The effect of partially or totally replacing milk fat by jojoba oil in Domiati cheese production on some nutritional and quality properties

Purpose The purpose of this study is to evaluate the effects of partial or total substitution of milk fat by various levels of jojoba oil on the nutritional, physicochemical and sensory properties of Domiati cheese during cold storage at 6°C for 45 days. Design/methodology/approach The fat percentage of milk used for cheese manufacture was standardized to 4% fat. Five formulas were produced by replacing milk fat with 0%, 25%, 50%, 75% and 100% of jojoba oil, respectively. The physicochemical and sensory properties of cheese samples at 0, 15, 30 and 45th days of cold store were evaluated. Findings No significant differences in moisture, fat, protein and acidity values amongst the control samples and those samples supplemented with different concentrations of jojoba oil. Significant differences (p = 0.05) in total volatile fatty acids were detected amongst experimental cheese samples. The highest values were recorded for control sample containing 100% milk fat, while the lowest values were recorded for cheese sample containing 100% jojoba oil (p = 0.05). Total nitrogen (TN), water-soluble nitrogen (WSN) and trichloroacetic acid soluble nitrogen (TCA-SN) levels of experimental cheeses were nearly same as for control. The results of fatty acids profile showed that jojoba oil has a unique structure of straight monounsaturated alcohols. Significantly (p = 0.05), the highest cholesterol content was recorded for control sample containing 100% milk fat; however, the lowest (p = 0.05) value was recorded for cheese sample containing 100% jojoba oil. At the end time of storage period, control sample manufactured with 100% milk fat had the highest (p = 0.05) values of free fatty acids, peroxide and thiobarbituric acid, while the lowest values were recorded for cheese sample with 100% jojoba oil as a source of fat. The sensory evaluation results demonstrated that blending milk fat with jojoba oil improved the sensory properties of Domiati cheese. Practical implications It is concluded that substitution of 25%, 50%, 75% and 100% of milk fat by equal amounts of jojoba oil enhanced the nutritional and sensory characteristics of Domiati cheese. Originality/value It is concluded that Domiati cheese formulated with substitution of 25%, 50%, 75% and 100% of milk fat by equal amounts of jojoba oil enhanced the nutritional characteristics and improved the sensory properties of produced cheese.