CN104001180A - Preparation method of alga natural antioxidant - Google Patents

Abstract

The invention discloses a preparation method of seaweed natural antioxidant. Fresh seaweed is pulped and crushed, extracted with hot water, centrifuged, dried, crushed, and sieved to obtain seaweed slag, which is further broken by biological enzyme method to obtain dry seaweed slag powder after breaking the wall; Extraction is carried out under leaching, the extract is collected, concentrated under reduced pressure and dried in vacuum to obtain the natural antioxidant product of seaweed. The product is in paste form and contains 5.2-13.7% by mass of total phenols, 3.6-8.4% by mass of total carotenoids, 0.5-1.3% by mass of terpenoids and 0.9-2.6% by mass of sterols. The invention uses seaweed residue as a raw material to prepare natural antioxidants with strong antioxidant activity to realize the comprehensive utilization of resources; the production process is simple, efficient, green and environmentally friendly, and suitable for industrial production; the product has strong antioxidant capacity, is green and natural, and can replace traditional antioxidants. Use of chemically synthesized antioxidants in the food industry.

Description

A kind of preparation method of seaweed natural antioxidant

technical field

The invention relates to the field of preparation technology of natural antioxidants, in particular to a preparation method of seaweed natural antioxidants.

Background technique

Studies have shown that oxidative stress is not only the common pathological basis for the occurrence and development of degenerative diseases such as cancer, aging, and cardiovascular disease, but also the main cause of causing or accelerating food spoilage. Traditional antioxidants mainly include tert-butylhydroquinone (TBHQ), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) and other chemical substances. The latest research has found that these chemical antioxidants are potentially harmful to human health and have been banned from being used in food for infants and children in developed countries in Europe and the United States. Therefore, the development of natural green antioxidants to replace traditional antioxidants in the food industry has become an urgent need.

There are a large number of natural antioxidant active substances in seaweed. Polyphenols are important antioxidant substances in seaweed, and their content can account for 1-14% of the dry weight of seaweed, and the polyphenols of seaweed and terrestrial plants are quite different in structure, and the polyphenols of terrestrial plants are mainly It is a derivative of gallic acid and ellagic acid, and seaweed polyphenol is a polymer of phloroglucinol (Holdt & Kraan, 2011). Studies have shown that brown algae polyphenols have outstanding performance in various biological activities such as anti-oxidation. By comparing the antioxidant evaluation methods of chemical system and cell system, it was found that the antioxidant activity of brown algae polyphenols is much better than that of vitamin C and vitamin E (Yotsu-Yamashita et al ., 2013). Fucoxanthin is another important functional active substance in seaweed, and its content can account for more than 0.5% of the dry weight of seaweed. Fucoxanthin, also known as fucoxanthin and fucoxanthin, belongs to xanthophylls, and its content accounts for more than 60% of the total carotenoids in kelp (Yan Xiaojun et al., 2001). Chen Wenjia et al. (2012) tested the scavenging ability of fucoxanthin on hydrogen peroxide, hydroxyl radicals, and DPPH free radicals, and proved that its antioxidant activity was significantly higher than that of vitamin C; Ha et al. (2011) found that fucoxanthin can effectively improve the Mouse plasma glutathione peroxidase and catalase activity reduce high-fat diet-induced oxidative stress. In addition, studies have shown that lipids, terpenes, halides, and sulfur-containing compounds in seaweed also have good antioxidant functions. Therefore, using seaweed to extract natural antioxidant substances has great development value.

However, the current development and utilization of seaweed is mainly seaweed polysaccharides, and seaweed polyphenols, fucoxanthin and other antioxidant substances are treated with seaweed residue as cheap feed or bio-fertilizer, resulting in a great waste of resources. It is still blank to obtain natural antioxidants from seaweed residue, a by-product of seaweed polysaccharide processing. Therefore, extracting natural antioxidant substances from seaweed residue has very important economic value and practical significance.

