الفهرس 
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Abstract
Blends of milk fat and vegetable fats are increasingly used in the food industry. The addition of extraneous fats to milk fat can be detected through several analytical methods. Methods of detecting food adulteration are based on physical, chemical, biochemical, and other techniques. Therefore, the goals of this investigation were to attempt the detection of milk butter fat (cow and buffalo) adulteration with some vegetable oils such as palm and coconut oil depending on some physical and chemical properties of different adulterated products. To achieve the objectives of this study, the work was planned in two parts as follows:
5.1. Adulteration of cow and buffalo milk fat with different ratios from palm oil
In the first part, different adulterated butter fat treatments were prepared using cow butter, (CB), buffalo butter, (BB) and palm oil (PO). Six treatments of adulterated butter milk fat were prepared according to incorporate the palm oil into either buffalo or cow butter at three different levels i.e. СP25 (25% PO and 75% CB), CP50 (50% PO and 50% CB), CP75 (75% PO and 25% CB), Also, ВP25 (25% PO and 75% BB), BP50 (50% PO and 50% BB), BP75 (75% CP and 25% BB). Three control samples (pure cow, buffalo butter and palm oil) were also prepared. All samples were stored at -20°C until physical and chemical analysis. The data obtained and recommended results can be summarized as follows:
1- No significant difference was observed between the RI value in cow and buffalos pure milk fat.
2- Palm oil showed the highest (RI) value while cow milk fat had the lowest.
3- Addition of palm oil to milk fat either cow or buffalo led to increase of RI value. Also, RI value was increased with increasing ratio of added palm oil into milk fat either cow or buffalo.
4- There were non-significant differences between pure milk fat either cow or buffalo and all adulterated milk fat with 25 to 75% palm oil.
5- The refractive index cannot be successfully used as a detected of blending cow or buffalo milk fat with palm oil.
6- The results indicated that, the pure palm oil showed the highest melting point among all treatment. On the other side, pure buffalo’s milk fat had the lowest melting point compared with other treatments.
7- Adulteration the milk fat with palm oil caused significant increase the melting point in both adulterated cow and buffalo butter fat.
8- Gradually increase the percentage of added palm oil into milk fat either cow or buffalo caused gradually increase the melting point in resulted mix.
9- In general, solid fat content of pure milk fat either cow or buffalo was lower than those of palm oil at 10 to 40°C.
10- The addition of palm oil to both pure milk fats caused a gradual increase in solid fat content compared with pure milk fat; the increasing was proportional to the addition level.
11- It is clear from the data that, acid value was lower in palm oil than that of milk fat either pure cow or buffalo milk fat.
12- Adulteration the pure samples either cow or buffalo milk fat with palm oil caused to significant decrease in acid value.
13- The acid value cannot be successfully used as a detected of blending cow or buffalo milk fat with palm oil.
14- The results indicated that, the pure palm oil showed the highest iodine value among all treatment. On the other side, pure cow’s milk fat had the lowest iodine value compared with other treatments.
15- The addition of palm oil to pure milk fat caused a significant gradual increase in iodine value of adulterated milk fat. The increase was proportional to the addition level.
16- The higher iodine value can be taken as an index of adulteration the pure milk fat either cow or buffalo with palm oil.
17- Saponification number was significantly affected by adulterating milk fat (cow & buffalo) with different palm oil ratios.
18- The data showed that palm oil possessed lower saponification number than that milk fat either cow or buffalo. Also, saponification value of pure buffalo milk fat was slightly lower than that of pure cow milk fat.
19- Addition of palm oil to pure milk fat either cow or buffalo led to significant decrease of saponification value in mixture of fat. However, saponification value was gradually decreased by increasing the ratio of added palm oil to milk fat either cow or buffalo.
20- Saponification number like iodine value, this analytical characteristic also could be used for detecting adulteration of milk fat with different ratios palm oil.
21- It is clear from the data that, peroxide value was lower in palm oil than that of milk fat either pure cow or buffalo milk fat.
