Quality and functionality of Chinese steamed bread and dough added with selected non-starch polysaccharides

Abstract

This study was devised to obtain a better insight into the effect of selected non-starch polysaccharides (NSP), namely carboxymethylcellulose (CMC), locust bean gum (LBG) and psyllium husk powder (PSY) on wheat dough rheological behaviour and quality attributes of Chinese steamed bread (CSB). NSP was added at levels of 0.2 % and 0.8 % w/w (wheat flour basis). Mixing properties and extensional properties of the dough produced were assessed by farinograph and extensograph, respectively. Spread ratio, specific volume and firmness of CSB were determined as a function of storage time. Addition of 0.2 % w/w NSP was found to decrease water absorption and strengthen the dough, and also to increase dough development time and dough stability. A reverse trend was observed at 0.8 % level. Among all the samples studied, addition of PSY at 0.2 % was found to confer an appropriate level of dough strength and extensibility that caused desirable spread ratio as well as specific volume in CSB. The results also revealed that NSP at high addition level helps to soften CSB and prevent staling from occurring, and hence warrant a longer shelf-life.