Donkey cheese production using pure milk or in mixture with goat or cow milk: preliminary results

Compared to conventional dairy species, the processing of donkey milk into cheese is very difficult due to its intrinsic chemical characteristics related to low contents in caseins and fat that determine poor clotting activity, and only a few researches have been made on cheese production. The aim of this study was to examine some cheesemaking parameters of cheese elaborated via appropriate technology using donkey milk alone or fortified with goat or cow milk. Three cheesemaking sessions on different days were performed in mini-vat heated by thermostatic water bath using fresh milk. In each trial, donkey milk and two mixtures (70/30, v/v) of donkey and goat milk, and donkey and cow milk were processed. After cooling, calcium chloride was added in milk and commercial starter cultures were inoculated. When the milk, maintained in a thermostatic water bath, reached the pH 6.3, liquid microbial rennet was added. The milk was then allowed to coagulate, and the coagulation behaviour was monitored by observation of milk clotting. After gel formation, the curd was cut, the whey was drained, and the obtained curds were placed into cheese moulds. The weight of cheeses was assessed, and the yields were calculated. Cheesemaking parameters were affected by the kind of milk, as pure donkey milk or in mixtures. Compared with the two mixtures, pure donkey milk exhibited longer time for gel formation (20min) and for total in-vat working (170min), and showed a visive weaker gel, highlighting a specific behaviour during cheesemaking. The cheese yield was 7.2% for donkey milk, 10.2% for the mixture of donkey and goat milk, and 11.4% for the mixture of donkey and cow milk. On the basis of visive evaluation, the cheese from pure donkey milk showed a more soluble texture and grainy structure compared to the cheeses from the milk mixtures. This preliminary study may be useful for further studies and potential industrial applications for the development of innovative kind of cheeses