Revealing the microstructural stability of a three-phase soft solid (ice cream) by 4D synchrotron X-ray tomography. (November 2018)

• Record Type: Journal Article
• Authors: Guo, Enyu; Kazantsev, Daniil; Mo, Jingyi; Bent, Julian; Van Dalen, Gerard; Schuetz, Peter; Rockett, Peter; StJohn, David; Lee, Peter D.
• Is Part Of: Journal of food engineering. Volume 237(2018)
• Page Start: 204
• Page End: 214
• Publication Date: 2018-11
• Subjects: Ice cream -- Microstructure -- Tomography -- Ice crystals -- Coarsening -- Soft solid; Food industry and trade -- Periodicals; Food -- Analysis -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Analyse -- Périodiques; Aliments -- Recherche -- Périodiques; 664.005
• DOI: 10.1016/j.jfoodeng.2018.05.027
• Languages: English
• ISSNs: 0260-8774

Abstract

Abstract: Understanding the microstructural stability of soft solids is key to optimizing formulations and processing parameters to improve the materials' properties. In this study, in situ synchrotron X-ray tomography is used to determine the temperature dependence of ice-cream's microstructural evolution, together with the underlying physical mechanisms that control microstructural stability. A new tomographic data processing method was developed, enabling the features to be segmented and quantified. The time-resolved results revealed that the melting-recrystallization mechanism is responsible for the evolution of ice crystal size and morphology during thermal cycling between −15 and −5 °C, while coalescence of air cells is the dominant coarsening mechanism controlling air bubble size and interconnectivity. This work also revealed other interesting phenomena, including the role of the unfrozen matrix in maintaining the ice cream's microstructural stability and the complex interactions between ice crystals and air structures, e.g. the melting and recrystallization of ice crystals significantly affect the air cell's morphology and the behavior of the unfrozen matrix. The results provide crucial information enhancing the understanding of microstructural evolution in multi-phase multi-state complex foodstuffs and other soft solids. Highlights: In situ synchrotron tomography reveals the dynamics of ice cream emulsion's thermal stability. A new tomographic data processing method was developed, enabling the features to be quantified. The melting-recrystallization mechanism is responsible for ice crystal evolution. Coalescence of air cells is the dominant coarsening mechanism controlling air bubble's evolution. The unfrozen matrix is important in maintaining the ice cream's microstructural stability.