Evaluation of total phenolic content, antioxidant activity and anti-amylase activity of different vegetable and fruit mixtures

Abstract

This work focused on determining the total phenolic content, antioxidant activity, and anti-amylase activity of twenty-one mixtures of vegetable and fruit juices. The results showed that the highest total phenolic content was found in the vegetable and fruit mixture containing guavas (10%), pineapples (10%), ivy gourds (60%), carrots (10%), and Chinese cabbages (10%), while the highest anti-amylase activity was found in the vegetable and fruit mixture containing guavas (10%), pineapples (10%), ivy gourds (50%), carrots (10%), and Chinese cabbages (20%). However, the highest antioxidant activity was found in guava juice. Moreover, the percentages of all vegetable and fruit mixtures, which showed synergistic effects by anti-amylase, total phenolic content, and antioxidant assays, were 81%, 9.5%, and 0%, respectively. For the antagonistic effect, it was only found for 4.8% by total phenolic content assay. Interestingly, a very strong positive correlation between the antioxidant activity and the number of guavas was detected (r = 0.883, p-value = 0.000). Moreover, total phenolic content and the number of carrots showed a weak negative correlation ( r =-0.389, p-value = 0.049), while total phenolic content and the number of guavas had a moderate positive correlation (r = 0.424, p-value = 0.031). Therefore, the synergistic formulation may help to manage type 2 diabetes. © 2021, Thammasat University. All rights reserved.