Abstract: The effect of low-water and pipeline grinding technology on the quality attributes (composition, particle size, centrifugal sedimentation rate, stability, color difference and sensory evaluation) of soybean milk obtained from different pulping processes were investigated. The results showed that compared with other treatments, a new low-water consuming immersion technique combined with colloidal grinding provided the highest extraction rate of protein. The protein content of the soybean milk was 3.89 g/100 g. In addition, the average particle size was smaller (2.55 μm); the particle size distribution was more uniform with a greater peak height and narrower peak width. The centrifugal sedimentation rate (1.81%) and turbiscan stability index were lowest. The stability of the system was significantly higher than that of soybean milk prepared by traditional soaking and grinding process (P < 0.05). Furthermore, the soybean milk had a significantly higher sensory score (96.20 points) with a brighter color and more delicate taste than other treatments (P < 0.05). The current work indicated that low-water consuming immersion combined with colloidal grinding significantly increased the extraction rate of soybean protein, reduced the particle size, and improved the stability and sensory quality of soybean milk.

Key words: soybean milk, wheel grinder, colloid grinder, low-water-consuming pulping technology, stability