Contents of the invention

The purpose of the present invention is to provide a preparation method for extracting natural antioxidant substances from seaweed residue, a by-product of extracting seaweed polysaccharides.

In order to achieve the above object, the present invention provides a method for preparing natural antioxidants from seaweed, which is characterized in that it includes the following steps,

Preparation of seaweed slag: fresh seaweed is beaten until there is no obvious lumps, added deionized water at a volume ratio of 1:5, extracted at 80 ℃ for 1 h, centrifuged, preferably at 3000 r/min, 5 min, and the sediment is taken to obtain seaweed slag ;

Optionally, it may also include continuing to add deionized water to the seaweed residue, repeating the previous steps, and collecting the seaweed residue;

Preparation of seaweed residue dry powder: seaweed residue is dried, crushed and sieved to make seaweed residue dry powder;

Biological enzymatic hydrolysis of seaweed residue dry powder: mix the seaweed residue dry powder and compound enzyme preparation, add deionized water, enzymolyze at room temperature for a certain period of time, centrifuge, preferably at 3000 r/min, 5 min, and collect the sediment , dried in an oven at 80°C for 6 h to obtain dry seaweed slag powder after breaking the wall;

Organic solvent extraction: add absolute ethanol to the dry seaweed residue after the wall breaking, extract for a certain period of time at room temperature, centrifuge, preferably at 3000 r/min, 5 min, and collect the supernatant and seaweed sediment respectively;

Optionally, it may also include continuing to add absolute ethanol to the seaweed sediment, repeating the preceding steps, and collecting the supernatant and the seaweed sediment respectively;

Obtaining seaweed natural antioxidants: the supernatant is concentrated to dryness under reduced pressure, and vacuum dried to obtain seaweed natural antioxidant products.

The seaweed is at least one of kelp, laver, wakame and hijiki.

The seaweed residue is the residue after polysaccharides are extracted from seaweed.

In the preparation of the seaweed residue dry powder, sieve with 80-100 mesh.

In the biological enzymatic hydrolysis of the dry seaweed residue powder, the weight ratio of the dry seaweed powder to the compound enzyme preparation is 1000:5; the compound enzyme preparation is composed of pectinase and cellulase, preferably in a composition ratio of w/w 1:1;

Optionally, the ratio of seaweed dry powder and compound enzyme preparation sum to deionized water is a weight/volume ratio of 1:15-25;

Optionally, enzymatic hydrolysis at room temperature for 5-8 hours after adding deionized water.

In the organic solvent extraction, food-grade absolute ethanol is added, after extraction at room temperature, the precipitate is removed by centrifugation, and the supernatant is taken;

Optionally, the ratio of the broken seaweed residue dry powder to food-grade absolute ethanol is a weight/volume ratio of 1:5-10;

Optionally, after adding food-grade absolute ethanol, extract at room temperature for 1-3 hours.

In the obtaining of the seaweed natural antioxidant, the supernatant is concentrated to dryness under reduced pressure, and dried in a vacuum to obtain the seaweed natural antioxidant product;

Optionally, the temperature of the supernatant concentrated under reduced pressure is 40-60°C;

Optionally, the vacuum drying temperature is 50-80°C;

Optionally, the vacuum drying time is 2-5 hours.

The seaweed natural antioxidant active extract obtained by the method is in the form of a paste, containing 5.2-13.7% by mass of total phenols, 3.6-8.4% by mass of total carotenoids, 0.5-1.3% by mass of terpenoids, and 0.5-1.3% by mass of sterols The compound is 0.9-2.6% by mass.

The present invention also protects the seaweed antioxidant obtained by any method.

The method of the invention is simple to operate, environmentally friendly and efficient, suitable for large-scale production, fully realizes the comprehensive development and utilization of seaweed resources, and improves economic benefits.

