Master Thesis      [Total: 35 ]


Zeinab hassan ahmed, 2019


In this study, ethanol (50 and 100%), methanol (70 and 100%), acetone (70 and 100%), chloroform 100% and water extract of grape seeds were evaluated for their antioxidant and antimicrobial activities. Extraction yield of grape seeds ranged from 6.0 to 14.50% depending on organic solvent type. Grape seed methanol 70% and ethanol 50% extract had significantly higher total phenolic (9.501 and 8.949 mg gallic acid/g), total flavonoids (6.707 and 6.398 mg quercetin /g) and antioxidant activity (702.37 and 636.50 µMolTrolox eq/gm), respectively than other grape seed extracts. While, grape seeds water extract showed the lowest total phenolic, flavonoids compounds and antioxidants activity. Twenty one phenolic and nine flavonoid compounds were identified by HPLC technique in each one of grape seed extracts


Noura El said, 2014


In this study the plant by-products and the waste of some food processing or farm land wastes are very rich in the natural antioxidants. There for the aim of this study was to investigate the utilization of these compounds in protection or prevention of some human diseases.
The present study was conducted to studying the effect of the polyphenols compounds extracted from dried (Artichoke leaf, Olives leaf and Red grape seeds) on some liver diseases. The main objective of this study is Comparison between the extraction solvents (water – ethanol) on the total content and the polyphenols fractions of (Artichoke leaf, Olives leaf and Red grape seeds) determine by HPLC. Effect of adding the polyphenols water extract of the above three materials on the cooking quality and sensory evaluation of the (paste) as a function food. Effect of adding these paste to the diet of the adult mail albino rats treated with carbon tetrachloride (CCl4) induced liver damage. It can be observed that , ethanol was the more effective solvent for extraction of poly phenols than water, where the ethanol extract contain phenol fractions higher than the water extract in both artichoke and olive leaves as well as ethanol extract showed high concentrate of the total phenolic compounds identified compared with those of water extract. Where artichoke, olive leaves and red grape seeds recorded 712.95, 235.19 and 463.38 for ethanolic extract compound with 426.5, 127.11 and 51.89 mg/100 g for the water extract, respectively.
Finally, the results obtained from the biochemical analysis of the rats serum and histopathological examination of the liver refer to a marked improvement in the health status of the rats after administration the water extracts of the artichoke, olive leaves and red grape seeds.
However, this study could not determine which of these extracts the better is. we suggest further studies with a focus on the extraction methods, doses used and experimental period

Key words: Waste, By-products, Artichoke leaves, Olive leafs, Red grape seeds, Polyphenols, Liver diseases, CCl4.


Abeer Zayan, 2012


The evaluation of quality and keeping quality of zabady
produced at Assiut city by small artisans was the aim of the
Zabady samples were collected from six small dairies in Assiut
city and stored at 5±2?C in their containers representing the first
group of samples.
As soon as samples of the first group arrived to the laboratory,
one cup from each sample was used as a starter for manufacturing
experimental zabady (the second group of samples) in
reconstituted skim milk (NIDO, 11%W/V) in distilled water.
All samples were analysed daily for: total bacterial count, count
of lactic acid bacteria, coliform and yeast & mold. As well, all
samples were chemically examined for: pH, acidity, total solids, fat,
total nitrogen, total protein and soluble nitrogen content. Regarding
samples of the group I the surface layer of one cup was
asceptically removed, then the surface portion and the bottom
portion were microbiologically analysed separately. On the other
hand samples of the group II were analysed as one portion.
The obtained results showed that at the beginning of
incubation period their was minor difference between the 2
portions of the group I and group II of samples concerning the
total bacterial count. However at the end of the incubation period
some times the surface layer contained higher bacterial counts as
compared with the bottom layer or with group II samples.
On the other hand, the total lactic acid bacteria (L.A.B) counts
showed that the difference between different samples was not
Regarding yeast and mould, the minimum count reached in
group I after 5 days and group II after 7 days and the maximum
count reached in group I after 5 days.
Only 2 samples both from the I and II group were positive for
coliforms overall the storage period.
Concerning chemical determinations, the pH of all samples of
the group I were lower compared to samples of the group II, on
the other hand the acidity was higher.
Only one sample from group I contained highest T.S. when
compared to all other samples, in the mean time, all samples of
group II always contained higher T.S.
Concerning fat content, there were great differences, between
fresh samples of group I with minimum value of 2.5% and a
maximum value of 4.7%. Also, percentage of total protein showed
the same trend with a minimum value of 2.676% and 3.662% as a
The obtained results showed great differences concerning the
S.N content between samples of group I either at the beginning
and at the end of storage period.
The organoleptic properties examination indicated that their
was big difference between the different samples of the first group,
which may be due to the difference in the raw milk used by each
dairies, on the other side approximately their was no big difference
between the samples of the second group, as no big difference
between the raw material used for manufacturing , also the
samples of the second group always had higher score in
comparison with the samples of the first group, normally this can
be explained by the quality of the raw material used and the
manufacturing process.

