Improving Probiotic Strawberry Dairy Beverages with High-Intensity Ultrasound: Syneresis, Fatty Acids, and Sensory Insights

Consumer acceptance of milk beverages as probiotic beverages is directly linked to their sensory qualities, such as flavor, consistency, visual appearance, and mouthfeel. Overall, products that exhibit syneresis are often viewed as inferior. Thus, this study was conducted to investigate the effects of high-intensity ultrasound on the production of probiotic strawberry beverages, aiming primarily to stabilize the beverage by reducing syneresis and improving sensory properties without compromising the viability of probiotic microorganisms. The effects of the ultrasound processing time (2.5, 5, 7.5, and 10 min) on the physical, chemical, and sensory properties of the beverages were analyzed. Ultrasound was applied using a 750-wW ultrasonic processor (Cole-Parmer^®, 750 W, Vernon Hills, IL, USA) at 40% amplitude, consuming 300 W and resulting in an acoustic power density of 1.2 W/mL. The results indicate that ultrasound significantly influenced the syneresis of the samples, with intermediate times (5 and 7.5 min) demonstrating lower liquid separation. Notably, the U7.5 treatment exhibited syneresis values of 52.06% ± 2.14, 60.75% ± 2.33, and 61.17% ± 1.90 at days 1, 14, and 28, respectively, corresponding to reductions of approximately 18%, 12%, and 11% compared to the control (63.43% ± 0.93, 68.81% ± 0.56, and 68.59% ± 0.10, respectively). The fatty acid composition showed changes according to storage time. Notably, palmitic acid (C16:0) concentrations were above 30 g/100 mL, and the ω6/ω3 ratio ranged from 5.92 to 7.47, falling within the recommended dietary values. Ultrasound also reduced the amount of sucrose in the samples, which may benefit the growth of probiotic microorganisms. In terms of sensory analysis, the ultrasound-treated samples (2.5 to 7.5 min) were preferred by the evaluators compared to the control sample. Furthermore, ultrasound treatment did not result in the inactivation of probiotics, supporting its potential for enhancing probiotic beverage quality. Thus, high-intensity ultrasound proved to be a promising technology for enhancing the quality of probiotic strawberry beverages by reducing syneresis, affecting fatty acid composition, and improving sensory characteristics. This may open up new opportunities in the food industry for more appealing and healthier probiotic products.