CN101514219B - Method for extracting black rice anthocyanins - Google Patents

Abstract

The invention relates to a novel method for extracting black rice anthocyanins, and especially to improvement for extraction and impurity removal process. The method is characterized in that the method includes steps of (1) preprocessing black rice; (2) extracting and removing impurities by using polar solvent; (3) removing impurities by using ethanol; (4) extracting by using acidified ethanol lixiviate liquid; and (5) employing auxiliary measure. The main improvement of the present invention is that the extraction process includes an impurity-removing process and a purification process, the invention has advantages of short time consuming, low cost, high purity, simple process and convenient operation.

Description

A kind of extracting method of black rice anthocyanins

Technical field

The present invention relates to a kind of anthocyanin extracting method, be specifically related to extract from black rice the method for anthocyanin.

Background technology

Black rice is the black brown rice of sloughing husk, color is because pigment (anthocyanidin) forms at kind of skin and husk deposition, the main active substances of black rice pigments is anthocyanin, be flavones anthocyanin compounds, the platymiscium polyphenolic compound, be a most important class in the water-soluble flavone class pigment, natural anthocyanin content is very high in the black rice, is 5000～15000mg/kg.Studies have shown that having of anthocyanin is biomedical active widely; As anti-oxidant and removing free radical function, improve blood fat and cholesterol, protect cardiovascular effect; Anti-inflammatory action, antimutagenic activity, intrusion and the transfer of antitumor and anticancer, hypotensive hypoglycemic isoreactivity.

At present, domestic preparation about black rice anthocyanins generally is extraction and two steps of anthocyanin separation and purification that are divided into black rice pigments.

The existing a lot of reports of the extraction of relevant black rice natural pigment, the resulting anthocyanin of conventional extracting method mostly exists extraction rate and percentage extraction is low, the lower shortcomings such as (below 10%) of purity, so generally can only use as foodstuff additive or natural colorant.Just must improve its purity and will bring into play the effective pharmacologically active of anthocyanin, use methods such as chromatography usually, chromatography column commonly used has silicagel column, alumina column, macroporous adsorptive resins and gel column.But these methods also exist length consuming time, cost height, complicated operation to be not easy to shortcomings such as a large amount of preparations.And since the work of these two steps normally finished respectively according to demand separately by the personnel with different professional backgrounds, will cause like this extracting and the separating or disconnection of two steps of separation and purification, time span is oversize, influences the extraction benefit of anthocyanin in the black rice.

So need a kind of simple and easy, effective black rice anthocyanins preparation method, in extracting link, can obtain the anthocyanin of higher degree (more than 10%).Can save time and the cost of later separation purifying like this, be conducive to the production of anthocyanin, also can be applied to some preliminary activity experiment researchs simultaneously.Application number is disclosed in 200510049274.0 patents " anthocyanin extracting method in the black rice ", has wherein used cellulase degradation, can reach extraction effect preferably, but because the problem of expense and operation has limited further popularization.

Summary of the invention

The purpose of this invention is to provide and a kind ofly can reduce extraction cost, technology is simple, has the black rice anthocyanins extracting method of higher degree again.Saving the column chromatography time and the cost that consume that can part.

The objective of the invention is to realize by the following technical solutions: it is that the basis of anthocyanin extracting method in existing black rice is improved and formed, and its main improvements are the extraction of anthocyanin is divided into two operations; Namely remove impurity operation and acidifying ethanol lixiviate operation, thereby reach the purpose that improves anthocyanin purity.

1, remove the impurity operation: black rice is processed into black rice flour, impurity is removed in the polar solvent lixiviate and impurity is removed in the ethanol lixiviate.Polar solvent is sherwood oil and water.The reflux extraction time that impurity is removed in the polar solvent lixiviate is 60min.Impurity is removed in the ethanol lixiviate, adopts 80-90% and the lixiviate of 10-20% alcohol concn respectively.

2, acidifying ethanol lixiviate operation: the alcohol concn of acidifying extraction using alcohol anthocyanin is 50-60%.Temperature 50-60 ℃, pH2-3, anthocyanin stability is best in this environment; Solid-liquid ratio 1: 5-7, time 1h-2h adjust the pH value with citric acid.

Anthocyanin extracting method in a kind of black rice, its processing step is as follows:

A, black rice carry out pre-treatment; Mainly be that the black rice epidermal area is separated with the rice core;

B, at the fat-soluble and water-soluble impurity that black rice exists, adopt the solvent of low-pole and strong polarity to carry out impurity elimination respectively;

C, again with impurity like the ethanol lixiviate removal of high density and lower concentration and the anthocyanin polar phase;

D, at last with 50-60% acidifying extraction using alcohol anthocyanin;

Assist measure in e, the leaching process is heating in water bath and ultrasonic auxiliary.

Advantage of the present invention is:

1. the productive rate of anthocyanin and purity are all higher;

2. have with respect to the column chromatography purification method with low cost, the advantage of weak point consuming time;

3. it is simple to have technical process, the characteristics of being convenient to operate.

Embodiment

Following mask body illustrates, but actually operating is not limited thereto example.

