The beneficial influences of xylo-oligosaccharides (XOS) obtained from alkali-pretreated corncob and fructo-oligosaccharides (FOS) obtained from cane sugar were evaluated in experimental diabetes. These oligosaccharides were supplemented at 10 % (w/w) in the basal diet of streptozotocin-induced diabetic Wistar rats, while the control rats were fed with a basal diet for a period of 6 weeks. Both the oligosaccharides exerted favourable influences in diabetic rats by significantly improving body weight and reducing hyperglycaemia and cholesterol. The characteristic diabetic complications such as severe glucosuria, proteinuria and advanced glycation end products in renal tissue, diabetic nephropathy, and blood creatinine and urea concentrations were notably reduced. Besides, these oligosaccharide supplementations significantly increased the activity of antioxidant enzymes -catalase and glutathione reductase -in the blood of diabetic rats. Supplementation of XOS and FOS resulted in a significant increase in the bifidobacteria and lactobacilli population in the caecum. The present study indicates that XOS and FOS have an ameliorating influence on metabolic abnormalities associated with diabetes, besides conferring an optimal milieu of lactobacilli and bifidobacteria, thus suggesting their potential health benefit in diabetics.Xylo-oligosaccharides: Fructo-oligosaccharides: Diabetes mellitus: Metabolic abnormalities: Nephropathy

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Permeabilized probiotic Lactobacillus plantarum was used as a source of β-galactosidase for the synthesis of galactooligosaccharides (GOS) from lactose. β-galactosidase activity was highest when galactose (1,724 Miller Units) was used as a carbon source compared to lactose, sucrose or glucose at 37 °C, 18 h. Permeabilized cells had the highest transgalactosylation activity resulting in 34 % (w/w) GOS synthesis from 40 % (w/v) lactose at 50 °C over 12 h. HPLC revealed that the GOS were composed of 13 % disaccharides (non-lactose), 17 % trisaccharides and 4 % tetrasaccharides that were further confirmed by ESI–MS.

Key nutritional factors were optimized for the maximum production of transgalactosylating β-galactosidase from Lactobacillus plantarum MCC2156. Galactose, yeast extract, sodium acetate and manganese sulphate were the most important nutrients affecting β-galactosidase production. Maximum β-galactosidase production (3015 miller units) was obtained by culturing L. plantarum in the optimized fermentation medium containing (w/v) galactose (4 %), yeast extract (2 %), sodium acetate (3 %) and manganese sulphate (0.075 %) with an optimum medium pH of 7.0, after 14 h of incubation at 35°C. Further, permeabilization of L. plantarum cells using various chemical/ solvents for maximum β-galactosidase activity was performed for use as whole cell biocatalyst. Mixture of ethanol: n-butanol was found to effectively permeabilize the cells with maximum β-galactosidase activity under the following optimum conditions; 1: 1 mixture of ethanol (10 %, v/v): n-butanol (30 %, v/v) with a contact time of 10 min at 28±2°C.

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 b-d-xylopyranosyl-(1,4)-d-xylanopyranose (xylobiose) using 13 C 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.