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Ouissam Abbas, Juan Antonio Fernández Pierna, Pierre Dardenne & Vincent Baeten

Walloon Agricultural Research Centre, CRA-W

Valorisation of Agricultural Products dpt Food and Feed Quality Unit

Gembloux, Belgium

How NIR spectroscopy and imaging are useful for the analysis of feed contamination by melamine?

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The aim of this work is to investigate the usefulness of a procedure based on Near Infrared (NIR) spectroscopy and Chemometrics for the characterization of a typical feed product (soybean meal) as well as for the detection the contamination by melamine.

Aim

This work was done in the framework of different projects: INGOT (http://www.aunir.co.uk/) EU Project QSAFFE (KBBE-2010-2-4-03) GFSV 20

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Plan

Laboratory level

• NIR spectroscopy Detection of contamination, Prediction of protein value

• NIR imaging Discrimination of contaminated samples

Feed plant level

• At-line NIR spectroscopy Detection of contamination

• On-line NIR spectroscopy Detection of contamination

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90% of soybean seeds produced in the world are used as feeds for animals, which corresponds to an amount over 160mln ton.

Soybean meal is the material remaining after solvent extraction of oil from soybean flakes; it consists of more than 36% protein, 30% carbohydrates, and excellent amounts of dietary fiber, vitamins, and minerals.

Soybean meal

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Melamine

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Melamine Outcomes from melamine contamination: • cat and dog illnesses/deaths • front-page national/international news • massive economic fallout • industry changes • new regulations & enhanced programs

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Melamine is an organic compound that is rich in nitrogen. When combined with formaldehyde it produces melamine-resin, which is widely used in several textiles, plastics, adhesives, flame-resistant products, and some cleaning agents. When combined with cyanuric acid, they form crystals which could cause severe renal problems leading to death

Melamine is illegally added to food/feed to artificially elevate the protein content values of products.

WHAT

WHY

Melamine

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NIR spectroscopy

Raman and MIR

spectroscopy

NIR spectroscopy

NIR/MIR microscopy

Fluorescence

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Melamine

Soybean meal non contaminated

Soybean meal contaminated with 5% melamine

A rapid

detection of any modification by non-authorized additives like

Melamine

Comparison of spectra of melamine and soybeanmeal

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SM01 SM02 SM03 SM04 SM05

Evolution of GH in function of the percentage of adulteration of soybean meal by melamine (application of general feed ingredient equation)

Detection of melamine contamination by NIR spectroscopy

Abbas O., Lecler B., Dardenne P. and Baeten V. (2013) Detection of melamine in feed ingredients by near infrared spectroscopy and chemometrics. Journal of Near Infrared Spectroscopy, 21(3), 183-194.

GFSV 2014

11 Comparison between predicted values of nitrogen obtained by spectroscopic analysis (selected region between 2130 and 2230 nm, full spectrum between 1100 and 2498 nm)

and reference values obtained by chemical analyses (Dumas and Kjeldahl) of studied samples

Prediction of protein value by NIR spectroscopy Soybean meal

Log

(1/R

)

Wavelength (nm)

2170

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Hyperspectral Imaging

NIR imaging

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PLS-DA model - validation

Discrimination models NIR Hyperspectral data

Detection of melamine contamination by NIR imaging

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PLS-DA model – application on contaminated data

1 soybean meal + melamine 0,5% 2 soybean meal + melamine 1% 3 soybean meal + melamine 1,5% 4 soybean meal + melamine 2% 5 soybean meal + melamine 2,5% 6 soybean meal + melamine 3% 7 soybean meal + melamine 3,5% 8 soybean meal + melamine 4% 9 soybean meal + melamine 5%

10 soybean meal

2200 lines x 320 pixels : 704000 pixels (260 MB) Conveyor belt speed: 0.5 mm/s Pixel size: 30 µm x 45 µm Sample weigth: 1 gr Length: 10 cm Width: 1 cm

Detection of melamine contamination by NIR imaging

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soyabean mealFull fat soyaSoya hulls

Regression equations

GH similarity Three criteria

Protein

Fat

Detection of melamine by NIR at-line spectroscopy at feed plant level

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Detection of melamine by NIR on-line spectroscopy at feed plant level

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Detection of melamine by NIR on-line spectroscopy at feed plant level

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Detection of melamine by NIR on-line spectroscopy at feed plant level

Example of an adulteration by whey

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GH

GH

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NIR spectroscopy /NIR Hyperspectral imaging and chemometrics make it possible to compare efficiently suspected spectra of new samples and detect melamine in feed. Use of developed calibration equations permits to: • Locate new spectra in the feed data base • Predict the chemical properties values

Application of at-line NIR spectroscopy is a good tool to detect contamination.

Conclusions & perspectives

New perspective: Installation of a NIR spectrometer in the production line and direct measurement of spectra intantaneous detection of contamination or undesirable substances

(Source: Bruker) GFSV 2014

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