DEVELOPMENT OF COMBINED OPTICAL METHOD FOR MILK COAGULATION RESEARCH

Abstract

Development of new methods and systems for control of physical properties of dairy products is a promising trend in the food industry. Using new methods of control improves product quality and helps to reduce manual labor at dairy plants. The aim of this study was to develop a methodology for monitoring of milk coagulation with combined infrared koagulograph. Whole unpasteurized milk was the object of our study. Chymosin solution with activity of 8,000 units under the CHY_MAX trademark was used as a coagulant. To control the process of rennet coagulation we used a combined nephelometer-turbidimeter of our own design. The technique of coagulation monitoring is based on receiving turbidimetric and nephelometric data from multiple optical sensors operating in the near infrared region of the spectrum. Data were recorded using a laboratory complex based on universal multichannel ZET210 data collection device. The flux data from the sensors were recorded in the database and displayed using the applied KoaguMilk software of our own design. Possible photocell set for the coagulograph is also described in the paper. As a demonstration of the method possibilities the dependence of coagulation on chymosin concentration has been analysed. The data on the effect of the rennet concentration on coagulation rate obtained under this study are found to be corresponding to the conventional data. This proves applied effectiveness of our optical method for milk clot structuring under the rennet coagulation. We obtained diagrams for dependence of the IR radiation flow on time under the rennet coagulation, showing a decrease in the degree of flux transmission in direct and sidewise scattering and increase in backscattering at the active stage of milk coagulation.

Keywords

• milk coagulation
• nephelometry
• turbidimetry
• infrared sensor
• coagulograph