CN103923225B - A kind of preparation method of citrus pectin - Google Patents

Abstract

The invention relates to a method for preparing citrus pectin. The method comprises the following steps: (1) weighing citrus raw materials, cleaning, rubbing and drying; (2) crushing, screening, and adding 5-15 times by volume of alcohol solution for extraction; (3) squeezing and filtering, adding 5-15 times by volume of water in the filter residues to regulate the pH to 2-4; (4) carrying out a high voltage pulsed electric field treatment, intermittent heating extraction, centrifuging, repeatedly carrying out the treatment for multiple times, mixing the filtrate, concentrating, adding an acidic alcohol solution, standing and suction filtrating; (5) adding 95% ethanol in the precipitate, suction filtrating, drying, crushing, and sieving through a sieve of 60 meshes to obtain a finished product of citrus pectin. The method can be used for not only greatly improving the yield and quality of the citrus pectin and shortening the production cycle, but also reducing the energy consumption and the environmental pollution.

Description

A kind of preparation method of citrus pectin

technical field

The invention relates to the preparation of pectin in the field of natural product processing, in particular to a preparation method of citrus pectin.

Background technique

Pectin is a colloidal polysaccharide compound. Its basic structure is that the main chain is connected by β-D-pyranuronic acid with 1,4-glycosidic bonds, and the side chain is O in the L-rhamnose residue. The molecular formula of galactose on ₄ linked with β-1,2-glycosidic bond by α-1,2-glycosidic bond is (C ₆ H ₁₀ O ₇ ) _n . It usually exists in the state of partial methyl esterification, the molecular weight is 10,000-400,000, and the corresponding degree of polymerization exceeds 1,000 units. Pectin exists in the cell walls of leaves, roots, stems, and fruits of higher plants, and is bonded to plant cells, especially in fruits and leaves. Pectin is the main component of intercellular layer adhesion cells .

Pectin is widely used in the food industry. It can be used as a gelling agent in the production of jelly, jam, soft candy, etc. In yogurt products, pectin can improve its flavor, stabilize and keep fresh, and prevent pulp from Floating and casein coagulation in yogurt prolong the shelf life of yogurt products. As a food additive, pectin has passed the review of the FAO/WHO Joint Committee on Food Additives, declaring that it is non-toxic and the amount of addition is not limited.

Pectin is also widely used in the fields of medicine and daily chemical industry. For example, it has good curative effect on hypertension, colon cancer and obesity, and can inhibit the proliferation of human colon cancer and leukemia cells. Pectin can also reduce serum cholesterol and blood sugar levels, prevent cancer occurrence and metastasis, and prevent heavy metal ion poisoning, especially lead poisoning. In addition, pectin can not only lower cholesterol, but also has antioxidant activity, and pectin modified with hydroxamic acid has stronger anti-free radical activity than natural pectin.

At present, there are many preparation methods of pectin. The most common method of industrial production of pectin is the traditional acid extraction method, which uses dilute acid solution to convert non-water-soluble protopectin into water-soluble pectin, and then adds alcohol or polyvalent metal salts. , the pectin precipitates out, and the pectin product is obtained by washing, drying and crushing. The traditional acid extraction method is simple in process and low in cost, but because it is greatly affected by the extraction conditions, the efficiency is low and the production cycle is also long.

Contents of the invention

The purpose of the present invention is to provide a method for preparing citrus pectin, which can not only significantly increase the yield and quality of pectin, shorten the production cycle, but also reduce energy consumption and environmental pollution.

The purpose of the present invention is to realize through the following technical solutions:

A preparation method of citrus pectin, said preparation method comprising the following steps:

① Weigh citrus as raw material, wash it, mince it, and dry it;

②Crush the dried raw materials in step ①, pass through a 40-80 mesh sieve, add an alcohol solution 5-15 times the volume of the raw materials, and extract at 60-80°C for 1-4 hours;

8. Squeeze and filter the raw material extracted in step 2, add 5-15 times the volume of water to the filter residue, and adjust it to PH2-4 with hydrochloric acid;

④Using high-voltage pulsed electric field treatment, intermittent heating and extraction, centrifugation, repeat this cycle 2 to 4 times, preferably 3 times, combine the filtrate, concentrate the filtrate, and add 1-5 times the volume of acidic alcohol solution to the concentrated solution , standing for 2-6h, suction filtration;

5. Add 95% ethanol to the precipitate after suction filtration in step 4 and stir for 10 min, suction filter, vacuum-dry the obtained precipitate at 45° C., pulverize, and pass through a 60-mesh sieve to obtain the finished product of citrus pectin.

Further, the citrus described in step ① is citrus residual fruit or citrus food processing waste.

Further, the drying temperature in step ① is 60-80°C.

Further, the alcohol solution described in step ② is a 40%-100% alcohol solution.

