WO2009020409A2

WO2009020409A2 - Method of producing edible oil from rapeseed

Info

Publication number: WO2009020409A2
Application number: PCT/PL2008/050010
Authority: WO
Inventors: Jerzy Tys
Original assignee: Instytut Agrofizyki Im. Bohdana Dobrzanskiego Polskiej Akademii Nauk
Priority date: 2007-08-09
Filing date: 2008-07-30
Publication date: 2009-02-12
Also published as: EP2222826B1; PL383110A1; EP2222826A2; WO2009020409A3; PL208504B1

Abstract

Method of production, in which for processing well-formed seeds of cultivars with 'salad' profile of fatty acids are selected, acquired at the late ripeness phase from an ecological cultivation, whose natural moisture, or after diying, is less than 7.5%, while the chlorophyll content measured with absorbance at wavelength of 666 nm does not exceed the value of 25, and the share of immature seeds in seed material is not higher than 1%, and seed purity at the moment of harvest, i.e. the amount of usable contaminations is not higher than 3%, and the content of organic contaminants is not higher than 5%, and there are no germinated seeds nor weed seeds present, consists in that seeds selected as above are stored in silos, in an inert gas atmosphere, preferably nitrogen, at temperature not exceeding 25° C and for periods not longer than 8 months, following which seed portions are taken, with weight not greater than 500 kgs, and placed in an air-tight hopper filled with an inert gas, from which seeds are transported to an expression press and subjected to oil expression in atmosphere of inert gas and with no light, and oil obtained in this manner is subjected to purification and then to microbiological evaluation of quality, and when the total content of fungi in 1 g of the oil does not exceed 5 x 104, the oil is poured into containers with darkened walls opaque to light rays, with an atmosphere of an inert gas, filling the empty space after closing the container, with the containers being of such volume that is adapted to complete one-time use.

Description

Method of producing edible oil from rapeseed

The subject of the invention is a method of producing edible oil from rapeseed.

The description of Patent No. PL 186045 gives a method for the isolation of oil from the seeds of oil-bearing plants through expression and extraction of oil from the oil cake, in which the seeds are subjected to expression at temperatures not exceeding 313 K, and the oil cake is subjected to extraction with carbon dioxide, used in amounts up to 50 kgs per 1 kg of oil cake under pressure in the range of 5 to 40 MPa, at temperatures up to 363 K, and then from the gas phase, through heating and/or decompression, a mixture of water, oil and wax is obtained, from which oil is isolated through separation of water and wax.

The description of Polish parent according to patent application P.341836 gives a method and an apparatus for the production of edible oil from rapeseed or other oil-bearing plants, in which seeds of oil-bearing plants, after sorting, are dried, fragmented, sifted and, after preparation, fed into an oil expression press. After sorting by means of a sifter, fractions are obtained that differ from one another in grain sizes, and in particular a fraction composed of contaminations, a fraction composed of cleaned seeds, and a fine fraction. Cleaned and sorted rapeseed is dried at a temperature up to 40° C until moisture content between 4.5% and 5.5% is obtained, while the contaminations and fine fraction are diverted to a container. Next, the dried rapeseed is fragmented in a system of rollers, and the fragmented seed is sorted into three fractions with various particle sizes. The usable fraction, containing parenchyma with seed coat, is subjected to further diminution in a system of rollers and, ground and containing seed coat, is expressed at ambient temperature using an expression press. Edible oil is obtained after removing solid intrusions from the non-purified oil expressed on the press. The essence of the invention is a method for the production of edible oil from rapeseed, in which for processing well-formed seeds of large- and/or small- seeded cultivars are selected, with "salad" profile of fatty acids, acquired at the late ripeness phase from an ecological cultivation. Well-formed seeds are determined on the basis of the share - up to 3% - of seeds with weight 10% lower from the mean weight of 1000 seeds. Meeting this condition requires, for coarse- seeded cultivars, sifting through a screen with mesh size dia. 1.8 mm, and for small-seeded cultivars - through a screen with mesh size dia. 1.7 mm. Cultivars with "salad" type of fatty acid composition contain not less than 65% of oleic acid, up to 2% of erucic acid, and up to 3.5% of saturated fatty acids. A cultivation has ecological character when after the period of blooming no application of any chemical agents is permitted - weed control agents, preparations against pests and plant diseases, as well as desiccants and ripening regulators. Moreover, for the processing seeds are selected such that their natural moisture content is lower than 7.5%, while the chlorophyll content measured with absorbance at wavelength of 666 nm does not exceed the value of 25. The share of immature seeds in seed material to be processed, defined on the basis of the amount of seeds with brown colouring, cannot be higher than 1%. Seed purity at the moment of harvest, i.e. the amount of usable contaminations that include micro- and macro-damage to seeds, cannot be higher than 3%, and the content of organic contaminants - resides of stems and pods - cannot exceed 5% and there are no germinated seeds nor weed seeds present. The method according to the invention is characterised by the fact that seeds selected as above are stored in silos, under pressure not exceeding 80 kPa, in an inert gas atmosphere, preferably nitrogen, at temperature not exceeding 25° C and for periods not longer than 8 months, and from seed prepared in this way portions are taken, with weight not greater than 500 kgs, and placed in an air-tight hopper filled with an inert gas, preferably nitrogen, at temperature not higher than 40° C and with no light. The obtained oil is subjected to purification and then to microbiological evaluation of quality, and when the total content of fungi in 1 g of the oil does not exceed 5 x 10⁴, that total including not more than 10³ of fusarium, not more than 10³ of gliocladium, and aspergillus at no more than 5 x 10³, including aspergillus flavus, aspergillus parasiticus, aspergillus nomius (alphatysines), aspergillus alutaceus (ochratoxin A), aspergillus clavatus (patuline) at not more than 1O x 10 , the oil is poured into darkened containers with walls opaque to light rays, with an atmosphere of an inert gas, preferably nitrogen, filling the empty space after closing the container, with the containers being of such volume that is adapted to complete one-time use.

