Evaluation of Seed Protein, Starch, Tocopherols, Phytosterols and Total Phenolics for Mung Bean (Vigna radiata) Germplasm and Application of Near-Infrared Reflectance Spectroscopy (NIRs) for Rapid Prediction

The objective of this study was to evaluate seed nutritional components in mung bean (Vigna radiata) germplasm which is conserved in genebank of Korea, National Agrobiodiversity Center (NAC). And NIR application for rapid determination of those seed components was performed in this study. The targeted components were protein, starch, tocopherols, phytosterols and total phenolics in the seeds of mung bean germplasm which were analyzed using liquid chromatography and ELISA analysis. A collection of mung beans was composed of 1125 accessions from diverse origins so that our results could be useful for breeders to develop advanced varieties. As the results of tocopherols, α-tocopherol, β-tocopherol, δ-tocopherol, γ-tocopherol and total tocopherol content were diverse as the range of 0.10~17.00, 0.20~0.90, 0.10~17.40, 85.40~126.50, and 89.70~144.60 µg g^-1, respectively. For the results of sterols, campesterol, stigmasterol, sitosterol and total phytosterol content were diverse as the range of 29.20~121.40, 147.60~297.50, 354.2~542.10, and 537.60~862.40 µg g^-1, respectively. Protein content was diverse as the range of 20.48~28.62 % and starch was 113.57~204.20 mg g^-1. Total phenolics content was diverse as the range of 651.00~991.00 µg g^-1. To develop the calibration equations for rapid and nondestructive determination of each components, near-infrared reflectance spectroscopy (NIRs) spectra (1104–2494 nm) of samples ground into flour (n=106) were obtained using a dispersive spectrometer. A modified partial least-squares model was developed to predict each component, the coefficients of determination (R²) of the models were poor except for protein. The R² for protein was 0.99 which could be useful for the mass screening and rapid quantification of seed protein in mung bean germplasm.

Key words: mung bean, germplasm, near-infrared reflectance spectroscopy