METHOD FOR REFINING LIQUID VEGETABLE OILS Russian patent published in 2017 - IPC C11B3/00 

FIELD: food industry.

SUBSTANCE: method involves the removal of free fatty acids, phospholipids, colour compounds, waxes and wax-like substances, oxidation products, non-fatty impurities and moisture, flavouring and odourizing substances at the gel sorption stage, followed by the control stages of bleaching and freezing and the deodorization stage. Gel sorption is carried out at a temperature of 16-20°C by means of mixing unrefined oil with gel solution and a coagulant, resulting in forming an insoluble suspension in the oil, which coagulates, precipitates and, upon settling, the system is divided into two phases, the gel sediment and the layer of clear oil, that are separated in the gravitational field. The gel solution is created by dissolving 9-hydrate sodium metasilicate in water to obtain the solution density of 1.10-1.41 g/cm³ and additionally introducing into it the calculated amount of silicon dioxide and increasing the water duty of the solution to 1.5; the amount of the gel solution is calculated before obtaining the results for gel sorption, which meet the requirements of the standards for each oil. After introducing the gel solution into the oil, an additional coagulant is introduced in the amount up to 100 g per 1 ton of oil in the form of a 20% solution, stirred within 15-30 minutes and settled for 8-9 hours. After the gel sorption, the oil is sent to the control bleaching, which is carried out within 30 minutes at the temperature of 18-20°C with the introduction of an adsorbent with the pH of 2-5 in the amount of 0.35-0.55%, wherein 0.2-0.25% of activated carbon is additionally introduced while bleaching soybean and corn oil, and 0.5-1.0% - while bleaching rapeseed oil. After bleaching, the oil is sent for control freezing at 6°C within 4 hours, with introducing 0.2-0.3% of sorbent, and the oil filtration is carried out at 12°C, and then the oil is sent for deodorization at the residual pressure up to 5 mm Hg at the temperature of 190-225°C.

EFFECT: invention allows to increase the oil refining line performance, to improve the quality of vegetable oils due to refining at low temperatures, to increase the yield of oils, to reduce waste, losses and the consumption of auxiliary materials.

3 cl, 2 tbl, 5 ex