title: Element distribution and morphology of spotted golden goatfish fish scales as affected by demineralisation.
abstract: Scales of spotted golden goatfish were subjected to non-collagenous protein removal followed by demineralisation with hydrochloric acid at different concentrations (0.25, 0.5, 0.75 and 1 M) for various times (30, 60 and 90 min). The morphology and element composition/distribution of scales from spotted golden goatfish as influenced by demineralisation conditions were determined. The appropriate demineralisation was pertained using 0.75 M hydrochloric acid for 30 min, in which the ash content was 0.62% (dry weight basis). The scales having non-collagenous protein removal with, and without, subsequent demineralisation were analysed for element content using X-ray fluorescence spectrometer. Images of different scales were determined using scanning electron microscopy (SEM) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). Based on the images, an external layer rich in inorganic elements was removed. Most of Ca and P were eliminated with the coincidental increases in organic substances (C, N and O) after demineralisation. Demineralisation therefore mainly removed the external layer of scales, which facilitated the further extraction of collagen or gelatin.
authors.affiliation: Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
authors.forename: Sira
authors.initials: S
authors.lastname: Chuaychan
authors.affiliation: Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand. Electronic address: soottawat.b@psu.ac.th.
authors.forename: Soottawat
authors.initials: S
authors.lastname: Benjakul
authors.affiliation: Scientific Equipment Center, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
authors.forename: Pornpot
authors.initials: P
authors.lastname: Nuthong
mesh_terms: D000825:Animal Structures / Q000737:chemistry* / Q000648:ultrastructure; D000818:Animals; D029941:Fish Proteins / Q000737:chemistry*; D005399:Fishes; D008855:Microscopy, Electron, Scanning; D013052:Spectrometry, X-Ray Emission
chemical_list: D029941:Fish Proteins
keywords: Demineralization; Element; Morphology; Scales; Spotted golden goatfish