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University of Mosul College of Agriculture and Forestry Manufacturing Of Spreadable Processed Cheese Analogues by Using Protein Preparations with Local Ras Cheese Ahmed Ibraheem Salih Al-Joburi M. Sc. Thesis Food Sciences and Biotechnology Supervised by Dr. Nazar Fakhry Muhammad Assistant Professor 2009 A.D. 1430 A.H. Summary The aim of this study was performed to produce high spreadable processed cheese using chickpea, dried soybean milk and Lebnah and this was aimed to increase the spreadability of the products. In addition to add the best emulsifying salt namely, kasomel 2280, which has high spreadablitiy and adding the best suitable color to the processed cheese which was formulated by mixing safflower pigment extract and orange and lemon pigments in addition to use mixture of two flavor tests of cheddar and butter. The results show the following facts: 1. The first treatment: Manufacturing processed cheese using local Ras cheese and dried skim milk curd by replacing part of dried skim milk with 5, 10 and 15% of chickpea powder and performing the curding to produce a mixture of skim milk curd and chickpea powder and using 2.2% of the blend kasomel 2280 as emulsifying salt. The mixture was cooked at 95°C for 10 minutes and the results were compared with control sample. Results show that there moisture, soluble nitrogen ash, fat and pH were increased and this increase was continued with increasing the percentage of the substitution except pH value which was gradually decreased with increasing the percentage of the substitution. The highest pH value (6.11) was observed comparing with 5.97 for control sample with 5% substitution. The changes were high at room temperature comparing with refrigerator temperature and with storage continuity. Results show that total nitrogen, acidity, lactose and salt percent were reduced and this reduction was continued with increasing the percentage of the substitution except acidity which was gradually increased with increasing the percentage of the substitution with chickpea powder. The changes were also high at room temperature comparing with refrigerator temperature and with storage continuity.. Results show that the product was free from yeasts, molds, spore forming anaerobic bacteria and Coliform bacteria. The microbial counting was sharply increased with increasing room temperature comparing with refrigerator temperature and with storage continuity. The highest bacterial total number (6.98x10 2 cell/gm) was observed in 8th week of storage period at room temperature and with 15% of substitution. The physical characteristics of the product were highly improved with increasing the substitution percent. The spreadability, slice ability tenderness of the texture and the capability to penetrate were increased with increasing the substitution percent. Less improvement in physical characteristics was noticed for processed cheese analogues which was stored at refrigerator temperature for 8 th week of storage and with 5% substitution. Results show that produced cheese had acceptable sensory features and preferable taste and smell (17.40 and 16.80 degrees) on the 1st week of manufacturing at refrigerator temperature and with highest percent of substitution. According to the structure, texture, appearance and color, they had high (great) characteristics and the degrees of sensory evaluation were increased with increasing substitution percent at room temperature and in the 8 th week of storage. 2. Second treatment: Processed cheese was manufactured by mixing dried soybean milk with dried skim milk and the curding and cooking were carried out with Ras cheese as such as treatment No 1 performed. Results show that moisture, fat and ash percent and acidity of the product were increased, whereas total protein and lactose percent, salt and pH were clearly decreased as well as the soluble protein in the 10 and 15 % of the substitution and this decrease was continued with the increase of substitution percent. These changes were continued with the storage period especially at room temperature and clearer and rapid comparing other changes occurred in refrigerator. Results also show that the highest value for microbial counting was at the 15% of substitution at room temperature and throughout storage period. The highest microbial number (7.21x102 cell/g) was in 8th week of storage period at room temperature. Further, spreadability, tenderness improvement, firmness and sliceability of the product were increased. Increasing the sliceability, i.e. reducing the time of slicing with increasing the percent of addition of dried soybean milk curd, and the improvement was continued with increasing the storage period at room temperature comparing with refrigerator temperature. Furthermore, results show that the better taste (19.2 degree) for the cheese when the substitution percent was the highest and after processing at room temperature, while the smell of the product had earned the highest evaluation values after processing at room temperature in 10% of substitution. The degree of acceptability of structure, texture, appearance and color of the product were increased with substitution percent. 3. The third treatment: Processed cheese was manufactured by substitution of part dried skim milk curd with Concentrated yogurt (Labna) and with the same of previous treatments and cooking with Ras cheese and as such as treatment No.1. Results show that moisture, fat percent, acidity and salt of the product were increased, while the ash was notably increased in concentration 10 and 15% and the increases were continued with increasing of the substitution. Whereas, moisture and fat were clearly decreased at room temperature and through the storage period. Results also show that total protein,soluble protein, lactose and pH were reduced and these changes were continued and clearly showed at room temperature for as long as storage time. Further, the results show that the highest value for microbial counting was (8.96x102 cell/g) in 8th week of storage period at room temperature with 15% substitution. Concerning to the physical tests, results show that spreadablitiy and product tenderness were increased as well as sliceability quickness and these proportions were recorded clear increase with increasing of the substitution percent and reduced with longer storage period at room and refrigerator temperatures but the reduction was more clear storage at room temperature. Furthermore, results show that preferable taste and smell (17.80 and 18.20 degree, respectively) were directly after manufacturing of the product with highest substitution percent at room temperature. Reduction was occurred for these characteristics with increasing storage period and temperature and became clear enough in 8th at room temperature. The evaluation of texture and structure of the product were the highest in 2 nd week of manufacturing at refrigerator temperature with higher substitution percent. It was obviously concluded that color and appearance grade was highly evaluate with higher substitution percent in 1 st week after manufacturing and at refrigerator temperature which was 9.20 degree for each of them. In conclusion, according to the chemical, physical and sensory examination, the preferable treatment was the first treatment in which used chickpea powder of 15 % concentration followed by second treatment in which used dried soybean skim milk of 15% concentration and finally the third treatment in which used Concentrated yogurt (Labna) with a concentration of 5%. While according to the microbial test, the preferable treatment was the first treatment in which used chickpea powder followed by second treatment in which used dried soybean skim milk and lastly Concentrated yogurt (Labna) used treatment.