Method Validation and Assessment of Total Antioxidants, Polyphenols, Flavonoids, and Vitamin C in Cultivated Mulberry in Yemen

Abstract

The nutritional quality of mulberries, particularly their antioxidant content, is vital for human health. Yemen produces mulberries in moderate quantities. This study validated the methods used to measure total antioxidant content (TAC), total polyphenols content (TPC), total flavonoid content (TFC), and vitamin C (Vit. C) in mulberry fruit samples Spectrophotometrically. The results demonstrated high repeatability, with relative standard deviation (% RSD) values ranging from 0.90 to 2.53 % for TAC, 0.65 to 1.87% for TPC, 1.55 to 3.48 % for TFC, and 0.64 to 2.64 % for vit. C. Additionally, the methods showed good linearity correlation coefficients (R²) values of 0.9964, 0.9984, 0.9985, and 0.9987, high sensitivity, LOD values of 0.089, 0.188, 0.585, and 8.070 ppm, respectively; LOQ values of 0.296, 0.630, 2.854, and 26.900 ppm, respectively, and satisfactory accuracy (%R values of 89.66 to 102.78 % for TAC, 99.76 to 105.14% for TPC, 90.93 to 103.66% for TFC, and 92.80 to 98.21% for Vit. C). Analysis of Yemeni mulberry samples revealed TAC values ranging from 3792.00±0.018 to 6333.33±0.027 mg AAE/kg fw, TPC from 1431.50±0.025 to 3729.60±0.007 mg GAE/kg fw, TFC from 215.20±0.051 to 541.85±0.020 mg QE/kg fw, and Vit. C from 410.26±0.100 to 850.82±0.050 mg AAE/kg fw. This study confirms the methods’ validity of antioxidants, which showed high sensitivity, accuracy, good linearity, and repeatability while testing Yemeni mulberry samples. The extracts exhibited high antioxidant activity, with potential applications in the prevention and treatment of oxidative stress-related diseases.