing (P The results of this study showed that commercial thermal processing of milk results in substantial changes in milk fatty acid concentration. Despite the gentle thermal process in pasteurization compared with sterilization, the decrease in fatty acids in this process was clearly higher than that in sterilization. Considering the importance of pasteurized milk in the public food basket, it is necessary to consider the above changes in the food composition table.