22- Adulteration the pure samples either cow or buffalo milk fat with palm oil caused to significant decrease the peroxide value in the mix. On the other hand, the peroxide value of pure cow milk fat was lower compared to the pure buffalo milk fat.
23- Pure milk fat either cow or buffalo was characterized by higher content of short-chain (TSC) fatty acids and lower content of long-chain (TLC) fatty acids than pure palm oil used in this study.
24- Pure palm oil contains higher USFA% than pure milk fat (cow and buffalo). On the other hand, the content of SFA in palm oil was lower compared with pure cow and buffalo milk fat.
25- Adulteration of pure milk fat either cow or buffalo with various levels of palm oil caused considerable changes in certain fatty acids; i.e., butyric, myristic, palmatic, stearic, oleic and linoleic acids.
26- In particular, with increasing levels of palm oil, butyric and myristic acids gradually decreased, while palmatic, oleic and linoleic acids gradually increased.
27- from these data, it could be noticed that, pure milk fat either cow or buffalo was characterized by higher percentage of (TSC/TLC) and lower percentage of USFA/SFA than pure palm oil used in this study.
28- Adulteration the pure milk fat either cow or buffalo with various levels of palm oil caused decrease in (TSC/TLC)% and increase the percentage of USFA/SFA.
29- In general, from the previous results, both fatty acids concentrations and fatty acids ratios can be used to detect the adulteration with palm oil in pure milk fat especially at the high ratio of adulteration.
30- Finally, it could be concluded that, some technical physical and chemical methods such as determination of iodine value, saponification number, percentage of TSC, saturated and unsaturated fatty acids may be useful to determine the adulterated of butter fat with different ratios of palm oil.
5.2. Adulteration of cow and buffalo milk fat with different ratios from coconut oil
In this part, different adulterated butter fat treatments were prepared using cow butter, (CB), buffalo butter, (BB) and coconut oil (CO). Three control samples (pure cow butter, 100% cow butter), pure buffalo butter (100% buffalo milk butter), and pure coconut oil (100% coconut oil) were prepared. Six treatments of adulterated butter milk fat were prepared according to incorporate the coconut oil into either buffalo or cow butter at three different levels i.e. СC25 (25% coconut oil and 75% cow butter), CC50 (50% coconut oil and 50% cow butter), CC75 (75% coconut oil and 25% cow butter), Also, ВC25 (25% coconut oil and 75% buffalo butter), BC50 (50% coconut oil and 50% buffalo butter), BC75 (75% coconut oil and 25% buffalo butter). All samples were stored at -20°C until physical and chemical analysis. The data obtained and recommended results can be summarized as follows:
1- No significant difference was observed between the RI value in cow and buffalos milk fat.
2- Coconut oil showed the highest (RI) value while cow milk fat had the lowest.
3- The data indicated that, addition of coconut oil to milk fat either cow or buffalo led to decrease of RI value. Also, RI value was decreased with increasing ratio of added coconut oil into milk fat either cow or buffalo.
4- There were non-significant differences in RI between pure milk fat and adulterated milk fat with coconut oil up to 50%.
5- The Refractive index as an analytical characteristic did not appear to show any significance in detecting adulteration of milk fat with coconut oil.
6- The results indicated that, the pure coconut oil showed the lowest melting point among all treatment, On the other side, pure cow’s milk fat had the highest melting point compared with other treatments.
7- Gradually increasing percentage of added coconut oil into milk fat either cow or buffalo gradually decreased the melting point.
8- There were significant differences in melting point between pure milk fat either cow or buffalo and all adulterated milk fat with 25 to 75% coconut oil.
9- Melting point may be useful to determine the adulterated the butter fat with different ratios of coconut oil.
10- In general, solid fat content of pure milk fat either cow or buffalo was lower than those of pure coconut oil at 10 °C. While solid fat content of pure milk fat was higher at temperatures between 20 to 40°C.
11- The same behavior was also observed concerning to the solid fat content of binary mixtures (milk fat adulterated with 25, 50 and 75% coconut oil), it was decreased by increasing the rate of blending from 25 to 75% of coconut oil with either cow butter fat or buffalo butter fat, especially at 20 to 40°C.
