A kind of method of extracting pectin from capsicum skin slag
Technical field
The invention belongs to plant milk extract technical field, particularly a kind of method of extracting pectin from capsicum skin slag.
Background technology
Capsicum originates in Central and South America, belongs to Solanaceae Capsicum, has the dish of improvement color and luster taste, improves a poor appetite, dispelling cold is induced sweat, the effect of active myogenic.China's pepper planting area occupies first place in the world, and the whole nation has more than 20 province to have cultivation, and as requisite seasonings in diet, capsicum is mainly used in eating raw, and also carry out some and simply process, as hot sauce, oleoresin capsicum etc.Oleoresin capsicum is the mixture of capsochrome and spicy substance, mainly as food-flavoring comps, often adopts organic solvent to soak and obtains.In the capsicum course of processing, can produce a large amount of residues, directly abandon both contaminate environment, cause again the wasting of resources, there are some researches show, in capsicum skin slag, contain abundant pectin and food fibre, if can extract pectin as product from capsicum skin slag, can improve the commodity value of capsicum skin slag, can deepen industrial chain again.
Pectin is the widely used natural food composition of a class, is the generally regarded as safe foodstuff additive that FAO/WHO foodstuff additive joint committee is recommended.Pectin has been widely used in the fields such as food, medicine, makeup, especially aspect food, can be used as emulsifying agent, jelling agent, thickening material, stablizer, also can replace fat to play reducing the effect of food fats content, pectin is praised highly by extensively in market because of its natural origin as functional additive.Business with pectin mainly from oranges and tangerines, apple and beet, this three kind of plant is the important raw and processed materials of squeezing the juice or refining sugar, in the course of processing, produce again a large amount of rich pectous wastes, so the extraction of pectin is actually to the recycling to waste, very environmental protection and energy saving.Capsicum skin slag is the same with above-mentioned three kinds of waste residues, cheap and contain abundant pectin resource, is the good source of pectin extraction.
At present, pectin extraction method mainly contains hot acid method, enzyme process, ion-exchange-resin process, ammonium oxalate method, microwave ultrasound auxiliary law both at home and abroad.Hot acid method's technique is simple, and cost is low, is the main method that present factory produces pectin in a large number, but easily environment is worked the mischief; Enzymatic Extraction mild condition, little to the destruction of pectin molecule chain, whole production process is little to environmental hazard, ion-exchange-resin process productivity ratio hot acid extraction method is high, and quality product is high, with short production cycle, but these two kinds of method production costs are high, in producing at present, use less; Ammonium oxalate extraction method can be converted into solubility ammonium salt by insoluble pectin acid calcium, and more insoluble pectins are dissolved, and improve productive rate, but the production cycle is longer; Microwave ultrasound auxiliary law is to be mainly extracted as master with hot acid, utilizes the stripping of the ultrasonic acceleration target compound of microblogging, reaches the object that shortens the operating time, improves yield.In pectin extracting soln, contain a large amount of impurity, the existence of these materials has a significant impact the quality of pectin, normal gac or the hydrogen peroxide of adopting removes the impurity such as pigment in extracting solution, these two kinds of methods are simple to operate, but can to pectin, cause damage to a certain extent, gac also often contains new impurity because removing not exclusively to cause in pectin; Flavonoids by Macroporous Adsorption Resin utilizes the difference of pectin and impurity molecule amount size to carry out removal of impurities, has good specificity; Membrane filter method is also to utilize the size of molecular weight to reach removal of impurities object, can concentrate pectin extracting soln in addition simultaneously, but expensive.Extracting solution after concentrated, generally by adding alcoholic solution, makes pectin molecule be caused solubleness to reduce owing to capturing water molecules, and the final precipitation that forms reaches separated object; Also there are the metal ions such as the carboxyl that utilizes in pectin molecule structure and aluminium, copper, zinc, potassium to generate water-fast pectin salt, reach the method for separated object.The patent of publication number CN1048011A discloses a kind of method of extracting pectin