Effect of Conventional and Ohmic Pasteurization on Some Bioactive Components of Aloe vera Gel Juice

Abstract

In this research the effect of conventional and ohmic pasteurization and storage time at different temperatures on some bioactive components of Aloe vera gel juice was investigated. Aloe vera gel juice was pasteurized conventionally and ohmically at 90 oC for 1 min. The effect of pasteurization on vitamin C, total phenolic content and juice color was evaluated. The samples pasteurized conventionally, stored up to 30 days at 4 and 25 oC. The effect of storage time on the stated components and also on glucomannan of the juice was evaluated. The results showed that pasteurization reduced vitamin C content and decreasing of vitamin C during ohmic heating was more than conventional heating. Total phenolic content increased during ohmic pasteurization more significant than conventional pasteurization. Browning index of samples after pasteurization increased but there were not any differences between browning index of samples pasteurized conventionally and ohmically. During storage at 4 and 25oC, total phenolic content remained stable, but vitamin C contents reduced from 84.47 to 54.96 at 4oC and 46.82 at 25oC mg vitamin C/100 g d.m and glucomannan contents reduced from 2.11 to 1.77 at 4oC and 1.71 g/L at 25oC.. Browning index increased significantly at both storage temperatures, which was more intensive at 25 than 4 oC.