RU2767364C1 - Sunflower meal processing method - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: group of inventions relates to food industry. Sunflower meal processing method is implemented as follows. Protein and carbohydrates are extracted from the meal by adding an aqueous solution of alkali of 5–20 % concentration to a suspension prepared from a mixture of meal and water in ratio of 1:10–20 until acidity of the suspension is set in range of 8.5–11 pH. Sodium sulphite is added to the suspension in an amount equal to 5–10 % relative to the weight of the meal; the suspension is held for 45–60 minutes at temperature of 45–60 °C. Hydrogen peroxide with concentration of not less than 37 % is added to the suspension and maintained after adding peroxide for 45–90 minutes at temperature of 45–60 °C with constant stirring. Suspension is purified from suspended particles successively, using at least one decanter centrifuge (decanter) for preliminary purification. As a result of purification, two phases are formed - liquid (extract) and solid, which is low-protein fibres (LPF). After separation on a decanter, the solid phase - wet LPF is sent for drying and granulation, and the liquid phase - the extract for final purification to a high-speed separator. Protein dissolved in the purified extract is extracted successively in two steps: at the first stage, a solution of hydrochloric or citric acid is added to the extract until the acidity value of the extract is set in range of 3.5–5 pH. Portion of the dissolved protein is deposited, then, when separating the extract, the serum formed after separating the precipitated protein is directed to an ultrafiltration (UV) membrane module, where the protein fraction not subject to acid deposition at the first stage is extracted. Precipitated protein, separated from the whey at the first stage, and the protein which has passed the ultrafiltration stage are combined and subjected to enzymatic treatment with proteolytic enzymes. Extraction of carbohydrates dissolved in the extract with formation of a saccharide solution is carried out on a reverse osmosis (RO) filtration unit, after which saccharides are subjected to concentration to obtain sugar syrup (SS). Disclosed is a version of sunflower meal processing.

EFFECT: group of inventions provides expansion of the range of optimum technologies for production of high-quality sunflower protein concentrate, LPF, SS from oil extraction by-products.

2 cl

Description

The invention relates to the food industry, in particular to the production of sunflower protein concentrate (SPC), low-protein fibers (NBV) and saccharide syrup (SS) from industrial sunflower meal by extraction, used in the following areas of the economy:

- KPB - food industry (protein supplements), feed for animals, poultry and fish;

- NBV - energy (combustion), agriculture (animal feed);

- SS - food industry (confectionery, beverage industry), animal feed.

Meal with a protein content of 35-45% (by weight) and a residual fat content of not more than 2.5% is used as a raw material for the processing of meal according to the claimed technology. A higher fat content may cause a change in the quality of the protein concentrate (increased fat content, the appearance of a "soapy" taste). It is possible to use meal with a lower relative protein content, however, it must be taken into account that the yield of CPB will be proportionally lower, and the yield of NBV will be higher.

Known (RU, Description of the invention to the patent No. 2340203, IPC A23J3 / 14, A23J1 / 14, published 10.12.2008) a method for obtaining food protein isolate from sunflower meal, including extraction of protein from meal (an aqueous solution of sodium chloride), separation of insoluble precipitate by filtration to obtain an extract, extracting the protein, separating the solid and liquid phases by centrifugation and drying the solid residue.

A two-stage method for obtaining a protein isolate from industrial sunflower meal is known (Scherbakov V.G., Gorshkova L.M., Kovalenko N.P., Rubina L.V., Kuznichenko V.N., Rakovsky P.P. On the quality indicators of food sunflower protein - "Proceedings of universities. Food technology" - 1976. - No. 1. - P. 154).

In the known method, the protein from sunflower meal is extracted in several stages (first with an aqueous solution of sodium chloride, and then with sodium hydroxide), which gives a large loss of protein in the process of using several extractants due to the multi-stage process and requires the use of a large number of technological solutions. In addition, the resulting protein has a high content of phenolic compounds that darken its color, and an increased chlorine content significantly limits the use of standard stainless steel industrial equipment due to active corrosion of stainless steel at high concentrations of free chlorine.

The objective of the present invention is to expand the range of economical (optimal) technologies for the production of high-quality CPB, NBV, SS from by-products of oil extraction production.

