Aqueous extracts and suspensions of restructured pork formulated with Undaria pinnatifida, Himanthalia elongata and Porphyra umbilicalis distinctly affect the in vitro α-glucosidase activity and glucose diffusion

Seaweed antidiabetic properties have been linked to changes in carbohydrate digestion and absorption. The effect of aqueous extracts and suspensions of restructured pork (RP) with 5 g/100 g of Porphyra umbilicalis (Nori), Undaria pinnatifida (Wakame) or Himanthalia elongata (Sea spaghetti) on α-glucosidase activity and glucose diffusion were in vitro tested. α-Glucosidase inhibition type was also assayed. Sea spaghetti-RP suspensions displayed, through a competitive mechanism, the highest α-glucosidase inhibitory effects (19.8% vs. control-RP at 45 min). Control-RP extracts vs. blank increased (15.4%) glucose diffusion while Nori-RP followed by Wakame-RP extracts significantly inhibited glucose diffusion (26.7% and 20%, respectively) and decreased AUC (18-20%) respect to control-RP counterpart. Stepwise analyses showed that maltose and polyphenols in the α-glucosidase inhibition- and Na in glucose diffusion-test, were significantly involved. In conclusion, Sea spaghetti-RP should be selected as α-glucosidase inhibitor while Nori-RP and Wakame-RP should be used as glucose diffusion reducers. As both hypoglycaemic effects were non-concatenated, generalizations about seaweed-RP should be avoided.