Short chain xylooligosaccharides: a potential prebiotic used to improve batter fermentation and its effect on the quality attributes of idli,a cereal–legume‐based Indian traditional food

Xylooligosaccharides (XOS), a potential prebiotic exhibits important technological characteristics and interesting nutritional properties. The major fraction in XOS produced enzymatically from corncob was characterised as β‐d ‐xylopyranosyl‐(1,4)‐d ‐xylanopyranose (xylobiose) using ¹³C and 2D‐HSQC NMR. The use of this XOS as a prebiotic in idli, a cereal/legume‐based fermented cake, and its effect on texture, fermentation and sensory characteristics was investigated. Idli batter was fermented with different concentrations of XOS (0, 0.2, 0.4 and 0.6% w/v) for 4–18 h conventionally. The addition of XOS markedly increased lactic acid bacteria number (9.88 ± 0.08 log cfu g^?1) which resulted in rapid reduction in pH (4.61 ± 0.03) and specific gravity after 6 h of fermentation when compared to conventional batter fermentation for 18 h without XOS (9.46 ± 0.06 log cfu g^?1). Instrumental (colour and texture) and sensory evaluation indicated that the optimum conditions were 0.4% XOS and 6 h fermentation. Idlis with XOS had higher moisture content and a softer texture. Addition of XOS benefits both fermentation and idli quality.