Xylooligosaccharides: Production and Use as Functional Foods
The functional foods and food-derived nutraceuticals support quality of health and wellbeing by reducing the risk of many chronic diseases such as cardiovascular disease, diabetes, cancer and osteoporosis. Most bioactive compounds in functional foods are aromatics and aliphatics that are directly involved in the cellular process, whereas a group of oligosaccharides is not involved in cellular processes directly, but influences the cellular process through modulation of gut microbiota. These are prebiotic oligosaccharides recognized as functional foods that have attracted attention in recent years. Xylooligosaccharides (XOS) have attracted increasing interest and are recognized as the emerging prebiotics. XOS are produced from low-cost lignocellulosic substrates by chemical or enzymatic hydrolysis. Enzymatic methods using free and immobilized xylanase have shown production of high pure XOS. XOS substituted with phenolic groups also exhibit antioxidant activity. In-vitro evaluation of XOS in a simulated human intestinal microbial ecosystem showed greater prebiotic influence of XOS than conventional prebiotic FOS. XOS also exhibit immunomodulation, anticancer, antimicrobial and psychobiotic activities through the modulation of gut microbiota. XOS showed bioactivity when tested in vivo in fish, poultry and humans. A few studies have shown metabolite cross-feeding between the XOS-utilizing probiotics and non-probiotic butyrate synthesizing colon bacteria. XOS are promising prebiotics due to their multiple health benefits.