Résumé:
Subject description: Camel milk transformation poses significant challenges due to its unique
composition and perceived difficulties in coagulation. This research explores the feasibility of
coagulating camel milk using proteases derived from wild cardoon flowers, Cynara cardunculus Var.
sylvestris.
Objectives: The primary objective of this study is to investigate the potential of cardoon flower
proteases for coagulating camel milk and compare their performance to a recombinant chymosin
enzyme designed specifically for camel milk coagulation.
Methods: Our methodology consisted of several key steps. Initially, cardosins were extracted,
purified, and characterized using chromatographic and electrophoretic techniques. Subsequently, we
measured their coagulating and proteolytic activities, cheese yields, and syneresis ability using camel
milk as the substrate. Additionally, we assessed the textural properties of the coagulums obtained with
the Optigraph by measuring firmness parameters (A20, A30, A40) and coagulation velocity (R and
OK20). The study was conducted by comparing the cardoon-derived proteases with a commercially
available recombinant enzyme developed specifically for camel milk coagulation.
Results and discussion: Our purification protocol allowed us to obtain three types of cardosins:
Cardosins A0, A, and B. All three are heterodimeric proteins composed of two chains, large and small,
with molecular weights ranging from 42 to 36 kDa for the large chains and 16 to 13 kDa for the small
chains. The analysis of coagulation properties and theoretical cheese yields demonstrated that the
purified cardosins exhibit promising coagulation potential for camel milk. Cardosins A and B displayed
activities similar to those of the commercial recombinant chymosin (23 ± 2 IUMC and 21 ± 1 for
cardosins A and B, respectively, compared to 25 ± 2 for the commercial enzyme). However, cardosin
A0 exhibited lower activity (9 ± 2 IUMC). Regarding textural properties assessed with the Optigraph,
no significant differences were observed between cardosins A and B and the commercial enzyme,
whereas cardosin A0 generated a friable and less firm coagulum.
Conclusion: Based on these findings, we believe that proteases from cardoon flowers can be
applied as coagulation agents for camel milk transformation into cheese. The cardoon-derived
proteases, particularly cardosins A and B, exhibit coagulation capabilities comparable to those of the
commercially available recombinant chymosin. This research contributes to the potential development
of more sustainable and cost-effective methods for camel milk processing in the cheese industry
