Pasteurized fresh milk requires an accurate estimation of shelf life under various conditions to minimize the risk of spoilage and product losses. Milk samples were stored for 56 h in an oven at 25 o C and for 15 days in a refrigerator at 4 o C. Samples were analyzed using an electronic nose (e-nose), total bacterial count, titratable acidity and pH to determine the quality of milk. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were used to analyze e-nose data of milk stored at 25 o C, and 4 o C. A clear shift in quality was identified by the e-nose, which also appeared in the total bacterial count after 24 h and 12 days for storage at 25 and 4 o C, respectively. On the other hand, titratable acidity exceeded the normal limits of 0.14 % - 0.21 % after 24 h for storage at 25 o C (0.247 ± 0.006 %) and after 15 days for storage at 4 o C (0.25 ± 0.01 %). If pH was a good indicator of quality for samples stored at 25 o C, it showed no clear trends for samples stored at 4 o C. Based on the microbial count data and e-nose output, the milk had a shelf life of 0.3 day (i.e. 8 h) when stored at 25 o C. Shelf life was extended to 9 days when stored at 4 o C.
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