The effect of pasteurization temperature and storage time on bioactive compounds of milk-carrot drinking

The aim of the research was to study the effect of pasteurization temperature, storage time and carrot juice ratios on pasteurized cow milk enriched with carrot juice. For this purpose, after carrot juice extraction and filtration, different ratio of carrot juice (10, 20, 30, 40 and 50 %) were added to pasteurized cow milk and mixed properly. Then samples were filled in glass bottles and pasteurized at different temperatures (65, 70 and 75 °C) for 30 min. The samples were quickly cooled and stored at 4 °C up to 13 days. The bioactive compounds (total carotenoids (ß-carotene equivalent), total phenols (Gallic Acid equivalent) and vitamin C) and were analyzed during storage time (1, 4, 7, 10 and 13th). The results showed that the carotenoid, vitamin C and total phenol content of milk carrot drinking were increased by increase of carrot juice ratio. Furthermore, higher pasteurization temperature resulted in higher loss of carotenoids, total phenols and vitamin C in samples. Also, during storage time, the amount of carotenoids, total phenols and vitamin C in samples were decreased due to oxidation, deformation or interaction with other compounds. Stability and phase separation test of samples showed that all of treatments are stable during storage time. The results showed that increase of carrot juice and pasteurization temperature resulted in increase and decrease of bioactive compounds respectively and proper shelf-life of milk-carrot drinking samples were 10 days.