Effect of inulin polymerization degree on sourdough fermented acorn-rice based gluten-free bread: a technological and nutritional perspective

Bread is one of the most important components of the diet all over the world. Failure to obtain the unique properties of gluten protein has made it difficult to obtain the desired properties of gluten-free bakery products. Inulin is one of the soluble nutritional fibers widely used in the food industry.

Textural, physicochemical, sensory and shelf life characteristics of inulin in gluten-free bread samples based on rice-acorn flour (70:30) enriched with 10% w/w-1 prebiotic inulin with different degrees of polymerization (less than 10, more from 23 and 60-2) and the conditions of mixed fermentation based on sourdough [MF-SD] were investigated.

Results indicated that MF-SD and using long-chain inulin was able to form a structure able to hold the gases produced during the fermentation and expanded through cooking process and improve the textural characteristics, which seems to be due to its potential ability to form a gel. Additionally, highest inulin stability is also observed at this sample. So that the optimized technological characteristics and lowest inulin loss ration (31% w/w-1) is found at gluten-free bread samples containing 30% w/w-1 of acorn flour and long-chain inulin fermented by MF-SD (A30R70SL).

The use of long-chain inulin is recommended to achieve desirable technological characteristics and high nutritional value in the formulation of gluten-free bread.