Optimization of Formulation of UF White Cheese with Flaxseed Oil as Milk Fat Replacer by Using of Response Surface Methodology

Cheese is a dairy product that commonly used and has lots of variety in the world. Among the various types of cheese, UF cheese is attracting more consumers in Iran. The need to change the flavor and make a diversity in this product has been considered for long time. Since high fat foods such as cheese are the main cause of some disorders like cordial disease, cancer, obesity and diabetes, formulation of dairy products with modified fat or fat replacer was considered by many researchers and suppliers. Vegetable oils can be used as a substitute for milk fat in cheese. Flaxseed oil consists high level of alfa-linolenic acids (Omega-3) and suitable amount of proteins could noticed as a fat replacer. In this study, we investigated the effect of milk fat replacement with flaxseed oil on the production of functional Feta cheese. The rheological, physicochemical, and organoleptic characteristics of such cheese and its optimal formulation were also determined
The effect of Flaxseed oil (FSO) at a range of 0-100 % and whey protein concentrate (WPC) (0-15%) was investigated on pH, synersis, Dry Matter, hardness, springiness as physicochemical and mechanical properties and mouth feeling, odor, taste overall acceptance as organoleptic properties of UF cheese production by RSM. For the preparation of cheese, a free fat retentate powder was used. To adjust fat to 20%, cream was used with 70% flaxseed oil and homogenized by ultraturrax method. All of the physicochemical, mechanical and organoleptic tests accomplished according to theIranian national Standards/
Results showed that by increasing the amount of FSO in the formulation of cheese, pH, stiffness and synersis increased. Also, with increasing flaxseed oil, the elasticity was initially decreased and increased in greater quantities afterward. However, by increasing the WPC, the elasticity decreased. The increase of flaxseed oil had a reversible effect on the taste, smell, color and overall cheese acceptance score compared with the control samples due to the presence of some impurities in oil. Increasing the amount of WPC and FSO also caused a decrease in pH and fat during ripening of cheese. Although increasing the level of WPC improved the odor of cheese, but did not have positive effect on appearance, color and general acceptance. The result of optimization of UF cheese production with the following indices: pH 4.82%, synersis 1.35%, fat 20.3%, dry matter 32.45%, hardness 631.46 nm, elasticity 0.94 mm, color 3.4, Odor 3.1, flavor 2.8, texture 3.1 and final acceptance 3.11, showed that the best formulation needs 96.01% of flaxseed oil and 9.73% whey protein concentrate. Finally, the predicted optimal formula by software was also determined as follow: pH 4.78, synersis 1.27%, fat content 19.8%, dry matter 31.4%, the firmness index 618.02, the elasticity 1.03 mm, and the sensory scores included color 3.4 , odor 3.15, Taste 2.97, Texture 3.64 and Final acceptance 3.21.