from beet pulp, through peracid, carries, and it is more than 140 grades that the step of resin removal of impurities obtains degree of gelation, and productive rate reaches 14~18% beet pectin; The patent of publication number CN102702379A discloses a kind of microwave heating method auxiliary salt acid extraction that utilizes, after spray-dried, obtain the technique of citrus pectin, the method yield is greater than 20%, and the pectin molecular-weight average obtaining is 1760,000Da, galacturonic acid content >=65%; The patent of publication number CN102827306 discloses a kind of preparation method of capsicum pectin, the capsicum that utilizes mineral acid and Sodium hexametaphosphate 99 hydrolysis to extract capsanthin, after activated carbon decolorizing is concentrated, through ethanol precipitation, clean, after freeze-drying or low-temperature reduced-pressure are dry, obtain off-white color to white, galacturonic acid content is more than 70%, the pectin product of yield 13% left and right.The present invention's capsicum skin used slag is that capsicum pericarp extracts the by product after oleoresin capsicum, adopt organic acid pyrohydrolysis raw material, destroy cell wall structure and accelerate pectin stripping, simultaneously gentle organic acid to the hydrolytic action of pectin molecule chain compared with mineral acid a little less than, can protect to greatest extent the integrity of pectin molecule chain; Except gac, introduce the method for hydrogen peroxide decolouring, avoided the normal carbon residue problem occurring in activated carbon decolorizing, improved pectin quality; Adopt organic solvent repeated precipitation process to realize the preparation of high purity pectin, should operation is simple, applied widely, can make purity up to 90% pectin sample.The research report about the utilization of capsicum skin slag for comprehensive mainly concentrated on the extraction of biologically active substance and evaluated above present stage, and the patent of publication number CN102127448A discloses a kind of methanol extraction that utilizes, the antioxidant extraction method of resin purification; The patent of publication number CN102614308A discloses a kind of method that subcritical water law is extracted bioactive ingredients in capsicum skin slag.
The present invention's capsicum skin used slag is that capsicum pericarp extracts the by product after oleoresin capsicum, contain abundant nutritive ingredient, and China has a large amount of capsicum skin slags directly to abandon as industrial waste every year, or uses as feed, has both wasted resource, again contaminate environment.The present invention extracts pectin from capsicum skin slag, can effectively utilize hot chili residue, improves the comprehensive utilization value of capsicum, avoids the wasting of resources.
Summary of the invention
Not enough for prior art, the invention provides a kind of method of extracting pectin from capsicum skin slag, the capsicum skin slag extracting after oleoresin capsicum of take is raw material, adopts there is (no) machine acid extraction, gac or hydrogen peroxide decolour, and obtain the complete processing of pectin after organic solvent purifying.
A method of extracting pectin from capsicum skin slag, its concrete steps are as follows:
(1) pre-treatment: capsicum skin slag is sieved after crushed;
(2) acid is carried: in the capsicum skin slag of processing through step (1), add water, after mixing, acid adding is adjusted pH to 0.5~4.5, is warming up to 50 ℃~90 ℃, stirs and be incubated 1h~5h, and centrifugal or suction filtration obtains pectin extracting soln;
(3) decolouring, concentrated, adopts one of following two kinds of modes:
A. left and right, regulating step (2) gained pectin extracting soln pH to 2~4; The ratio that is 1.0%~20.0% in the mass percent concentration of gac in mixed solution by gac and pectin extracting soln is fully uniformly mixed, filtered while hot after decolouring; Under vacuum condition, gained filtrate is concentrated into 1/3~1/5 of original volume;
B. or under vacuum condition step (2) gained pectin extracting soln is reduced to 1/3~1/5 of original volume; The ratio that pectin extracting soln by hydrogen peroxide and after concentrating is 5%~30% in the volume percent of hydrogen peroxide is fully uniformly mixed, and after decolouring, filters;
(4) alcohol precipitation: step (3) gained destainer is cooled to 4 ℃~25 ℃, add alcohol precipitation reagent to carry out alcohol precipitation;
(5) purifying: gained mixing solutions is centrifugal after step (4) alcohol precipitation, gained precipitation is uniformly mixed by solid-liquid mass ratio 1:5~1:40 and organic solvent, carries out purifying;
(6) dry: will after step (5) purifying, gained precipitation to be dried to obtain pectin product, and with galacturonic acid system, to measure product purity, titration measuring gamma value.
