阅读说明：本技术 一种柚皮膳食纤维的制备方法 (Preparation method of shaddock peel dietary fiber ) 是由 郑培君 齐明 李清泉 姚政校 于 2021-07-21 设计创作，主要内容包括：本发明提供了一种柚皮膳食纤维的制备方法,属于食品加工技术领域。所述制备方法包含灭酶、干燥、脱脂、粉碎、酶解、超声波处理、离心、醇沉干燥上清液以及水洗干燥滤渣等步骤。本发明的制备方法克服了现有技术中柚皮膳食纤维品质差、提取率低的问题。通过一系列制备方法能够有效提高柚皮的膳食纤维持水力、膨胀力、持油力,且提取率高,易于操作,适合工业化生产。通过本申请制备方法得到的水溶性膳食纤维(SDF)得率能够达到15.13％,水不溶性膳食纤维(IDF)得率能够达到65.72％。(The invention provides a preparation method of shaddock peel dietary fiber, and belongs to the technical field of food processing. The preparation method comprises the steps of enzyme inactivation, drying, degreasing, crushing, enzymolysis, ultrasonic treatment, centrifugation, alcohol precipitation for drying supernatant, washing for drying filter residue and the like. The preparation method of the invention overcomes the problems of poor quality and low extraction rate of the shaddock peel dietary fiber in the prior art. The dietary fiber water holding capacity, expansibility and oil holding capacity of the shaddock peel can be effectively improved through a series of preparation methods, and the method is high in extraction rate, easy to operate and suitable for industrial production. The yield of the water-Soluble Dietary Fiber (SDF) obtained by the preparation method can reach 15.13%, and the yield of the water-Insoluble Dietary Fiber (IDF) can reach 65.72%.)

1. A preparation method of shaddock peel dietary fiber is characterized by comprising the following steps:

s1, inactivating enzyme of the shaddock peel;

s2, drying the shaddock peel after enzyme deactivation;

s3, degreasing the dried shaddock peel;

s4, crushing the degreased shaddock peel to obtain shaddock peel powder;

s5, sequentially carrying out enzymolysis, ultrasonic treatment and centrifugation on the obtained shaddock peel powder to obtain supernatant and filter residue;

s6, concentrating the supernatant obtained in the step S5 to obtain a concentrated solution, and sequentially performing alcohol precipitation and drying to obtain water-soluble dietary fibers;

and S7, washing and drying the filter residue obtained in the S5 sequentially to obtain the water-insoluble dietary fiber.

2. The method for preparing the shaddock peel dietary fiber according to claim 1, wherein the drying temperature in the step S2 is 60-85 ℃ and the drying is carried out to a constant weight.

3. The preparation method of the shaddock peel dietary fiber according to claim 1 or 2, wherein the degreasing is carried out by soaking in petroleum ether, the volume ratio of the petroleum ether to the shaddock peel in the step S3 is 3-6: 1, and the soaking time is 3-6 h.

4. The preparation method of the shaddock peel dietary fiber as claimed in claim 3, wherein the particle size of the shaddock peel powder is 40-60 mesh.

5. The preparation method of the shaddock peel dietary fiber as claimed in claim 4, wherein the enzyme used in the enzymolysis is cellulase or pectinase, the addition amount of the enzyme is 2.5-3.5% of the weight of the shaddock peel powder, the enzymolysis temperature is 40-50 ℃, and the enzymolysis time is 60-90 min.

6. The preparation method of the shaddock peel dietary fiber as claimed in claim 1 or 5, wherein the ultrasonic treatment power is 200-400 w, and the treatment time is 20-40 min.

7. The preparation method of the shaddock peel dietary fiber as claimed in claim 6, wherein the rotation speed of the centrifugation is 7000 to 9000r/min, and the time of the centrifugation is 10 to 20 min.

8. The method for preparing dietary fiber from pomelo peel as claimed in claim 7, wherein the concentration in step S6 is 1/4-1/2 of the volume of the supernatant.

9. The preparation method of the shaddock ped dietary fiber as claimed in claim 8, wherein the alcohol used in the alcohol precipitation is absolute ethyl alcohol, the volume ratio of the absolute ethyl alcohol to the concentrated solution is 3-5: 1, and the alcohol precipitation time is 8-12 h.

10. The method for preparing the pomelo peel dietary fiber according to the claim 1, 8 or 9, wherein the drying temperature in the step S6 and the drying temperature in the step S7 are independently 50-65 ℃, and the drying is carried out to constant weight.

Technical Field

The invention relates to the technical field of food processing, in particular to a preparation method of shaddock peel dietary fiber.

