Tannin Concentrations of Gyrinops Tea with Different Leaf Processing Methods and Addition of Herbal Medicine Ingredients

摘要

Gyrinops tea is the new type of agarwood tea from Lombok Island, which has a good prospect to be developed. Addition of herbal medicine ingredients could improve the quality of this product as a healthy good taste herbal tea. One of chemical standard to measure quality of herbal tea product is tannin measurement. The aim of this research is to examine tannin concentration of Gyrinops tea with different leaves processing and addition of herbal medicine ingredient. Factorial Completely Randomize Design was used as experimental design with three replications and two treatment factors. i.e. leaf processing methods (Pi= leaves without oxidation, P2: leaves with oxidation), and addition of herbal medicine ingredients (Hi: Zingiber officinale, H2: Cymbopogon citratus, H3: Citrus aurantiifolia). Tannin measurement was carried by titrimetric method using KMnO_4 and Indigo carmine reagent. Tannin concentration data were analyzed using analysis of variance (ANOVA) and DMRT at 5% level of significance. The results indicated that both treatment factors showed significant effects on tannin concentrations. However, there was no interaction effect between those two factors. Oxidation of Gyrinops leaves increased tannin concentration of the Gyrinops tea. Addition of Cymbopogon citratus resulted in the highest tannin concentration compared with other ingredients. Thus oxidation of Gyrinops leaves combined with addition of Cymbopogon citratus could produce herbal tea with high quality of tannin concentration.