CURRENT RESEARCH PROJECTS (2002-2003)

• Cutting Time Prediction in Enzymatic Coagulation of Milk

Cheese processing efficiency could be improved if the coagulum cutting time could be determined precisely. The optical backscatter changes that occur during the enzymatic coagulation of milk give an optical fingerprint of the chemical reactions occurring. A robust algorithm relating optical parameters to cutting time was obtained. A sensor was developed to measure light backscatter during enzymatic coagulation and applied with the algorithm to predict cutting time. The system has been commercially tested with success.

• Endpoint Prediction in Acid Coagulation of Milk

            Yogurt and Cottage cheese processing efficiency and product consistency could be improved if the fermentation endpoint could be automatically determined. The end point of these fermented products is generally selected by direct pH measurement. However, the measurement of pH in a vat using glass electrodes is usually not allowed for product safety reasons. Typically, product samples are collected and the pH determined manually.  A light backscatter sensor was used to measure the optical fingerprint during fermentation and optical parameters obtained from the response. These parameters were used to develop an algorithm for predicting the endpoint.  This technique is being investigated in the laboratory however commercial systems have been tested.

• Curd Syneresis Monitoring and Control

The moisture content of cheese could be standardized if a sensor was capable of monitoring whey release from the curd. Control of curd moisture content would reduce the damage of cheese during ripening and improve its final quality. Concepts for monitoring syneresis in a vat are being developed and tested. This effort is at an early stage of investigation.

Laser displacement sensor designed for measuring one-dimensional shrinkage of acid gel during the syneresis process