Development and screening of byproduct for its secondary metabolites, antioxidant and anti-diabetic potential from anthracnose-infected fruits of pomegranate: a sustainable approach

Abstract

The main focus of the present study was to analyze the antioxidant and anti-diabetic potential of fermentative byproduct, developed from anthracnose-infected pomegranate fruits. The analysis of fermented juice showed a reduction in total phenolic content, total flavanoid content, anthocyanins, and antioxidant potential over the time in 6 months as compared to fresh juice, while total protein and alcohol percent (11%) were increased. Measurements of antioxidant activity by DPPH, ABTS, superoxide radical scavenging activity, and reducing power assays were highly correlated to total phenolic content, with corresponding R² values as r_DPPH = 0.88, r_ABTS = 0.90, r_SRS = 0.67, r_RPA = 0.80. High-performance liquid chromatography clearly revealed that the increment of antioxidant activity is associated with the release of gallic acid, vanillin, and ferulic acid. LC–MS analysis identified 1263 metabolites in fresh juice, 1580 metabolites after 1 month of fermentation, and 1063 metabolites after 6 months of fermentation. Most of the detected metabolites are linked with antioxidant, anti-diabetic, phenolics, flavanoids, cardiac glycosides, anticancer, and anti-vomiting activity. Mainly, naphthofluorescein, CAY10599, CAY10506, aminofluoropropionic acid, and 8-azaadenosine anti-diabetic compounds were found in fresh juice and fermented juice. Administration of fresh juice and fermented juice for 1 month helped in the reduction of blood plasma glucose level from 112.6 to 94.73 mg/dL before food and 142.43 to 133.20 mg/dL after food as compared to prescribed medicine. The sensory attributes of fermented juice were well appreciated for taste, after taste, and flavor. Further research is necessary to improve the quality and stability of metabolites during storage.