Impact of Ultrasonication on Milk Fat Globule Size and Inhibition of Salmonella enteritidis Growth

Abstract

One significant effect of ultrasonic treatment is the inactivation of microorganisms. This characteristic causes ultrasound to be widely used in food processing, healthcare devices, and water treatment. Ultrasonication is an innovative technology that holds promise for accelerating processes and producing high-quality products. The ultrasonic process in milk processing includes homogenization and sterilization. Milk homogenization standardizes fat globule size, while sterilization targets pathogenic microbes harmful to humans. This study aims to evaluate the effect of ultrasonication on milk fat globule size and inhibition of Salmonella enteritidis growth, as well as the stability of pH values and temperature increase. To determine the effect of ultrasound on milk fat globule size, exposure was conducted for 30, 40, and 50 minutes on raw milk. The samples were then photographed, and the size of the formed fat globules was measured using a pixel-based approach. Furthermore, to determine the effect of ultrasonication on bacterial growth inhibition, exposure was conducted for 5 minutes, 15 minutes, and 25 minutes on UHT milk that had been cultured with Salmonella enteritidis bacteria. The ultrasonic wave frequency used in this study was approximately 35 kHz. The results showed a significant reduction in fat globule size after ultrasonication. The study also demonstrated that ultrasonication inhibited the growth of Salmonella enteritidis. Ultrasonication increased the temperature but did not affect the pH value. It can be concluded that ultrasonication has the potential to make the milk processing process more efficient because it can reduce the size of milk fat globules and inhibit pathogenic bacteria, where the current process is carried out through homogenization and pasteurization.