Evaluation of turbidity: correlation between Kerstez turbidimeter and nephelometric turbidimeter

Turbidity is a quality parameter that has an important role in food liquid acceptance. Cloudiness of beverages and covering liquid are a consequence of manufacture processes and storage conditions. Spanish legislation defines the covering liquid turbidity in canning by Kerstez turbidimeter units (KTU), which is a sensorial measure. It is necessary to find a correlation between sensorial and instrumental measurements. This work studied the relationship between KTU and nephelometric turbidimeter units (NTU) and established a mathematical model, which allowed the expression of the turbidity of liquid products in KTU from measurements in nephelometric turbidimeter units. This mathematical model corresponds to a non-linear simple correlation model (KTU/NTU). The best adjustment was a Reciprocal-Y model.