The processing of oil crops in order to obtain vegetable fat and by-products is carried out using a technology similar to that used for sunflower:
Seed preparation. When collecting and transporting raw materials, weeds, pollution and metal impurities can get into it. For cleaning in production, magnetic and sieve separators are used, and only after that the product is sent for drying in order to reduce the overall moisture content to a minimum. For this, mining-type equipment is most often used. Then the seeds are cooled to + 35 °C, husked and placed in an aspirating fan in order to separate the shell.
Grain processing. The next stage is the cellular structure destruction, or, more simply, the kernels grinding. This process requires roller units or specialized machines. The finished meal is processed hydrothermally, i.e. the humidity is increased with saturated air vapor, and then the meal is fried and dried again. This is necessary to make the workpiece plastic and more pliable for extraction. After the meal is heated to 115 °C, it is called pulp.
Extraction. There are two types of oil extraction. The first is direct extraction using a gasoline or hexane solvent. The second one is pressing. It is the stage when a mixture of oil with a solvent and compressed fiber, called meal, or vegetable fat with particles of kernels and cake, are formed.
Additional processing. The direct extraction does not require pressing and also allows the extraction of the biggest quantity of the oil. Therefore, sometimes the primary cake, which can contain up to 17% vegetable fats, is additionally grinded, crushed, moistened and then chemically treated under the influence of a solvent. After this procedure, refined oil is produced.
The demand for cake is also justified by the characteristics of the processed grain. Passing all stages of extraction allows a significant increase of nutritional and beneficial qualities of oil cake in comparison with raw crops. Saturation with fats, proteins and many important macronutrients increases the energy value of the product several times.
Thanks to the use of cake, livestock breeders can abandon feed oil and solve other equally important tasks:
- to support the growth and development of young animals;
- to optimize metabolism;
- to increase milk yield and egg production;
- to strengthen immunity.
Studies with two control groups of beef cattle being at a standard diet and consuming compound feed with the addition of sunflower oil cake showed a percentage advantage of the second type of feeding. The digestibility of useful components has increased significantly:
- dry matter - by 1.2%;
- protein and fiber - by an average of 0.7%;
- crude fats and nitrogen-free extractive substances - 1.4%;
- nitrogen - 23%,
- calcium - by 8.5%;
- phosphorus - by 1.4%.
Also, an improvement in blood elements and an increase in carcass muscle mass of up to 7% were noted. By the way, the total nutritional value of the consumed feed increased to 5%. In general, the use of oil cake has increased the sales of beef, and, consequently, the income of the enterprise up to 5%.
The final by-product of pressing processing of sunflower seeds cannot contain more than 11% liquid, the remaining percentages are distributed as follows:
- 30% - proteins;
- 7% - fat;
- 5% - fiber.
It is worth separately mentioning the need for the proper storage of the cake. The product is extremely moisture sensitive and hygroscopic. Natural enzymes in its composition break down into glycerin and fatty acids, which increase the likelihood of mold and rot formation. These processes are accompanied by the appearance of a perceptible specific smell. Therefore, it is worth storing the cake in dry ventilated rooms with a humidity of no more than 12%.
Before adding to the feed after drying, it is also required to grind the product in crushers and dilute with water. Avoiding proximity to pests, dust and heat sources is necessary too. The normal temperature for cake is 35 °C and below. It is recommended to periodically turn and move the bags.
Based on the materials of gelznt.ru