Solid Fat Replacement with Canola Oil-Carnauba Wax Oleogels for Dairy-Free Imitation Cheese Low in Saturated Fat

Canola oil was structured into oleogels with different amounts of carnauba wax, and their processing performances were assessed as an alternative to solid fat for imitation cheese low in saturated fat. The contents of solid fat in the oleogels were less vulnerable to the change in temperature than the palm oil. The replacement of palm oil with oleogels produced cheese samples with harder and more cohesive/chewy textures. Dynamic and transient viscoelastic measurements demonstrated that the use of oleogels was effective in increasing the elastic nature of the cheeses. Two distinct components with different proton mobilities were observed in the imitation cheeses, and longer T2 relaxation times were detected in the oleogel samples. The meltability of the cheese with palm oil was not significantly different from those with 3% and 6% oleogels. The saturated fat level of the oleogel cheese was significantly reduced from 45.70 to 5.20%. The application of canola oil-carnauba wax oleogels could successfully produce imitation cheese high in unsaturated fat and low in saturated fat. This study thus demonstrated that the health-functional properties of imitation cheese could be enhanced by using oleogels.

Detection of Leguminous Protein in Casein by Nitrogen Stable Isotopes

Casein can legally be substituted with cheaper leguminous proteins in processed foods, such as imitation cheese, as long as the ingredients are declared. The detection of illegal admixtures of leguminous protein requires analytical procedures to identify an undisclosed adulteration of milk products. To investigate the suitability of stable isotope analyses as an alternative to more sophisticated methods, variations in d15N of soya (n = 27) and peanut (n = 10) protein, as well as casein (n = 14) were determined. Significant differences were established between d15N of casein (4.45 – 6.94‰) and soya (0.25 – 2.37‰) as well as peanut (0.70 – 2.13‰) protein. An average limit of detection for leguminous protein in casein was determined to be 2.1%, provided both components were available for additional analyses. Under practical conditions of food control, i.e., without having access to the actual ingredients, the variability of d15N resulted in an average limit of detection of 26.4%. Because protein d15N can be determined rapidly in crude food samples without elaborate sample preparation, stable isotope analysis can be used as a rapid screening method to determine the presence of higher amounts of leguminous protein in cheese and, in particular, to easily distinguish imitation cheese from cheese.