a1 Leatherhead Food Research Association, Randalls Rd, Leatherhead, Surrey, KT22 7RY, UK
Many LDCs currently on the market are not digested in the upper gastrointestinal tract and become fermented in the large intestine. They possess physiological benefits similar to those of dietary fibre. For some of these materials the fermentation process is highly specialised and leads to the selective stimulation and growth of beneficial gut bacteria, e.g. bifidobacteria. These materials are described as prebiotics, which are defined as nutrients fermented in the large bowel that favour the growth of desirable large bowel microflora. This activity has been demonstrated for inulin and oligofructose. Two other carbohydrates with low digestibility that offer desirable physiological properties are resistant starch (RS) and polydextrose (PD). These ‘functional’ benefits have led to considerable interest from the food industry leading to the use of these ingredients in the development of new ‘healthy’ products. This paper describes the use of these materials in the development of ‘healthy’ products, some of their functional properties, and the benefits they confer on different food systems.