Enhancement the fermentation of lactose- whey using genetically modified strains of Lactobacillus



Studies on the role of natural improvers for bread production

El Sayed El - Fadaly, 2009


This study is made to know the best additional quantities from the molt flour and the palm oil and it's effects on the Rheological properties and so the effect on sensory evaluation , staling . fourteen operations were used and the molt flour was added by 1% , 2% , 3% , 4% and 5% and the palm oil was added by 2% , 3% , 4% and 5% each lonely and then the molt flour and the palm oil were added together by 2% , 3% , 4% and 5% .
this operations are :
1- control ) wheat flour 82% extraction )
2- 99% wheat flour + 1% malt flour
3- 98 % wheat flour + 2% malt flour
4- 97% wheat flour + 3% malt flour
5- 96% wheat flour + 4% malt flour
6- 95% wheat flour + 5% malt flour
7- 98% wheat flour + 2% palm oil
8- 97% wheat flour + 3% palm oil
9- 96% wheat flour + 4% palm oil
10- 95% wheat flour + 5% palm oil
11- 96% wheat flour + 2% malt flour + 2% palm oil
12- 94% wheat flour + 3% malt flour + 3% palm oil
13- 92% wheat flour + 4% malt flour + 4% palm oil
14- 90% wheat flour + 5% malt flour + 5% palm oil
These studies was conduced to estimate the following criteria :
- chemical composition of raw materials
- Rheological properties for dough ( farinograph – extensograph – Falling number )
- Organoleptic evaluation of bread production
- The records analyes for the balady bread and pan bread
- Staling of balady bread and pan bread
- Chemical composition for bread production
In conclusion , results of the present study show that supplementing malt flour and palm oil particularly as a combination Improved in Rheological properties , organoleptic evaluation and staling
Key words ( Not more than 10) :
Wheat flour , malt flour , palm oil , chemical composition , Rheological properties , Dough , organoleptic evaluation , staling.




In this study, galactomannan was extracted from different sources (fenugreek, guar, and locust bean). Chemical composition and rheological properties of raw materials and galactomannans were determined. Glactomannans were also determined using HPLC to calculate the galactose / mannose ratio. Galactomannans were added to wheat flour at different levels as improvers and to produce healthy pan bread and cakes. Rheological properties of dough measurements and sensory evaluation of pan bread and cake were studied. The effect of galctomannans on staling rates for pan bread and cake were also studied. The results showed that galactomannan characterized by low contents of ash, ether extract, protein and crude fiber, whereas, it contained higher percentage of gum. The yields of extracted galactomannans with cold water from all previous used materials were higher than those extracted with hot water. They were 13.63, 16.45, 14.20, 12.99, and 14.72 for cold water extraction, and 8.46, 14.54, 11.42, 10.48, and 11.88 for hot water extraction for untreated fenugreek, treated fenugreek, black guar, white guar, and locust bean, respectively. The galactose to mannose ratio of galactomannans was 1.0 : 1.1 for fenugreek, 1.0 : 1.7 for guar and 1.0 : 2.4 for locust bean. The best used concentration of extracted galactomannan solutions were 1.0 % at shear rate (γ) 60 r.min-1. The rheological properties of dough made using 1.0 % level of extracted galactomannan from all used sources exhibited significant increase in each of water absorption, arrival time, mixing time, and stability. Meanwhile, physical and sensory properties of pan bread and cake were accepted at galactomannan concentration till 1.0 %. The effect of galactomannans extracted from different sources retard staling of pan bread and cake and improved keeping quality during storage periods till 1% levels than that of the other levels and control. On the other hand, galactomannans of carob beans was the best gum to retard staling than the other gums extracted from fenugreek and guar seeds.
Key words: galactomannans, fenugreek, guar, locustbean, bakery products, pan bread, cake.

Effect of Food preparation treatments on pesticide residues in Foods.