When in the process of selection rapeseed moisture level exceeds 7.5%. the seed is dried until the moment when the moisture gets down to maximum 7.5%, using seed deposit ventilation with a drying agent, preferably air warmed to a temperature not exceeding 35° C. Rapeseed oil produced with the method according to the invention, based on raw material with specific properties - ecological production, special methods of harvest, drying and storage, expression without access of light and oxygen, permits the retention of a number of substances in the oil that have a strong pro- health effect. The particular stages of acquisition of rapeseed plants, and especially harvest, delayed to achieve full ripeness, ensure a high content of carotenoid pigments and at the same time a minimum amount of undesirable chlorophylls.

Example of execution For the production of edible rapeseed oil rapeseeds were used obtained from a plantation where the sowing material was seed of cv. Contact with the following fatty acid profile:

- oleic acid (Cis_:i) above 70%

- linoleic acid (Cis:3) below 5%

- erucic acid (C_2I; i) below 2% - saturated fatty acids below 3%.

All the plant protection measures were applied by the end of April. After that period, no chemical agents were applied on the plantation. Harvest was made at the phase of full ripeness, i.e. four days after the determination of that phase of ripeness at seed moisture of 7.5%. The content of chlorophyll in the seeds, measured by absorbance at wavelength of 666 run, was 21. The seeds contained:

- usable contaminations in the amount of 2.9% organic contaminations in the amount of 4.5% - unripe seeds in the amount of 0.9%

- there were no germinated seeds nor weed seeds.

Before placing in storage, the seeds were subjected to cleaning to eliminate small seeds. Seeds of coarse-seed cultivars were sifted through a screen with mesh size dia 1.8 mm, and those of small-seeded cultivars through a screen with mesh size dia, 1.7 mm. For seed storage a silo was used, 12 m high and with a diameter of 3 m, which ensured that pressure exerted by the seed deposit on the silo bottom did not exceed 80 kPa at full charge. Prior to filling with seeds, the silo was filled with nitrogen whose amount was topped up during the whole cycle of rapeseed storage. The duration of the full storage cycle, i.e. taking of the final batch of seeds, was completed before 8 months elapsed. The temperature of storage varied up to a maximum of 25° C. Seed portions of 500 legs in weight were taken from the silo and placed in an air-tight hopper filled with nitrogen. From the hopper the seeds were transported continuously to the pressing room and subjected to oil expression in nitrogen atmosphere and at temperature not exceeding 40° C and with no access of light. The expressed oil was subjected to purification on a sedimentation filter a centrifuge filter, then subjected to microbiological evaluation of oil quality for the content of fungi. It was that the total content of fungi in 1 g of oil was less than the limit values of 5 x 10⁴, that total including fusarium up to 10³, gliocladium up to 10³, and aspergillus at up to 5 x 10³, including aspergillus flavus, aspergillus parasiticus, aspergillus nomius (alphatysines), aspergillus alutaceus (ochratoxin A), aspergillus clavatus (patuline) in amount up to 1O x 10². The obtained oil was poured into containers with dark, opaque to light rays walls, with volume of 150 ml. The filling of the containers was performed in an atmosphere of nitrogen that, after the containers were closed, filled the space above the oil surface.

Claims

1. The method for the production of edible oil from rapeseed, in which for processing well-formed seeds of large- and/or small-seeded cultivars are selected, with "salad" profile of fatty acids, acquired at the late ripeness phase from an ecological cultivation, whose natural moisture, or after drying, is less than 7.5%, while the chlorophyll content measured with absorbance at wavelength of 666 nm does not exceed the value of 25, and the share of immature seeds in seed material to be processed, defined on the basis of the amount of seeds with brown colouring, cannot be higher than 1%, and seed purity at the moment of harvest, i.e. the amount of usable contaminations is not higher than 3%, and the content of organic contaminants is not higher than 5% and there are no germinated seeds nor weed seeds present, characterised in that seeds selected as above are stored in silos, under pressure not exceeding 80 kPa, in an inert gas atmosphere, preferably nitrogen, at temperature not exceeding 25° C and for periods not longer than 8 months, and from seed prepared in this way portions are taken, with weight not greater than 500 kgs, and placed in an air-tight hopper filled with an inert gas, preferably nitrogen, from which seeds are transported to an expression press and subjected to oil expression in atmosphere of inert gas, preferably nitrogen, at temperature not higher than 40° C and with no light, and oil obtained in this manner is subjected to purification and then to microbiological evaluation of quality, and when the total content of fungi in 1 g of the oil does not exceed 5 x 10⁴, that total including not more than 10³ of fusarium, not more than 10³ of gliocladium, and aspergillus at no more than 5 x 10³, including aspergillus flavus, aspergillus parasiticus, aspergillus nomius, aspergillus alutaceus, aspergillus clavatus at not more than 10 x 10², the oil is poured into containers with darkened walls opaque to light rays, with an atmosphere of an inert gas, preferably nitrogen, filling the empty space after closing the container, with the containers being of such volume that is adapted to complete one-time use.

2. The method in accordance with claim I₃ characterised in that the process of selection, when the rapeseed moisture level exceeds 7.5%. the seed is dried until the moment when the moisture gets down to maximum 7.5%, using seed deposit ventilation with a drying agent, preferably air warmed to a temperature not exceeding 35 ° C .