Further, the alcohol solution is 60%-75% ethanol solution

Further, the electric field strength of the high voltage pulsed electric field described in step ④ is 10 to 24 kV/cm, the number of pulses is 5 to 12, and the temperature is 40-80°C.

Further, the specific process of the intermittent heating and extraction described in step ④ is: first conduct high-voltage pulse electric field treatment, and then perform heat preservation and stirring extraction, the temperature of the heat preservation and stirring extraction is 40-80 ° C, and the time of heat preservation and stirring extraction is 10-60min.

Further, in step ④, add 2-4 times the volume of acidic alcohol solution to the concentrated solution while stirring.

Further, the acidic alcoholic solution described in step ④ is an alcoholic solution containing 0.5mol/L HCl.

Further, the alcohol solution is 95% ethanol solution.

The invention provides a preparation method of citrus pectin, which mainly has the following beneficial effects.

① The present invention applies high-voltage pulsed electric field treatment technology to the extraction process of pectin, adopts intermittent high-voltage pulsed electric field-assisted acid extraction method, and can quickly and effectively extract pectin within the determined electric field strength, pulse number and temperature range, Pectin yield and quality are stable.

②In addition, the method of the present invention can effectively remove impurities such as pigments and lipid components by carrying out alcohol treatment on raw materials before extraction, which is beneficial to the subsequent process and improves the quality of pectin products.

3. the inventive method is simple and easy to operate, and extraction efficiency is high, is suitable for industrialized production, has solved the extraction time long that traditional pectin extraction method exists, and production efficiency is low, pectin yield rate is low, pectin quality is poor, problems such as instability, have It is conducive to improving the competitiveness of pectin products in the market.

④ The method of the present invention has important industrial market application value, and the pectin product can be widely used in fields such as food, health products, cosmetics, and medicine.

detailed description

The preparation method of a kind of citrus pectin described in the embodiment of the present invention, the preparation method comprises the following steps: 1. Weigh the citrus as raw material, wash it, mince it, and dry it; 2. Dry the raw material in step 1. Crush, pass through a 40-80 mesh sieve, add 5-15 times the volume of alcohol solution, and extract at 60-80°C for 1-4 hours; ③Press and filter the raw materials extracted in step ②, and add 5-15 times the volume of the filter residue volume of water, and adjusted to PH2-4 with hydrochloric acid; ④Using high-voltage pulse electric field treatment, intermittent heating extraction, centrifugation, repeating this cycle 2 to 4 times, combining the filtrate, and concentrating the filtrate, adding 1-5 Double the volume of acidic alcohol solution, let stand for 2-6h, and suction filter; ⑤add 95% ethanol to the precipitate after suction filtration in step ④, stir for 10min, and suction filter, and vacuum-dry the obtained precipitate at 45°C, Pulverize and pass through a 60-mesh sieve to obtain the finished product of citrus pectin.

As further preferably, the citrus described in step ① is citrus residual fruit or citrus food processing waste.

As a further preference, the drying temperature in step ① is 60-80°C.

As a further preference, the alcohol solution described in step ② is a 40%-100% alcohol solution.

As further preferably, the alcohol solution is 60%-75% ethanol solution

As a further preference, the electric field strength of the high-voltage pulsed electric field described in step ④ is 10-24 kV/cm, the number of pulses is 5-12, and the temperature is 40-80°C.

As a further preference, the specific process of the intermittent heating and extraction described in step ④ is: firstly perform high-voltage pulse electric field treatment, and then perform heat preservation and stirring extraction, the temperature of the heat preservation and stirring extraction is 40-80 ° C, and the heat preservation and stirring extraction The time is 10-60min.

As a further preference, in step ④, add 2-4 volumes of acidic alcohol solution to the concentrated solution while stirring.

As a further preference, the acidic alcoholic solution described in step ④ is an alcoholic solution containing 0.5mol/L HCl.

As a further preference, the alcohol solution is 95% ethanol solution.

In practice, high-voltage pulsed electric field is a non-thermal treatment technology, which has great advantages in the treatment of heat-sensitive substances. The high-voltage pulsed electric field can use the high potential difference to destroy the plant cell membrane, which can not only inactivate intracellular enzymes, but also significantly increase the dissolution of intracellular substances.

The following uses specific experimental cases as examples to illustrate specific implementation methods. It should be understood that the specific embodiments described here are only used to explain the present invention, and are not intended to limit the present invention.

