Phenolic bioactive-linked antioxidant and anti-hyperglycemic functionalities of blackberry cultivars grown under organic and conventional production practices

Blackberries are a rich source of dietary bioactive phenolics with potential human metabolism modulating functionalities. Therefore, blackberries can be targeted in dietary intervention strategies to potentially counter diet and chronic oxidative stress-linked non-communicable chronic diseases such as early stages of type 2 diabetes (T2D). The aim of this study was to screen and compare food grade relevant cold water extracts of blackberry cultivars 'Prime-Ark 45' and 'Prime-Ark Freedom' grown over one year under six different production practices, four organic practices (mulch-based weed management + organic fertilizers) and two conventional practices (herbicide + chemical fertilizers). Total soluble phenolic content, phenolic acid profiles, antioxidant activity, alpha-amylase, and alpha-glucosidase enzyme inhibitory activities of blackberry extracts were determined using in vitro assay models. Overall, high soluble phenolic content, high antioxidant activity and high alpha-amylase and alpha-glucosidase enzyme inhibitory activities were observed in both blackberry cultivars. However, blackberry grown under organic weed management and with organic fertilization had higher phenolic-linked antioxidant and anti-hyperglycemic properties. 'Prime-Ark 45' grown under black fabric and black plastic mulch with feather meal had greater phenolic-linked antioxidant and anti-hyperglycemic properties. Results suggest that these organic production strategies, especially with 'Prime-Ark 45' should be advanced in the Northern Plains to potentially improve phenolic content and associated T2D-linked health benefits in blackberry.