No abstract

No abstract

No abstract

No abstract

Results obtained showed that all strains were able to reduce cholesterol and had βgalactosidase activity especially yeast strains and the viable form (free and microencapsulated) of all microbial stains had higher cholesterol reducing ability and βgalactosidase activity than nonviable form. However the nonviable form of all tested microorganisms had the highest antioxidant power compared with the others. The yeast strains had higher antioxidant activity than bacterial strains in the different forms. All strains in different forms exhibited antitumor activity by using potato disc assay. Antibacterial activity was observed in lactobacilli and Bifidobacterium strains against spoilage and pathogenic bacteria.

No abstract

examined for their growth activity in skim milk containing (7% w/v) six different natural sweeteners (sucrose, glucose, fructose, honey, cane molasses and dibis). The growth activity were monitored by determining the pH and OD at 0, 4, 8, 24 h interval L. bulgaricus displayed the highest growth activity throughout the incubation period followed by S. thermophilus. While L. reuteri and L. johnsonii showed the slowest growth activity in skim milk with the natural sweeteners. Regarding the effect of the different sweeteners, dibis and molasse improved the growth and acid production of L. bulgaricus. While glucose affected the acid production of S. thermophilus and the pH values were the least (4.25) after 24 h of incubation, however no significant differences in the OD value were observed. The different types of sweeteners were not stimulatory or inhibitory to L. reuteri or L. johnsonii. There was a decline in the viable counts of all of the examined microorganisms with different rates during the refrigerated storage. However their populations were still above 5 log cycles especially when dibis was used. Stirred yoghurt was manufactured from sweetened buffaloes' milk, L. reuteri or L. johnsonii were used as adjunct, the stirred yoghurt was analyzed physiochemically and evaluated organoleptically. Yoghurt manufactured by L. johnsonii gained the highest score especially with dibis, molasse or honey.

Aflatoxin adsorption property of lactic acid bacteria could be used as a detoxification method which is most appropriate for food and dairy products. Seven strains of lactic acid bacteria (Lactobacillus casei, Lactobacillus gasseri, Lactobacillus reuteri, Lactobacillus bulgaricus, Lactobacillus acidophilus, Streptococcus thermophilus, Bifidobacterium bifidium) plus two mixed commercial cultures FD-DVS YCX11 50U (Lactobacillus bulgaricus+ Streptococcus thermophilus) and FD-DVS ABT2 50U (Lactobacillus acidophilus+ Streptococcus thermophilus +Bifidobacterium bifidum) were tested for their AFB1 and AFM1 adsorption rate, Factors affecting such adsorption were studied. The bioavailability of the adsorbed toxin was determined by feeding rats with L. casei-AFB1, L. casei-AFM1 complexes, and both toxins and rats liver tissues were examined. Adsorption reaction was carried out in 1 ml of phosphate buffer saline containing 1µg of the toxin and about 1.7x10 11 CFU of bacteria at 37° C for 2 hrs and pH of 7.3. out of the tested strains,L. casei showed the highest toxin removal rate of 34.1% and 27.7% for AFB1 and AFM1, respectively. These rates were increased by reducing the toxin into 0.5µg /ml, lowering the reaction pH into acidic pH and using acid or heat killed cells. Moreover, the rate was increased by adapting L. casei to toxin adsorption by repeated exposure to toxin, the rate increased from 34.1% to 50% of AFB1. Toxin concentration higher than 0.5µg / ml reduced the adsorption and caused changes in cell morphology. Aflatoxin bound by bacteria showed no toxicity effect on rats. Liver tissues of rats fed on the toxin complex were normal structure as compared to tissues of rats fed on free toxins which showed macroviscular fatty change, hydropic degeneration and congested hepatic sinusoids. the toxin complex was not absorbed since it did not adhere to intestinal wall. Yoghurt and sweet cultured milk were processed from AFM1 contaminated milk using L. casei culture.