Muhammad Hasan *(1), Suhiel Ibrahim Basha (1)and Mohammed Kassem (2)
(1). Dept. of Food Science, Faculty of Agricultural Engineering, Aleppo University, Aleppo, Syria.
(2). Dept. department of basic Science, Faculty of Agricultural Engineering, Aleppo University, Syria.
(*Corresponding author: Eng. Mahammad Hasan. E-Mail: muhammad.hasan15346@gmail.com).
Received 13 / 07/ 2020 Accepted 2 / 09 / 2020
Abstract
The current study was to determine the possibility of reducing the amount of tannin in fresh pomegranate juice (French cultivar) after its treatment with an enzymatic extract of a fungal isolate Aspergillus niger of which has the enzymatic effectiveness (27.48 U\ml), and The effect of this treatment on the qualitative characteristics of pomegranate juice output. The optimal conditions for this treatment were initially determined by the effect of the amount of enzyme added (0.5, 1, 1.5 ,2) ml, and the duration of the treatment (30, 60, 90, 120, 150) minute, this study was investigated at the laboratories of the Department of Food Sciences at the Faculty of Agriculture, University of Aleppo in 2019. The results of the statistical analysis showed that the optimum treatment in reducing tannins content was by adding 1 ml of the raw enzymatic extract of tannase to 9 ml of juice, and continuing the treatment for 120 minute, as an enzymatic treatment in these conditions reduced the content of tannins in the juice by 43% compared to control, and the results showed a positive effect of this treatment on the degree of juice turbidity and its content of reducing sugars and the ratio of soluble solids. The enzymatic treatment decreased significantly in the degree of juice turbidity by 39%, and an increase in the content of reduced sugars and the proportion of soluble solids by 13%, 2% respectively. when compared to control. Whereas this treatment hurt the juice’s content of phenolic and anthocyanin compounds and ascorbic acid, which caused a loss of 7, 5, 30% respectively. This enzymatic treatment did not show any meaningful differences from total pH and pH level compared to the control.
Keywords: Tannase, Tannins, Enzymatic treatment, Pomegranate juice
Full paper in Arabic: PDF