Background

The fiber is the main component in the pomelo peel, and the dietary fiber which can be digested and utilized by human body is extracted. The shaddock peel dietary fiber keeps the special fragrance of shaddock, has faint scent and pleasant smell, and can be used as an ingredient of food. The shaddock peel dietary fiber has the advantages of easily accepted flavor, color and luster, low cost and certain physiological and biochemical characteristics, can be used as a food ingredient for bakery foods such as bread, biscuits and cakes and other high-fiber/low-calorie foods, and can supplement the deficiency of the dietary fiber content in the products, reduce the calorie of the products and improve the structure and the flavor of the products.

The preparation method of the dietary fiber in the prior art comprises the following steps:

1. the chemical method comprises the following steps: although the chemical method is the most common method at present and has the characteristics of low preparation cost, simplicity, rapidness and the like, the change of the structural properties and the like of the dietary fibers is easy to cause and the loss of the activity, and the yield is low. The fiber product prepared by the acid-base method has poor color, difficult bleaching and poor quality, and has serious corrosion to an extraction container, a pipeline and a material pump under the conditions of high acid, high alkali and high temperature, and has the defects in the aspect of environmental protection.

2. An enzyme method comprises the following steps: the enzyme method for extracting the water-insoluble dietary fiber in the shaddock peel avoids the defects of low extraction efficiency and large damage to products of a chemical method, but the cost is too high due to the high price of an enzyme preparation, so that the industrial production is difficult to realize.

3. Ultrasonic assisted extraction method: the ultrasonic-assisted extraction of the water-soluble dietary fiber of the shaddock peel has the advantages of high extraction rate, white color and light smell. However, the cavitation effect generated by the ultrasonic wave destroys the cell structure of the pomelo pocket coating layer, so that the specific surface area of fiber particles is increased, more hydrophilic groups are exposed, and partial insoluble components are melted or molecular chains are broken, so that the fiber characteristics are changed.

Disclosure of Invention

The invention aims to provide a preparation method of shaddock peel dietary fiber, which is used for solving the problems of poor quality and low extraction rate of shaddock peel dietary fiber in the prior art.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a preparation method of shaddock peel dietary fiber, which comprises the following steps:

s1, inactivating enzyme of the shaddock peel;

s2, drying the shaddock peel after enzyme deactivation;

s3, degreasing the dried shaddock peel;

s4, crushing the degreased shaddock peel to obtain shaddock peel powder;

s5, sequentially carrying out enzymolysis, ultrasonic treatment and centrifugation on the obtained shaddock peel powder to obtain supernatant and filter residue;

s6, concentrating the supernatant obtained in the step S5 to obtain a concentrated solution, and sequentially performing alcohol precipitation and drying to obtain water-soluble dietary fibers;

and S7, washing and drying the filter residue obtained in the S5 sequentially to obtain the water-insoluble dietary fiber.

Preferably, the drying temperature in the step S2 is 60-85 ℃, and the drying is carried out until the weight is constant.

Preferably, the degreasing step is carried out by soaking in petroleum ether, the volume ratio of the petroleum ether to the shaddock peel in the step S3 is 3-6: 1, and the soaking time is 3-6 h.

Preferably, the particle size of the shaddock peel powder is 40-60 meshes.

Preferably, the enzyme used in the enzymolysis is cellulase or pectinase, the addition amount of the enzyme is 2.5-3.5% of the weight of the shaddock peel powder, the enzymolysis temperature is 40-50 ℃, and the enzymolysis time is 60-90 min.

Preferably, the ultrasonic treatment power is 200-400 w, and the treatment time is 20-40 min.

Preferably, the rotating speed of the centrifugation is 7000-9000 r/min, and the time of the centrifugation is 10-20 min.

Preferably, the concentration in the step S6 is 1/4-1/2 of the volume of the supernatant.

Preferably, the alcohol used for alcohol precipitation is absolute ethyl alcohol, the volume ratio of the absolute ethyl alcohol to the concentrated solution is 3-5: 1, and the alcohol precipitation time is 8-12 hours.

Preferably, the drying temperature in the step S6 and the drying temperature in the step S7 are independently 50-65 ℃, and the drying is carried out until the weight is constant.

The invention has the technical effects and advantages that:

the invention provides a preparation method of shaddock peel dietary fiber, which comprises the steps of enzyme deactivation, drying, degreasing, crushing, enzymolysis, ultrasonic treatment, centrifugation, alcohol precipitation for drying supernatant, water washing for drying filter residue and the like. The preparation method can effectively improve the water holding capacity, the expansibility and the oil holding capacity of the dietary fiber, has high extraction rate, is easy to operate, and is suitable for industrial production.

