In conventional oil-in-water emulsified compositions, the emulsified state has been stabilized by reducing the diameter of emulsion particles so as to realize fine uniform particles. This has resulted in the problem of flat taste or indistinct, featureless flavor. According to the invention there is provided the technology of obtaining an oil-in-water emulsified composition having an emulsified particle median diameter adjusted to a relatively large particle diameter, e.g. 5-100 .mu.m, by the use of soybean-derived water-soluble polysaccharides in a stable composition. The emulsified composition has a good body and satisfactory taste attributed to the fat and oil components, and is stable over time. The soybean-derived water-soluble polysaccharides can be obtained by heat extraction from soybean or processed soybean products at a temperature of above 100.degree. C. and a pH lower than the isoelectric point of soybean protein, preferably at an acidic pH of 2.4-4.0 or more preferably 3.0-3.5.