Thermal energy generated during ultrasonication dominates pinto bean hydration

• Published in: Journal of food engineering 2025-01, Vol.385, p.112255, Article 112255
• Main Authors: Kumar, Gaurav, Perera, Dilini, Le, Dang Truong, Devkota, Lavaraj, Dhital, Sushil
• Format: Article
• Language: English
• Subjects: Acoustic cavitation; Legume; NMR; Soaking; Tomography
• ISSN: 0260-8774
• DOI: 10.1016/j.jfoodeng.2024.112255

Ultrasound-assisted hydration (UAH) stands out as a potent strategy, offering multiple advantages over conventional thermal hydration methods. It is an energy efficient, cost and time effective, easily scalable and relatively greener approach. Acoustic cavitation is the major working mechanism in aqueous phase sonication. Cavitation creates immense localised heat and pressure, which ultimately ends up heating the liquid media. To the best of our knowledge, no study dealing with the synergistic relationship between the physical effects of ultrasound and the consequent temperature rise during UAH is available in open literature. This work investigates this complex interplay with aim to identify the dominant working mechanism leading to the hydration of the pinto beans (Phaseolus vulgaris), a variety of common beans. Three different hydration protocols were devised to discern these effects, normal hydration (N) at 25 °C, temperature-controlled UAH (TC) between 18 and 20 °C using an ice bath, and temperature-uncontrolled UAH (TuC). Additionally, the post sonication residual effects of ultrasound treatment were examined. Our findings reveal that sonication induces changes in both TC and TuC treated beans, but more pronounced effects were observed in the absence of temperature control. During TC, acoustic streaming emerged as the predominant sonic action mechanism. Conversely, during TuC, temperature itself emerged as the dominant force, leading to irreversible alterations in the bean's physical and chemical structures. •Ultrasound assisted hydration (UAH) enhances the rate of hydration.•Acoustic streaming is the dominant mechanism when temperature is controlled during UAH.•Ultrasound induced changes are reversible when temperature is controlled.•Temperature dominates the physical effects of ultrasounds when temperature is not controlled.•Ultrasound induced changes are irreversible when temperature is not controlled.