In the market, there are various vegetable oil. And they have different press methods according to the different oil crops features.
The tea-seed oil is of great quality with green, environmental friendly, health care. Its price is quite high. Tea seed has hard shell, and the oil content rate of its kernel is higher, and concentration is too strong. So the processing technology and methods standard of tea-seed is higher than tung seed, sunflower seed and pepper seeds. So far, from traditional manual, mechanical, hydraulic press to the later horizontal oil press machine, people have not solve problem of turning waste into treasure to make full use of the precious resource.
Then I will introduce you some pressing methods of several main oilseeds:
Sesame: before pressing, roast the sesame seeds until light gray with a burst phenomenon. At the same time, the sesame oil will outflow when pinching the sesame seed with your hand. Using big fire to roast sesame seeds, the temperature may be 120-150℃. Then press the roasted sesame seeds thoroughly to get the pure oil at one time. And the sesame oil meal (de-oiled cake) has strip shape with 0.7-15mm thickness.
Rapeseeds: first roast the rapeseeds until hot using the big fire, when there is burst, roast the rape seeds until red-brown. During the roasting, don’t add water. When pressing the rapeseeds, the most appropriate temperature is 120-130℃. The processed rapeseeds oil almost doesn’t contain residue. And the rapeseeds oil cake (oil meal)
has 1-1.5 mm thickness which is small pieces and brown-red.
Peanut kernel: before roasting peanut kernel, soak them in the water lightly. In the process of roasting seeds, you should add a proper amount of water, so as to keep the good flexibility and plenty of moisture. Roast peanut kernel until eight mature. When you pinch the peanut with your hands, the peanut kernel and shell are separated; also the kernel would break into two parts then the material can be pressed. The oil meal cake is 0.7 mm thickness. Get peanut oil smoothly.
Cotton seeds: before pressing cotton seeds, roast the oilseeds until light yellow, the seeds temperature is 120-130℃. Then press them, the thickness of cotton seeds oil meal (de-oiled cake) is 1-1.5 mm.
Soya bean: before pressing soybean, roasted soya bean until pop and edible, the temperature is 120-130℃. Press completely at on time, but the over parched oil cake would cause large quantity loss of protein. So in general, the pressing time would be two times the general. Roast soya bean until six-seven mature, the pressing temperature is 80-100℃, and the moisture content is 5-6%. The oil cake thickness is 1.52 mm in the first time, and 0.7 mm at the second time. The oil cake is a long strip-like wrinkles shape. Thus the oil yield is high and the capacity is large.