Optimization of yeast β-glucan and additional water levels, and chilled storage time on characteristics of chilled bread using response surface methodology

This research aimed to investigate the optimum levels of yeast β-glucan and additional water, and chilled storage time for producing chilled bread using response surface methodology. Yeast β-glucan, a natural hydrocolloid extracted from yeast cell wall, possesses not only functional properties but also human health benefits to be used in food products. A Box–Behnken design with three independent variables (yeast β-glucan, additional water, and chilled storage time) and three levels was used to develop models for the different characteristic responses. Superimposition of contour plots of the significant responses (spread ratio, crumb color L* and b* values, crumb hardness and cohesiveness, and moisture content) was performed to obtain the optimum chilled bread formula. Using the qualities of one-day-on-shelf commercial bread as a reference, the optimum chilled bread contained 0.28% yeast β-glucan and 11.69% additional water (wheat flour basis) with 4 days chilled storage. The optimum chilled bread had superior qualities to the basic formula bread at 4 days of chilled storage. The bread staling during chilling can be retarded by incorporating yeast β-glucan and additional water in the bread formula.