Example 1

Take citrus raw materials, clean them, mince them, dry them at 65-75°C, crush them, pass through a 40-80 mesh sieve, add 15 times the volume of 70% ethanol solution, extract at 75-80°C for 1 hour, squeeze and filter, and add 12 Double the volume of water, adjust the pH to 2 with hydrochloric acid; then use high-voltage pulse electric field treatment, the electric field strength of the high-voltage pulse electric field treatment is 10kV/cm, the number of pulses is 10, and the temperature is 60°C. After the high-voltage pulse electric field treatment, keep the temperature Stir and heat extraction at 60°C for 30 minutes, centrifuge, and repeat this cycle 3 times, combine the filtrate, concentrate the filtrate, add an equal volume of 95% ethanol solution containing 0.5mol/L HC1 to the concentrated solution while stirring, let it stand for 2 hours, pump Filtrate, add 95% ethanol to the obtained precipitate, stir for 10 min, suction filter, vacuum dry the obtained precipitate at 45°C, pulverize and pass through a 60-mesh sieve to obtain the finished product of citrus pectin.

Example 2

Take citrus raw materials, clean them, mince them, dry them at 60-70°C, crush them, pass through a 40-80 mesh sieve, add 10 times the volume of 80% ethanol solution, extract at 60-70°C for 3 hours, squeeze and filter, and add 10 Double the volume of water, adjust the pH to 3 with hydrochloric acid; then use high-voltage pulse electric field treatment, the electric field intensity of the high-voltage pulse electric field treatment is 15kV/cm, the number of pulses is 12, and the temperature is 80 ° C. After the high-voltage pulse electric field treatment, keep the temperature Stir and heat at 80°C for 40 minutes, centrifuge, and repeat this cycle 3 times, combine the filtrate, concentrate the filtrate, add 2 times the volume of 95% ethanol solution containing 0.5mol/L HC1 to the concentrated solution while stirring, and let it stand for 3~ After 5 hours, filter with suction, add 95% ethanol to the obtained precipitate, stir for 10 min, filter with suction, vacuum-dry the obtained precipitate at 45°C, pulverize and pass through a 60-mesh sieve to obtain the finished product of citrus pectin.

Example 3

Take citrus raw materials, clean them, mince them, dry them at 70-80°C, crush them, pass through a 40-80 mesh sieve, add 6 times the volume of 60% ethanol solution, extract at 75-80°C for 1.5h, squeeze and filter, and add the filter residue 15 times the volume of water, adjust the pH to 4 with hydrochloric acid; then use high-voltage pulse electric field treatment, the electric field strength of the high-voltage pulse electric field treatment is 20kV/cm, the number of pulses is 8, and the temperature is 40 ° C. After high-voltage pulse electric field treatment, keep Stir and heat at 40°C for extraction for 45 minutes, centrifuge, repeat this cycle 3 times, combine the filtrate, concentrate the filtrate, add 3 times the volume of 95% ethanol solution containing 0.5mol/L HC1 to the concentrated solution while stirring, and let it stand for 4.5 h, filter with suction, add 95% ethanol to the obtained precipitate, stir for 10 min, filter with suction, vacuum dry the obtained precipitate at 45°C, pulverize and pass through a 60-mesh sieve to obtain the finished product of citrus pectin.

The present invention is not limited to the above-mentioned best implementation mode, and anyone who makes any modifications or changes related to the present invention under the inspiration of the present invention, who has the same or similar technical solutions as the present application, all falls under the protection of the present invention. within range.

Claims (5)

1. a kind of preparation method of citrus pectin it is characterised in that: described preparation method comprises the following steps:

1. weigh Citrus as raw material, rub after cleaning up, dry；

2. the raw material after step 1. middle drying is pulverized, 40-80 mesh sieve excessively, and added the alcoholic solution of 5-15 times of volume, 60- 80 DEG C of extraction 1-4h；

3. the raw material of step 2. middle extraction is carried out squeeze and filter, filtering residue adds the water of 5-15 times of volume, and is adjusted to hydrochloric acid ph2-4；

4. adopt high voltage pulse electric field processing, the electric field intensity of described high-pressure pulse electric is 20kv/cm, and umber of pulse is 8, temperature Spend for 40-80 DEG C；Then at 40-80 DEG C, insulated and stirred extracts 10-60min, centrifugation, such circulating repetition 2～4 times, merges Filtrate, and filtrate is concentrated, add the acidity alcohol solution of 2-4 times of volume in concentrated solution while stirring, stand 2-6h, take out Filter, described acidity alcohol solution is 95% ethanol solution containing 0.5mol/l hci；

5. add 95% ethanol stirring 10min, sucking filtration in the precipitation after step 4. middle sucking filtration, be deposited at 45 DEG C by obtain Row vacuum drying, pulverizes, and crosses 60 mesh sieves, obtains citrus pectin finished product.

2. citrus pectin according to claim 1 preparation method it is characterised in that: the 1. described Citrus of step be Citrus Cull fruit or orange food processing waste material.

3. citrus pectin according to claim 1 preparation method it is characterised in that: the temperature of step 1. described drying is 60-80℃.

4. citrus pectin according to claim 1 preparation method it is characterised in that: step 2. described in alcoholic solution be 40%-100% alcoholic solution.

5. citrus pectin according to claim 4 preparation method it is characterised in that: step 2. described in alcoholic solution be 60%-75% ethanol solution.