الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 169 |  |  |
| | | from | 169 | | |
Abstract
There was a drastic change in the last period in the nutritional
consumption of the Egyptian, especially the youth group. There was an
increased demand in taking foods outdoors, particularly the fast foods and ready
meals. Most of these foods from nutrition unbalance in its nutrient components.
Also some of its components are of less quality standards i.e fats because most
of its fat are saturated (unhealthy) and this increase the possibility of many
health disease such as heart attack, high blood pressure, obesity……………
Therefore, it was necessary to find out a way to improve and enhance the
nutritional and health properties of these foods in order to reduce r minimize its
hazards on the consumer’s health. These attempts include improving both
protein and fat profiles of these foods and introducing dietary fiber to the meal
to prevent constipation and enhance the digestibility. So, two products were
selected from these fast foods pizza and burger. Pizza suffers from lacks of both
protein and fibers meanwhile, burger contains high levels of saturated fats
(animal fats) which are known as unhealthy fats also it does not contains any
dietary fiber. Based on that the ground flaxseed attracted great attention to be as
a good source for protein, oil and fiber as well as some minerals and antioxidant
(especially lignans) that means flaxseed addition covers many nutritional aspects
led to improve the quality of these two products. Therefore ground flaxseed
addition enhances and improves both the health and nutrition properties of these
products.
In pizza the ground flaxseed was used at two levels of 5 and 10% as a
substitute of wheat flour of 72% extraction, but in burger the addition rate was
10 and 20% from the used beef meat. Both products were analyzed to monitor
the changes accrued f frozen storage at -18 c°, also the chemical analysis of the
raw materials was done. The results of the research revealed the following
important data.
Summary
106
Pizza result
1- Ground flaxseed added to wheat flour showed changes on the rheological
properties of the flour due to farinograph data.
2- Water absorption, arrival time, mixing tolerance index and dough
weakening were increased as the addition level of G.F.S increased.
3- Only dough developing time and its stability were decreased due to added
G.F.S.
4- The chemical analysis showed low carbohydrates content in ground
flaxseed 9.62% compared to 80.93% for wheat flour.
5- Flaxseed oil chemical characters such as acid value, saponification number,
peroxide value, iodine value and TBA were as 0.8 mg KOH/g, 190 mg
KOH/gm, 0.95 meq O2/kg, 177gm I2/100gm and 0.23mg malonaldehyde
/kg, respectively.
These results prove that oil is of good nutrition quality and suitable for
cooking uses and food uses.
6- Fatty acid profile of flaxseed oil showed that total monounsaturated oleic
(17.25%) poly unsaturated lenoleic and lenolenic (17.25 and 53.21%) and
both represented 88.97% of the total oil content.
Omega-3 fatty acids and omega-6 were of 53.21 and 17.25%, respectively
with ratio of 17.25%.
7- The amino acids composition of flaxseed protein showed that Flaxseed
protein had high contents of isoleucine, valine, total aromatic amino acids
and tryptophan than those reported in FAO/WHO (1973) profile. Flaxseed
is rich in the most essential amino acids and poor in leucine and lysine.
Total essential amino acids were 36.28 and total nonessential amino acids
were 63.72.
Summary
107
8- The addition of ground flaxseed to wheat flour for pizza preparation
increased the contents of protein, fat, ash and dietary fiber and reduced the
starch content. The rate of charge was dependent to the added ground
flaxseed.
Effect of frozen storage on the pizza oil chemical properties
1- The storage increased the acid value of all pizza samples. The increase was
lowest in the control due to its low fat content. The third month of storage
showed the highest increase and reached to 3.2, 4.1 and 5.1 mg KOH/ g oil
for control, 5 and 10% ground flaxseed added respectively.
2- The peroxide value also showed the some trend as acid value but the
increase in the control was clearer than other two treatments containing
ground flaxseed.
3- The change in TBA value during the frozen storage followed also the same
trend of both acid and peroxide values. The increase was high in control
sample compared to the other two treatments contained ground flaxseed.
Effect of frozen storage on the sensory properties of pizza
1- The texture was affected due to the ground flaxseed and it became hard
also the storage time increased this texture deterioration.
2- The odor (smell) was high in control pizza and reduced after ground
flaxseed incorporation. The decrease was gradually with storage time.
3- The taste of pizza was also affected negatively due to ground flaxseed
presence. It was correlated with changes in the odor.
4- The color was affected markedly in the treatments compared to control. It
became darker as the level of added ground flaxseed increased also with
Summary
108
the storage period. The color was more significant in pizza containing
10% ground flaxseed.
5- The overall acceptability was higher in control compared to the flaxseed
treatments. The total acceptability reduced gradually in all samples with
increased storage time.
Beef burger
1- The protein content of beef burger meat was 23.2% which is lower than
35.64% of flaxseed. Also, the beef meat is lacking ash (1.1%) fat (3.9%)
and no fiber. Therefore, the nutritional and health properties will be
improved due to the addition of ground flaxseed.
2- The chemical properties of beef fat such as acid, peroxide, iodine and
TBA numbers were 4.18 mg KOH/gm, 0.12 meq O2/kg, 52.33gm I2/100
gm and 0.131 mg malonaldehyde/Kg fat, respectively.
3- Fatty acid composition of beef fat showed that beef meat contained 3.9%
as total fats indicating a poor source of fats saturated fatty acids were
myristic, pentadecylic, palmitic, margaric and stearic acids contents were
2.89, 0.51, 28.36, 1.37 and 25.36% respectively total unsaturated fatty
acids was 41.47%.Represented in myristoleic, palmitoleic, oleic, linoleic
and linolenic acids.
4- Utilization of ground flaxseed in beef burger increase the total fat of the
product from 4.2% in the control to 6.9 and 12.1% in 10 and 20% ground
flaxseed added respectively. Regarding the total ash and fibers increased
in the same trend of fat and protein, also the increase higher in 20%
ground flaxseed compared to 10% treatment.
Summary
109
Effect of burger frozen storage on the fat chemical properties
1- The acid value of the burger fat increased with increasing storage period.
The increase was highest in 20% ground flaxseed sample and lowest for
control sample.
2- The change occurred in peroxide value of burger fat during frozen storage
was in the same trend of acid value changes. TBA changes during frozen
storage were the highest in control (100% beef meat) followed 10%
ground flaxseed. Meanwhile 20% treatment showed the lowest increase in
TBA value. After 3 months of frozen storage the TBA value was 1.4, 0.61
and 0.43 mg malonaldehyde/Kg burger fat of control, 10 and 20% added
ground flaxseed respectively.
Effect of frozen storage of beef burger on its sensory properties
1- Ground flaxseed addition to beef burger significantly improved the
texture compared to control throughout the 3 months of storage. All
treatments showed reduced texture in the 3rd month of storage and the
control was markedly affected compared to ground flaxseed containing
burger.
2- The addition of ground flaxseed significantly affected the odor (negative
effect) compared to control sample. The effect also was pronounced with
increasing storage time.
3- The changes in burger taste was parallel to the changes occurred in odor.
Ground flax seed addition to meat beef reduced the taste of the final
burger.
4- The burger juiciness significantly reduced after ground flax seed addition.
It was highest for control and lowest for 20% added ground flaxseed.
5- The overall acceptability of the burgers proved that 10% of ground
flaxseed made burger was highly accepted compared to control or burger
contains 20% ground flaxseed.