Yield stabilization with at-line monitoring of milk coagulation

Cheese is obtained by coagulation of milk and subsequent separation of the milk gel into liquid (whey) and solid (curd) phases. An essential step of the cheesemaking process involves cutting the formed milk gel into small cubes to allow whey separation by increasing curd surface/volume ratio. Cutting time selection greatly affects the yield, moisture and quality of cheese. Cutting the gel too soon when the curd is not firm enough leads to lower cheese yield through increased curd fines and fat loss, whereas delayed cutting results in higher cheese moisture content due to reduced collapse of the gel. This may further alter the ripening process and final product quality. In this context, optimizing yield and reducing the variability in quality are of great economical interest. As milk production is responsible for more than 90% of the carbon footprint of the cheese industry, maximizing the yield would also reduce the environmental impact of the industrial manufacturing processes. Milk gels are usually cut at a predetermined time or according to the cheesemaker’s subjective evaluation of gel texture and appearance. These can lead to considerable variation in yield, because many factors affecting the gel strength do not remain constant. There is a pressing need for objective and quantitative real-time milk gelation and cutting time determination that help refine the cheesemaking process, improve process automation, reduce the variations, and maximize yield. For this purpose, Rheolution Inc. has developed CoaguSens™ Connect the first testing instrument allowing:

• Quantitative measurement of milk gel firmness during coagulation.
• At-line monitoring of milk gel formation in real time.
• Precise monitoring of cutting time.
• Maximum coagulation speed Vmax

This application note presents the results of a study performed in a cheese plant to evaluate the impact of controlling milk gel firmness at the cutting step using of CoaguSens™ Connect on the variability of cheese yield. This study was conducted in a Canadian medium-sized cheese plant manufacturing cheddar cheese. This application note describes in detail the second phase of the yield optimization journey: Cheese yield stabilization through at-line monitoring of coagulation.