الفهرس 
Review of LiteratureOnly 14 pages are availabe for public view
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Abstract
Wild strains considered the renewable source of promising cultures in technological field as they lead to development in fermentation industry in particularly fermented milk products. The current generation of functional foods is centered on gastrointestinal interaction, particularly those containing health-enhancing microorganisms; namely probiotics or substances stimulating beneficial microorganisms; namely prebiotics or combination to both; namely synbiotics.
Probiotic bacteria, according to their definition, must be prepared in a viable form. They should be stable during preparation and storage. The viability and actual level of probiotic bacteria in the intestinal tract must be investigated because the effect of a probiotic depends on its viable count in the gastrointestinal tract. Therefore, their resistance to gastric acid, bile salts, and digestive enzymes is important. In order to exert health benefits, probiotic bacteria are expected to be at the level of 107 CFU of live microorganisms per milliliter of product at the time of consumption. Selection criteria for probiotic microorganism can summarized as follows; acid and bile stability, adhesion to mucosal surfaces, safe for food and clinical use, clinically validated and documented health effects and good technological properties.
Dairy foods containing probiotics are a major and growing segment of the world’s market for functional foods capable of producing health benefits. Fermented milks can be considered true synbiotics since they provide both live beneficial bacteria (probiotics) and products of fermentation such as exopolysaccharides which may affect the intestinal microflora in positive way (prebiotic). Yoghurt is the most popular fermented dairy product in Egypt and worldwide. Many health benefits have been attributed to yoghurt such as improved lactose intolerance, protection against gastrointestinal infection, effective treatment for specific types of diarrhea and cholesterol reduction. Prebiotics are non digestible food ingredients that beneficially affect the host by selectively stimulating the growth and or the activity of a limited number of bacteria in the colon. Synbiotics are mixture of probiotics and prebiotics together. Talbina is a gentle soup made from barley bran flour, milk like. Because of its whiteness and gentility, the name ”Talbina” is derived from Laban (milk in Arabic). It has a considerable therapeutic value and has been prescribed as a cure for many diseases in Sunnah.
The objective of the present study was the isolation, identification and of new LAB strains from different dairy sources; Laban Rayeb, Zabady and human breast milk and selecting probiotic strains, to investigate their efficacy and health promoting in vivo represented in; their influences on physiological status in treated animals and assuring safety considerations of potential probiotic strains through blood chemical analysis and histological examination.
For guaranteeing strains’ maintenance of viability and acceptable organolyptic characteristics during cold storage, selected isolated probiotic strains were used as starter or adjunct cultures in three types of functional fermented dairy products, in order to validate convenient probiotics for human consumption as starter cultures in fermented dairy industries.
The above aim was achieved by:
1. Isolation of LAB from human breast milk , Laban Rayeb and Zabady which considered two of the most famous Egyptian traditional fermented milks.
2. Phenotypic and technological identification followed by genetic identification using 16s rRNA approach.
3. Studying physiological and technological characteristics of these strains.
4. In vitro tests assessment represented in acid and bile salts tolerance for selecting probiotic strains.
5. In vivo tests assessment by feeding animal models (rats) on fermented milks prepared using selected strains determining; their influences through GIT on health promoting represented in their influences on physiological status in treated animals and assuring safety considerations of potential probiotic strains using chemical and histological examination.
6. Evaluation of the convenience of recommending these newly selected LAB probiotics for human consumption as starter cultures in fermented dairy industries.
7. Monitoring the viability as well as chemical and organolyptic aspects of these strains in new products during cold storage.