Production of low-fat white cheese powder: Determining the effects of fat reduction and the use of microparticulated protein on emulsion characteristics and powder quality and trying them in model foods

There has been an increasing trend of reduced fat and ready-to-eat foods. These trend have driven the food producers to produce fat reduced versions of foods in which cheese powder is added. In this research, determination of positive and negative situations caused by fat reduction and effects of using microparticulated protein (MP, Simplesse) in cheese powder production was aimed. The research was carried out in four stages. In the first two stages, the effects of the reduction of fat and the use of different ratios of dry-matter, emulsifying salt and MP on the cheese emulsion were investigated. In the third stage, full-fat cheese powder, low-fat cheese powders with or without MP were produced. Cheese powders were named according to the classification of the fat content of the cheese used. In the last stage, cheese powders were used on potato wedges and in salty cookies to evaluate the application of cheese powders on food surface and as a food ingredient, respectively, then the consumer test was performed. Increased protein content in emulsions by fat reduction promoted stability in the lower dry-matter content by providing resistance to the structure, but caused problems in conveying to spray drier because of increased viscosity. The addition of MP to low-fat cheese emulsions greatly reduced the apparent viscosity, and emulsions with 20% dry-matter and 10-20% MP over dry-matter were provided a flowability similar to full-fat emulsion with 25% dry-matter. The fat reduction caused a decrease in free fat level, which improved the flowability, caking degree, wettability and dispersibility of the powder. The use of MP caused a similar tendency with full-fat powder due to the formation of a smaller and smoother particle structure. While the creamy flavour was lower in low-fat cheese emulsion and powder, the use of MP increased the creamy flavour perception of low-fat powder. Volatile compounds were mainly determined by the cheese used but the preparation of emulsion and drying process also caused significant changes in some components. In addition, different volatile components in the drying process were formed by the addition of MP. The use of cheese powders improved the consumer acceptance of model foods, and supported the cooking of the potatoes and samples prepared with microparticulated protein had similar results to full-fat. As a conclusion, fat reduction in cheese powder improved the physical properties of cheese powder, but caused adverse effects on the application of model foods. Addition of MP created the similar situation with full-fat powder by providing similar morphological characteristics.