The present invention uses seaweed dregs after extracting polysaccharides to extract natural antioxidant substances from seaweeds. Since most of the polysaccharides in the cell walls of seaweeds are extracted, the thickness of the cell walls is reduced, so that the effect of breaking the walls of biological enzymes is better, and the active substances contained in the cells can be fully released. The extraction rate of antioxidant substances is between 4% by mass and 6.7% by mass. The main components contained in the seaweed antioxidant extract at this time are seaweed polyphenols, carotenoids, terpenoids, and sterols. Antioxidant active substances obtained according to the method of the present invention and patent application: a method for enzymatically preparing fucoidan and fucoxanthin (application number: 201310142757.X application date: 2013-04-24, publication date : 2013-08-07), the obtained active ingredients are more comprehensive, thus realizing the maximum utilization of resources.

The present invention uses the by-product of seaweed polysaccharides processed by seaweed processing enterprises—seaweed slag as a raw material to prepare natural antioxidants with strong antioxidant activity to realize comprehensive utilization of resources; the production process is simple, efficient, green and environmentally friendly, and is suitable for industrial production; Strong oxidation ability, green and natural, can replace the use of traditional chemically synthesized antioxidants in the food industry.

This invention degrades the hard brown algae cell wall through the bio-enzyme wall breaking technology, so that the antioxidant components such as seaweed polyphenols and fucoxanthin existing in the cells are fully dissolved, and the rapid preparation of seaweed natural antioxidants is realized.

Advantage and beneficial effect of the present invention are:

1. my country is rich in seaweed resources. After seaweed processing enterprises extract polysaccharides from seaweed, seaweed residue is treated as cheap feed or bio-fertilizer. Antioxidants such as polyphenols and fucoxanthin in seaweed have not been processed well Utilization causes a great waste of resources, so the industrialized development and utilization of natural antioxidant active substances in seaweed residue has significant economic and social benefits;

2. The process of the present invention is simple (see Figure 1 for the process flow), environmentally friendly and efficient, suitable for large-scale operation, and can be applied to industrial production.

An embodiment of the present invention provides a method for preparing natural antioxidants from seaweed such as kelp. In Example 1, 100 g of laver residue dry powder finally obtained 6.5 g of antioxidant extract; in Example 2, 100 g of laver residue dry powder finally obtained 6.7 g of antioxidant extract; in Example 3, 100 g of wakame residue dry powder, finally obtained 5.2 g of antioxidant extract; in Example 4, 100 g of hijiki dregs dry powder, finally obtained 4.9 g of antioxidant extract.

According to the steps of the present invention, biological enzymes are used to treat the seaweed to break the wall, so that the antioxidant components in the seaweed cells can be fully dissolved, thereby significantly improving the extraction efficiency. In the experiment, the dry powder of kelp slag was used as raw material, and the wall-breaking effect of pectinase, cellulase and the composite preparation composed of them was compared and studied. The ratio of kelp powder (80 mesh) to biological enzyme was fixed at 1000:5 (w/ w), hydrolyzed at room temperature for 5 h, and judged the optimal ratio of biological enzymes based on the yield of ethanol extract, the results are shown in Table 1. The results of the experiment found that the yield of ethanol extract was significantly increased after the treatment with biological enzymes, and the effect of using pectinase and cellulase alone was not as good as that of using the two enzymes at the same time. At the same time, the test found that when the ratio of pectinase and cellulase is 1:1 (w/w), the wall breaking effect is statistically significantly different from other ratios. At the same time, by changing the ratio of pectinase and cellulase, it was found that the wall-breaking effect of various compound enzymes, whether it is to increase the specific gravity of pectinase or cellulase, the effect is not as good as that of pectinase and cellulose When the ratio of enzyme is 1:1 (w/w), the breaking effect is good, so the optimal ratio of pectinase and cellulase is 1:1 (w/w).

