Sesame doesn’t need to be peeled in common sesame oil processing. However, the content of cellulose and oxalate in sesame skin and cuticula is high, which would deepen the color of oil and cakes and bitter the cakes. Thus the cakes could only be used for cattle feed and fertilizer and couldn’t be the protein source of human or single-stomach animals. In another word, sesame which process sesame oil and cakes as food have to be peeled first.
Traditional sesame peeling is to destroy sesame skin by soaking and separate the kernel and skin by buoyancy. We can also regulate the density of water by adding salt in to get better separation.
Black sesame before peeling
White sesame before peeling
The other traditional sesame peeling is to rub sesame with destroyed skin by soaking on rough slate to separate the kernel and skin. After that, we can also separate the kernel and skin by buoyancy.
We can also peel sesame by mechanical method. Wet sesame pass through the crack between two discs with hard surface, one disc fixed and the other revolving. We can get mixture of water, sesame skin and kernel. Finally, we can utilize wire-steel net to screen sesame skin from the mixture and get sesame kernel .