Effect of two barley β-glucan concentrates on in vitro glycaemic impact and cooking quality of spaghetti

Abstract

The in vitro glycaemic impact and cooking quality of functional spaghetti made with semolina plus the addition of one of either two types β-glucan barley concentrates, Glucagel ® (GG) and Barley Balance™ (BB) was investigated. For each β-glucan type, five spaghetti samples containing different percentages of β-glucan (2, 4, 6, 8 and 10 g/100 g) were developed and compared to a control (0 g/100 g of β-glucan). The glycaemic potency of the samples was measured in vitro as the release of glucose during pancreatic digestion. Further tests were carried out on the spaghetti samples to determine optimal cooking time (OCT), cooking losses (CL), dry matter, swelling index, colour, hardness and adhesiveness. Barley Balance, but not GG, significantly reduced the susceptibility of spaghetti to pancreatic digestion in vitro compared to the control at all concentrations. Results indicated moreover that the spaghetti added with GG and BB (all the treatments) did not have different colour and hardness properties compared to spaghetti without β-glucan. Except for the spaghetti with 2 g/100 g BB, all the other treatments demonstrated significantly higher CL and adhesiveness values compared to the control. Cooking losses (CL) and adhesiveness are important parameters and they were significantly different for samples with added barley β-glucan concentrates. BB appears to be a better treatment for reducing the glycaemic potency of spaghetti and justifies further in vivo study.