Incorporating Pooled Donkey Milk from Autochthonous Balkan and Banat Donkey Breeds into Traditional Dairy Products: Effects on Technological Properties, Nutritional Profile, and Sensory Acceptability of Podliveni Cheese

Abstract

Podliveni cheese is a traditional fresh cheese produced in Serbia, typically made from fresh cow’s milk. Donkey milk is recognized for its nutritional benefits, particularly its hypoallergenic properties; however, its use in cheese production is partially limited due to its specific protein composition and low casein content. In addition, information in the scientific literature regarding its application in cheese production remains limited. In this study, Podliveni cheese was produced from raw cow’s milk, while in a second experimental group, 30% milk from autochthonous Balkan and Banat donkey breeds was added to obtain a value-added Podliveni cheese. The selected proportion (30%) was based on previous studies using lower inclusion levels (10% and 20%), which demonstrated measurable but limited effects on cheese properties. The technological production process was identical in both groups and is described for each type of cheese. Microbiological parameters analyzed included total lactic acid bacteria (LAB), Enterobacteriaceae, Escherichia coli, coagulase-positive staphylococci (CPS), Salmonella spp., and Listeria monocytogenes. Sensory analysis was conducted using a five-point hedonic scale with a panel of 21 participants (male and female, aged 20–60 years). The following chemical composition parameters were also evaluated: dry matter, fat content, fat in dry matter, fat-free dry matter, protein, ash, pH, and salt. The content of essential minerals and trace elements was determined, including Ca, P, Na, K, Mg, Zn, Cu, Fe, and the Ca/P ratio. The addition of donkey milk significantly affected curd formation, which required six times longer compared to cheese produced exclusively from raw cow’s milk. Furthermore, the inclusion of donkey milk reduced cheese yield and resulted in increased whey separation during storage, indicating reduced water-holding capacity. No statistically significant differences were observed in microbiological parameters, and pathogenic bacteria (Salmonella spp. and Listeria monocytogenes) were not detected in either cheese. No significant differences were observed in most sensory attributes, except for texture. Conversely, the inclusion of donkey milk significantly affected the majority of chemical parameters and the mineral composition of the cheese. The addition of donkey milk resulted in a significant decrease (p < 0.05) in fat, fat in dry matter, fat-free dry matter, Ca, P, K, Zn, Cu content and the Ca/P ratio, while a significant increase (p < 0.05) was observed in dry matter, protein, salt, Na, Mg, and Fe content. The incorporation of donkey milk represents an innovative approach that expands the range of traditional cheeses without compromising the absence of tested pathogenic bacteria and preserving traditional production practices, simultaneously offering new value-added products. Further research is required to better understand the health benefits associated with the inclusion of donkey milk in cheese production. This study contributes to expanding knowledge on the use of donkey milk and supports the conservation of autochthonous breeds and the improvement of human health.