Phenolic bioactive-linked antioxidant, and anti-hyperglycemic functionalities of blackberry (Rubus sp.) from two different maturation stages

Blackberries (Rubus sp.) are rich sources of dietary antioxidants such as phenolic bioactives with diverse human health protective functionalities. Previous in vitro and in vivo model-based studies found high phenolic bioactive-linked antioxidant and anti-hyperglycemic properties in blackberries indicating relevance as anti-dote against diet-linked non-communicable chronic diseases (NCDs) such as early stages of type 2 diabetes (T2D). However, phenolic bioactives and associated antioxidant and anti-hyperglycemic properties of blackberry vary widely due to differences in fruit ripeness/maturation stages. Such variations in phenolic bioactives and associated health benefits from different maturation stages can lead to inconsistent nutritional qualities affecting targeted value addition and subsequent end-use. Therefore, the aim of this study was to investigate phenolic bioactive-linked antioxidant and T2D relevant anti-hyperglycemic properties of blackberry fruits from two different maturation stages (not fully ripe and fully ripe) using rapid in vitro assay models. Overall, glossy reddish-purple blackberry, which was not fully ripe, had significantly lower total soluble phenolic content and associated ABTS and DPPH assay-based antioxidant activity when compared to fully ripe glossy black blackberry. Similarly, high T2D relevant α-amylase and α-glucosidase enzyme inhibitory activities were also observed in fully ripe blackberry fruits. The results of this study therefore suggested that ripeness/maturation of blackberry fruits have a significant impact on phenolic-linked antioxidant and anti-hyperglycemic properties and fully ripe blackberries are ideal targets for advancing dietary support strategies against early stages of T2D and associated health risks.