Present Situation of Dehulling-process Technology of Soybean

Traditional soybean pretreatment processes includes: cleaning, crushing, softening, billets and green body drying, etc. Since the late 1980s, soybean is used as one kind of oilseeds for process, the traditional pretreatment process has been used to nowadays.

Small and medium-sized processing plants as well as a considerable number of large processing plants are still using this technology in China, after years of practice, the traditional processing technology becomes more mature and stable, the advantage is that the process is simple and investment in equipment is less. The downsides are that the cell damage in the green compacts is little and more powder in it; the cake is dense texture; infiltration and drip dry is slow in the leaching process; the leaching rate is low and so on. All the factors above would lead to these problems: more evaporation system, poor crude oil quality, poor meal appearance and palatability.

Soybean dehulling technologies are already quite mature now. Soybean contains about 8% of the skin; use Dehulling Machine to take off more than 80% of the skin would greatly increase the handling amount of the equipment in the large-scale production. And fiber content of meal after removal of soybean skin is reduced, so palatability of meal is good. There are several ways to realize dehulling process, for example: put heated soybeans on fluidized bed to fast-dried would make the water in the soybean skin evaporate rapidly, thus the skin will burst and is easy to remove. Peeling rate of semi-hulling process is about 50%-70%, while the whole peeling process almost reaches 90%.