Potent α-amylase inhibitory activity of sprouted quinoa-based yoghurt beverages fermented with selected anti-diabetic strains of lactic acid bacteria

The in vitro inhibitory effect of sprouted quinoa yoghurt beverages (QYB) fermented with anti-diabetic lactic acid bacteria on α-amylase was investigated. In vitro studies using porcine pancreatic α-amylase showed that quinoa yoghurt beverages fermented with Lactobacillus casei Zhang and Lactobacillus casei SY13 dose-dependently inhibited the activities of α-amylase. The saponin content, reducing and total sugars were also quantified to determine their potency as anti-hyperglycemic agents against type 2 diabetes mellitus. The saponin contents of the yoghurt beverages were relatively low at a range of 0.19–0.41%, and significantly reduced as germination time increased. Germination significantly decreased the reducing sugars in all samples. A total of 4 sugars were identified using HPLC. Quinoa yoghurt beverages can be targeted as a potential dual-inhibitory strategy to attenuate type 2 diabetes mellitus by their ability to inhibit α-amylase activity as well as reduce or prevent hyperglycemic conditions associated with elevated levels of sugar glucose in the blood.