阅读说明：本技术 一种黑糯玉米色素的详细提取方法 (Detailed extraction method of black waxy corn pigment ) 是由 翟瑞宁 钦洁 邹成林 黄爱花 莫润秀 黄开健 韦新兴 杨萌 黄艳芬 于 2021-09-07 设计创作，主要内容包括：本发明公开了一种黑糯玉米色素的详细提取方法,属于天然产物提取技术领域,方法包括称取一定量的黑糯玉米干籽粒,用粉碎机粉碎；加入石油醚中,用超声提取法提取,除去玉米皮中的弱极性物质,称取预处理过的黑糯玉米粉4g,加入95％的乙醇,然后分别旋转蒸发,将浓缩后的色素加到已处理好的填充有724弱酸性阳离子交换树脂的离子交换柱中,待色素和交换树脂充分交换后,用去离子水洗涤,将色素中的糖类杂质除去；用乙醇溶液将色素洗脱下来,旋转蒸发后得到色素浓缩液。提取剂成本较低、用量小、提取率高,可明显提高黑糯玉米色素溶出率,保持黑糯玉米色素的原有结构和活性,产品色素的色价高,对黑糯玉米提取2次,色素提取率为92.04％,色素获得率为18.26％。(The invention discloses a detailed extraction method of black waxy corn pigment, belonging to the technical field of natural product extraction, and the method comprises weighing a certain amount of dry black waxy corn grains, and crushing the dry black waxy corn grains by a crusher; adding into petroleum ether, extracting with ultrasonic extraction method, removing weak polar substances in corn bran, weighing pretreated black glutinous corn flour 4g, adding 95% ethanol, respectively rotary evaporating, adding concentrated pigment into treated ion exchange column filled with 724 weak acidic cation exchange resin, washing with deionized water after pigment and exchange resin are fully exchanged, and removing saccharide impurities in pigment; eluting the pigment with ethanol solution, and rotary evaporating to obtain pigment concentrated solution. The extracting agent has the advantages of low cost, small dosage, high extraction rate, high color value of the product pigment, 92.04% of pigment extraction rate and 18.26% of pigment yield rate, and can obviously improve the dissolution rate of the black waxy corn pigment, maintain the original structure and activity of the black waxy corn pigment, and extract the black waxy corn pigment for 2 times.)

1. A detailed extraction method of black waxy corn pigment is characterized by comprising the following steps: the method comprises the following steps:

step 1: crushing: weighing a certain amount of black glutinous corn dry seeds, and crushing by a crusher;

step 2: degreasing: adding the substance obtained in the step (1) into petroleum ether, extracting by an ultrasonic extraction method, removing fat-soluble components in the corn bran, filtering and air-drying;

and step 3: impurity removal: ultrasonically extracting the substance obtained in the step 2 by using ethyl acetate, removing the weak polar substances in the corn bran, filtering and drying;

and 4, step 4: removing ethanol: weighing 4g of the black waxy corn powder pretreated in the step 3, adding 95% ethanol, and carrying out ultrasonic treatment for 45 min; then respectively carrying out rotary evaporation to remove ethanol;

and 5: adding the pigment concentrated in the step 4 into a treated ion exchange column filled with 724 weak-acid cation exchange resin, staying for half an hour, and after the pigment is fully exchanged with the exchange resin, washing with deionized water to remove saccharide impurities in the pigment;

step 6: elution and concentration: eluting the substance obtained in step 5 with 70% ethanol solution to obtain pigment concentrate, and rotary evaporating.

2. The detailed extraction method of black waxy corn pigment according to claim 1, characterized in that: the pH of the ethanol solution in the step 4 and the step 6 is 1.

3. The detailed extraction method of black waxy corn pigment according to claim 2, characterized in that: the temperature of the petroleum ether in the step 2 is 30-60 ℃.

4. The detailed extraction method of black waxy corn pigment according to claim 3, characterized in that: and 2, extracting the crushed corn kernels twice, and crushing the crushed corn kernels for one time after the first extraction.

Technical Field

The invention relates to the technical field of natural product extraction, in particular to a detailed extraction method of black waxy corn pigment.

Background

The black waxy corn is a new variety of corn, the cob (core) of the black waxy corn is deep purple black, the kernel is purple black, the black waxy corn is sweet and delicious, the nutritive value is higher, the contents of protein, amino acid, fat, life element selenium and natural melanin are obviously higher than those of the common waxy corn, and the black waxy corn also contains trace elements such as Zn, Fe, Ca, P and the like which are necessary for human bodies. Has high nutritive value. The previous research shows that melanin belongs to anthocyanin pigment, is flavonoid compound, has strong capacity of eliminating free radicals and resisting oxidation, and is a natural edible pigment resource with medicinal value. The existing method for extracting the pigment has the defects of residual organic solvent, long phase separation time and incapability of removing a large amount of impurities and solid substances.