In described step (1), capsicum skin slag is the residue of capsicum pericarp after normal hexane extraction oleoresin capsicum, after pulverizing, crosses 60 mesh sieves.
The middle water add-on of described step (2) is 10~50 times of capsicum skin slag dry weight; Described acid is organic acid or mineral acid; Described centrifugal centrifugal rotational speed is 4200r/min, and centrifugation time is 20min.
Described organic acid is one or more of citric acid, tartrate, lactic acid or acetic acid; Described mineral acid is one or more in hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid.
While using gac in described step (3), with sodium hydroxide regulating step (2) gained pectin extracting soln pH; The bleaching temperature of described decolouring is 50 ℃~90 ℃, and bleaching time is 30min~150min; Described vacuum tightness is-0.90Mpa~0.95Mpa that concentrated thickening temperature is 50 ℃.
While using hydrogen peroxide in described step (3), described vacuum tightness is-0.90Mpa~0.95Mpa that concentrated thickening temperature is 50 ℃; The bleaching temperature of described decolouring is 50 ℃~70 ℃, and bleaching time is 6h~24h.
In described step (4), alcohol precipitation reagent is one or both in ethanol and Virahol; The alcohol precipitation reagent adding in described concentrated solution accounts for 45%~85% of gained precipitation solution total volume fraction; The alcohol precipitation time of described alcohol precipitation is 1.5h~24h.
In described step (5), centrifugal centrifugal rotational speed is 4200rpm, and centrifugation time is 20min; Described organic solvent is one or more in ethanol, Virahol, methyl alcohol, acetoneand ethyl acetate; The churning time of described stirring is 10min~40min, and temperature is 25 ℃~40 ℃; The purifying number of times of described purifying is 1~3 time.
The volume fraction of described organic solvent is 75%~95%.
In described step (6), dry drying temperature is 50 ℃, and be 12h time of drying.
Beneficial effect of the present invention is:
Compare with existing related process, the waste that the present invention be take after capsicum pericarp extraction oleoresin capsicum is raw material, advantage is to use organic acid to be hydrolyzed to raw material, the gentle sour environment providing can reduce the degree that local hydrolysis occurs pectin molecule, improve the molecular weight of the pectin of hot acid extraction method acquisition, promote capsicum pectin product quality, reduced the harm of prior art to environment; In capsicum skin slag, contain a certain amount of pigment, provide physisorphtion (gac) and two kinds of methods of chemical oxidization method (hydrogen peroxide) to decolour to capsicum pectin, with low cost, solved the saturate problem of capsicum skin slag pectin; Adopt the organic solvent repeated precipitation capsicum pectin of different concns, impurity in utilization precipitation and the difference of pigment solubleness under different concns, polarity are extracted, and reach the object of purifying, contrast other purification process cheap, be easy to realize the raising successful to pectin purity.
Accompanying drawing explanation
Fig. 1 is a kind of process flow sheet that extracts the method for pectin from capsicum skin slag of the present invention;
Fig. 2 is galacturonic acid typical curve.
Embodiment
The invention provides a kind of method of extracting pectin from capsicum skin slag, below in conjunction with the drawings and specific embodiments, the present invention will be further described.
