Effect of amount of bentonite and pH level on color and clarification of Stevia (Stevia rebaudiana Bertoni) extracts.

In order to investigate the effect of different levels of bentonite and pH of the extract on exposure to bentonite on the healing rate of stevia extract (Stevia rebaudiana Bertoni), a study was conducted on two factors in a completely randomized design with four replications. The first factor contains bentonite in four levels with concentrations of 0 (control), 10, 20 and 30 g / l and the second factor contains different pH of crude extract in five levels with 5.9 (control), they were 5.5, 5, 4.5 and 4, respectively. The results of analysis of variance showed that treatment with different amounts of bentonite had a significant effect on phenol, carotenoid, chlorophyll a, chlorophyll b and chlorophyll and flavonoid extracts. Also the best level of bentonite with the least amount and maximum clarification was 20 g / l with 0.07 mg / ml phenol, 0.36 mg / l carotenoid, chlorophyll a 1 mg / l, Chlorophyll b.03, Chlorophyll 3.03 mg / l and flavonoid content of 2.69 µg / ml were selected for subsequent experiment. The pH of the extract showed a significant effect on the phenol content of the extract and a significant effect on other traits. The best level of pH of the extract with the highest clarification and attention to human health, pH (5) with 0.15 mg/ml phenol, 1.42 mg / l carotenoid, 0.77 mg chlorophyll a Chlorophyll b 0.84 mg/l, chlorophyll b 1.61 mg / l and flavonoid with 2.17 µg / ml were selected. Therefore, the results of this study show that by considering appropriate amounts of dye compounds such as bentonite (20 g / l) at a suitable pH (5), the crude extract, color and transparency of stevia extract can be improved.