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ARS Home » Northeast Area » Beltsville, Maryland (BHNRC) » Beltsville Human Nutrition Research Center » Food Composition and Methods Development Laboratory » Research » Publications at this Location » Publication #328051

Research Project: Metabolite Profiling and Chemical Fingerprinting Methods for Characterization of Foods, Botanical Supplements, and Biological Materials

Location: Food Composition and Methods Development Laboratory

Title: Spectroscopic analysis of wheat fractions and reconstituted whole wheat mixtures by 1H NMR and NIR

item RAMAKRISHNAN, VENKATESH - Us Forest Service (FS)
item Luthria, Devanand - Dave
item Harnly, James - Jim
item RIDGE, CLARK - Food And Drug Administration(FDA)
item MAZZOLA, EUGENE - Food And Drug Administration(FDA)

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/24/2016
Publication Date: 9/17/2016
Citation: Ramakrishnan, V., Luthria, D.L., Harnly, J.M., Ridge, C., Mazzola, E. 2016. Spectroscopic analysis of wheat fractions and reconstituted whole wheat mixtures by 1H NMR and NIR. Journal of Food Science. 94:471-479.

Interpretive Summary: Wheat and its processed products are consumed globally as important energy sources. Wheat-based foods provide a majority of the carbohydrates, some proteins, dietary fibers, and other micronutrients. In Asia, nearly half of the annual caloric consumption is rice, while the major grain consumption in Europe and US is wheat. In this manuscript, we have investigated the application of simple 1H-NMR and NIR spectroscopic methods for the differentiation of three different wheat fractions (bran, germ, refined flour) in addition to the whole wheat flour from two wheat varieties. Furthermore, we have applied the same spectral fingerprinting approach to classify reconstituted whole grain composed with different proportions of bran, germ, and refined wheat Finally, we have compared the two methods, 1H-NMR and NIR, with respect to their ability to discriminate between the wheat fractions.

Technical Abstract: Commercial success of whole wheat products has warranted development of new analytical approaches for differentiating whole grain products from conventional food products made from refined grains. Here, we have analyzed three different wheat fractions namely bran, germ, and refined flour of two wheat varieties. In addition, a whole wheat sample containing all the three fractions was also included in the study to investigate the application of two spectral fingerprinting methods, proton nuclear magnetic resonance (1H-NMR) and near infrared (NIR) spectroscopy for differentiating the 3 fractions and the whole wheat. Results show that both these methods provide unique spectral fingerprints for the bran, germ, refined, and whole wheat flours. In addition, we were able to distinguish whole grain composed of different ratios of the germ, bran and refined grain, exemplifying the potential applicability of both fingerprinting methods (NIR and NMR) for the differentiation of whole and refined wheat samples. PCA analysis on 1H-NMR data with four different bin sizes (0.02, 0.04, 0.08 and 0.16 ppm) did not have significant influence on differentiation of the four fractions.