Abstract: In this paper, the effect of addition of modified soybean phospholipids on structural properties (particle size and specific surface area, scanning electron microscopic (SEM) structure, particle size distribution, and optical microscopic changes), physicochemical properties (dispersibility, wettability, precipitation coefficient, bulk density, dry matter solubility index (DSI), emulsifying activity, and emulsifying stability) and sensory properties of soybean flour prepared from soybean hydrolysate from aqueous enzymatic extraction of soybean oil was examined. The results showed that the average particle size of soybean flour with 0.6% modified soybean phospholipids was small, and the specific surface area was large; small particles were observed in the microstructure with some of them being shrunken. Its solution exhibited a uniform particle size and droplet dispersion and was stable, which indicated that the addition of modified soybean phospholipids could significantly affect the structural properties of soybean flour. The addition of 0.6% modified soybean phospholipids decreased wetting time by 24.5 s, dispersion time 30 s, precipitation coefficient by 0.008 and bulk density by 0.16 g/mL and increased DSI by 12.87% when compared with the blank control, thus significantly improving the physicochemical properties of soybean flour. The findings of this study provide a basis for the development and utilization of soybean flour from soybean hydrolysate from aqueous enzymatic extraction of soybean oil and for the production and application of modified soybean phospholipids in the soybean processing industry.

Key words: modified soybean phospholipids, aqueous enzymatic extraction, soybean flour, structure, physicochemical properties