Acta Scientiarum Polonorum Technologia Alimentaria

Background. Due to its low casein-k content (only 3%, compared to 13% for cow’s milk), processing camel milk into cheese is a critical and challenging step.
Materials and methods. The objective of the present study was to determine the optimal time for camelmilk clotting using a microbial enzyme (Rhizomucor miehei) and plant extract (Cynara cardunculus L.) at two different concentrations (1 and 2 IMCU) while investigating the effect of physicochemical parameters, namely, pH, temperature, and calcium chloride (CaCl2). This was achieved by developing a mathematical equation for each coagulant, where each model is related to the physicochemical composition, acidity of the analyzed milk, and clotting properties of the used coagulant.
Results. Based on the conducted experiments, the two mathematical models were established to exploit all the physicochemical parameters that have a significant level (p value < 5%). The two obtained models using the microbial enzyme and the plant extracts explained 98.14% and 99.68% of the variability of the response data around their means, respectively. The Pareto analysis identified temperature as the most influential parameter on the clotting time by the microbial enzyme. Afterwards, the combination of pH and temperature appeared as the second most significant parameter, followed by pH and enzyme concentration, while calcium chloride content was found to be the least effective parameter on clotting time among all the studied parameters. In the case of the plant extracts, the temperature induced the highest effect, followed by pH, the combination between pH*temperature, the concentration of the used coagulant and, finally, the CaCl2 concentration. Hence, by using the plant extracts (Cynara cardunculus L.), the obtained results revealed that adding a low concentration of CaCl2 is associated with a minor effect on camel milk-clotting time.
Conclusion. A mathematical model was developed to optimize the parameters that affect the clotting time of camel milk for each coagulant. As a result, the used microbial enzyme and the Cynara cardunculus L. flower extracts showed excellent coagulating properties and immense potential as coagulants for cheese production using camel milk.