Dietary fibre, protein profile and technological characteristics of durum spaghetti enriched with refined / whole grain hull-less barley flour

Abstract

Durum wheat semolina (DWS) was substituted with refined or whole grain hull-less barley flour (RHBF or WHBF, respectively) for producing nutritionally enriched spaghetti. The substitution levels were between 10 and 50%, and spaghetti made of DWS was used as control. Then, ash and protein contents, dietary fibre changes, protein profile and technological characteristics were assessed. Total dietary fibre contents of DWS, RHBF and WHBF were 6.3, 7.6 and 20.8%, respectively. β-glucan contents of RHBF and WHBF were 2.40% and 5.0%, respectively. Ash, protein, total-, soluble- and insoluble dietary fibres and β-glucan contents of uncooked spaghetti products increased according to the control after hull-less barley flour (HBF) substitutions. Resistant starch (RS3) contents of the control and HBF substituted spaghetti products considerably increased after cooking, the increment was more noticeable in RHBF substituted ones. Brightness (L) and yellowness (b) values decreased and redness (a) values increased while increasing of WHBF substitution. The total extractable proteins of uncooked spaghetti products were investigated on sodium dodecyl sulphate polyacrylamide gel electrophoresis in order to monitor the changes on polymeric protein distributions in HBF substituted spaghetti products. The HBF substitutions could be an effective way to increase the dietary fibre intake, especially β-glucan and resistant starch.