Predicción en línea del módulo elástico de la cuajada

Abstract

The present research deals with the development, implementation, calibration and validation of a system for measuring at real time the elastic modulus of the curd, G', using the signal of a NIR light backscatter sensor, to determine a target cutting time, which would allow the automation of this part of the cheese making process._x000D_ This work was performed in five phases. The first was devoted to obtaining a mathematical model to predict the elastic modulus of the curd, at various temperatures and percentages of protein. This phase was carried out at laboratory level using reconstituted skim milk powder and two protein and temperature levels. A model based on the sensor signal and the protein percentage in milk was found to have a good predictive quality. The second phase consisted in the mathematical model calibration and validation at a laboratory level using cow milk at three coagulation temperatures, and achieving also a very good predictive quality. The third phase was the implementation of a pilot plant/industrial monitoring and data acquisition (hardware and software) system that allowed the prediction of the elastic modulus at real-time in the cheese vat, which was also validated. The fourth phase involved the calibration and validation of the elastic modulus monitoring system, at pilot plant scale. Thus, cheese manufacturing was performed using cow milk at constant temperature. Using the cutting time set by the prediction system, made possible to replicate yields, texture characteristics and cheese colour with regard to those obtained using the cutting time estimated by the cheesemaker master. The fifth phase consisted of the mathematical model calibration and validation at industry level. The model was used to perform the curd cutting during fresh cheese manufacturing as an alternative procedure to the typical cutting methodology applied by the cheese plant consisting on cutting at a predetermined and constant time. Evidences show that cutting time set by the system would increase the yield in those cases were the cutting is performed at a fixed time.

Date of Award	13 Jul 2018
Original language	Spanish
Supervisor	Manuel Castillo Zambudio (Director)