During industrial manufacturing, stirred yogurt undergoes several processing steps that exert significant mechanical stress on its structure. Stirring, pumping, smoothing, and cooling can weaken the gel formed during fermentation and lead to a loss of texture or viscosity, or to whey separation, known as syneresis. These defects have a direct impact on product quality.
The objective of this project was to better understand the combined effect of yogurt composition and processing parameters on the stability and textural properties of stirred yogurt. The hypothesis was that targeted adjustments to the process and formulation would make it possible to better control gel structure and improve the final quality of the product.
To achieve this, the research team collaborated with the Saint-Hyacinthe Research Centre to develop a pilot test bench reproducing industrial conditions. Various parameters were studied, including smoothing temperature and sequence, cooling rate, fat content, and the proportion of milk proteins. The yogurts produced were evaluated during storage to measure firmness, viscosity, and stability. This work made it possible to identify concrete levers to optimize stirred yogurt production.
