DD249917A1 - PROCESS FOR PREPARING GREASE OIL SEEDS - Google Patents

Abstract

The invention relates to a process for the preparation of high-fat oilseeds, preferably sunflower and rapeseed, for the purpose of effecting the peeling, improving the quality of the end products crude oil and extraction meal and obtaining a shell-free core fraction. The object of the invention is to indicate process conditions which enable a nearly complete shell separation and an improvement of the oil and Schrotqualitaet by lowering the sterol and Rohfaser- or increase in protein content. According to the invention, the object is achieved by treating purified oilseeds by combination of tempering and drying by addition of moisture and equalization followed by dehumidification in a temperature-time regime so that the positive moisture-potential difference between the humidities of the shell and core fractions Annealing and addition of water vapor in a closed system aligned and moved by drying in negative ranges of the moisture potential difference of shell and nuclear fraction.

Description

Characteristic of the known technical solutions

Traditionally, traditional seed dressing processes typically involve partial casing and thermal conditioning of the crushed seeds prior to pressing and / or extraction. The degreasing of oil-rich seeds by direct extraction also requires special treatment processes, such as pressure conditioning and intermediate comminution; Extraction meal obtained in this way, however, have a strong protein denaturation and are usually only used for animal nutrition.

Modern processing methods, which also aim to utilize the Schilfer or extraction pellets as raw material sources for protein recovery for human nutrition or a physical refining of crude oils, also require special peel and conditioning processes. The former have extensive shell separation, allowing the latter enzyme activation and intensification of diffusion processes before or during degreasing to guarantee high oil and phosphatide yields with high material throughputs.

Effective peeling processes require crushers with special roller arrangement or special impact and acceleration or pressure and relaxation devices, which require only small amounts of unpeeled seeds and pulp particles with adhering shell. Similar peeling methods, which are based on a reduction in the husk content of seeds even below 3%, further envisage multiple fractionation of the broken seeds by means of screen and / or air separators, with electrostatic precipitation now being singled out as the method of choice.

Alternative methods for effective shell separation are also sedimentation in aqueous / nonaqueous media and flotation.

Practical peeling methods for enriching extraction slices with crude proteins with simultaneous elimination of crude fiber components are, moreover, the fractionation of defatted seed flours using special classifiers after comminution.

An improvement u.a. of the peeling effect, in particular of soybeans, should be obtained by annealing, i. moisture balance between the shell and core fractions under certain storage conditions, and for sunflower seeds a reduction in moisture potential between the shell and core fractions to 6-7% by drying should prove beneficial.

As serious disadvantages of said peeling process is to highlight a low efficiency in terms of the shell separation of the throughput or a high procedural effort.

Object of the invention.

The aim of the invention is therefore once the effectiveness of the traditional peeling process of oil seeds, preferably of sunflower and rapeseed seeds, by reducing the proportion of unbroken or adherent shell particles exhibiting seeds, on the other hand to ensure a so-called zero peel, d. H. extensive shell separation.

Explanation of the essence of the invention

The invention is therefore based on the object of demonstrating process conditions that allow a partial or almost complete shell separation and, consequently, an improvement in oil and meal quality by lowering the sterol and crude fiber or increasing the protein content.

According to the invention the object is achieved by intact purified high-fat oilseeds, preferably sunflower and rapeseed, by combination of moistening, annealing and drying after size classification successively by moisture addition and -leichleichg with subsequent dehumidification at a so coordinated temperature-time regime in that the original positive moisture potential difference between the humidities of the shell and core fractions by tempering after the addition of water, preferably in the form of water vapor, in a closed system are equalized and dried in negative ranges of the moisture potential difference of Shell and kernel fraction, d. H. in favor of the nuclear fraction, is postponed.

As has been found, there is a relatively high species-specific moisture potential difference between the kernel and shell fractions of fatty oilseeds, such as sunflower and rapeseed, but in contrast to low-fat legume seeds, such as soybeans and lupins, which includes successive ranges of magnitude in selected seeds :

Water content of oil and legume seeds

substratum Water content% Water content% Water content% potential husk fraction core Group Seeds, totally Difference% Sunflower seeds 10-12 5-7 7-10 about 5 rape seed 8-10 6-8 7-10 about 2 soybeans 9-11 9-11 9-12 0 lupins 8-10 8-10 8-11 0

In the annealing usually carried out independently of a formwork, this potential difference is only slightly changed, so that still occur the known problems of too low brittleness of the shell fraction, which manifest themselves in a high shell content after the formwork. In the case of an exclusive drying in accordance with WP B 03 C / 255 554, although the original potential difference is reduced, this also leads to a sharp decrease in the water content of the nuclear fraction, which in turn results in a high proportion of core fractures. By the inventive approach of a coordinated combination of humidification, annealing and drying both the necessary high elasticity of the core fraction, as well as a high brittleness of the shell fraction is ensured, with the setting of a moisture-potential difference between the humidities of shell and core fraction after annealing of at most + 2% and after drying of at least -2% has proved to be particularly useful.

The wetting, tempering and drying of the oilseeds as a necessary prerequisite for the effectiveness of the peeling process is carried out according to the invention in several independent or coupled to each other process stages, preferably using the fluidized bed or fluidized bed principle. During wetting, the increase in the water content in the seeds is between 10 and 20%, based on the total seed mass, preferably 12 to 15%, optionally by short-time heating with saturated steam over periods of 0.5 to 5 minutes, preferably 1 to 3 minutes. accomplished; the moisture adjustment is by annealing in a closed Systenrbei temperatures of 20 to 80 ⁰ C, preferably 40 to 60 ° C, for periods of 1 to 48 hours, preferably 3 to 12 h, performed, and the moisture removal is carried out by drying under adjustment of water content of between 5 and 10%, preferably 6 to 8%, by shock heating at temperatures of 100 to 15O ⁰ C, preferably 110 to 120 ⁰ C, for periods of 0.5 to 5 min, vorzugsweisei bis2min.

