Recent Developments in Functional Dairy Products and their Health Benefits

摘要

Fermented foods are of great importance since they provide and preserve various desirable quantities of nutritious foods in a wide variety of flavor, aroma, texture and palatability that enrich the human diet. The manufacture of cultured dairy products represents the second most important fermentation industry next to the alcoholic beverages (Adwan, 2003). Probiotic drinking yoghurt was the fastest growing dairy product sector between 1998 to 2003, followed by soymilk, flavored milk drinks with juiceand fermented dairy drinks. The increasing demand for dairy products with functional properties is a key factor for sales growth in developed markets. This led to the promotion of value added products such as probiotic and other functional yoghurts, reduced fat and enriched milk products and fermented dairy drinks and organic cheese in the market. Lactic acid bacteria play an important role in the manufacture of functional foods (Fitgerald et al, 1998, Hillam, 1998). Hence probiotic (live microbial feed such as lactobacilli and bifidobacteria that are added to food and that possess health promoting properties) and prebiotics i.e. non digestible food ingredients that stimulate the bifidobacteria present in the colon may be considered as driving forcesof the functional foods market (Ziemer and Gibson, 1998, Lilly and Stillwell, 1965). In common fermented products such as yoghurt, lactic acid is produced by the starter culture bacteria to prevent the growth of undesirable microorganisms. Food fermentation has a great economic value and it has been established that these products contribute in improving human health. Lactobacilli for instance Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus gasseri, Lactobacillus paracasei, Lactobacillus ruteri and Lactobacillus rhamnosus and bifidobacteria for instance Bifidobacterium bifidum, Bifidobacterium adolescentis, Bifidobacterium breve, Bifidobacterium infantis and Bifidobacterium longum contribute a significant proportion of probiotic lactic acid bacterium cultures used in developed countries.Lactic acid bacterial strain exhibits unique properties viz. growth rate, metabolic rate, proteolytic activity and flavor and aroma production.