الفهرس 
List of contentsOnly 14 pages are availabe for public view
 |  | from | 116 |  |  |
| | | from | 116 | | |
Abstract
Fast food industry encompasses all meals and snacks, which are prepared outside home. Therefore, this definition includes all the takeout meals and beverages. In fast food restaurants, food is served typically from a limited menu, cooked in bulk in advance and served hot. Frying oils is a common and popular method of preparing foods. This is because it is fast, simple, develops a typical flavor of foodstuffs and is very efficient from a culinary point of view. This study was performed to compare and evaluate the different types of frying oils, which are used in some fast food restaurants that are categorized as (international, national and local grades) in El Dakahlia governorate -El Mansoura, Egypt. The study is divided into two methods, while the results could be presented as the following : A)First evaluation using some physical and chemical properties for different fast food restaurants grade (international, national and local): 5.1Acid value (AV) : Acid values in samples, which were collected from international grade restaurants were 1.33 before the frying process and respectively reached to 8.63 after the frying process, while in national grade restaurants, acid values were 0.66 before frying and reached to 2.40 after the frying process. On the other hand, the acid values in local grade restaurants were 0.63 before the frying process and reached to 2.13 after the frying process. 5.2Peroxide Values (PV) :-Peroxide values in international grade restaurants were 224.36 ml eqv./kg oil before the frying process and increased to 417.39 ml eqv./kg oil after the frying process, while in the national grade restaurants were 78.57 ml eqv./kg oil, then reached to 275 ml eqv./kg oil and it was increasing dramatically. 5.3Smoke point and specific gravity: -Smoke point was 160° C/10.07min. and 110° C/7.45 min., respectively specific gravity was (0.706 and 0.824) in the oil samples that were collected from the international grade restaurants. -While in the national grade restaurants smoke point was 160 o C/11min. and 130o C/ 7. 5 min, the specific gravity was (0.794 and 0.912) after and before the frying process. -Smoke point was 120 o C / 9.00 min before the frying process and reached to 180 o C / 7.23 min after the frying process, while specific gravity was 0.647 before the frying process and reached to 0.882 after the frying process and this was in local grade restaurants. 5.4Fatty acids profile: Results from G C analysis illustrated that there was 10 saturated fatty acids followed with 8 unsaturated fatty acid before the frying process. The fatty acid also reached to 9 saturated and 6 unsaturated after the frying process in oil samples collected from international grade fast food restaurants. While in national grade restaurants the total saturated fatty acids were 38.345 and 35.859 % before and after the frying process respectively. The predominant fatty acids percentage before the frying process was 22.965 for palmitic and 12.113. There was an observed decrease for palmitic acid, which reached 3.261, followed by a high increase for stearic acid that reached 57.261% also. An observed increase in the total saturated fatty acids was 63.223 %. -Changes in unsaturated fatty acids (USFA) were 68.509% and 22.463% In the local grade restaurants, saturated fatty acids namely stearic, myristic and heneicylic acid represented at 29.401% before the frying process. While the total unsaturated fatty acid was 69.738 % and, oleic acid was (C18:1), the predominate fatty acids and presented 64.957 %. Highly changes were observed in total saturated fatty acids profile in fried oil from international, national and local fast food grade restaurants. 5.5Trans fatty acids : 6-The Two types that were only presented fried oils were oleic acid(C 18:1t) and eliadic acid(C 18:2t ). All trans fatty acids were progressively increased to 36.619 and 7.793 gm/100gm for Eliadic (C18:1t) and Linoelaidic (C18:2t) respectively. -b)Secondly, the survey study consists of two parts; the first part is concerned with the staff who works in fast food restaurants, while the second part is concerned with the guests who usually eat some fast foods meals : -Results showed that the age of the staff who works in fast food restaurants, is less than 25 years, 25 to 35 years and 36 – 45 more and the high percentage was for 36 – 45 more. -It’s obvious that the gender was male with 100% and the age was between 25-35 with 48.6 % and 36 - 45 and more with 50 %. The reasons of using the most common frying oils are varied and they relate to price, oil smell, flavor and other reasons. -In addition, about 90 % from the staff who work in fast food restaurants put away the remaining waste oil and reput another new one. -The majority clean their fryers with hot water and soap and many of them within 77.1 % don’t perform any way for extending the usage life of the oil. -Finally, high prices is the biggest problem that they face in this field within 70 %. -For the second questionnaire the most important results were that the gender of people who eat fried products is more than the others and it presents 50 % for males and 50 % for females. The age of the customers who eat in fast food restaurants which answered to 45.7% were from 20 to 30 years and 30 to 40 and more with 37 %. -The stability in the taste of the fried product that the customers eat in the restaurant and the result was 42.4 % with yes and 26.1% with no and 31.5 % with sometimes. -Finally, the flaws that the customers have seen before in fried food from their point of view have been found out. The biggest flaw was changing the taste with 52.2 % then changing the color with 31.5 % then 16.3 % was for the changing of the smell. -So, it’s obvious from the results of previous tests and questionnaires that there is a need to focus on the process of frying and oil change to avoid the formation of harmful compounds to health, particularly trans fatty acids and saturated fatty acid. -from the previous results, improving the chemical and physical properties of our frying oils in fast food restaurants can be improved by following these steps: -Fryer capacity for every part must not exceed 25- 30 liter. -It`s necessary to change the paper of the filter each three hours of working. -The temperature of the frying should not exceed 180˚C. -It must follow the procedures of frying time operations, such as three minutes for the potatoes no more or less. -Palm oil is one of the best frying oils.