Physical and Chemical Properties of Rat Taro Simplicia From Various Drying Methods

Rat taro is a potential plant as a raw material for medicine. Rat taro contains an active compound that is useful as an anticancer, antibacterial, and antioxidant. Standardization of raw materials is important to obtain reproducible effects and safe consumption. This study is aimed at obtaining an appropriate drying method to produce high-quality rat taro simplicia from the tuber and leaf. The drying methods applied were sun drying, modified sun drying covered with black fabric, and oven drying. Simplicia of rat taro was made from the tuber and leaf. Simplicia quality was observed for moisture content, dry weight yield, ash content, water- and alcohol-soluble essence, flavonoids, and antioxidant activity (IC₅₀). The results showed that the average drying temperature for the tuber was around 37.5°C-39°C, and for the leaf, it was 32.5°C-37°C. The drying time for the tuber was around 15-16 h, and for the leaf, it was 20-26 h. The average moisture content of rat taro simplicia ranged from 8.27% to 10.84%. The water-soluble extract content of the tuber was around 10.92%-12.81%, and of the leaf, it was 35%-39.10%. Alcohol-soluble extract content of the tuber was 1.88%-2.28%, and of the leaf, it was 6.35%-9.19%. The flavonoid content of the tuber was around 0.2-0.3 mg QE/g, and of the leaf, it was 4.1-5.6 mg QE/g. The IC₅₀ value of the tuber was around 6477.70-8847.77 ppm, and of the leaf, it was 585.01-1189.63 ppm. The results revealed that the drying method influenced antioxidant activity (p = 0.028) and flavonoid levels (p = 0.009) in rat taro simplicia. The moisture content, antioxidant activity, and flavonoid content of the leaves were higher than the tubers. The most effective drying method for rat taro simplicia was oven drying at 37°C-38°C, which yielded flavonoid contents of 0.3 mg QE/g in the stems and 5.6 mg QE/g in the leaves, along with antioxidant activities of 6477.70 ppm in the stems and 585.01 ppm in the leaves, representing the best results obtained.