The feasibility of near-infrared reflectance spectroscopic analysis on flour swelling power and water-soluble protein content of buckwheat flour

Yuji Mukasa¹, Clayton Campbell², Yutaka Honda¹ and Tatsuro Suzuki¹

¹ National Agricultural Research Center for Hokkaido Region, Memuro, Hokkaido 082-0071, Japan ² Kade Research Ltd., Morden, Manitoba, R6M 1E9, Canada

Yuji Mukasa, Clayton Campbell, Yutaka Honda and Tatsuro Suzuki. 2005. The feasibility of near-infrared reflectance spectroscopic analysis on flour swelling power and water-soluble protein content of buckwheat flour Fagopyrum 22: 51-56.

Abstract: The feasibility of near-infrared (NIR) reflectance spectroscopy was evaluated for the determination of flour swelling power and water-soluble protein content in buckwheat flour. 0.7 grams of flour sample was placed into a scintillation vial (10 mL) and the reflectance spectrum of the sample was scanned using an NIR spectrophotometer set up with a Rapid Content Analyzer (RCA) as a sample presentation module. Multiple linear regression (MLR), partial least square regression (PLS) and modified PLS regression (MPLS) were carried out using first derivative spectra and reference data to develop calibration models. Optimal calibrations were obtained with MPLS on both flour swelling power and water-soluble protein content. In the optimal calibrations, the coefficient of correlation (r) and the standard error of prediction (SEP) were 0.82 and 0.55 (g gel/ g d.w.) for flour swelling power and 0.89 and 0.35 (% d.w.) for water-soluble protein content, respectively. Both calibrations should be useful for initial screening of breeding lines. In addition, the precision of the spectral scanning was evaluated using 0.7 g and 7 g of the sample amounts. When estimated from the coefficient of variability (CV) of the optical density, a larger sample weight should improve the precision of scanning and give improved results for both calibration and prediction.

Key words:flour swelling power, MPLS, NIR, water-soluble protein