A Rapid High‐Throughput Method for Determining Albumin and Globulin Contents in Pea and Soybean Seeds

ABSTRACT Protein fractionation and characterization are essential to understanding the functional properties of seed proteins, which are valuable ingredients for modern plant breeding and the food industry. To address the need for a rapid, cost‐effective, and high‐throughput (HPT) method for assessing the albumin/globulin ratio in pea and soybean, we adopted a selective extraction procedure using a high‐salt buffer at neutral pH. We have further modified this method for highly selective extraction that operates on a microscale, utilizing approximately 20 mg of seed meal per assay, which has been highlighted with improved efficiency and accuracy. This approach mitigates issues of cross‐contamination between albumin and globulin fractions that are encountered in older methods. The albumin/globulin ratios for extracted protein isolates were obtained by applying the Bradford method. The findings of the HPT technique have remained within usual ranges, in contrast to large‐scale extraction (LSE). The albumin/globulin ratios of green peas were 0.12 ± 0.01 and 0.13 ± 0.01, attained by LSE and HTP, respectively. The LSE and HTP values for soybeans were 0.14 ± 0.01. The protein isolates from yellow pea yielded the results of 0.17 ± 0.02 using LSE and 0.19 ± 0.02 with HTP. The assay was validated by comparing the albumin/globulin fractions with electrophoretograms, which are obtained by curve integration of Coomassie blue‐stained SDS‐PAGE gels of pea and soybean seed protein isolates. This method was also successfully applied to analyze commercially available green and yellow pea varieties, each exhibiting distinct albumin/globulin ratios, emphasizing the effectiveness and distinctive functionality of this method.