Abstract
ABSTRACT The present study was conducted to evaluate the effects of storage time and temperature on physicochemical and sensory properties and to measure the spoilage of pasteurized fluid milk stored at different temperatures via nanoparticles on pasteurized fluid milk. The mean values for pH of milk samples decreased (from 6.81 to 6, 5.46, and 4.37), acidity increased (10%, 21%, and 35%), fat contents decreased (13%, 24%, and 32%), protein contents decreased (7%, 18%, and 24%), lactose contents decreased (5%, 7%, and 12%), and total free fatty acids increased (14%, 19%, and 27%) respectively at 4°C, 7°C, and 10°C. Similarly, the score of sensory parameters like aroma, taste, and overall acceptability decreased 16%, 23%, and 45%; 31%, 43%, and 52%; and 33%, 42%, and 53% respectively in linear pattern along with increasing the time and temperature. The L* values were non-significantly changed or decreased with mean values of 64.82 ± 0.08 to 64.13 ± 0.07 at 4°C and significantly with 64.81 ± 0.03 to 63.87 ± 0.07 and 64.77 ± 0.02 to 61.43 ± 0.05 at 7°C and 10°C respectively at 0–19th day of milk storage. During storage, the pasteurized milk stored at all temperatures 4°C, 7°C, and 10°C showed that a* value non-significantly decreased from 48.69 ± 0.18 to 48.63 ± 0.18, 48.74 ± 0.14 to 48.57 ± 0.11, and 48.68 ± 0.18 to 47.97 ± 0.07 respectively. Values of b* decreased non-significantly at 4°C and 7°C with the values of −17.56 ± 0.23 to −18.58 and −17.54 ± 0.25 to −19.85 ± 0.85 but significantly decreased at 10°C from −17.56 ± 0.23 to −43.22 ± 0.11. The results suggested that pasteurized milk can be kept for 17–19 days at 4°C but this shelf life drastically reduced at 7°C and 10°C. Color of nanoparticles was significantly changed from pink to dark blue from 14th day of storage onwards to the end at 10°C. Conclusively, nanoparticles can be used for the rapid and at the post-spoilage measurement of pasteurized milk.
Highlights
Physicochemical reactions during storage of food especially pasteurized milk may result in unwanted changes which undermine its sensory and nutritional qualities
During post-pasteurization cold storage, pH, fat, protein, and lactose contents decreased while the rates of Free Fatty Acids (FFA) and acidity increased significantly at 10°C as compared to 7°C and 4°C at the 19th day
Our research has shown that at 4°C the change in color of nanoparticles by the reaction with volatiles is negligible even at 19th day of milk storage
Summary
Physicochemical reactions during storage of food especially pasteurized milk may result in unwanted changes which undermine its sensory and nutritional qualities. Changes in the physicochemical properties on pasteurized milk may lead to deterioration of product quality and impart a negative cause of the shelf life of the product. The preventing condition of pasteurized milk.[1] The ingredients that control shelf life of refrigerated pasteurized milk products are (1) time and temperature of pasteurization; (2) presence and actual post-pasteurization pollutants; (3) type and activity of pasteurizationresistant microorganisms; and (4) storage temperature after pasteurization.[2] pasteurization is supposed to inactivate pathogenic bacteria in milk, it usually does not damage all of bacteria which are present in the product. Bacterial spoilage is the key limiting factor in bringing the shelf life of general HTST pasteurized milk beyond 14 days
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