Anthocyanin extraction process in 1 one kinds of black rices of embodiment

1. choose and outer crossed 40 mesh sieves by the black polished rice of color depth through rice milling machine, make black rice flour, purpose is that the black rice top layer and the black rice core that are rich in anthocyanin are peeled off, and has also improved the contact area of itself and solvent.

2. take by weighing a certain amount of black rice flour, add sherwood oil, solid-liquid ratio 1: 5, reflux lixiviate 60min, drop goes the sherwood oil part, to remove oil-soluble impurities.

3. use distilled water (being equivalent to concentration of ethanol is 0) then, solid-liquid ratio 1: 5, lixiviate 60min, the drop part of anhydrating is to remove water-soluble impurity.

4. use 90% ethanol (ethanol of high density) again, solid-liquid ratio 1: 5, lixiviate 60min, drop go the ethanol part, remove alcohol dissolubility impurity.

5. use 10% ethanol (ethanol of lower concentration) again, solid-liquid ratio 1: 5, lixiviate 60min, drop go the ethanol part, remove impurity.

6. at last with vat liquor (containing 1.0% citric acid, 60% ethanol), solid-liquid ratio 1: 5, lixiviate 60min repeats 2 times, removes pigment ground rice, united extraction liquid, vacuum filtration impurity elimination.

7. simultaneously with 60 ℃ of water-baths and the auxiliary lixiviate of ultrasonic 50KHz.

8. with the filtered liquid underpressure distillation, get Powdered black rice anthocyanins through lyophilize.

The method of embodiment 2 routines (leaf is believed damp method)

1. black rice filters with vat liquor lixiviate 1d, repeats 2 times, merges 3 times vat liquor, removes pigment brown rice;

2. vat liquor is reclaimed in vat liquor underpressure distillation, obtains the paste black rice pigments;

3. add sherwood oil and reflux, lixiviate 1h removes fatty sherwood oil, reclaims sherwood oil simultaneously;

4. it is molten that black rice pigments adds the methyl alcohol weight, filters, and removes not solution of methyl alcohol;

5. pigment methanol solution, underpressure distillation gets black rice pigments, 80 ℃ of dry black rice pigments.

Embodiment 3 produces by 200510049274.0 patents

With application number be in 200510049274.0 patents in the disclosed black rice anthocyanin extracting method produce.

1. the brown rice grain with black rice is raw material, after the selected impurity elimination, with the top layer of cellulase degradation black rice grain, makes anthocyanin be easy to separate;

2. use ethanol lixiviate and the enzymolysis reaction of 90-95% again, drop removes alcohol dissolubility impurity;

3. will be through enzymolysis and the black rice grain after removing alcohol dissolubility impurity with the alcohol extraction of 45-55% concentration;

4. the solution decompression after will extracting is removed ethanol, and the extraction liquid behind the removal ethanol is spray dried to the black rice anthocyanins powder.

The result relatively

Embodiment 1 and 2,3 is extracted the anthocyanin that obtains carry out relevant detection and evaluation.Wherein purity detecting adopts high performance liquid chromatography, and structure is identified and adopted ultraviolet-visible spectrum and mass spectrometry.

The results list contrast, its content relatively mainly is productive rate and purity project, it is as shown in the table in contrast:

As can be seen from the table, the present invention is that the black rice anthocyanins that embodiment 1 extracts is compared with embodiment 2: institute's time-consuming is short, productive rate is high, purity is then higher; Compare with embodiment 3: consuming time all very approaching with purity, but owing to do not use cellulase, so the simple and easy relatively grasp of technology, cost is also comparatively cheap, is fit to macro preparation.The anthocyanin purity that embodiment 1 method obtains is higher, can be directly used in the research of pharmacologically active.

Claims (1)

1. a black rice anthocyanins extraction process is characterized in that comprising the steps:

1. choose the black polished rice of crust color depth, cross 40 mesh sieves through rice milling machine, make black rice flour;

2. take by weighing a certain amount of black rice flour, add sherwood oil, solid-liquid ratio 1: 5, reflux lixiviate 60min, drop goes the sherwood oil part, to remove oil-soluble impurities;

3. use distilled water then, solid-liquid ratio 1: 5, lixiviate 60min, the drop part of anhydrating is to remove water-soluble impurity;

4. use 90% ethanol again, solid-liquid ratio 1: 5, lixiviate 60min, drop go the ethanol part, remove alcohol dissolubility impurity;

5. use 10% ethanol again, solid-liquid ratio 1: 5, lixiviate 60min, drop go the ethanol part, remove impurity;

6. at last with vat liquor, solid-liquid ratio 1: 5, lixiviate 60min repeats 2 times, removes pigment ground rice, united extraction liquid, vacuum filtration impurity elimination; Described vat liquor contains 1.0% citric acid, 60% ethanol;

7. simultaneously, with 60 ℃ of water-baths and the auxiliary lixiviate of ultrasonic 50KHz;

8. with the filtered liquid underpressure distillation, get Powdered black rice anthocyanins through lyophilize.