Palatable functional cucumber juices supplemented with polyphenols-rich herbal extracts

This study aimed to produce a palatable functional cucumber juice: non-supplemented cucumber juice, control juice (J-con), and supplemented with different herbal extracts. Four juices were prepared and evaluated, as supplemented with the ethanolic extracts of cinnamon, mint, ginger, and clove denoting as; J-cin, J-min, J-gin, and J-clov, respectively as compared to J-con. HPLC analysis indicated that J-clov followed by J-min were the richest juices in the phenolic and flavonoid compounds compared to control. Pyrogallol, catechin, gallic, and chlorogenic acid were the most prominent phenolics in J-clov, while hesperidin and apigenin-6-arabinose were the most abundant flavonoids. Clove extract showed the highest (p < 0.05) antioxidant activity (80%), followed by the mint extract. Clove and mint extracts significantly reduced the growth of the tested bacteria and fungi. The antioxidant activities in all juices significantly (p < 0.05) decreased during the storage period (0, 2, 4, and 6 months) at 25 degrees C as polyphenols and flavonoids content declined. The pH and vitamin C significantly decreased; however, the titratable acidity increased. Clove and mint extracts (p < 0.05) reduced the decay of total sugars by reducing the microbial load. J-clov showed the highest sensorial taste and flavor scores; however, J-min and Jcin were the best colors.

Automated summary

Four cucumber juices were prepared and evaluated with the addition of cinnamon, mint, ginger, and clove extracts. Clove and mint extracts showed the highest antioxidant activity and inhibited microbial growth, although antioxidant activities decreased during storage.