As further found, prior size classification of the seeds in at least 2 fractions with nearly uniform seed size prior to actual formation is considered to be a sufficient condition for achieving high peel effects in the method of the invention. Under the above conditions of the process management in wetting, tempering and drying prove the nachzuschaltenden process stages of the actual shell separation and separation as uncritical, but the use of squeegee or beater strips, in combination with sieve and air separation systems, optionally also electrostatic precipitators is particularly advantageous.

embodiment

The invention will be explained in more detail with reference to the following embodiments:

example 1

100kg of sunflower seeds (shell content 29.3%) are classified by screening in 3 fractions, with a main fraction with a mean seed diameter between 3 and 5mm (about 70%) in addition to larger and smaller seeds, breakage and stocking. This main fraction is moistened after pre-heating to 70 ° C for 2 min with saturated steam while increasing the water content and annealed for 12 h at 40 ⁰ C in a closed system.

The tempered seeds are dried for 2 min in a fluidized bed dryer at 120 ⁰ C, struck by SchIagleistenschäler and further fractionated by plan and air classification.

In the individual process stages the following water contents result in% in the intact seeds as well as the shell and nuclear fraction:

process stage seed Peel cores Potential- difference% before moistening 8.4 10.8 5,6. +5.2 after moistening 15.8 18.2 13.2 +5.0 after tempering 15.7 16.0 15.5 +0.5 after drying 8.0 6.8 9.3 -2.5

The main fraction obtained after screening separation by sieving and screening has the following masses and shell content:

Sieve fraction visual fraction; "V

(2-4 mm) (2-4 mm)

% By weight of shell% by mass of shell%

55.2 12.8 41.6. 0.5

Example 2

100 kg of rapeseed (shell content 15.7%) are classified by sieving into 2 fractions, among others a main fraction having a mean seed diameter between 1.6 and 2.6 mm (about 90%) is obtained The water content is humidified and annealed for 3 h at 6O ⁰ C in a closed system. , Subsequently, 3 min in the fluidized bed at 110 ⁰ C dried, peeled by rubber roller peeler, pre-fractionated by air classification and finely fractionated by means of electrostatic precipitator.

After the individual process steps, the following water contents result in% in the intact seeds as well as the shell and nuclear fraction:

process stage seed Peel cores potential difference% before moistening 7.2 9.3 6.4 +2.9 after moistening 17.1 19.2 16.7 + 2.5 after tempering 17.2 17.4 17.2 +0.2 after drying 9.0 7.3 9.3 -2.0

The main fraction obtained after peel separation by screening and electrodeposition has the following masses and shell contents:

Visible fraction of electrostatic precipitator fraction

(1-2 mm) (1-2 mm)

% By weight of shell% by mass of shell%

75.6 7.3 68.4 0.9

Claims (7)

1. A process for the preparation of fatty oilseeds, preferably of sunflower and rapeseed, for the purpose of peeling and degreasing, by combination of humidifying, annealing and drying, characterized in that intact purified seeds successively after size classification by addition of moisture and subsequent dehumidification in such a coordinated Temperature-time regime that the originally positive moisture potential difference between the humidities of the shell and core fraction by tempering in a closed system after addition of water, preferably water vapor, aligned and subsequently by drying under shock heating in negative areas the moisture potential difference of shell and nuclear fraction is shifted. 2. The method according to item 1, characterized in that the seeds subjected to formwork before a size classification in at least 2 fractions with almost uniform seed size and these fractions are processed separately. 3. The method according to item 1 and 2, characterized in that classified seeds to water contents between 10 and 20% * based on the total seed mass, preferably 12 to 15%, optionally with short-term heating with saturated water vapor over periods of 0.5 to 5min, preferably 1 to 3min, are adjusted and followed by tempering a moisture equalization at temperatures of 20 to 8O ⁰ C, preferably 40 to 60 ⁰ C, over periods of 1 h to 48h, preferably 3 to 12 h, takes place. 4. The method according to item 1 to 3, characterized in that the drying of the tempered seeds while adjusting a water content of 5 to 10%, preferably 6 to 8%, by shock heating at temperatures of 100 to 150 ^c C, preferably 110 to 130 ^0th C, over periods of 0.5 to 5min, preferably 1 to 2min takes place. 5. The method according to item 1 to 4, characterized in that the moisture potential difference between the humidities of the shell and core fraction after annealing at most + 2%, after drying is at least -2%. 6. The method according to item 1 to 5, characterized in that the moistening, annealing and drying is carried out in several independent or mutually coupled process stages. 7. The method according to item 1 to 6, characterized in that the tempered and dried seeds are peeled immediately according to known methods and separated into seed kernels and trays.  /? Field of application of the invention The invention relates to a process for the preparation of fatty oil seeds, preferably sunflower and rapeseed, for the purpose of effecting the formwork and with a view to improving the quality of the final products Rohöfund extraction shot, as well as on the recovery of a pure, d. H. almost cup-free nuclear fraction. The resulting end products are virtually shell-free and predestined in direct use as a nut or almond substitute and for further processing into protein-enriched secondary products, such as seed flours, protein concentrates or isolates.