Recent Advance in Extraction of Prebiotics from Plants: A Review

Abstract

Prebiotics are termed as substrates that can confer health benefits with selective utilisation by host microbiota. They are oligosaccharides that can withstand gastric and enzymatic digestions in the small intestine. Prebiotics can be selectively fermented by probiotics in the large intestine to produce short-chain fatty acids, vitamins, and other compounds. These compounds can enhance the host immunity against diseases, normalise bowel movements, improve mineral absorption, and lower blood cholesterol level. Inulin, fructooligosaccharides (FOS), galactooligosaccharides (GOS), lactulose, and xylooligosaccharides (XOS) are some examples of prebiotics. Prebiotics may be incorporated as nutritional ingredients into various functional foods or presented as nutraceuticals in the form of tablets or capsules, sometimes with probiotic cultures, for the benefit of consumer’s health. Most naturally occurring prebiotics can be found in some fruit and vegetables such as beans, cereals, asparagus, onion, raw garlic, tomatoes, and legumes which can be extracted through several techniques. This review paper provides the theoretical background on traditional extraction techniques such as chemical extraction, enzymatic hydrolysis, autohydrolysis and several novel extraction techniques including microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE). The operating conditions, advantages and disadvantages are also discussed.Keywords: Prebiotics, traditional extraction, novel extraction, lignocellulosic and plant materials