阅读说明：本技术 一种天然油脂抗氧化剂的制备方法及用途 (Preparation method and application of natural oil antioxidant ) 是由 姚宏亮 唐艳 石琪鑫 钱金旖 杨佳妮 秦莹 于 2020-05-07 设计创作，主要内容包括：本发明公开了一种天然油脂抗氧化剂的制备方法及用途,天然油脂抗氧化剂为甘薯叶黄酮,制备方法包括如下步骤：步骤1,将甘薯叶制备成甘薯叶超微粉,然后将超微粉放入提取液中,提取液为乙醇,提取条件为：乙醇浓度50%-90%,液料比30:1-70:1(mL/g),超声提取,提取时间30-150min,提取温度40-80℃；步骤2,随后离心(4000r/m,4℃,10min)去上清液,将上清液旋转浓缩至无明显醇味,步骤3,再次离心(4000r/m,4℃,10min)取上清液即为甘薯叶黄酮提取液；然后再提纯处理。本发明,以现有的甘薯叶为原料提取黄酮并应用于食用油脂天然抗氧化剂的开发具有重要的现实意义,原料来源广泛,且成本低,具有良好的经济效益。(The invention discloses a preparation method and application of a natural oil antioxidant, wherein the natural oil antioxidant is sweet potato leaf flavone, and the preparation method comprises the following steps: step 1, preparing sweet potato leaves into sweet potato leaf superfine powder, then putting the superfine powder into an extracting solution, wherein the extracting solution is ethanol, and the extracting conditions are as follows: extracting with 50-90% ethanol at a liquid-to-material ratio of 30:1-70:1(mL/g) under ultrasonic conditions for 30-150min at 40-80 deg.C; step 2, centrifuging (4000r/m, 4 ℃ and 10min) to remove supernatant, concentrating the supernatant in a rotating manner until no obvious alcohol smell exists, and step 3, centrifuging again (4000r/m, 4 ℃ and 10min) to obtain supernatant which is the sweet potato leaf flavone extracting solution; then purifying. The invention has important practical significance for extracting flavone from the existing sweet potato leaves as the raw material and applying the flavone to the development of the natural antioxidant of the edible oil, has wide raw material source and low cost, and has good economic benefit.)

1. A natural oil antioxidant is characterized in that: the natural oil antioxidant is sweet potato leaf flavone.

2. A preparation method of a natural oil antioxidant is characterized by comprising the following steps: the natural oil antioxidant is sweet potato leaf flavone, and the preparation method of the sweet potato leaf flavone comprises the following steps:

step 1, preparing sweet potato leaves into sweet potato leaf superfine powder, then putting the superfine powder into an extracting solution, wherein the extracting solution is ethanol, and the extracting conditions are as follows: extracting with 50-90% ethanol at a liquid-to-material ratio of 30:1-70:1(mL/g) under ultrasonic conditions for 30-150min at 40-80 deg.C;

step 2, centrifuging (4000r/m, 4 ℃, 10min) to remove supernatant, concentrating the supernatant in a rotary manner until no obvious alcohol smell exists,

step 3, centrifuging again (4000r/m, 4 ℃ and 10min) and taking supernatant fluid, namely the sweet potato leaf flavone extracting solution;

step 4, purifying the sweet potato leaf flavone, which comprises the following steps: purifying the crude extract of sweet potato leaf flavone by using macroporous adsorption resin, wherein the purification process comprises the following steps: pretreating the macroporous adsorption resin, weighing the macroporous adsorption resin, filling the macroporous adsorption resin into a column, respectively adding the crude sweet potato leaf flavone extract, adsorbing by a rotary mixer, performing suction filtration, adding an ethanol solution into the macroporous adsorption resin after suction filtration, desorbing by the rotary mixer, and performing suction filtration to obtain the purified sweet potato leaf flavone extract.

3. The method for preparing the natural oil antioxidant as claimed in claim 2, wherein the natural oil antioxidant comprises: step 1 minimum ultrasound power 320W.

4. The method for preparing the natural oil antioxidant as claimed in claim 2, wherein the natural oil antioxidant comprises: the extraction conditions of the step 1 are as follows: the extraction temperature is 70 ℃, the extraction time is 120min, the ethanol concentration is 80%, and the liquid-material ratio is 70: 1.

