Development of an ultrasonic device for quality evaluation of yogurt / Zlatin Zlatev, Tanya Pehlivanova, Antoaneta Dimitrova, Stanka Baycheva, Ira Taneva, Krasimira Keremidchieva.

In this article a possibility of application of the ultrasonic non-contact method for assessing the quality of yogurt was researched. A prediction assessment was made by an ultrasound based on four parameters – pH, conductivity, fat content, and viscosity. An ultrasonic device was developed to determine the parameters of yoghurt by modified ultrasound sensor available commercially. In order to obtain data for post-processing, a software application was designed for recognizing the ultrasonic signal through the image processing and analysis techniques. The developed algorithms and procedures were applied to determine the distance between the object and the sensor, whereby basic physico-chemical parameters of yogurt could be predicted with the lowest relative error. The working distance was 35 cm for the considered system. The survey results show that the parameters fat content, pH, conductivity, and viscosity of yogurt could be predicted by the proposed system for contactless measurement with accuracy of 94-97%.