Phenolic profile and carbohydrate digestibility of durum spaghetti enriched with buckwheat flour and bran

The potential of common buckwheat flour (Supreme) and bran (Farinetta) in improving upon the phenolic and antioxidant properties of durum spaghetti was investigated. The cooking quality and carbohydrate digestibility of products were also studied. Significantly large increments of between 114 and 522% for total phenolic content (TPC), 50 and 242% for total flavonoids content (TFC), and over 359% for 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity were recorded for uncooked experimental spaghetti samples over the control. Farinetta contributed more phenolic and antioxidant compounds than Supreme flour. Processing and cooking resulted in decreases in phenolic content and antioxidant activity. Cooking losses of up to 8.8% were recorded for the experimental samples and were higher in Farinetta-substituted products. These were generally higher than that of the control (6.3%). The introduction of buckwheat increased carbohydrate digestibility of products, but at the same time, resulted in an overall lower amount of reducing sugars after 120 min of in vitro hydrolysis. Results show that the phenolic and antioxidant properties of durum spaghetti fortified with buckwheat milling fractions can compare favourably with those of 100% whole buckwheat soba pasta, and at the same time, maintain a higher cooking quality due to the presence of semolina.