Mixolab, retrogradation and digestibility behavior of chapatti made from hulless barley flours

Barley flours can be utilized for preparation of chapatti after blending with 7% vital wheat gluten. Mixolab analysis revealed a significant role of non-starchy polysaccharides in increasing dough consistency after mixing (C1) and heating (C3). A significant negative correlation (R = −0.63) of mixolab retrogradation (%) was observed with soluble arabinoxylan contents of flours indicating their positive effects on chapatti quality. Soluble arabinoxylans also exerted beneficial effects by promoting lower rate of shrinkage (R = −0.69) and bake loss (R = −0.77) in chapatti, however β-glucans and insoluble arabinoxylans increased the chapatti shrinkage (p ≤ 0.05). Fresh barley chapatti displayed lower soluble starch contents (1.8-2.6%) as compared to wheat chapatti, which may indicate an inhibitory effect of barley β-glucans on starch swelling, leading to lower retrogradation (R = −0.62). Reduced rapidly digestible starch contents were observed for barley chapatti. Presence of higher levels of total β-glucans in barley flours also promoted the formation of slowly digestible starches in retrograded chapatti (R = 0.61). Upon storage of chapatti for 48 h, both soluble amylose and soluble amylopectin content decreased and starch crystallinity increased. These factors were significantly affected by the presence of β-glucans and arabinoxylans.