CHARACTERISTICS AND ACCEPTABILITY OF A FLOUR PREPARED FROM SODIUM BICARBONATE SOAKED AND STEAMED SOYBEANS

Abstract

A soyflour was prepared by soaking the beans in 9 volumes of 0.5% NaHCO3 overnight (pH 8.5), steamed at 100°C for 30 min, dried at 50–60°C under vacuum, then ground to flour. The flour had a light tan color and no objectional beany odor. The composition of the flour was 48% protein, 19% flour, 5% ash, and 3.5% moisture. No lipoxygenase nor antitrypsin activity was detected in the flour. The phytate content was 0.75%. Protein solubility, emulsifying capacity, foaming capacity, oil and water absorption of the flour was determined. The results showed that the flour prepared from biocarbonate soaked and steamed soybeans possessed desirable functional characteristics except protein solubility was decreased. Two products, noodles and bread, were prepared by using the soyflour as an ingredient. Sensory evaluation of the products revealed that both products were well accepted. This study was supported in part by the George Washington Carver Agricultural Experiment Station, (USDA/CSRS Grant No. Al X-3JYL-05). The authors acknowledge the assistance of Mr. Leo G. Holmes, U.S. Army Natick Research and Development Command, Natick, Mass., in conducting amino acid analysis of soyflour.