The technical result of the invention consists in the implementation of a technological and economical method for processing sunflower meal, characterized in that the extraction of protein and carbohydrates from the meal is carried out by introducing into a suspension prepared from a mixture of meal with water in a ratio of 1: 10-20, an aqueous solution of alkali 5-20 % concentration until the acidity of the suspension is established in the range of 8.5-11 pH, followed by the introduction of sodium sulfite into the suspension in an amount equal to 5-10% relative to the mass of the meal, holding the suspension for 45-60 minutes at a temperature of 45-60°C; subsequent introduction of hydrogen peroxide with a concentration of at least 37% into the suspension and exposure after the introduction of peroxide for 45-90 minutes at a temperature of 45-60 ° with constant stirring. As a result, most of the proteins and carbohydrates are released into the solution, but the extract solution does not turn bright green. The extract is white to light brown in color. Purification of the extract from suspended particles is carried out in two stages, using at least one decanter centrifuge (decanter) for preliminary purification, after which the solid phase is sent for drying and granulation, and the liquid phase for final purification is sent to a high-speed separator.

Extraction of the protein dissolved in the purified extract is carried out sequentially in two stages. At the first stage, a solution of hydrochloric or citric acid is introduced into the extract until the acidity index of the extract is established in the range of 3.5-5 pH. As a result, part of the proteins contained in the extract becomes insoluble (precipitates) and is separated using successively a decanter centrifuge, then a high-speed separator. At the second stage of separation of the extract, the whey formed after the separation of the insoluble protein precipitated is sent to the ultrafiltration (UV) membrane module; where the protein fraction is isolated, which is not subject to acid precipitation at the first stage. Both protein fractions after the first and second stages are combined and subjected to enzymatic treatment with proteolytic enzymes in order to reduce the viscosity before the stage of drying the CPB.

Extraction of the dissolved protein according to the described method is also possible without the use of a UV membrane module in one step using hydrochloric or citric acid solutions. The second stage of extraction allows increasing the quantitative yield of CPB, but does not affect the technological process as a whole.

The extraction of carbohydrates dissolved in the extract, with the formation of a saccharide solution, is carried out on a reverse osmosis (RO) filtration unit, after which the saccharides are subjected to concentration to obtain a sugar syrup.

Before extraction, to intensify the process, the meal is cleaned by removing impurities from it using a metal detector and/or vibrating sieves.

The increase in the amount of water per part of the meal during the preparation of the suspension is determined by the increase, on the one hand, in the yield of protein and sugars, and, on the other hand, in the costs of operation and investment in equipment.

As an aqueous solution of alkali, it is possible to use, for example, NaOH (caustic, sodium hydroxide) or KOH. The preferred choice of NaOH or KOH is due to the fact that these alkalis are a) strong (with less alkali required, the product is cleaner), b) industrially produced, c) relatively inexpensive.

The recommended holding time of the suspension in the specified temperature range after adding the extractant to it is 45-120 minutes (the extraction steadily increases until the holding time is 30-40 minutes, then it grows very slowly). Under these conditions, most proteins and carbohydrates are released into solution. Above the indicated right values of the acidity and temperature intervals, protein denaturation begins.

To increase the yield of the extract at the stage of its purification from suspended particles, an additional decanter centrifuge can be used, where the solid phase mixed with water is sent after the first decanter centrifuge. In this case, the solid phase after the second decanter centrifuge, as well as after the first one, is sent for drying and granulation, and a mixture of extracts after the first and second decanter centrifuges is fed to the high-speed separator. Drying of the solid phase is carried out, as a rule, on a disk dryer, and an extruder is used for granulation.

At the stage of purification of the extract from suspended particles, it is possible to use centrifugal equipment other than a decanter centrifuge, for example, self-discharging high-speed separators. However, decanters are cheaper and more reliable. The number of decanters used depends on their capacity and type.

The proposed two-stage successive purification of the extract using a decanter centrifuge and then a high-speed separator is the most technologically advanced and economical, as it provides:

- processing of a large amount of suspensions at the entrance to the decanter,

- high purity of the extract at the outlet of the separator,

- relatively low investment.

The pores of the UV membrane used to extract the protein dissolved in the extract must be selected in such a way that water and dissolved hydrocarbons pass through and protein molecules do not pass through. As a result, the protein is concentrated above the membrane surface, while water and dissolved carbohydrates pass through the membrane.

