Ahmed H. A. A.¹, Khalil R. A. M.^1,, AbouElNour A. M.¹, El-Sisi A. S.², Aida H. Ibrahim²

Aiming to improve the proteolysis of Edam cheese by using 0.2% ultrasonic treated lactobacilli as adjunct cultures on cheese curd based on the quantity of cheese-milk and followed its impact on the quality characteristics. Edam cheese was made with a traditional starter to serve as control cheese. Other treatments were made by using traditional starter with 0.2% ultrasonic treated Lb. casei (T₁), Lb. helveticus (T₂) and Lb. plantarum (T₃). The changes in the composition, ripening indices, rheological properties and sensory attributes of Edam cheese from different treatments were followed during 60 days’ ripening. Ultrasonic treated cultures cheeses had no significant effect on the gross composition with lower pH values as compared to control. Also, using treated lactobacilli in Edam cheese enhanced all the ripening indices expressed as soluble nitrogen coefficient, non-protein nitrogen coefficient, free amino acids and total volatile fatty acids. The rheological characteristics of Edam cheese with ultrasonic treated cultures had less hardness, cohesiveness, gumminess and chewiness than control. Edam cheese made with Lb. helveticus (T₂), showed the highest proteolysis rate, significantly lower hardness, gumminess, and improved the sensory attributes than control cheese. Using ultrasonic treated Lb. helveticus, Lb. casei and Lb. plantarum as an adjunct culture for Edam cheese making had a pronounced effect on both flavour and body & texture of the resultant cheese and accelerated the ripening period to 45 days instead of 60 days for control cheese. Using Lb. helveticus as adjunct culture at 0.2% on cheese curd improved the cheese quality more effectively.

Edam cheese, ultrasonication lactobacilli, rheological characteristics, sensory properties