Nadia Saleh, 2009


The aim of the study was directed to determine the effect of household treatments on pesticides residues in some Foodstuffs (vegetables, meat, fish and chicken. Two pesticides were used (Fenitrothion, Fenvalerate). Treatments included peeling, removing inedible parts, washing and cooking.
The most important results could be summarized as follows:
Concerning the effect of preparation on green beans, Squash and potatoes Residue level varied according to the pesticide and commodity. Fenvalerate residues were lower than the maximum levels (MRLs) according to FAO/WHO (1993). The preparation procedures further decreased these levels. However, before treatment, Fenitrothion residues exceeded the allowed limits. Peeling and removing inedible parts and washing lowered residue levels. Before washing, residue levels exceeded MRLs in green beans and squash. Washing decreased residue in squash to the accepted level. Heat treatment (Stewing, Frying and baking) completely removed pesticide residues in all vegetables. However, microware cooking decreased residues to the acceptable levels in squash and potatoes. Residue in green beam exceeded the recommendations (120%) of FAO/WHO (2003).
With regard to salad vegetables, before treatment, Fenitrothion residues were higher than MRLs, being 140% in tomatoes, 120% in cucumber, 150% in radish. It reached the maximum level in carrots. Preparation reduced its levels to the acceptable limits in tomatoes and cucumber, while totally removed it from peppers, carrots and radish. Fenvalerate residues were low in tomatoes (6%), peppers (80%) and carrots (60%). It exceeded MRLs in cucumber (200%) and radish (120%). Preparation procedures totally but removed the residues it from tomatoes, cucumber and peppers but reduced it to acceptable levels in both carrots and radish. For leafy vegetables, Fenitrothion levels were higher than MRLs in dill, coriander and lettuce before treatment. However, Fenvalerate residues were 150% of MRL in dill and reached the maximum level in coriander. Preparation and washing decreased both residues in all vegetables to be lower than MRLs except dill that reached MRL.
Before treatment, Fenitrothion residue were higher than MRLs, 140% in meat, 120% in fish 180% in chicken with skin and 160% in chicken without skin. Preparation procedures, reduced these residues to 120%, 60%, 140% and 120% of MRLs respectively. However, Feuveralerate residues were 200%, 250%, 150% and 100% in meat, fish, chicken with skin and without skin, respectively. Preparation totally eliminated these residues except from fish and meat which reached the maximum level Baking reduced Fenestration residues from all the commodities to levels lower than the recommendations except chicken with skin that lowered the maximum levels and eliminated Fenvalerate from fish and meat.
Key words: Pesticide, Residues, Fenitrothion, Fenvalerate, Household preparation, Poultry, Maximum residues limits.




There is an increasing interest on production of wheat in Egypt because of its great importance and since it is considered the main component of bread which is considered the main item of meal. Since there is shortage in wheat production in Egypt, it is not sufficient for the increasing Egyptians, consumption.
In this regard, the present study has been devoted to investigate the replacement of some of the mineral nitrogenous fertilizers with bio-fertilizer to induce high economic crop with high quality and low environmental pollution which is caused by the excess use of mineral nitrogenous fertilizers.
The effect of bio-fertilizer, i.e., yeast, bacteria or their combind mixture in the presence of half and full recommended dose of nitrogen mineral fertilizer and Fe, Zn

Chemical and technological studies onfruits of some olive varieties

Mounir Khahil, 2008


Olives (Olea europeae L.) belong to the family Oleaceae, and this tress is among the oldest known cultivated trees in the world. Olive tree is known as the symbol of peace. It is one of the most important plants that have been mentioned in holy books. Olive oil is an important commodity in the daily diet of Mediterranean people. The consumption of olive oil in the world has been increasable from year to year. The beneficial effects of olive oil are due to not only its high unsaturated/saturated fatty acid ratio, but also its antioxidants such as vitamin E, carotenoids and phenolic compounds. Antioxidants in virgin olive oil protect against cancer and arteriosclerosis.
This investigation was carried out on fruits of foqr olive varieties namely; Chemlali, Kronaki, Frantoio and Mission at unripe and ripe stage obtained from EI-Dakhala Oasis, New Valley Governorate.
The olive fruits were compared of their physical and chemical properties and gross chemical composition. The physical and chemical properties of olive oil, as well as fatty acid and unsaopnifable matter composition were determined. The total polyphenols were extracted, quantitatively determined and fractionation by HPLC method. On the other hand, evaluate the unitization of unsaopnifable matter and total polyphenols as natural source of antioxidants. Besides, detection of virgin olive oil adulteration by sunflower or soybean oils using UV Spectrophotmetric method, as well as determination of fatty acid composition.

Utilization of some food plantes wastes as a source of dietary fiber in Africa

Ahmed El Rashidy, 2008