## 1 Introduction
### Nutritional Properties of Raw Whey Proteins  
Raw whey proteins found in milk are highly prized owing to their nutritional value, fast absorption, and high levels of antioxidants, amino acids, and peptides [35]. Whey protein (WP) preparations can be divided into three categories: protein isolates, concentrates, and hydrolysate [36; 37]. Whey protein isolates and concentrates are highly adopted in the sports industry, where they help to enhance whole-body protein metabolism and skeletal muscle growth [36; 38]. Whey proteins have been shown to increase satiety and suppress the feeling of hunger, thereby reducing short-term food intake [39; 40]. Studies have reported that WP can reduce postprandial glycemia and have a glucose-lowering effect [41; 42]. People affected by Phenylketonuria must adhere to daily nutritional plans free of phenylalanine amino acid. In these cases, whey protein glycomacropeptide can be a good substitute and can serve as a new food supplement for people suffering from Phenylketonuria [43]. Studies on whey-protein-enriched food production and their nutritional value have recently gained increased interest. It has been reported that adding erythroid in the production of WP isolate meningues can help to improve the overall structural properties of the final product [44]. Additionally, yoghurts enhanced with WP isolates have been shown to possess improved textural properties, as well as higher nutritive value [45].  
Whey proteins mostly consist of \(\beta\)-lactoglobulin, \(\alpha\)-lactalbumin, glycomacropeptide, immunoglobulins, bovine serum albumin, lactoferrin, and lactoperoxidase [46; 47]. It has been reported that \(\beta\)-lactoglobulin has a high concentration of cysteine and other amino acids, which stimulate the production of glutathione in mice for protection against intestinal tumors [48]. Lactose synthesis is supported by \(\alpha\)-lactalbumin, which is the main energy source for newborn children [49]. However, due to the high temperatures used during the pasteurization of raw milk, whey protein content is affected [50]. This is a huge issue in developing countries, where the daily intake of food products and their nutritional content are low. Malnutrition in the long term leads to undernourishment and hunger.  
PEF can bridge the gap between safe food processing and products with high nutritional value. However, there is still much to be done to achieve complete bacterial inactivation using PEF in liquid food pasteurization. It is a known fact that the efficacy of the microbial inactivation by PEF mainly depends on the proper selection of technological parameters such as PEF strength, treatment duration, specific energy input, pulse repetition frequency, conductivity, temperature, pH, and the shape and composition of the electrodes [8; 51; 52; 53]. However, PEF technology has many variables that differ from one liquid to another; therefore, finding the optimal parameters for these variables and their compositions might be challenging.  
The working hypothesis of this study was that PEF can lead to efficient milk pasteurization while preserving nutrient value. Hence, the aim of this study was to examine the effect of PEF on whey protein content and bacterial inactivation compared to traditional pasteurization techniques used in the food industry.