Detailed Description

The invention provides a preparation method of shaddock peel dietary fiber, which comprises the following steps:

s1, inactivating enzyme of the shaddock peel;

s2, drying the shaddock peel after enzyme deactivation;

s3, degreasing the dried shaddock peel;

s4, crushing the degreased shaddock peel to obtain shaddock peel powder;

s5, sequentially carrying out enzymolysis, ultrasonic treatment and centrifugation on the obtained shaddock peel powder to obtain supernatant and filter residue;

s6, concentrating the supernatant obtained in the step S5 to obtain a concentrated solution, and sequentially performing alcohol precipitation and drying to obtain water-soluble dietary fibers;

and S7, washing and drying the filter residue obtained in the S5 sequentially to obtain the water-insoluble dietary fiber.

The method also preferably comprises a pretreatment step before the enzyme deactivation step, and the pretreatment step preferably comprises the steps of removing the surface layer of the yellow oil cell layer of the shaddock peel, and cutting into fine particles.

The enzyme deactivation of the invention is preferably carried out by hot water bath.

The drying according to the invention is preferably a baking drying. In the invention, the drying temperature in the step S2 is preferably 60-85 ℃, more preferably 65-80 ℃, and further preferably 70-75 ℃; the drying is preferably to constant weight.

The degreasing is preferably carried out at room temperature by soaking in petroleum ether; in the invention, the volume ratio of the petroleum ether to the shaddock peel in the step S3 is preferably 3-6: 1, and the preferred volume ratio is 4-1; the soaking time is preferably 3-6 h, more preferably 4-5.5 h, and still more preferably 4.5-5 h.

The invention also preferably comprises a spreading and drying step before the crushing step; in the invention, the particle size of the shaddock peel powder is preferably 40-60 meshes, more preferably 45-55 meshes, and further preferably 48-52 meshes.

According to the invention, cellulase or pectinase is preferably adopted for enzymolysis, and the addition amount of the enzyme is preferably 2.5-3.5% of the weight of the shaddock peel powder, more preferably 2.8-3.2%, and still more preferably 2.9-3.0%; in the invention, the enzymolysis temperature is preferably 40-50 ℃, more preferably 42-48 ℃ and still more preferably 44-46 ℃; the enzymolysis time is preferably 60-90 min, more preferably 70-85 min, and still more preferably 75-80 min.

The ultrasonic treatment power is preferably 200-400 w, more preferably 250-350 w, and still more preferably 280-320 w; in the invention, the ultrasonic treatment time is preferably 20-40 min, more preferably 25-35 min, and still more preferably 28-32 min.

The centrifugal rotating speed is preferably 7000-9000 r/min, more preferably 7500-8500 r/min, and still more preferably 8000-8200 r/min; the time for centrifugation is preferably 10-20 min, more preferably 12-18 min, and still more preferably 14-16 min.

The concentration in step S6 is preferably reduced pressure concentration, and in the present invention, the concentration is preferably 1/4-1/2, and more preferably 3/10-2/5 of the volume of the supernatant.

The alcohol used for alcohol precipitation is preferably absolute ethyl alcohol; the alcohol precipitation is preferably carried out at room temperature; in the invention, the volume ratio of the absolute ethyl alcohol to the concentrated solution is 3-5: 1, and the preferred volume ratio is 3.5-4: 1; the alcohol precipitation time is preferably 8-12 h, and further preferably 9-11 h.

The method also preferably comprises a washing step before the drying step, wherein the washing is preferably 95% ethanol washing, and the washing is preferably 5-7 times; in the invention, the drying in the step S6 and the step S7 is preferably vacuum drying, and the drying temperature is independently preferably 50-65 ℃, and further preferably 55-60 ℃; the drying is preferably to constant weight.

The present invention preferably further includes a pulverization step after the drying step in the step S6 and the step S7, wherein the pulverized particle size is preferably 50 to 70 mesh.

The technical solutions provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.

Example 1

Step 1:

removing surface layer of butter cell layer from fresh pericarpium Citri Grandis, cutting into fine granules, inactivating enzyme in water bath, taking out, cooling, draining, and oven drying at 65 deg.C to constant weight.

Step 2:

soaking the sample in petroleum ether with the volume 4 times that of the material at room temperature for 4 hours, spreading and drying in the air after soaking to obtain a degreased sample, and finally crushing the degreased sample and sieving the degreased sample with a 45-mesh sieve for later use.

And step 3:

adding 3.5% cellulase, acting at 45 deg.C for 65min, performing ultrasonic assisted extraction with 200w for 25min, centrifuging at 8000r/min for 10min, and collecting supernatant and residue.

And 4, step 4:

concentrating the supernatant under reduced pressure to 1/3, transferring into a beaker, adding 4 times of anhydrous ethanol, standing at room temperature for precipitating with ethanol for 10h, filtering, washing with 95% ethanol for 6 times, vacuum drying at 50 deg.C to constant weight, and pulverizing to obtain SDF (water soluble dietary fiber).

And 5:

washing the residue with distilled water to neutral, vacuum drying at 55 deg.C to constant weight, and pulverizing to obtain IDF (water insoluble dietary fiber).

