PHYTOCHEMICALS, ANTI-OXIDANT AND SENSORY ANALYSIS OF GURJO (Tinospora sinensis) STEM INCORPORATED GREEN TEA (Camellia sinensis)

Abstract

The present work was carried out to prepare gurjo stem incorporated green tea (blend) powder and evaluate its sensory, phytochemical analysis and antioxidant activity. Gurjo stem (Tinospora sinensis) and green tea leaves (Camellia sinensis) were mixed in different proportions naming Sample A, B, C, D and Control (35:65, 17.5:82.5, 26.25:73.75, 8.75:91.25, 0:100) to obtain an optimum formulation of a blended tea using Design Expert v 13.0.1.0 software. Green tea, gurjo stem and the selected tea blend was subjected to organic solvent of methanolic extraction. Major phytochemicals (phenol, flavonoid, and tannin) content along with DPPH radical scavenging activity were determined for all the prepared extracts. The sensory analysis was carried out for color, aroma, taste, mouthfeel and overall acceptance of five tea infusions using a 9-point hedonic scale rating test. Analysis of variance (ANOVA) was done and Tukey’s honesty test was performed by JMP version 14 to check the significant relationship between the mean values of the samples at p<0.05. R version 4.02 was used for multivariate analyses using correlation and principal component analysis (PCA). From ANOVA and PCA result, Sample D having 91.25% green tea and 8.75% gurjo powder was obtained as best blend among four samples of mixture formulation. The Sample D was found to be superior than others samples on the basis of color, aroma, taste, mouthfeel and overall acceptance of infusion from statistical analysis at P<0.05. The moisture, protein, fat, crude fiber and ash content in blend were found to be 5.267%, 21.534%, 2.709%, 14.214% and 5.946% and were significantly different (P<0.05) than that of control product green tea. As there was no significance difference in nitrogen free extractive (NFE) of blend and green tea, the NFE in blend was found to be 55.590%. The methanolic extract of blend had TPC 69.353 mg GAE/g, TFC 49.781 mg QE/g, TC 28.167mg GAE/g dry weight, DPPH radical scavenging activity 69.143% inhibition and was significantly different (P<0.05) than that of control product green tea. The principal component analysis (PCA) showed that the closet proximity of blend extract with TPC and DPPH had strong correlation. Likewise, TC & DPPH and TC & TFC were found to be very strongly correlated with each other (99.7%) followed by TPC & DPPH and TPC & TC (99.4%) respectively. This finding indicated that TPC, TFC, TC and % DPPH of blend was found to be significantly different from green tea.