الفهرس 
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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.