Effects of high-intensity ultrasonic bath on the quality of strawberry juice

Abstract

The effects of ultrasound (US) application conditions on microbiological, physicochemical, microscopic, and sensory features of strawberry juice were evaluated. Conditions comprised US (40 kHz) for 5, 10, or 15 min at 25, 40, or 50°C. All US treatments reduced the microbial count in juice. US treatment (40°C/10 min; 50°C/15 min) reduced the °Brix value. All treatments maintained the pH, total titratable acidity, phenolic compounds, and antioxidant capacity of the samples. The thermal treatment sample presented a higher decrease in bioactive compounds. Hue angle values and changes in optical microscopy have increased as treatment temperature and time increased. The sample sonicated at 50°C for 15 min presented lower sensory acceptance indices for all the evaluated attributes. Ultrasound application at 50°C for 5 min presented effective juice properties' conservation, a good sensory acceptance, and is a promising alternative to help preserve strawberries. Efectos del baño de ultrasonido de alta intensidad en la calidad del jugo [zumo] de fresaEn el presente estudio se evaluaron los efectos de las condiciones de aplicación de ultrasonidos (US) en las características microbiológicas, fisicoquímicas, microscópicas y sensoriales del jugo de fresa. Las condiciones comprendieron la aplicación de ultrasonido (40 kHz) durante 5, 10 o 15 minutos a 25, 40 o 50°C. Se pudo constatar que todos los tratamientos de US redujeron el recuento microbiano en el jugo. Además, se observó que el tratamiento de US (40°C/10 min; 50°C/15 min) redujo el valor °Brix. Por otra parte, se constató que todos los tratamientos aplicados mantuvieron el pH, la acidez total valorable, los compuestos fenólicos y la capacidad antioxidante de las muestras. La muestra sometida a tratamiento térmico mostró una mayor disminución de los compuestos bioactivos. Los valores del ángulo de tonalidad y los cambios en la microscopía óptica aumentaron a medida que se incrementaban la temperatura y el tiempo de tratamiento. La muestra sometida a prueba sónica a 50°C durante 15 minutos registró menores índices de aceptación sensorial para todos los atributos evaluados. La aplicación de ultrasonido a 50°C durante 5 minutos dio lugar a una efectiva conservación de las propiedades del jugo, una buena aceptación sensorial, por lo que es una alternativa prometedora para ayudar a conservar la fresa.

Effects on quality characteristics of ultrasound-treated gilaburu juice using RSM and ANFIS modeling with machine learning algorithm

“…Menelli et al (2021) studied strawberry juice, comparing samples subjected to heat treatment and controlled ultrasound. It was reported that in the flavor category, the scores of samples treated with heat at 90 °C for 60 s were lower than those of samples treated with ultrasound at 50 °C, with a decrease observed as the application time increased [62] . It is believed that as the application time of ultrasound treatment increases, the flavor score levels decrease due to the further decrease in solid matter content [63] .…”

Influence of ultrasound on the microbiological, physicochemical properties, and sensory quality of different varieties of pumpkin juice

“…After ultrasound treatment, C. moschata juice showed the highest particle size reduction, with the greatest reduction and the most significant effect at 200 W. The reduction in effective particle size was due to the shear forces generated by ultrasonic cavitation, which caused large suspended particles to break up into smaller fragments. A significant reduction in the effective diameter of the cellular debris can be clearly observed in the microstructure image, and it has been found that a significant reduction in particle size correlates with the disruption of the microstructure, owing to the cavitation effect during sonication [ 49 ]. This also provides some evidence of increased bioactives in ultrasonically treated pumpkin juice.…”

Stability parameters during refrigerated storage and changes on the microstructure of orange-carrot blend juice processed by high-power ultrasound

“…Ultrasounds treatments contributed to obtain higher homogeneity and turbidity of samples and can delay the sedimentation of blended fruit and vegetable juices. Time and temperature could be factor associated to the modification of microscopic structures on juices samples (Ertugay and Başlar, 2014;Menelli et al, 2021). Longer ultrasound treatment times could determine higher damage and rupture observed in the cell structure (Rojas et al, 2016;Campoli et al, 2018;Huang et al, 2018;Wang et al, 2019Wang et al, , 2020Zhang et al, 2019).…”

“…Ultrasonication, which consists of treating the foods with high-intensity ultrasound waves (>1 Wcm −2 , 20-100 kHz), and has been shown as a promising technology to increase the shelf life of juices due to the inactivation of enzymes and microorganisms (Kentish, 2017;São José et al, 2018;Alvarenga et al, 2020). The principal mechanism of action is cavitation, consisting of the formation, growth, and collapse of bubbles (Martínez-Flores et al, 2015;Rojas et al, 2016;Pokhrel et al, 2017;Campoli et al, 2018;Menelli et al, 2021). The modifications associated to the pressure exerted during bubble collapse also promotes microscopic changes such as particle surface erosion and size reduction and increase of suspended particles in the medium (Aadil et al, 2013;Ertugay and Başlar, 2014;Rojas et al, 2016;Campoli et al, 2018).…”