A prebiotic is a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the large intestine, and thus improves host health (Gibson and Roberfroid, 1995). Prebiotics must be resistant to enzymatic digestion and absorption in the gastrointestinal tract and must be fermented by intestinal bacteria (Roberfroid, 2007).
Prebiotics such as fructooligosaccharide galactooligosaccharide xylooligosaccharide, beta-glucans and inulin are a non-digestible food ingredients that induce growth or activity of probiotic bacteria (Birkett and Francis 2010; Nauta e t al., 2010 and Paineau et al., 2010). Among prebiotics Gum Arabic (GA) is one of the prebiotics when mixed with probiotic synbiotic product to enhance the growth and survival of probiotic bacteria in fermented dairy products (Desai et al.
, 2004).2.2.
Sources of Prebiotics Prebiotics are mainly derived from fiber, like inulin. Often, yogurt marketed as probiotic yogurt will contain inulin (prebiotic) and live active cultures (probiotic). Other good sources of prebiotics include acacia gum, dandelion greens, garlic, asparagus, beans, oats, and chicory root ( Gibson & Roberfroid,1995). Traditional dietary sources of prebiotics include soybeans, inulin sources (such as Jerusalem artichoke, Jicama, and chicory root), raw oats, unrefined wheat, unrefined barley, and yacon. Some of the oligosaccharides that naturally occur in breast milk are supposed to play an important role in the development of a healthy immune system in infants (( Gibson & Roberfroid,1995). 2.3.
Dietary fibersDietary fibers are part of the plant cell which cannot be digested by the human enzymes. Two various groups of dietary fibers are recognized: soluble and non-soluble dietary fiber. They are notable by their solubility in water and show different physiological effects. The benefit of dietary fiber for a healthy diet is widely known. Different diseases, such as constipation, coronal heart diseases and cancer just to name a few, have been correlated to an unhealthy diet, low in dietary fiber (ditary references.
2005).2.4. Gum Arabic A gums, is any water-soluble polysaccharide that is extracted from marine and land plants, or from microorganisms that possess the ability to contribute viscosity or gelling ability to their dispersions (Abu Baker et al.
,2007). The most fundamental property of a gum is its water solubility and high viscosity in aqueous dispersions. For this reason, resins, latexes and other hydrophobic gums are not regarded as true gums. Among the advantages of natural gums over their synthetic counterparts are their bio compatibility, low cost, low toxicity and relative widespread availability (Abu Baker et al., 2007).Gum Arabic is obtained from a tree of genus; Acacia, subfamily; Mimosodieae, family; Leguminosae (Smolinske, 1992). It is known as gum acacia, a natural gum taken from two species of the acacia tree; Acacia senegal and Acacia seyal.
Gum Arabic is a pale to orange-brown solid which break along a glassy fracture. The best grades are whole, spheroidal-tear shaped, orange, brown, with a matt surface texture. It is a national and international exported commodity, (Unanaonwi, 2011). Gum export has been the mainstay of the Sudanese economy for over 400 years, (Lawal, 1998).
It was used at least 4000 years ago when it was shipped as an article of trade by Egyptian fleets.
