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Title: DETERMINATION OF TOTAL DIETARY FIBER OF INTACT CEREAL FOOD PRODUCTS BY NEAR-INFRARED REFLECTANCE

Author
item Archibald, Douglas
item Kays, Sandra

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/16/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: The study develops and evaluates a new instrumental method for estimating the total dietary fiber content of diverse cereal food products including breakfast cereals, snack foods, baking mixes, flours and whole grains. The method is intended to replace a time-consuming and waste-producing wet-chemical method that is used in nutritional laboratories and by the FDA Aand FSIS to support the Nutrition Labeling and Education Act. Unlike the previous spectral methods, the cereal food specimen does not need to be milled - it is simply poured out of the box or bag into the instrument, and the fiber content can be obtained within one minute. The performance of this system is comparable to previous spectral methods requiring the milled samples and a wider spectral range, and furthermore, the measurement should not be affected by the degree of product breakage or the moisture level of the product, a common interference for this type of instrumental method. The model was optimized with an ovel computational approach that has applications outside the aims of this study. Moreover, because the method is rapid, the principles and models may also find use in sensors for the food processing industry.

Technical Abstract: Near-infrared reflectance spectra of cereal food products were acquired with a commercial dual diode array (Si, InGaAs) spectrometer customized to allow rapid acquisition of scans of intact breakfast cereals, snack foods, whole grains and milled products. Substantial gains in the performance of multivariate calibration models generated from this data were obtained by a acomputational strategy that systematically analyzed the performance of various spectral windows. The calibration model based on 137 cereal food products determined the total dietary fiber (TDF) content of a test set of 45 intact diverse cereal food products with root mea-squared error of cross-validation of between 1.8 and 2.0% TDF, relative to the laborious enzymatic-gravimetric reference method. The calibration performance is adequate to estimate TDF over the range of values found in diverse types of cereal food products (0.7 - 50.1%). The method requires no sample preparation and is relatively unaffected by specimen moisture content.