Rapid analysis and identification of meat species by laser‐ablation electrospray mass spectrometry (LAESI‐MS)

Abstract

RATIONALE: Laser-ablation electrospray ionization mass spectrometry (LAESI-MS) was applied to analyze fresh meat species without sample pretreatment. The study demonstrates that the LAESI-MS technique is a promising, rapid and accurate method for meat identification using a protocol combining principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). METHODS: A focused IR-laser was used for meat sample ablation at a wavelength of 2940 nm. The ablated particulates were carried through a transfer PTFE tube using air as carrier gas, delivered to the electrospray plume and ionized. A TOF-MS was used to detect the ion signal. The raw mass spectra were analyzed using the PCA and PLS-DA protocol. RESULTS: Five fresh meat samples, chicken, duck, pork, beef and mutton, were identified by the developed LAESI-MS technique using the protocol combining PCA and PLS-DA. The discrimination accuracy of all meat species is 100%, and the score plot also shows good identifying ability. CONCLUSIONS: Five fresh meat samples were analyzed using the LAESI-MS technique. Each set of raw mass data was collected within 30 s and analyzed by the PCA and PLS-DA protocol. Eighteen, 19, 18, 17, and 15 markers for chicken, duck, pork, beef, and mutton, respectively, have been selected successfully for meat identification. The results demonstrate that LAESI-MS is a new reliable and rapid method for meat identification. Copyright © 2016 John Wiley & Sons, Ltd.The consumption of meat keeps constantly increasing in the world. As reported by Sans et al., meat consumption rose worldwide from 23.1 kg per person per year in 1961 to 42.20 kg per person per year in 2011. [1] As a result, the safety of meat has drawn extensive attention by society. Consumers are increasingly concerned about the quality of the meat they eat due to the many meat scandals which have occurred recently. [2] In order to detect fraudulent species in meat, many techniques have been developed. Enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) methods are routinely used for the specification of meat. [3] The ELISA method can be used as a fast qualitative or quantitative technique. One hundred meat samples and meat products have been analyzed for species determination by the ELISA method. The results showed that 22.0% of the samples were not in compliance with Turkish Food Codex, violating consumer rights and presenting a potential public health risk. [4] However, using an ELISA it is difficult to analyze different species in a single run, and also is quite expensive. [3] PCR methods are widely applied to identify meat species in routine laboratories. Only 0.1% of raw pork in poultry was detected by the PCR method. [5] However, the PCR method is not widely implemented in food control programs due to complex operation or financial reasons.Recently, mass spectrometry has become an important tool for the identification of meat due to its intrinsic high sensitivity and high specificity. Matrix-assisted laser desorption ionizat...

Comparison of Dimensionality Reduction Methods in Mass Spectra of Astrocytoma and Glioblastoma Tissues

“…The most widely used DR techniques in mass spectrometry are classical linear methods such as PCA and PLS-DA [12][13][14][15][16][17] . Recently a number of new DR algorithms were developed, such as non-negative matrix factorization (NNMF) 30 , isometric mapping (Isomap) 31 , UMAP 32,34 .…”

“…Analysis of the high-dimensional mass spectrometric (MS) data usually employs dimensionality reduction (DR) algorithms as the preliminary step for statistical analysis and visualization. Among DR methods most widely used are linear methods such as PLS-DA and PCA [12][13][14][15][16][17] . Recently more advanced non-linear methods, for example, t-SNE and UMAP to name a few, were developed 18 .…”

Comparison of different machine learning methods and dimensionality reduction for classification astrocytoma and glioblastoma tissues by mass spectra

“…For the analysis of large mass spectrometry (MS) data, dimension reduction (DR) algorithms are commonly used as a previous step for statistical analysis and visualization. The most widely used DR methods are linear methods such as PLS-DA and PCA [10][11][12][13][14][15][16] . More advanced nonlinear methods have recently been developed, such as t-SNE and UMAP, to name a few 17 .…”

Flesh ID: Nanopore Sequencing Combined with Offline BLAST Search for the Identification of Meat Source

“…So far, the meat origin can only be clarified by very specific analytical methods such as immunological assays or DNA-based amplification technologies [ 6 , 7 ]. The mass spectrometry has emerged as a rapid and accurate method for the identification of meat source [ 8 , 9 ]. The gold-standard in the authentication process of meat and meat products is the real-time PCR [ 10 ].…”