Table 1 The effect of biological enzyme wall breaking on the yield of ethanol extract from kelp residue

2. It is found through test and analysis that the seaweed natural antioxidant obtained by the present invention has a high content of antioxidant active substances, and is suitable for food antioxidants, functional foods and raw materials in medicine and other industries. The composition analysis of seaweed antioxidant extract is shown in Table 2:

Table 2 Component analysis of different seaweed antioxidant extracts

3. The seaweed natural antioxidant obtained in the present invention has the characteristics of high antioxidant activity and can effectively remove free radicals in cells (as shown in Figure 2). As can be seen from Fig. 2, the seaweed natural antioxidant obtained by the present invention has a maximum scavenging rate of 42%-54% for intracellular free radicals, and the maximum scavenging rate of vitamin E is 35%, which shows that the natural antioxidant effect of seaweed is anti-oxidant. Oxidative activity is better than that of vitamin E, and it can be used in the development of food antioxidants and antioxidant functional foods.

Description of drawings

Fig. 1 is a process flow diagram of the present invention. the

Figure 2 is a graph showing the effective removal of intracellular free radicals by seaweed natural antioxidants obtained in the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention. If no specific technique or condition is indicated in the examples, it shall be carried out according to the technique or condition described in the literature in this field or according to the product specification. The reagents or instruments used were not indicated by the manufacturer, and they were all commercially available conventional products.

The compound enzyme used in the following examples is a 1:1 (w/w) compound enzyme of pectinase and cellulase.

Embodiment 1: Kelp prepares seaweed natural antioxidant

(1) Take 500 g of fresh kelp, cut it into pieces with scissors, beat with a beater, add 2.5 L of deionized water, and stir evenly;

Extract at 80°C for 1 h, centrifuge in a tubular continuous centrifuge (3000 r/min, 5 min), take the sediment, and obtain 356.9 g of seaweed residue; the seaweed residue is dried, crushed, and passed through an 80-mesh sieve to make seaweed residue dry powder 75.8 g;

(2) Take 50 g of the dry kelp slag powder and 0.25 g of compound enzyme and mix well, add 754 mL of deionized water, and stir evenly. After reacting for 5 h at room temperature at 20 °C, centrifuge in a tubular continuous centrifuge (3000 rpm, 5 min) to get kelp residue. In this step, the seaweed residue is treated with biological enzymes to break the wall, so that the polyphenols, fucoxanthin and other antioxidant substances in the seaweed can be fully dissolved, thereby significantly improving the extraction efficiency. The damage effect of biological enzymes on the cell wall of seaweed was judged by the extraction rate of ethanol extract (see Table 1). It can be seen from Table 1 that the extraction rate of ethanol extract before enzyme treatment was 1.52 ± 0.36 g/100 g. When the ratio of cellulase and cellulase is 1:1 (w/w), the extraction rate of ethanol extract reaches 6.53±0.13 g/100 g, the effect is very significant;

(3) Put the above kelp slag into an oven and dry at 80°C for 6 hours to obtain 45 g of seaweed slag dry powder after breaking the wall;

(4) Add 225 mL of food-grade absolute ethanol to the dry seaweed residue after breaking the wall, extract for 2 hours at room temperature at 20 °C, centrifuge (3000 rpm, 5 minutes), and collect the supernatant and seaweed respectively Precipitate;

(5) Repeat step 4, and combine the supernatant obtained in step 4 and step 5;

(6) The above supernatant was concentrated to dryness under reduced pressure at 60 °C, and then dried in vacuum at 70 °C for 3 h to obtain 3.29 g of seaweed natural antioxidant product.

the

Embodiment 2: Seaweed natural antioxidant prepared by Hijiki

(1) Take 500 g of hijiki, cut it into pieces with scissors, beat it with a beater, add 2.5 L of deionized water, and stir evenly.