12- It is clear from the data that, acid value was significant lower in pure coconut oil than that of milk fat either pure control or adulterated with different ratios of coconut oil.
13- Addition of coconut oil to milk fat either cow or buffalo resulted in significant lower acid value being decreased with increasing the ratio added both.
14- The acid values were slightly higher in cow milk fat than buffalo milk fat at any ratio added of coconut oil.
15- The acid value cannot be successfully used as a detected of blending cow or buffalo milk fat with coconut oil.
16- The results indicated that, the pure coconut oil showed the lowest iodine value among all treatment. On the other side, pure cow’s milk fat had the highest iodine value compared with other treatments.
17- The addition of coconut oil to pure milk fat caused a gradual significant decrease in iodine value of adulterated milk fat. The decrease was proportional to the addition level.
18- Lower iodine value can be taken as an index of adulteration of ghee with coconut oil.
19- Saponification number was significantly affected by adulterating milk fat (cow & buffalo) with different coconut oil ratios.
20- The data showed that coconut oil possessed higher saponification number than that milk fat either cow or buffalo. Also, saponification value of buffalo milk fat was slightly lower than that of cow milk fat.
21- Addition of coconut oil to pure milk fat either cow or buffalo led to significant increase of saponification number in mixture of fat. However, saponification value was gradually increased by increasing the ratio of added coconut oil to milk fat either cow or buffalo.
22- Saponification number like iodine value, this analytical characteristic also could be used for detecting adulteration of milk fat with different ratios coconut oil.
23- It is clear from the data that, peroxide value was lower in coconut oil than that of pure milk fat either pure cow or buffalo milk fat.
24- Adulteration the pure samples either cow or buffalo milk fat with coconut oil caused to significant decrease the peroxide value in the mix.
25- The obtained data showed that, in coconut oil butyric, htptadecenoic Cis 10, linoleic (trans), linolenic (cis), linolenic and docosanoic fatty acids, were not found, while caprilic, lauric, myristic and oleic fatty acids were the most abundant.
26- Percentage of caprilic, capric, lauric, myristic and oleic fatty acids in coconut oil were higher than that in pure fat milk either cow or buffalo. While other fatty acids% (butyric, caproic, tridecylic, tetradecenoic, pantadecylic, pantaadecenoic ME, palmitic, palmitoleic d, heptadecanoic, heptadecanoic Cis 10, stearic, olic, linolenic (cis), linolenic, arachidic, eicosenoic and docosanoic) in pure coconut oil were lower than that in pure cow and buffalo milk fat.
27- Pure milk fat either cow or buffalo was characterized by lower content of short-chain (TSC) fatty acids than that pure coconut oil used in this study.
28- There were non-significant differences in content of TLC fatty acids between coconut oil and pure milk fat either cow or buffalo.
29- Pure coconut oil contains lower USFA% than pure milk fat (cow and buffalo). On the other hand, the content of SFA in coconut oil was higher compared with pure cow and buffalo milk fat.
30- Adulteration the pure milk fat either cow or buffalo with different ratios of coconut oil caused considerable changes in certain fatty acids; i.e., butyric, caprilic, lauric, palmatic, stearic and oleic acids, the change was increased with increasing percentages of coconut oil.
31- TSC and SFA gradually increased while USFA gradually decreased with the increasing of coconut oil levels in milk fat.
32- It could be noticed that, pure milk fat either cow or buffalo was characterized by lower percentage of (TSC/TLC) and higher percentage of USFA/SFA compared with pure coconut oil used in this study.
33- Adulteration the pure milk fat either cow or buffalo with various levels of coconut oil caused increase in (TSC/TLC) % and decrease the percentage of USFA/SFA.
34- Finally, it could be concluded that, some technical physical and chemical methods such as determination of melting point, iodine value, saponification number, percentage of TSC, saturated and unsaturated fatty acids may be useful to determine the adulterated butter fat (either cow or buffalo) with different ratios of palm or coconut oils.