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Abstract Objectively, the aim of this study was to evaluate the drinking bioyoghurt fortification with some suitable herbs in relation to the antioxidant activity besides the chemical, physical, microbiological, sensory and biological attributes of the resultant products. Technically, Heat treatment yoghurt milk (3% fat) at 85°C for 5 min was fortified with boiled water extract (10% w/w) either of lemongrass (LG), green tea (GT), rosemary (RM) or ginger (GN) at the levels of nil (the control), 1 and 2 %. The fortification level was exceeded to 3 and 4% for LG or GT according to the panelist acceptance of the primary pilot plan questionnaire. All milks were thematically adjusted to 45°C , inoculated with 2% fresh probiotic starter culture (ABT-2) and then incubated at 42 oC. Incubation was terminated till pH 4.6. At this point, the drinking bioyoghurt was stored in a refrigerator (5±1 °C) for overnight. The yoghurt was stirred and filled into100 ml plastic cups. Three replicates were done for each treatment. The resultant drinking yoghurt were analyzed at 0, 3, 7, 14 and 21 days of cold storage intervals. The plain drinking bioyoghurt and those fortified with water herbal extract at the highest level of each were exposed for biological evaluations continued 28 days. The obtained results could be summarized as follow: 1. Compositionally, there were significant differences between all treatments in all of dry matter (DM), fat, total nitrogen, and ash contents. But both of DM and fat contents stilled surrounding on the Egyptian standards. 2. Physically, the dynamic viscosity and pH values were significantly varied between treatments. Moreover, opposite to the titratable acidity %, pH value decreased as the cold storage period (CSP) prolonged. 3. Antioxidant activity, all of radical scavenging activity %, total phenolic content and total flavonoids content heightened significantly as the level of the water herbal extract in the drinking bioyoghurt increased especially when RM or GN was used. There were gradual reduction in all parameters of antioxidant activity due to CSP progressing. 4. Microbiologically, all herbs possessed an inhibitory impact on the growth of probiotic bacterial strains added, namely, Lactobacillus acidophilus, Streptococcus thermophilus and Bifidobacterium sp. correlated proportionally with the herbal level. The herb RM exhibited the greatest harmful effect, followed by LG, on the growth of all strains. While GN caused the lowest harmful effect on all strains, those achieved their maximum count in all treatments at the end of the 14th day of CSP. Neither coliform nor yeasts and molds were detected in all treatments until the end of the experimental period. 5. Organoleptically, the appearance score of drinking bioyoghurt containing 1% herbal extract was as high as that of the plain one (the control) especially when GN was used followed by descending score correlated with the increase in the herbal level, which did not affect the consistency score regardless the kind of herb. The flavour scores of drinking bioyoghurt was as high as these of control until the herbal fortification level of 2% especially when GN or LG was used, while the flavours score of drinking bioyoghurt of 4% herbal extract came in the last order. The overall organoleptic scores of GN or LG drinking bioyoghurt came in the second order after the control followed by those of GT and RM, respectively, providing that the fortification level did not exceed 2%. 6. Biologically, the rats injected with1, 2-dimethylhydrazine showed a reduce feed consumption (FC), body weight gain (BWG) and feed conversion ratio (FCR) versus the un-injected rats. The presence of herbal portion regardless its kind in the drinking bioyoghurt resulted in increase of FC or BWG especially when GT or GN was used, respectively, and increase of FCR especially when LG was used. The blood serum analysis showed that, high density lipoprotein (HDL), urea and uric acid were high in the injected case versus the un-injected ones. While cholesterol (Ch) and triglycerides were lower in the former than the later. The herbs led to decrease in the Ch, HDL and urea level versus the plain drinking bioyoghurt. The level of Ch was the highest when RM was used, while the level of triglycerides was the highest when LG was used, HDL was the highest when GN was used, while both of urea and uric acid were highest when GT was used versus the other herbs. The creatinine level was not influenced either by the rat status (un- or injected) or the presence of herb, but its level was lowered by the feeding on LG drinking bioyoghurt. The colon and liver weights were increased due to rats injected with1, 2-dimethylhydrazine while the kidney weight was reduced, whilst the spleen weight was not changed. Moreover, the presence of herb caused an increase in the weights of all organs except of spleens, which their weights were decreased. GN drinking bioyoghurt caused the lowest weight for colon and liver, while GT drinking bioyoghurt caused the highest weight of kidney and spleen. 7. Histologically, the feeding on plain, LG, GN or RM drinking bioyoghurt led successfully to protect or resulted in a therapeutical benefits for the spleen of injected rats with1, 2-dimethylhydrazine. Moreover, the feeding on LG or GN drinking bioyoghurt possessed similar protection or therapeutical advantages for both of kidney and colon of the same inducted rats as indicated from the histopathological findings. Finally, the foregoing results led satisfactory to conclude that, drinking bioyoghurt could further carry more healthy benefits when it was fortified with herbal extract up to 2% especially either of ginger or lemongrass to achieve the multi healthy benefits as indicated from the biological investigations. |