Extract at 80°C for 1 h, centrifuge with a tubular continuous centrifuge (3000 r/min, 5 min), take the sediment, and obtain 385.7 g of seaweed residue; the seaweed residue is dried, crushed, and passed through an 80-mesh sieve to make seaweed residue dry powder 81.4 g;

(2) Take 50 g of the above-mentioned seaweed residue dry powder and 0.25 g of compound enzyme and mix well, add 1005 mL of deionized water, and stir evenly. After reacting for 5 hours at room temperature at 20°C, centrifuge in a tubular continuous centrifuge (3000 rpm, 5 minutes) to get seaweed residue;

(3) The above-mentioned seaweed residue was put into an oven and dried at 80°C for 6 hours to obtain 46 g of dried seaweed residue after breaking the wall;

(4) Add 368 mL of food-grade anhydrous ethanol to the dry seaweed residue after breaking the wall, extract for 2 hours at room temperature at 20 °C, centrifuge (3000 rpm, 5 minutes), and collect the supernatant and seaweed respectively Precipitate;

(5) Repeat step 4, and combine the supernatant obtained in step 4 and step 5;

(6) The above supernatant was concentrated to dryness under reduced pressure at 60 °C, and then dried in vacuum at 70 °C for 3 h to obtain 2.47 g of seaweed natural antioxidant product.

Embodiment 3: seaweed natural antioxidant prepared by wakame

(1) Take 500 g of fresh wakame, cut it into pieces with scissors, beat with a beater, add 2.5 L of deionized water, and stir evenly;

Extract at 80°C for 1 h, centrifuge with a tubular continuous centrifuge (3000 r/min, 5 min), take the sediment, and obtain 322.5 g of seaweed residue; the seaweed residue is dried, crushed, and passed through an 80-mesh sieve to make seaweed residue dry powder 65.2 g;

(2) Take 50 g of the above-mentioned seaweed residue dry powder and 0.25 g of compound enzyme and mix well, add 1256 mL of deionized water, and stir evenly. After reacting for 5 hours at room temperature at 20°C, centrifuge in a tubular continuous centrifuge (3000 rpm, 5 minutes) to get seaweed residue;

(3) The above-mentioned seaweed residue was put into an oven and dried at 80°C for 6 hours to obtain 43 g of seaweed residue dry powder after breaking the wall;

(4) Add 430 mL of food-grade absolute ethanol to the dry seaweed residue after breaking the wall, extract at room temperature at 20 °C for 2 hours, centrifuge (3000 rpm, 5 minutes), and collect the supernatant and seaweed respectively Precipitate;

(5) Repeat step 4, and combine the supernatant obtained in step 4 and step 5;

(6) The above supernatant was concentrated to dryness under reduced pressure at 60 °C, and then dried in vacuum at 70 °C for 3 h to obtain 2.66 g of seaweed natural antioxidant product.

the

Embodiment 4: laver prepares seaweed natural antioxidant

(1) Take 500 g of fresh seaweed, cut it into pieces with scissors, beat it with a beater, add 2.5 L of deionized water, and stir evenly;

Extract at 80°C for 1 h, centrifuge in a tubular continuous centrifuge (3000 r/min, 5 min), take the sediment, and obtain 349.7 g of seaweed residue; the seaweed residue is dried, crushed, and passed through an 80-mesh sieve to make seaweed residue dry powder 70.6 g;

(2) Take 50 g of the above-mentioned seaweed residue dry powder and 0.25 g of compound enzyme and mix well, add 1005 mL of deionized water, and stir evenly. After reacting for 5 hours at room temperature at 20°C, centrifuge in a tubular continuous centrifuge (3000 rpm, 5 minutes) to get seaweed residue;

(3) The above-mentioned seaweed residue was put into an oven and dried at 80°C for 6 hours to obtain 47 g of dried seaweed residue after breaking the wall;

(4) Add 376 mL of food-grade absolute ethanol to the dry seaweed residue after breaking the wall, extract for 2 hours at room temperature at 20 °C, centrifuge (3000 rpm, 5 minutes), and collect the supernatant and seaweed respectively Precipitate;

(5) Repeat step 4, and combine the supernatant obtained in step 4 and step 5;

(6) The above supernatant was concentrated to dryness under reduced pressure at 60 °C, and then dried in vacuum at 70 °C for 3 h to obtain 3.38 g of seaweed natural antioxidant product.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limitations to the present invention. Variations, modifications, substitutions, and modifications to the above-described embodiments are possible within the scope of the present invention.