Embodiment 1
Capsicum skin slag is mixed with the ratio of mass ratio 1:20 with water, add hydrochloric acid and adjust pH to 1.5, be warming up to 90 ℃, stir 2h, suction filtration obtains pectin extracting soln, with sodium hydroxide, regulate pH to 3.0, the ratio that is 1.0% in the mass percent concentration of gac in mixed solution (w/v) by gac and pectin extracting soln is fully uniformly mixed, 60min decolours at 80 ℃ of temperature, suction filtration in being lined with diatomaceous Büchner funnel while hot, under the vacuum condition that is-0.90Mpa~0.95Mpa in vacuum tightness by filtrate, be concentrated into 1/3 of original volume, to adding ethanolic soln to make its volume fraction in gained concentrated solution, be 65%, standing 3h at 15 ℃ of temperature, centrifugal must precipitation, by volume fraction, be respectively 75% and 85% aqueous ethanolic solution successively and in solid-liquid mass ratio, respectively be the ratio washing 40min of 1:10 and 1:5, gained is deposited at 50 ℃ of temperature and obtains pectin product after dry 12h, its yield is 8.21%, purity is 90%, gamma value is 70.4%, belong to high ester pectin.
Embodiment 2
Capsicum skin slag is mixed with the ratio of mass ratio 1:40 with water, adding citric acid is adjusted pH to 4.0, be warming up to 70 ℃, stir 3h, suction filtration obtains pectin extracting soln, under the vacuum condition that is-0.90Mpa~0.95Mpa in vacuum tightness, be concentrated into 1/4 of original volume, the ratio that pectin extracting soln by hydrogen peroxide and after concentrating is 10% in the volume percent of hydrogen peroxide (v/v) is fully uniformly mixed, 24h decolours at 60 ℃ of temperature, filter and collect filtrate, to adding aqueous isopropanol to make its volume fraction in gained filtrate, be 70%, standing 6h at 4 ℃ of temperature, centrifugal must precipitation, the ratio washing 30min that the isopropanol water solution that is 85% by volume fraction is 1:20 in solid-liquid mass ratio, gained is deposited at 50 ℃ of temperature and obtains pectin product after dry 12h, its yield is 8.65%, purity is 72%, gamma value is 58.3%, belong to high ester pectin.
Embodiment 3
Capsicum skin slag is mixed with the ratio of mass ratio 1:50 with water, add sulfuric acid and adjust pH to 0.5, be warming up to 60 ℃, stir 1h, suction filtration obtains pectin extracting soln, with sodium hydroxide, regulate pH to 3.0, the ratio that is 0.8% in the mass percent concentration of gac in mixed solution (w/v) by gac and pectin extracting soln is fully uniformly mixed, 90min decolours at 60 ℃ of temperature, suction filtration in being lined with diatomaceous Büchner funnel while hot, under the vacuum condition that is-0.90Mpa~0.95Mpa in vacuum tightness by filtrate, be concentrated into 1/4 of original volume, to adding ethanolic soln to make its volume fraction in gained concentrated solution, be 45%, standing 6h at 25 ℃ of temperature, centrifugal must precipitation, the methanol aqueous solution that is 75% by volume fraction is successively followed successively by the ratio washing 15min of 1:5 in solid-liquid mass ratio, gained is deposited at 50 ℃ of temperature and obtains pectin product after dry 12h, its yield is 7.89%, purity is 85%, gamma value is 61.3%, belong to high ester pectin.
Embodiment 4
Capsicum skin slag is mixed with the ratio of mass ratio 1:10 with water, add acetic acid and adjust pH to 3.5, be warming up to 80 ℃, stir 2h, suction filtration obtains pectin extracting soln, with sodium hydroxide, regulate pH to 3.0, the ratio that is 5.0% in the mass percent concentration of gac in mixed solution (w/v) by gac and pectin extracting soln is fully uniformly mixed, 30min decolours at 90 ℃ of temperature, suction filtration in being lined with diatomaceous Büchner funnel while hot, under the vacuum condition that is-0.90Mpa~0.95Mpa in vacuum tightness by filtrate, be concentrated into 1/3 of original volume, to adding aqueous isopropanol to make its volume fraction in gained concentrated solution, be 90%, standing 1.5h at 4 ℃ of temperature, centrifugal must precipitation, the aqueous acetone solution that is 75% by volume fraction is successively followed successively by the ratio washing 15min of 1:15 in solid-liquid mass ratio, gained is deposited at 50 ℃ of temperature and obtains pectin product after dry 12h, its yield is 10.3%, purity is 67%, gamma value is 56.3%, belong to high ester pectin.
