Evaluation of secondary metabolites, antioxidant activity, and color parameters of Nepali wines

We evaluated the quality of wines produced in Nepal in terms of phenolic, flavonoid, anthocyanin and tannin content, antioxidant capacity, and color parameters using spectrophotometric methods. The total phenolic content, total flavonoid content, and total antioxidant activities in Nepali wines ranged from 85.5 to 960.0 (mean = 360.5 +/- 268.7) mg/L GAE, 40.9-551.3 (mean = 188.9 +/- 161.5) mg/L QE, and 66.6-905.0 (mean = 332.8 +/- 296.5) mg/L AAE, respectively. These parameters were significantly higher in red wines compared to white wines. The phenolic and flavonoid content showed strong correlation with each other as well as with antioxidant activities. Additional parameters measured included various color parameters and carbohydrates. The wine color showed strong correlation with phenol, flavonoid, and antioxidant activity, whereas this correlation was not significant with anthocyanin content. Multivariate analysis was carried out to better describe and discriminate the wine samples. Finally, we compared Nepali wines with wines from other countries.