Comparison of Chemical Properties, Antioxidant Activity and Microbial Count in Filtered and Non-Filtered Dry Wolffia arrhiza Kombucha.

Abstract

<b>Background and Objective:</b> Nowadays, consumers are more health conscious and choose good food to maintain good health. <i>Wolffia arrhiza</i> contains vitamins A, B-complex, C, E, K and key minerals (Iron, Calcium, Zinc and Magnesium), Omega-3, fiber and antioxidants (Folate, Beta-carotene, Zeaxanthin and Lutein). The study aimed to examine the chemical properties, antioxidant activities, total phenolic content, total flavonoid content and microbial count of 2 types of <i>Wolffia arrhiza</i> kombucha. <b>Materials and Methods:</b> The production of 2 types of dry <i>Wolffia arrhiza</i> Kombucha (filtered and non-filtered) was fermented for 21 days. Acetic acid content and alcohol content were analysed by High-Performance Liquid Chromatography (HPLC). Antioxidant activity was analysed by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, total flavonoid was analysed by aluminium chloride colorimetric assay and total phenolic content was analysed by Folin-ciocalteu method. Yeast and bacteria counts of the <i>Wolffia arrhiza</i> Kombucha samples were done using the standard plate count procedure. The results were because of the Mean±Standard Deviation (SD). The obtained data were analysed by independent sample t-test, using SPSS software version 22.0. As p<0.05 is regarded as significant. <b>Results:</b> The physicochemical of the fermented products revealed that the non-filtered <i>Wolffia arrhiza</i> kombucha had acetic acid content, alcohol content, antioxidant activity, total flavonoid content and total phenolic content higher than filtered <i>Wolffia arrhiza</i> kombucha. The values were 2.35%, 1.31%, 18.38±0.18 mg/mL, 482.00±8.08 μg RE/mL and 818.88±0.00 mg/L, respectively. On the 21st day of fermentation, the filtered <i>Wolffia arrhiza</i> kombucha had yeast and bacteria counts higher than the non-filtered <i>Wolffia arrhiza</i> kombucha. The values were 94.5 and 189.5 CFU/mL, respectively. <b>Conclusion:</b> This study found that non-filtered kombucha had higher acetic acid and phytochemicals, but microbial counts were low due to acid shock. Future research should focus on optimizing kombucha production conditions for more beneficial fermented drinks.