WO2002038690A1 - A method of extracting flax gum from flax seed - Google Patents

Abstract

The method for extracting flax gum from flax seed includes the following steps: removing impurities from flax seed raw material, washing and extracting flax seed by using water, separating solid phase and liquid phase to obtain extracted gum solution, concentrating the extracted gum solution under normal pressure, drying concentrated gum solution and crushing to obtained the invented product. The invented process with high gum output rate up to 6-15 % is simple in technological process. It does not cause environmental pollution and reduces the cost of producing. The invented flax gum is widely used as thickener, humectant, stabilized, emulsifier and binding agent in food, pharmaceuticals and cosmetics industry, and the like. It has high viscosity, humudification and stability.

Description

 Method for extracting linseed gum from linseed TECHNICAL FIELD

 The invention relates to a method for preparing a novel vegetable gum-linseed gum. Background technique

 Flaxseed gum is a pure natural, pollution-free, multifunctional, nutrient-rich vegetable gum. It is a green food additive certified by the National Green Food Development Center. It is mainly used as a thickener and humectant in food, pharmaceutical, and cosmetics fields. , Stabilizers, emulsifiers and adhesives.

 There are currently many methods for extracting linseed gum from linseed, see, for example, CN 1221771A and CN 1242952A. However, the existing extraction methods generally have lower yields and cause serious environmental pollution. In addition, traditional solid glue products cannot be obtained by traditional spray drying methods. Vacuum drying and freeze drying methods are costly, but the yield is low. Summary of the Invention

 An object of the present invention is to provide a method for extracting linseed gum from linseed. The method of the invention has simple process, stable rubber extraction yield above 6%, no environmental pollution, and greatly reduced production cost.

 The method for extracting linseed gum from linseed according to the present invention includes the following steps:

 a) After the flaxseed material is removed, washed with water, water is extracted;

 b) obtaining the extracted gum through liquid-solid phase separation;

 c) concentrated extracted gum solution under normal pressure or reduced pressure;

 d) The concentrated gum solution is dried and pulverized to obtain a flaxseed gum product.

 In the present invention, the steps of extraction, liquid-solid phase separation and concentration are all performed in an extraction tank with a stirring blade and a filter filter plate. A filter plate is installed in the lower part of the extraction tank, and a rotatable filter plate is installed. Scraper. The extraction tank is disclosed in Chinese Patent Application No. 00247105.1, which is incorporated herein by reference.

 In step a of the present invention, the water extraction is performed 2 to 6 times. The weight ratio of flax seed to water at the first extraction is 1: 3-15, and the weight ratio of flax seed to demineralized water at each subsequent extraction is 1: 2-8. Demineralized water is preferably used in the extraction. During the extraction process, the temperature is maintained at 35-100 ° C, and the extraction time is 10-100 minutes. During the extraction process, constant stirring is required, but no other chemical reagents are added.

In step b of the present invention, the liquid-solid phase separation is performed by pressurizing or pumping filtration in the extraction tank, and at the same time Rotate the stirring blade so that it continuously sweeps the filter plate to keep the filter surface clean and unobstructed. And the filtrate can be heated at the same time to reduce the temperature of the filtrate to facilitate filtration. One of the difficulties in extracting linseed gum is the separation of the leaching solution from the linseed after the extraction. The present invention solves this problem well through the above method.

 In the step c of the present invention, the concentration is performed under normal pressure or reduced pressure (500-700 mmHg), with stirring by a scraper, and the glue solution is concentrated to 1/2 to 1/20 of the original volume. The concentration time can be greatly reduced by reducing pressure and scraping the agitation. The concentrated gum solution obtained by the above method can be directly dried, and the properties of the flaxseed gum can be kept unchanged.

 After the concentration step, optionally, the method further comprises the step of adding an ethanol solution with a weight ratio of 1: 0.6-1.5 to the concentrated gum solution at room temperature under stirring, to precipitate the gum solution, and drying after the solid-liquid separation. Among them, the ethanol solution is preferably a 95% ethanol solution.

 In step d of the present invention, the drying may be carried out by hot air purging drying, wherein the temperature of the hot air is 70-140 ° F. Drying can also be carried out by coating the concentrated gum solution on a carrier and drying it by microwave heating.

 The yield of the method of the invention is as high as 6-15%, and the process is simple, does not cause environmental pollution, and the production cost is greatly reduced. Flaxseed after extraction can still be used for oil extraction, and the oil yield is not significantly different from that before extraction. The performance of the obtained flaxseed gum product is better than similar gums, such as carrageenan and konjac gum, etc., and it is an ideal substitute product. It can be widely used as thickener, humectant, stabilizer, emulsifier in food, pharmaceutical, cosmetics and other fields. Adhesives and adhesives have the advantages of high viscosity, high moisture retention, and good stability. BEST MODE EXAMPLE 1

 To extract flaxseed gum:

 1. After washing the selected flaxseed, add demineralized water with a weight ratio of 1:10 to the raw material and a temperature of 55 ° C, and stir under normal pressure for 20 minutes to separate the seed liquid to obtain glue solution eight.

