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THE NEAR INFRARED SPECTROSCOPY FOR

A RAPID ASSESSMENT OF NUTRITIONAL

QUALITY AND SAFETY

OF CEREAL GRAIN

21th FOSS Grain Network Meeting-March 18th -20th 2015, Milan

CRA-QCE

Council for Agricultural Research

and Economics

Research Unit for Cereal Quality

Rome

Department of Chemistry

University «La Sapienza»

Rome

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Quantitative analysis of cereal bioactive compounds and

mycotoxins (Deoxynivalenol, DON) by NIRS reflectance

FOSS NIR-system model 6500

400-2500 nm-2 nm

Chemical measurements

Statistically predictive equation(s)

Spectra collection

Reference data

Chemometric

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Quantitative analysis of cereal bioactive compounds

by NIRS reflectance

ARABINOXYLANS (AX)

ALKYLRESORCINOLS (AR)

Durum wheat

β-GLUCANS

Oat

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CHEMICAL MEASUREMENTS: β-glucans were measured by using the

enzymatic β-glucan assay kit (Megazyme) McCleary and Codd (1991); Åman and Graham (1987); Lee et al. (1997)

SOLUBLE β-GLUCANS TOTAL β-GLUCANS

Oat products are important sources of dietary fibre, β-glucans, proteins,

vitamins and other components, which are demonstrated to be

beneficial for human health

β-glucans improve growth, viability and colonization of probiotic

microorganisms

In general, as components of soluble fibres reduce the risk of coronary

heart disease and type 2 diabetes

Quantitative analysis of oat β-glucans by NIRS reflectance

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Quantitative analysis of oat β-glucans by NIRS reflectance

Husked and naked oat genotypes (from different European countries-

AVEQ Project):

300 genotypes (TRAINING SET) for calibration development

50 genotypes (TEST SET) for validation

NIR calibration models developed with PLS regression methods

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The VIP values, computed for each wavelength, evidence

the regions contributing the most to the regression model

for β-glucan are those between 400 and 700 nm, around

1150 nm and between 1900 and 2300 nm

Variables Importance on PLS projections (VIP)

Quantitative analysis of oat β-glucans by NIRS reflectance

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Quantitative analysis of durum wheat arabinoxylans (AX) by

NIRS reflectance

AX are one of the most important dietary fiber components in the

cereal kernels. An interesting property of AX is their ability to

form highly viscous water solutions and this peculiarity affects

the technological characteristics of flours and determines a

positive physiological influence on human health

WATER EXTRACTABLE AX (WEAX)

TOTAL AX (TOAX)

CHEMICAL MEASUREMENTS: TOAX and WEAX were determined by

GC-FID (Ciccoritti et al., 2011)

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Quantitative analysis of durum wheat arabinoxylans by

NIRS reflectance

The dataset comprised durum wheat samples (n=100/200 spectra)

grown in different Italian regions during three crop years (2012-2014)

Spectra pretreatment+PLS

AX

fractions on milled grain

Mean value

(% as is)

RMSEC RMSECV RMSEP R2

TOAX 4.11±0.27 0.159 0.205 0.266 0.659

WEAX 0.54±0.23 0.176 0.192 0.192 0.309

TOAX

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Quantitative analysis of durum wheat 5-n-alkylresorcinols

(AR) by NIRS reflectance

AR have been reported to have antioxidant, antimutagenic, anticancer (in

colon), antimicrobial, antiparasitic and antifungal activities

In plant they are thought to serve important roles as "PHYTOANTICIPINS"

CHEMICAL MEASUREMENTS: AR were measured by using the colorimetric

method FAST BLUE RR

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Quantitative analysis of 5-n-alkylresorcinols on durum wheat

milled grain by NIRS reflectance

To have a broad variability, the dataset comprised a durum wheat F6 progeny

(n=135/270 spectra) from the cross Ardente X Mohawk, showing contrasting AR

content (Mean 130 µg/g as is; range of variability 19-268 µg/g as is)

90 samples (TRAINING SET) for calibration development

45 samples (TEST SET) for validation

Spectra pretreatment + PLS regression

LV RMSE R2 Bias

Calibration

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31 0.86 0

Cross-validation 41 0.74 -1

Prediction 42 0.72 3

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NIR-based approach for quantification and/or assessment of the

contamination status. Deoxynivalenol (DON) in durum wheat

DON is one of the several mycotoxins produced by some Fusarium species

DON affects human and animal health causing acute temporary nausea,

vomiting, diarrhea, abdominal pain, headache, dizziness and fever

EU limit of 1750 ppb for wheat grain to be considered contaminated

CHEMICAL MEASUREMENTS: DON was determined by using using test

ELISA -RIDASCREEN® DON (R-BIOPHARM). [DON]=ppb

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Quantitative analysis of DON on durum wheat milled

grain by NIRS reflectance

The dataset comprised more than 200 durum wheat samples (range 750-

12350 ppb)

170 durum wheat samples (TRAINING SET)

45 samples left aside as independent test set (TEST SET)

Pre-treatment LV RMSEC RMSECV RMSEP

MSC 9 15.99 18.25 21.30

MSC+ II der. 4 14.79 19.45 20.76

oTraining set x Test set

NIR calibration model developed with PLS regression methods

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The VIP values, computed for each wavelength, evidence

the regions contributing the most to the regression

model for DON are those between 400 and 700 nm,

around 1350-1460 nm and between 2000 and 2150 nm

Quantitative analysis of DON in durum wheat by NIRS reflectance

Variables Importance on PLS projections (VIP)

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Classification analysis of durum wheat grain (sound and unsound)

by NIRS reflectance

Chemometric method of classification (SIMCA-Soft Independent

Modeling of Class Analogy) to discriminate samples on the basis

of their DON content just above (UNSOUND) and below

(SOUND) the limit set by UE regulation for durum wheat flour

(1750 ppb).

Pretreat. Class Sensitivity Specificity

Cal CV Pred Cal CV Pred

MSC SOUND 100 84.62 55.56 81.73 82.21 91.43

UNSOUND 97.11 90.38 71.43 76.93 49.22 66.67

MSC+d2 SOUND 96.15 88.46 66.67 76.81 79.90 85.71

UNSOUND 97.11 92.31 51.43 76.92 50 66.67

CONCLUSIONS

NIRS allows the rapid and accurate quantification of

different health-relevant compounds of cereals. This

results in the possibility of speeding up the overall

quality control of the samples and make breeding

programmes easier

NIR spectroscopy could be used to monitor DON

contamination in wheat, however an increase of the

dataset and robust multivariate calibrations are needed

to improve our predictive model

21th FOSS Grain Network Meeting-March 18th-20th 2015, Milan

D. Sgrulletta

R. Ciccoritti

V. Del Frate

F. Nocente