Evaluation of Soybean Cultivars for Processing and Product of Nimame

Seasoned Boiled Beans

Abstract

In Japan, soybean seeds are used to make Nimame by cooking them with sugar and salt syrup. Since the quality of Nimame is mainly affected by that of raw soybean seeds, the good quality seeds are required for Nimame processing. In this paper, the seeds of 4 cultivars cultivated at 2 locations were used to evaluate their suitability for Nimame. The items for examination were chemical constituents (moisture, protein, oil, total sugar, free sugar, and total carotenoid contents) and suitability for Nimame processing (weight of 100 seeds, weight increase ratio of soaked seeds, germination ratio, solid matter content in soaked water, weight increase ratio of soaked seeds by steaming, softness, appearance, and color of boiled beans). Sensory quality of Nimame and its change in color by storage were also tested. The characteristic chemical compositions observed were high free susugar andtotal carotenoid contents in Otsuru, low protein and high oil and free sugar contents in Tamahomare, and low free sugar and total carotenoid contents in Enrei. Otsuru had a largeseed size, a low germination ratio, and a high content of solid matter in soaked water of the seeds and the low coefficient of variation (CV) of hardness, low a and high b in the color values in boiled beans. Many swelled husks were observed in the boiled beans of Enrei. In the sensory test of Nimame, Otsuru was highly rated in appearance, taste, hardness, color, and overall evaluation. Tamahomare was appraised low in hardness, but the highest in color. From those results, it was presumed that the large seed size, a low CV value of hardness, and a high color value of b in boiled beans were the most important factors affecting the quality of Nimame. In the storage test of Nimame at 30°C in a polypropylene bag for 7, 14, 21, and 28 days, color damage was high in Enrei, but low in Tamahomare. The b value reduced rapidly in Otsuru.