Example 2

Step 1:

removing surface layer of butter cell layer from fresh pericarpium Citri Grandis, cutting into fine granules, inactivating enzyme in water bath, taking out, cooling, draining, and oven drying at 75 deg.C to constant weight.

Step 2:

soaking the sample in petroleum ether with the volume 4 times that of the material at room temperature for 3 hours, spreading and drying in the air after soaking to obtain a degreased sample, and finally crushing the degreased sample and sieving the degreased sample with a 50-mesh sieve for later use.

And step 3:

adding 3.0% pectase, acting at 50 deg.C for 80min, performing ultrasonic assisted extraction with 300w for 35min, centrifuging at 8000r/min for 15min, and collecting supernatant and residue.

And 4, step 4:

concentrating the supernatant under reduced pressure to 1/2, transferring into a beaker, adding 5 times of anhydrous ethanol, standing at room temperature for precipitating with ethanol for 8h, filtering, washing with 95% ethanol for 5 times, vacuum drying at 55 deg.C to constant weight, and pulverizing to obtain SDF (water soluble dietary fiber).

And 5:

washing the residue with distilled water to neutral, vacuum drying at 65 deg.C to constant weight, and pulverizing to obtain IDF (water insoluble dietary fiber).

Example 3

Step 1:

removing surface layer of butter cell layer from fresh pericarpium Citri Grandis, cutting into fine granules, inactivating enzyme in water bath, taking out, cooling, draining, and oven drying at 60 deg.C to constant weight.

Step 2:

soaking the sample in petroleum ether with the volume 5 times that of the material at room temperature for 3 hours, spreading and drying in the air after soaking to obtain a degreased sample, and finally crushing the degreased sample and sieving the degreased sample with a 60-mesh sieve for later use.

And step 3:

adding 2.5% cellulase, acting at 50 deg.C for 75min, performing ultrasonic extraction at 400w for 40min, centrifuging at 8200r/min for 10min, and collecting supernatant and residue.

And 4, step 4:

concentrating the supernatant under reduced pressure to 2/5, transferring into a beaker, adding 3 times of anhydrous ethanol, standing at room temperature for precipitating with ethanol for 11h, filtering, washing with 95% ethanol for 7 times, vacuum drying at 65 deg.C to constant weight, and pulverizing to obtain SDF (water soluble dietary fiber).

And 5:

washing the residue with distilled water to neutral, vacuum drying at 65 deg.C to constant weight, and pulverizing to obtain IDF (water insoluble dietary fiber).

Test examples

The following experimental groups were set up: the following measurement methods were used to measure the water retention, swelling power and oil retention in 12 experimental groups, i.e., microwave-assisted enzymatic extraction (SDF), microwave-assisted alkaline extraction (SDF), chemical extraction (acid-base combination method) (IDF), enzymatic extraction (SDF), enzymatic extraction (IDF), ultrasonic-assisted extraction (SDF), ultrasonic-assisted extraction (IDF), extraction by the method in example 1 (SDF), and extraction by the method in example 1 (IDF):

and (3) determining the water retention of the dietary fiber:

accurately weighing 1.000g of dietary fiber, soaking in distilled water for 2h at 25 deg.C, filtering with filter paper until no water drops, transferring the obtained dietary fiber into a small beaker after drying, and weighing.

Water holding capacity ≡ [ sample wet weight (g) -sample dry weight (g) ]/sample dry weight (g)

Determination of the expansibility of the dietary fiber:

1.000g of dietary fiber was accurately weighed and poured directly into a 10mL graduated cylinder, at which time the volume (mL) was recorded. The fiber was immersed in distilled water at room temperature for 24 hours, and the volume (mL) of the fiber freely expanded in the cylinder was read, and the expansion force per gram of fiber was converted.

Expansion force ≡ [ fiber volume after expansion (mL) -dry matter volume (mL) ]/dry weight of sample (g)

Determination of dietary fiber oil-retaining ability:

accurately weighing 1.000g dietary fiber in a 50mL centrifuge tube, adding 20g vegetable oil, standing at room temperature for 1h, centrifuging at 3000r/min for 20min, removing upper layer oil, and sucking dry the residual vegetable oil in the centrifuge tube with filter paper.

Oil holding force ═ sample mass after oil absorption (g) -sample dry weight (g) ]/sample dry weight (g)

The results of the experiment are shown in table 1:

TABLE 1

The preparation method of the shaddock peel dietary fiber comprises the steps of enzyme deactivation, drying, degreasing, crushing, enzymolysis, ultrasonic treatment, centrifugation, alcohol precipitation and drying of supernatant, washing of dried filter residue and the like. The preparation method can effectively improve the water holding capacity, the expansibility and the oil holding capacity of the dietary fiber, has high extraction rate, is easy to operate, and is suitable for industrial production.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.