A rapid analytical and quantitative evaluation of formaldehyde in squid based on Tri-step IR and partial least squares (PLS). (15th August 2017)

• Record Type: Journal Article
• Authors: Gu, Dong-Chen; Zou, Meng-Jun; Guo, Xiao-Xi; Yu, Pan; Lin, Zhi-Wei; Hu, Tu; Wu, Ya-Fen; Liu, Yuan; Gan, Jian-Hong; Sun, Su-Qin; Wang, Xi-Chang; Xu, Chang-Hua
• Is Part Of: Food chemistry. Volume 229(2017)
• Page Start: 458
• Page End: 463
• Publication Date: 2017-08-15
• Subjects: Squid (Illex argentinus) -- Formaldehyde -- Tri-step infrared spectroscopy -- Partial least squares -- Spectral curve-fitting analysis -- Quantitative detection model; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2017.02.082
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Tri-step IR was developed for qualitative and quantitative profiling of squids. Formaldehyde concentration in squid soaked water play a role in formaldehyde in squid. Spectral curve-fitting was applied to further disclose the variation rule of protein secondary structure. Tri-step IR combined with PLS can accurately predict formaldehyde concentration in squids. Abstract: Formaldehyde abuse for retaining squid freshness is detrimental to public health. The aim is to establish a rapid and quantitative detection method of formaldehyde in squid for screening massive samples. A linear relationship between formaldehyde concentration in squid and formaldehyde concentration in squid soaked water was observed using HPLC. Chemical profile variances of squids were rapidly analyzed by Tri-step infrared spectroscopy. Specifically, with increasing formaldehyde concentration, peak intensities of 2927 cm −1 ( v as (CH2 )), 1081 cm −1 (glycogen), 1631 cm −1 ( β -sheet proteins) decreased while 1655 cm −1 ( α- helix proteins) increased. Spectral curve-fitting results further disclosed that β -sheet proteins were transformed to α -helix and β -turn conformations. Furthermore, a quantitative prediction model based on IR spectra was established by PLS (R 2, 0.9787; RMSEC, 5.51). The developed method was applicable for rapid (c.a. 5 min) and quantitative analysis of formaldehyde in squids with LOD of 15 mg/kg.