Interaction with Semolina Proteins Allows Retention of Bioactives in Pasta From Purple Wheat

Abstract: Postprandial hyperglycemia, is the earliest metabolic abnormality occur in type-2 Diabetes Mellitus. The major source of glucose in the body comes from the hydrolysis of dietary carbohydrates, like starch by the action of pancreatic ɑ-amylase and intestinal ɑ -glucosidase enzymes which hydrolyze the glycosidic bonds in starch components from the diet. Therefore, the inhibition of these enzymes can be an important concept for management of type 2 diabetes (Rios, Francini et al. 2015) Grains and cereals containing high amounts of dietary fibers are generally recommended for diabetic patients to control their blood glucose level. Recently food-based active ingredients, such as polyphenols, have shown the ability to modulate blood glucose level (Thondre 2013). Colored cereal grains contain higher amount of phenolics and flavonoids, including anthocyanins than common grains (Liu, Qiu et al. 2010). Total polyphenols and anthocyanins in different cereal grains showed positive correlation with ɑ -glucosidase inhibition activities (Yao, Sang et al. 2010). Previous studies indicate that anthocyanins such as cyanidin-3-rutinoside exhibits an inhibitory effect on ɑ-glucosidase in a non-competitive manner, although other anthocyanins may inhibit the ɑ-amylase and ɑ -glucosidase enzymes activity in different ways (Akkarachiyasit, Charoenlertkul et al. 2010). The structure of different anthocyanins that affect the inhibitory activity against these enzymes has been recently studied (Xiao, Ni et al. 2013). Anthocyanins also significantly protect beta-cells against glucose-induced oxidative stress (Yan, Zheng et al. 2017). In this study we aimed at characterizing the anthocyanin profile in different varieties of pigmented corn and wheat and in some of their milling fraction. In the second phase of study four different types of purple pasta was prepared incorporating debranned fractions, wholegrain flour of purple wheat and semolina flour. Acid/ethanol extracts were used to assess total anthocyanins, overall antioxidant activity, the overall polyphenol profile, and for evaluating the inhibition of pancreatic ɑ-amylase and of intestinal ɑ-glucosidase both in corn/wheat flours, and in the extracts from produced pasta (before and after cooking procedure).