Disclosure of Invention

The invention aims to provide a detailed extraction method of black waxy corn pigment, which solves the technical problems of residual organic solvent, long phase separation time and incapability of removing a large amount of impurities and solid matters in the existing pigment extraction method. The method aims to extract melanin from black waxy corn grains by a physical and chemical combination method, so that the melanin is applied to synthesis of natural edible pigments and food additives.

A detailed extraction method of black waxy corn pigment comprises the following steps:

step 1: crushing: weighing a certain amount of black glutinous corn dry seeds, and crushing by a crusher;

step 2: degreasing: adding the substance obtained in the step (1) into petroleum ether, extracting by an ultrasonic extraction method, removing fat-soluble components in the corn bran, filtering and air-drying;

and step 3: impurity removal: ultrasonically extracting the substance obtained in the step 2 by using ethyl acetate, removing the weak polar substances in the corn bran, filtering and drying;

and 4, step 4: removing ethanol: weighing 4g of the black waxy corn powder pretreated in the step 3, adding 95% ethanol, and carrying out ultrasonic treatment for 45 min; then respectively carrying out rotary evaporation to remove ethanol;

and 5: adding the pigment concentrated in the step 4 into a treated ion exchange column filled with 724 weak-acid cation exchange resin, staying for half an hour, and after the pigment is fully exchanged with the exchange resin, washing with deionized water to remove saccharide impurities in the pigment;

step 6: elution and concentration: eluting the substance obtained in step 5 with 70% ethanol solution to obtain pigment concentrate, and rotary evaporating.

Further, the ethanol solution in the step 4 and the step 6 has a pH of 1.

Further, the temperature of the petroleum ether in the step 2 is 30-60 ℃.

Further, the crushed corn kernels are extracted twice in the step 2, and after the first extraction, the crushed corn kernels are crushed and extracted once.

TABLE 1 selection of extraction temperatures

TABLE 2 selection of extraction time

TABLE 3 selection of liquid-to-feed ratio

Within the range of selected factors, the optimal extraction process of the black waxy corn pigment is obtained by analyzing a regression model Minitab 15 software, wherein the extraction temperature is 60 ℃, the extraction time is 24h, and the liquid-material ratio is 1:10 (mL/g). Under the process condition, the black waxy corn is extracted for 2 times, the pigment extraction rate is 92.04%, and the pigment yield is 18.26%.

By adopting the technical scheme, the invention has the following technical effects:

the extracting agent has the advantages of low cost, small dosage and high extraction rate, can obviously improve the dissolution rate of the black waxy corn pigment, keeps the original structure and activity of the black waxy corn pigment, has high color value of the product pigment, is extracted for 2 times from the black waxy corn, has the pigment extraction rate of 92.04 percent and the pigment yield of 18.26 percent,

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, preferred embodiments are given and the present invention is described in further detail. It should be noted, however, that the numerous details set forth in the description are merely for the purpose of providing the reader with a thorough understanding of one or more aspects of the present invention, which may be practiced without these specific details.

A detailed extraction method of black waxy corn pigment comprises the following steps: weighing a certain amount of black glutinous corn dry seeds, and crushing by a crusher;

(1) degreasing: adding petroleum ether (30-60 deg.C) into the obtained product in step (1), extracting with ultrasonic extraction method, removing fat-soluble components from corn bran, filtering, and air drying;

(2) impurity removal: ultrasonically extracting the corn bran obtained in the step (2) by using ethyl acetate, removing weak polar substances in the corn bran, filtering and drying;

(3) removing ethanol: weighing 4g of the black waxy corn powder pretreated in the step (3), adding 95% ethanol (pH is 1), and performing ultrasonic treatment for 45 min; then respectively carrying out rotary evaporation to remove ethanol;

(4) and then impurity removal: adding the pigment concentrated in the step (4) into a treated ion exchange column filled with 724 weak-acid cation exchange resin, staying for half an hour, and after the pigment is fully exchanged with the exchange resin, washing with deionized water to remove impurities such as saccharides in the pigment;

(5) elution and concentration: and (3) eluting the pigment from the step (5) by using a 70% ethanol (pH is 1), and performing rotary evaporation to obtain a pigment concentrated solution.

Within the range of selected factors, the optimal extraction process of the black waxy corn pigment is obtained by analyzing regression model Minitab 15 software, wherein the extraction temperature is 60 ℃, the extraction time is 24 hours, and the liquid-material ratio is 1:10 (mL/g). Under the process condition, the black waxy corn is extracted for 2 times, the pigment extraction rate is 92.04%, and the pigment yield is 18.26%. The method has the advantages of low cost, small dosage, high extraction rate, high dissolution rate of black glutinous corn pigment, retained original structure and activity of black glutinous corn pigment, and high color value of product pigment.

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