5. the method for preparing the natural oil antioxidant as claimed in claim 2, wherein the natural oil antioxidant comprises: the macroporous adsorption resin in the step 4 is AB-8 macroporous resin.

6. The method for preparing the natural oil antioxidant as claimed in claim 2, wherein the natural oil antioxidant comprises: the purification process of the step 4 comprises the following steps: loading macroporous resin into column by wet column loading method, and loading sweet potato leaf flavone crude extract with concentration of 2.0mg/mL-40.0mg/mL into sample solution with pH of 3-7; passing through the column at a flow rate of 1BV/h-5BV/h for adsorption, and then passing through the column with 3BV ultrapure water for removing impurities on the surface of the resin; passing 60-100% ethanol solution through the column at a flow rate of 1BV/h-5BV/h for desorption, and collecting the desorption solution after passing through the column.

7. The method for preparing the natural oil antioxidant as claimed in claim 6, wherein the natural oil antioxidant comprises: the purification process comprises the following steps: the optimal concentration of the crude extraction liquid of the sweet potato leaf flavonoid is 2.5mg/mL, and the optimal pH value of the sample liquid is 5; the optimal sample feeding flow rate is 2 BV/h; the optimal concentration of the ethanol solution is 100 percent; the flow rate of the desorption solution is 2 BV/h.

8. The application of the sweet potato leaf flavone is characterized in that: the sweet potato leaf flavonoid has an antioxidant effect on edible oil; the sweet potato leaf flavone is used as a natural antioxidant of edible oil.

Technical Field

The invention relates to the technical field of plant extraction, in particular to a preparation method and application of a natural oil antioxidant.

Background

In recent years, with the continuous pursuit of nutrition and health, sweet potato leaves are increasingly popular as a functional vegetable. A certain new variety of vegetable sweet potatoes with good taste and high quality is planted in China in a certain scale, and the economic benefit is remarkable. Sweet potato leaves are rich in protein and mineral substances and flavonoid compounds, and the flavonoid has a plurality of functional activities such as oxidation resistance, antibiosis and the like, so that the flavonoid is widely concerned and researched by people. The antioxidant research on flavone mostly focuses on the analysis of in vitro free radical scavenging capacity, and the research on the antioxidant application of edible oil is less. At present, synthetic antioxidants such as dibutyl hydroxy toluene (BHT), Butyl Hydroxy Anisole (BHA), tert-butyl hydroquinone (TBHQ) and the like which are used in more edible oil and fat play a good role in antioxidation, but have certain toxicity and carcinogenic possibility. Therefore, the amount of the edible oil and fat is limited, and the maximum amount of the edible oil and fat is 0.2 g/Kg. The edible oil natural antioxidant with high safety and strong antioxidant capacity is increasingly concerned, the storage period of the sweet potato leaves is short, and the fresh sweet potato leaves are easy to yellow and rot, so that the deep processing research of the sweet potato leaves is necessary to be carried out, and the edible oil natural antioxidant has important practical significance for extracting flavone from the sweet potato leaves and applying the flavone as a raw material to the development of the edible oil natural antioxidant.

Disclosure of Invention

In order to solve the problems, the invention discloses a preparation method and application of a natural oil antioxidant.

In order to achieve the above purpose, the invention provides the following technical scheme:

a natural oil antioxidant is sweet potato leaf flavone.

The preparation method of sweet potato leaf flavone comprises an extraction process and a purification process, and comprises the following steps:

step 1, preparing sweet potato leaves into sweet potato leaf superfine powder, then putting the superfine powder into an extracting solution, wherein the extracting solution is ethanol, and the extracting conditions are as follows: extracting with 50-90% ethanol at a liquid-to-material ratio of 30:1-70:1(mL/g) under ultrasonic conditions for 30-150min at 40-80 deg.C;

step 2, centrifuging (4000r/m, 4 ℃, 10min) to remove supernatant, concentrating the supernatant in a rotary manner until no obvious alcohol smell exists,

and 3, centrifuging again (4000r/m, 4 ℃ and 10min) and taking supernatant fluid, namely the sweet potato leaf flavone extracting solution.