Embodiment 5
Capsicum skin slag is mixed with the ratio of mass ratio 1:30 with water, add nitric acid and adjust pH to 2.5, be warming up to 60 ℃, stir 4h, suction filtration obtains pectin extracting soln, under the vacuum condition that is-0.90Mpa~0.95Mpa in vacuum tightness, be concentrated into 1/3 of original volume, the ratio that pectin extracting soln by hydrogen peroxide and after concentrating is 15% in the volume percent of hydrogen peroxide (v/v) is fully uniformly mixed, 12h decolours at 40 ℃ of temperature, filter and collect filtrate, to adding ethanolic soln to make its volume fraction in gained filtrate, be 85%, standing 12h at 25 ℃ of temperature, centrifugal must precipitation, the ratio washing 40min that the ethyl acetate aqueous solution that is 75% by volume fraction is 1:15 in solid-liquid mass ratio, gained is deposited at 50 ℃ of temperature and obtains pectin product after dry 12h, its yield is 9.72%, purity is 80%, gamma value is 67.7%, belong to high ester pectin.
In above-described embodiment, the concrete grammar of pectin purity testing is: in test tube, add the 6mL vitriol oil, the sample 1mL that gets concentration and be 0.1mg/mL slowly adds, in boiling water bath, heat 20min, take out, be cooled to rapidly room temperature, then each pipe adds 0.2mL carbazole ethanol (anhydrous alcohol solution, the concentration of carbazole ethanol is 0.15%m/v) solution, shake up, lucifuge is placed 2h, under 517nm, surveys absorbancy; Blank replaces sample to react with deionized water; Pectin total amount in sample represents with galacturonic acid.
The drafting of typical curve: accurately take galacturonic acid 100.0mg, with distilled water, dissolve, be settled to 100mL, the galacturonic acid solution that formation concentration is 1.0mg/mL, the galacturonic acid solution that the concentration of getting respectively 0mL, 2mL, 4mL, 6mL, 8mL, 10mL is 1.0mg/mL, being diluted to respectively concentration is the galacturonic acid standard series of 20 μ g/mL, 40 μ g/mL, 60 μ g/mL, 80 μ g/mL, 100 μ g/mL.Measure according to the method described above, take concentration as X-coordinate, absorbancy is ordinate zou drawing standard curve.
The extract that embodiment 1~5 is obtained is measured according to the method described above, according to the typical curve obtaining, can obtain pectin content in extract.
The concrete grammar that in above-described embodiment, pectin esterification degree is measured is: get 0.2g pectin and be placed in Erlenmeyer flask, adding 20mL deionized water dissolves completely, to solution, add 2 phenolphthalein again, and be titrated to pink with the NaOH that concentration is 0.1mol/L, remember that sodium hydroxide volume used is V1, the stirring at room of jumping a queue 2h, continuation adds the HCl that 10mL concentration is 0.1mol/L in solution, the NaOH neutralization that excessive HCl is 0.1mol/L by concentration, to titration end point sodium hydroxide volume used be V2, pectin esterification degree is measured formula and is:
The extract that embodiment 1~5 is obtained is measured according to the method described above, according to formula, can obtain pectin esterification degree.
The present invention utilizes acid system to extract pectin in capsicum skin slag, have simple and easy to control, cost is low, economic dispatch advantage, production and use procedure meet the requirement of national security foodstuff production, have good industrial prospect, have larger implementary value and social economic value.