Claims (9)

1. a preparation method of seaweed natural antioxidant, is characterized in that, comprises the steps, Preparation of seaweed slag: fresh seaweed is beaten until there is no obvious lumps, added deionized water at a volume ratio of 1:5, extracted at 80 ℃ for 1 h, centrifuged, preferably at 3000 r/min, 5 min, and the sediment is taken to obtain seaweed slag ; Optionally, it may also include continuing to add deionized water to the seaweed residue, repeating the previous steps, and collecting the seaweed residue; Preparation of seaweed residue dry powder: seaweed residue is dried, crushed and sieved to make seaweed residue dry powder; Biological enzymatic hydrolysis of seaweed residue dry powder: mix the seaweed residue dry powder and compound enzyme preparation, add deionized water, enzymolyze at room temperature for a certain period of time, centrifuge, preferably at 3000 r/min, 5 min, and collect the sediment , dried in an oven at 80°C for 6 h to obtain dry seaweed slag powder after breaking the wall; Organic solvent extraction: add absolute ethanol to the dry seaweed residue after the wall breaking, extract for a certain period of time at room temperature, centrifuge, preferably at 3000 r/min, 5 min, and collect the supernatant and seaweed sediment respectively; Optionally, it may also include continuing to add absolute ethanol to the seaweed sediment, repeating the preceding steps, and collecting the supernatant and the seaweed sediment respectively; Obtaining seaweed natural antioxidants: the supernatant is concentrated to dryness under reduced pressure, and vacuum dried to obtain seaweed natural antioxidant products. 2. The preparation method of a kind of seaweed natural antioxidant according to claim 1, characterized in that: said seaweed is at least one of seaweed, seaweed, wakame and hijiki. 3. The preparation method of a kind of seaweed natural antioxidant according to claim 1, characterized in that: the seaweed residue is the residue after extracting polysaccharides from seaweed. 4. The preparation method of a kind of seaweed natural antioxidant according to claim 1, characterized in that: in the preparation of said seaweed dregs dry powder, sieve 80-100 mesh. 5. the preparation method of a kind of seaweed natural antioxidant of claim 1 is characterized in that: in the biological enzymolysis broken wall of described seaweed residue dry powder, the weight ratio of described seaweed dry powder and compound enzyme preparation is 1000:5; The compound enzyme preparation is made up of pectinase and cellulase, and the preferred composition ratio w/w is 1:1; Optionally, the ratio of seaweed dry powder and compound enzyme preparation sum to deionized water is a weight/volume ratio of 1:15-25; Optionally, enzymatic hydrolysis at room temperature for 5-8 hours after adding deionized water. 6. The preparation method of a kind of seaweed natural antioxidant of claim 1, is characterized in that: in described organic solvent leaching, add food-grade dehydrated alcohol, centrifuge to remove precipitation after leaching at normal temperature, get supernatant; Optionally, the ratio of the broken seaweed residue dry powder to food-grade absolute ethanol is a weight/volume ratio of 1:5-10; Optionally, after adding food-grade absolute ethanol, extract at room temperature for 1-3 hours. 7. the preparation method of a kind of seaweed natural antioxidant according to claim 1, is characterized in that: in the obtaining of described seaweed natural antioxidant, supernatant liquid is concentrated to dryness under reduced pressure, obtains seaweed natural antioxidant product through vacuum drying; Optionally, the temperature of the supernatant concentrated under reduced pressure is 40-60°C; Optionally, the vacuum drying temperature is 50-80°C; Optionally, the vacuum drying time is 2-5 hours. 8. The seaweed natural antioxidant product according to claim 7, characterized in that: the seaweed natural antioxidant active extract is in paste form, contains 5.2-13.7 mass % of total phenols, and 3.6-8.4 mass % of total carotenoids % by mass, 0.5-1.3% by mass for terpenoids, and 0.9-2.6% by mass for sterols. 9. the seaweed antioxidant obtained by any method of claim 1-8.