PROSPECTS OF OIL EXTRACTION PROCESS FROM PUMPKIN SEEDS

Abstract

As a first step the seed/bean is cleaned and dried. Foreign material (like stones, glass and metal) is taken out by sieving and magnets and disposed of outside the feed chain. Drying is performed by avoiding contact with combustion gasses unless natural gas is used. The preparation of the seeds before an extraction step depends on the kind of seed/bean and the required quality of the meal. Some oilseeds, like soybeans and sunflower seed, may be dehulled after the cleaning step. After dulling the meal will have a lower crude fiber content, and hence a higher protein content. The hulls can also be used for feeding purposes, as such or in pelletized form. In the past, crushing was done between mill stones that later became steel rolls. Hence the factories are known as oil mills and the process as oil milling or oilseed crushing. Seeds with high oil content, like rape seed and sunflower seed, are usually mechanically pressed in expellers after a preheating step in indirectly heated conditioners.