For packaging dry CPB after spray drying, it is advisable to use a semi-automatic packaging line.

Simultaneously with the extraction of carbohydrates dissolved in the extract, water is regenerated at the RO filtration unit (membrane). The pores of the RO filtration unit are selected in such a way that only water passes through, and dissolved carbohydrates and other dry substances are concentrated above the membrane surface, forming a saccharide solution. Purified water, which has passed through the RO membrane, is returned to production. The volume of reclaimed water can be up to 80% of the total water consumption for technological purposes.

The result of the proposed method is to obtain a sunflower protein concentrate from white to light brown in color with a protein content in terms of absolutely dry matter of 75-90%, low-protein fibers and sugar syrup.

Claims (2)

1. A method for processing sunflower meal, characterized in that the extraction of protein and carbohydrates from the meal is carried out by introducing into a suspension prepared from a mixture of meal with water in a ratio of 1:10-20, an aqueous solution of alkali of 5-20% concentration until the acidity index of the suspension is established in the range of 8.5-11 pH, followed by the introduction of sodium sulfite into the suspension in an amount equal to 5-10% relative to the mass of the meal, holding the suspension for 45-60 minutes at a temperature of 45-60°C; subsequent introduction of hydrogen peroxide into the suspension with a concentration of at least 37% and exposure after the introduction of peroxide for 45-90 minutes at a temperature of 45-60°C with constant stirring; purification of the suspension from suspended particles is carried out sequentially, using at least one decanter centrifuge (decanter) for preliminary purification, while as a result of purification two phases are formed - liquid (extract) and solid, which is low-protein fibers separating the solid phase on the decanter - wet NBV is sent for drying and granulation, and the liquid phase - the extract for final purification to a high-speed separator; the extraction of the protein dissolved in the purified extract is carried out sequentially in two stages: at the first stage, a solution of hydrochloric or citric acid is added to the extract until the acidity of the extract is established in the range of 3.5-5 pH, while part of the dissolved protein precipitates, then, when separating the extract, whey , formed after the separation of the precipitated protein, is sent to the ultrafiltration (UV) membrane module, which separates the protein fraction that is not subject to acid precipitation at the first stage, the protein that precipitated, separated from the whey at the first stage, and the protein that passed the ultrafiltration stage are combined and subjected to enzymatic treatment with proteolytic enzymes, and the extraction of carbohydrates dissolved in the extract with the formation of a saccharide solution is carried out on a reverse osmosis (RO) filtration unit, after which the saccharides are subjected to concentration to obtain a sugar syrup (SS). 2. A method for processing sunflower meal, characterized in that the extraction of protein and carbohydrates from the meal is carried out by introducing into a suspension prepared from a mixture of meal with water in a ratio of 1:10-20, an aqueous solution of alkali of 5-20% concentration until the acidity index of the suspension is established in the range of 8.5-11 pH, followed by the introduction of sodium sulfite into the suspension in an amount equal to 5-10% relative to the mass of the meal, holding the suspension for 45-60 minutes at a temperature of 45-60 ° C, followed by the introduction of hydrogen peroxide into the suspension with a concentration of at least 37% and exposure after the introduction of peroxide for 45-90 minutes at a temperature of 45-60°C with constant stirring; purification of the suspension from suspended particles is carried out sequentially, using at least one decanter centrifuge (decanter) for preliminary purification, while as a result of purification two phases are formed - liquid (extract) and solid, which is low-protein fibers separation on the decanter, the solid phase - wet NBV is sent for drying and granulation, and the liquid phase - the extract for final purification - to a high-speed separator; extraction of the protein dissolved in the purified extract, where a solution of hydrochloric or citric acid is added to the extract until the acidity of the extract is established in the range of 3.5-5 pH, while part of the dissolved protein precipitates, then, when separating the extract, the whey formed after separation of the insoluble protein , is sent directly to the reverse osmosis filtration unit (RO), the protein that precipitated, separated from the whey, and the protein that passed the RO stage are combined and subjected to enzymatic treatment with proteolytic enzymes, and the extraction of carbohydrates dissolved in the extract with the formation of a saccharide solution is carried out on a reverse osmosis filtration installation, after which the saccharides are subjected to concentration to obtain a sugar syrup.