Physico-chemical characterization of dairy gel obtained by a proteolytic extract from Calotropis procera - A comparison with chymosin

- Cheese yields obtained by Calotropis procera extract and chymosin were similar.
- Calotropis procera extract hydrolysed different bounds in κ-casein.
- Gel obtained by Calotropis procera extract was a regular network of casein micelles.
- Gel microstructure obtained by Calotropis procera was similar to those made by rennet.

Chymosin is the major enzyme used in cheesemaking but latex enzymes are also used. The aim of this work was to characterize the composition and the structure of dairy gel obtained by an extract of Calotropis procera leaves in comparison with those obtained by chymosin. The biochemical and mineral compositions of the curds and the cheese yields obtained by using Calotropis procera extract or chymosin were relatively similar. Quantitative and qualitative evaluations of proteolysis after milk coagulation, determined by the non-protein nitrogen content and chromatography coupled to mass spectrometry, indicated that Calotropis procera extract was more proteolytic than chymosin and that κ-casein was proteolyzed. The main consequence of proteolysis by Calotropis procera extract or chymosin was the formation of a similar and regular network with the presence of aggregates of casein micelles. These results support that Calotropis procera extract can be used as effective coagulant in cheesemaking.