Application of ultrasound to extend the shelf life of shalgam juice: Changes in various physicochemical, nutritional, and microbiological properties

Shalgam juice is a traditional lactic acid fermented beverage, which has intense red color and sourish taste. This study aimed to determine various physicochemical and microbiological changes in shalgam juice after ultrasound application to extend the shelf life of the juice. Ultrasound was applied to the samples at different amplitudes, temperatures, and times in combination. Analyses were performed on the samples at five different stages throughout the storage. The lactic acid amount, lactic acid bacteria count, color values, except a*, were higher in the samples that were treated with ultrasound, whereas the amounts of ethyl alcohol, acetic acid, propionic acid, and the pH values were lower compared to the control at the end of the storage. Ultrasound application had no significant changes in anthocyanins, antioxidant activity, and color of the samples. It can be said that ultrasound application to shalgam juice can be an alternative method to improve its shelf life. Novelty impact statement Shelf life of shalgam juice is limited to 3 months and it can be extended to 1–2 years by adding preservatives or pasteurization. However, pasteurization has negative effects on the sensory properties of the product and chemical preservatives are being replaced by alternative methods in recent years due to consumer sensitivity. In this study, ultrasound was applied to shalgam juice to extend the shelf life of the product.