Step 4, adopting macroporous adsorption resin to purify the sweet potato leaf flavone crude extract, wherein the purification process comprises the following steps: pretreating the macroporous adsorption resin, weighing the macroporous adsorption resin, filling the macroporous adsorption resin into a column, respectively adding the crude sweet potato leaf flavone extract, adsorbing by a rotary mixer, performing suction filtration, adding an ethanol solution into the macroporous adsorption resin after suction filtration, desorbing by the rotary mixer, and performing suction filtration to obtain the purified sweet potato leaf flavone extract.

Further, step 1 minimum ultrasound power 320W.

Further, the extraction conditions of the step 1 are as follows: the extraction temperature is 70 ℃, the extraction time is 120min, the ethanol concentration is 80%, and the liquid-material ratio is 70: 1.

further, the macroporous adsorption resin in the step 4 is AB-8 macroporous resin.

Further, the purification process of step 4 is: loading macroporous resin into column by wet column loading method, and loading sweet potato leaf flavone crude extract with concentration of 2.0mg/mL-40.0mg/mL into sample solution with pH of 3-7; passing through the column at a flow rate of 1BV/h-5BV/h for adsorption, and then passing through the column with 3BV ultrapure water for removing impurities on the surface of the resin; passing 60-100% ethanol solution through the column at a flow rate of 1BV/h-5BV/h for desorption, and collecting the desorption solution after passing through the column.

Further, the purification process of step 4 is: the optimal concentration of the crude extraction liquid of the sweet potato leaf flavonoid is 2.5mg/mL, and the optimal pH value of the sample liquid is 5; the optimal sample feeding flow rate is 2 BV/h; the optimal concentration of the ethanol solution is 100 percent; the flow rate of the desorption solution is 2 BV/h. Under the optimal conditions, the purification recovery rate can reach 45.61 +/-0.02%.

An application of sweet potato leaf flavone with antioxidant effect on edible oil and fat; the sweet potato leaf flavone is used as a natural antioxidant of edible oil.

The invention has the following beneficial effects:

1. the extraction method of the sweet potato leaf flavonoid has high overall extraction efficiency and good extraction effect, and provides the natural edible oil antioxidant with high safety performance and strong antioxidant capacity.

2. The purification method of sweet potato leaf flavonoid has the advantages of high purification recovery rate, obvious purification effect and short purification time.

3. The sweet potato leaf flavonoid can be used as a natural antioxidant of edible oil, has the advantages of high safety system energy and good antioxidant effect, is a pure natural component, and is safer and more relieved to eat.

4. The invention has important practical significance for extracting flavone from the existing sweet potato leaves as the raw material and applying the flavone to the development of the natural antioxidant of the edible oil, has wide raw material source and low cost, and has good economic benefit.

Drawings

FIG. 1 is a graph comparing the extraction yields of several sweet potato leaf flavonoids;

FIG. 2A is a graph of the results of single-factor experiments in extracting sweet potato leaf flavonoids (different extraction temperatures);

FIG. 2B is a graph showing the results of a single-factor experiment for extracting sweet potato leaf flavonoids (different extraction times);

FIG. 2C is a graph showing the results of a single-factor experiment of sweet potato leaf flavonoid extraction (different ethanol concentrations);

FIG. 2D is a diagram showing the results of a single-factor experiment for extracting sweet potato leaf flavonoids (different liquid-to-material ratios);

FIG. 3 is a diagram showing the purification effect of different macroporous resins;

FIG. 4A is a graph showing the results of a study on the influence factors of the purification process (different concentrations of the sample solutions);

FIG. 4B is a graph showing the results of the study of the influence factors on the purification process (different pH values of the loading solution);

FIG. 4C is a graph showing the results of a study of the influence factors on the purification process (different flow rates of the feed solution);

FIG. 4D is a graph showing the results of a study of the influence factors on the purification process (different concentrations of the desorption solvent);

FIG. 4E is a graph showing the results of a study of the influence factors on the purification process (different desorption solvent flow rates);

FIG. 5A is a graph showing the antioxidant effect of sweet potato leaf flavonoids on edible oils and fats (lard);

FIG. 5B is a graph showing the antioxidant effect of sweet potato leaf flavonoids on edible oils and fats (peanut oil);

FIG. 5C is a graph showing the antioxidant effect of sweet potato leaf flavonoids on edible oils and fats (blend oil);

fig. 6 is a rutin standard curve.

Detailed Description

The present invention will be further illustrated with reference to the accompanying drawings and specific embodiments, which are to be understood as merely illustrative of the invention and not as limiting the scope of the invention.