 2. Add the solid material separated in step 1 to 1:10 demineralized water at a temperature of 55 ° C, stir at normal pressure for 30 minutes, separate the seed solution, and repeat the extraction 3 times to obtain glue solution 8, C , D.

 3. Combine the glue solutions A, B, C, and D, and heat them at 90 ° C with hot air and stir with a scraper to concentrate the glue solution to 1/3 of the original volume.

4. The concentrated glue solution is coated on a polyester net, blown under 90 ° C hot air, and the coating is scraped off at the same time, and the flaxseed gum product is obtained after drying. The yield of linseed gum was 13.6%. Example 2

 To extract flaxseed gum:

 1. After washing the selected flaxseed, add demineralized water with a weight ratio of 1: 4 to the raw material and a temperature of 40 ° C, and stir under normal pressure for 20 minutes to separate the seed solution to obtain glue solution eight.

 2. Add the solids separated in step 1 to demineralized water with a weight ratio of 1: 5 and a temperature of 40 ° C, stir for 30 minutes under normal pressure, separate the seed liquid, and repeat the extraction three times to obtain glue solutions 8, C, and D. .

 3. Combine the glue solutions A, B, C, and D, and heat the glue solution to 90% of the original volume under stirring with a 90Ό hot air.

 4. The concentrated glue solution is coated on a polyester mesh, dried by microwave heating, and a flaxseed gum product is obtained after drying.

 The yield of linseed gum was 12.4%. Example 3

 1. After washing the selected flaxseed, add demineralized water with a weight ratio of 1:12 to the raw material and a temperature of 70 ° C, and stir under normal pressure for 20 minutes to separate the seed liquid to obtain glue solution eight.

 2. Add the solids separated in step 1 to demineralized water with a weight ratio of 1:10 and a temperature of 70 ° C, stir for 20 minutes under normal pressure, separate the seed liquid, and repeat the extraction three times to obtain gums 8, C, and D.

 3. Combine the glue solutions A, B, C, and D, and reduce the glue solution to 1/10 of the original volume under reduced pressure, hot air heating at 130 ° C, and stirring with a scraper.

 4. After cooling the concentrated gum solution to room temperature, add a weight ratio of 1: 1.5 95% ethanol solution under stirring. After the precipitation is complete, separate the solid phase and dry at 85 ° C to obtain flaxseed gum. product.

 The yield of linseed gum was 6.0%. Example 4

The composition and viscosity of the flaxseed gum obtained in Example 1 were analyzed, and the analysis results are shown in Table 1: Table 1 Flaxseed gum analysis results Item measurement results Moisture (%) 11 Ash (%) 6-10 pH (l% aqueous solution) 6.2 ± 0.5 Viscosity (%) 5000-30000 Water insoluble matter (mpa.s, 1% Aqueous solution) 1.8 Pectinic acid (%) <4

Claims

Rights request 1. A method for extracting flaxseed gum from flaxseed, comprising the following steps-a) after removing flaxseed raw materials, washing with water, and leaching with water;  b) obtaining the extracted gum solution by liquid-solid phase separation;  c) concentrated extracted gum solution under normal pressure or reduced pressure;  d) The concentrated gum solution is dried and pulverized to obtain a flaxseed gum product.  2. The method according to claim 1, characterized in that in the extraction step, demineralized water is used for leaching 2-6 times, and the weight ratio of flaxseed to demineralized water during the first extraction is 1: 3-15. The weight ratio of flaxseed to demineralized water during the second extraction is 1: 2-8.  3. The method according to claim 2, characterized in that the temperature of each extraction is 35-100 ° C, and the extraction time is 10-100 minutes.  4. The method according to claim 1, characterized in that said liquid-solid phase separation step is performed by pressurizing in an extraction tank or by suction filtration.  5. The method according to claim 4, characterized in that said pressurizing or pumping filtration is performed under heating and stirring by a scraper, so that it continuously sweeps the filter plate.  6. The method according to claim 1, characterized in that said concentrating step is performed with a scraper stirring to concentrate the gum solution to 1/2 to 1/20 of the original volume.  7. The method according to claim 1, further comprising a step of adding an ethanol solution having a weight ratio of 1: 0.6-1.5 to the concentrated gum solution 1 at room temperature under stirring after the concentration step to precipitate the gum solution and separate the solid and liquid Allow to dry.  8. The method according to claim 1, characterized in that said drying step uses hot air purging and drying, wherein the temperature of the hot air is 70-140 ° C. '  9. The method according to claim 1, characterized in that in the drying step, a concentrated glue solution is coated on a carrier and dried by microwave heating.