The principal objective of this study was to develop a combination between lactic leavens (Lactobacillus thermophilus) and the cardoon flower powder (Cynaracardunculus) and their application on yoghurt. The milk clotting was optimized by using the two coagulant agents (with fresh and immobilized states).
The results obtained revealed that a quantity of the cardoon flower powder has a very interesting clotting rate (2.55 min) in comparison with the use of the optimized mixture M2 (75% of cardoon flower powder and lactic leavens 25%) and the optimized quantity of the leavens (0.1 g) with (3.6 and 22.58 min) as respective rates. The immobilization of the various coagulant agents improves the milk-clotting rate. Indeed, a quantity of 6 g of the beads prepared from cardoon flower powder shows a very fast speed (1.06 min) in comparison to the same quantity of the beads prepared starting from the mixture M2 (3.71) and the immobilized leavens (73 min).
The beads prepared starting from the cardoon flower powder and the mixture M2 can completely substitute the immobilized lactic leavens according to the matrix of similarity (similarity of 70%). Moreover, on the one hand, the beads containing the cardoon flower powder improve the speed of yoghurt clotting (75 min) in comparison toimmobilized leaven yoghurt (270 min). On the other hand, the rheological properties were also improved (smooth structure and absence of syneresis phenomenon).