title: Simultaneous imaging of fat crystallinity and crystal polymorphic types by Raman microspectroscopy.
abstract: The crystalline states of fats, i.e., the crystallinity and crystal polymorphic types, strongly influence their physical properties in fat-based foods. Imaging of fat crystalline states has thus been a subject of abiding interest, but conventional techniques cannot image crystallinity and polymorphic types all at once. This article demonstrates a new technique using Raman microspectroscopy for simultaneously imaging the crystallinity and polymorphic types of fats. The crystallinity and β' crystal polymorph, which contribute to the hardness of fat-based food products, were quantitatively visualized in a model fat (porcine adipose tissue) by analyzing several key Raman bands. The emergence of the β crystal polymorph, which generally results in food product deterioration, was successfully imaged by analyzing the whole fingerprint regions of Raman spectra using multivariate curve resolution alternating least squares analysis. The results demonstrate that the crystalline states of fats can be nondestructively visualized and analyzed at the molecular level, in situ, without laborious sample pretreatments.
authors.affiliation: NARO Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization (NARO), Ikenodai 2, Tsukuba, Ibaraki 305-0901, Japan. Electronic address: mmichiyo@affrc.go.jp.
authors.forename: Michiyo
authors.initials: M
authors.lastname: Motoyama
authors.affiliation: Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, Wakamatsuchou 2-2, Shinjuku, Tokyo 162-8480, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ando
authors.affiliation: NARO Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization (NARO), Ikenodai 2, Tsukuba, Ibaraki 305-0901, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: NARO Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization (NARO), Ikenodai 2, Tsukuba, Ibaraki 305-0901, Japan.
authors.forename: Ikuyo
authors.initials: I
authors.lastname: Nakajima
authors.affiliation: NARO Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization (NARO), Ikenodai 2, Tsukuba, Ibaraki 305-0901, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Chikuni
authors.affiliation: NARO Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization (NARO), Ikenodai 2, Tsukuba, Ibaraki 305-0901, Japan.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Aikawa
authors.affiliation: Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, Wakamatsuchou 2-2, Shinjuku, Tokyo 162-8480, Japan; Department of Applied Chemistry, College of Science, National Chiao Tung University, Taiwan, 1001 University Road, Hsinchu 300, Taiwan, Republic of China.
authors.forename: Hiro-O
authors.initials: HO
authors.lastname: Hamaguchi
mesh_terms: D000273:Adipose Tissue; D000818:Animals; D003460:Crystallization; D005223:Fats / Q000737:chemistry*; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D007091:Image Processing, Computer-Assisted; D016018:Least-Squares Analysis; D008962:Models, Theoretical; D015999:Multivariate Analysis; D013059:Spectrum Analysis, Raman; D013552:Swine
chemical_list: D005223:Fats; D005227:Fatty Acids
keywords: Fat crystalline states; Lard; Meat; Microstructures; Physical properties; Raman imaging