Nowadays, with organic food and green food processing technology being held in high regard, the production of various kinds of cold pressed oil has reached new heights in international market. Cold press is the completely physical and mechanical way of oil production. The oil obtained need to be filtered or dried to meet the requirements of consumption. The production process avoids the contact of cold pressed oil with organic solvent, acid, alkali, activated clay and high temperature and the possible touch contamination and keeps the nutrient in cold pressed oil.
1. The origin of cold press
In the 1980s, with the improvement of living standards and higher requirements for health care, the consumption of natural green organic food became quite popular in Europe. The Germany company CIMBRIA SKET began to dedicate to the research of rapeseed dehulling, cold press technology and the corresponding research of cold press machine with other research institutions. The main problems need to be solved in cold press:
A) Cold press process. Cold pressed oil obtained in this process can meet the standards of direct consumption only through filtering without any further refining, especially low colloid content standards. To meet this standard requirements, the whole process should be carried out at low temperature.
B) The corresponding cold press machine.It should have the effect of cooling and temperature control when operating; more than one year of continuous use without replacing the press screw and press rod of the cold oil press machine and high energy efficiency ratio. Therefore, the cold oil press machine should have a special cooling system and make special treatment for the press screw and press rod.
2. Cold press technology
Because the raw material of cold pressed oil is not cooked before pressing, the fat particles in the material are in scattered distribution in the undenatured protein cells, thus cold press has higher requirement on the cold oil press machine. In general, the handling capacity of cold press machine is only half of the hot press machine of the same installed capacity, and the amount of residual oil in cold pressed cake is 1 to 2 times higher than hot pressed cake.
Basic process of cold pressed oil: removing impurity – > drying – > crushing and shelling – > cold press – > drying and filtering – > cold pressed oil packing.