Evaluation of crystal nanoplatelet aggregation in intact butter by atomic force microscopy. (April 2021)

• Record Type: Journal Article
• Authors: Matsui, Kotaro; Kamigaki, Takamichi; Wakui, Ryota; Nishino, Yuri; Ito, Yoshiko; Miyazawa, Atsuo; Yoshioka, Koichiro; Shiota, Makoto
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 140(2021)
• Publication Date: 2021-04
• Subjects: Butter -- Atomic force microscopy -- Crystal nanoplatelets -- Transmission electron microscopy -- X-ray diffraction; AFM atomic force microscopy -- TEM transmission electron microscopy -- MF-CNPs milk fat-crystalline nanoplatelets -- SAXS small-angle X-ray scattering; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2020.110801
• Languages: English
• ISSNs: 0023-6438

Abstract

Abatract: The physical properties of butter are influenced by its microstructure; therefore, observation techniques should be employed to improve this structure. Current observation methods are coupled with the pretreatment process, which destroys the microstructure. In this study, therefore, we provide a novel approach without the pretreatment process to observe fat crystal platelets—aggregated to provide a network structure—by using atomic force microscopy (AFM) while the sample was immersed in water at a temperature of 10 °C; in particular, we used Young's modulus mode for the observation. To confirm the structure, the measurements of milk fat-crystalline nanoplatelets (MF-CNPs) were observed with the transmission electron microscopy (TEM) and the small-angle X-ray scattering (SAXS). Thus, the milk fat particles were found to measure 796 nm × 223 nm, and the thickness of MF-CNPs was found to be 20.1 nm by SAXS. These measurements corresponded to the images of fat crystals observed by AFM. Using this observation method, the relationship between the physical properties of butter and its fat crystal network can be discerned; therefore, the bread and confectionery industries can improve their butter processing conditions. Highlights: Butter's network structure was observed via AFM without destroying its structure. Observations were done in Young's modulus mode in water. The crystal shape of butter was confirmed by TEM and small-angle scattering. AFM is a powerful tool for evaluating crystal network aggregation.