Studies on the Quality of Soybean Curd

We determined the contents of moisture, protein, fat and calcium in soybean curd obtained directly from makers all over Yamaguchi pref.. The average values of them were 87.23%, 6.23%, 3.34%, and 14.9mg%, respectively. Of all contents, especially on calcium, the value varied much widely. The number of E. coli cells in soybean curd obtained from makers and shops was measured and it was observed that all samples were contaminated with E. coli, and the cantamination was more marked in soybean curd obtained from shops. Daily changings of pH, contents of true protein and free amino acids in soybean curd preserved under various conditions were examined. The values of all of them were more remarkably changed under the condition whitch was suitable for microbial grouth. The effects of some food additives such as magnesium chloride, 8-glucolactone and sodium hexametaphosohate used in soybean curd on the growth of microorganisms was examined and it was suggested that these compounds, especially 8-gluconolactone, might be useful for the control of the microbial growth in soybean curd at the early time from its production.