Summary Phenolic compounds have been shown to deliver numerous health benefits. Research has also shown that starch and phenolic compounds interact. This study aimed to investigate the effects of blackcurrant and strawberry powder on the physicochemical and in vitro predicted glycaemic response of sweet potato and potato starches. Sweet potato, or potato, starches were mixed with 0%, 5%, 10% and 15% (w/w) of blackcurrant, or strawberry, powder, to form blackcurrant and strawberry‐enriched starch pastes. The results showed that enrichment with 5%, 10% and 15% blackcurrant or strawberry powder for sweet potato and potato starch significantly altered the pasting viscosity and colour profiles (P < 0.05), increased the phenolic content and antioxidant activities of starch pastes (P < 0.05). Blackcurrant or strawberry powders mixed with sweet potato or potato starches reduced amount of reducing sugar released during in vitro digestion. Addition of 15% blackcurrant powder for the starch exerted stronger in vitro antioxidant and hypoglycaemic properties than that of 15% strawberry powder. Collectively, these findings suggested that addition of blackcurrant or strawberry powder into sweet potato and potato starches manipulated the hypoglycaemic property of pastes.

Summary Incorporation of bioactive‐containing fruits and/or vegetables into the carbohydrate‐rich food matrix are effective strategies to develop food products with functional health benefits. In this study, blackcurrant powder was added into pea starch and mung bean starch to form pastes to investigate the effects of blackcurrant powder on physicochemical and nutritional properties of the starch pastes. The predictive in vitro glycaemic response of the pastes was highlighted by in vitro glycaemic glucose equivalent assay and alpha‐amylase inhibitory activity assay. Both assays showed that blackcurrant powder attenuated (P < 0.05) reducing sugar released, through the inhibition of α‐amylase. The colour profiles and textural properties of the pastes were modified by the additions of blackcurrant berry powder at different levels. Nutritional characteristics of the pastes, including total phenolic content and antioxidant activity, were significantly changed (P < 0.05) with the addition of blackcurrant powder.

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