Background technology
Dextrose-delta-lactone is a kind of colourless crystallization or white powdery crystallization, and is soluble in water.It is soluble in water can be broken down into gluconic acid gradually, and under the condition of heating, then decomposition rate is accelerated.Dextrose-delta-lactone can make soybean protein solidify, and the soybean protein retentiveness that is solidified in the time of 80 ℃-90 ℃ is good, the bean curd quality exquisiteness of making, and the elasticity foot, energetically.Dextrose-delta-lactone is fit to do the packed bean curd of magma, is convenient to mechanize production.In cryogenic soya-bean milk, add dextrose-delta-lactone, then soya-bean milk is poured in the bag and seal, reheat, make the soya-bean milk in the bag be transformed into gluconic acid by Gluconolactone, be frozen into bean curd (Zhong Weimin etc., the use main points of bean product peptizer, storage processing, 2000 the 7th phases), general add-on is about 0.3~0.4% (w/v).
Dextrose-delta-lactone is also used in the making of uncongealed beancurd at present, the per kilogram soybean restrains (who with dextrose-delta-lactone 9, uncongealed beancurd high yield new technology, the new technology in rural areas, 2000 the 12nd phases), dextrose-delta-lactone is to be produced by D calglucon and sulfuric acid reaction, has listed People's Republic of China's foodstuff additive (State Standard of the People's Republic of China GB7657-87) in, therefore, to be used for food be safe to dextrose-delta-lactone.
Summary of the invention
Never report in the prior art that dextrose-delta-lactone as the purposes of flocculation agent with the acquisition isoflavone precipitation, especially obtains the sedimentary purposes of soybean isoflavones or Radix Puerariae isoflavone.
The inventor finds dextrose-delta-lactone is added in the soybean isoflavones medicinal extract through big quantity research, after heating is placed, has a large amount of precipitations to separate out, and this may be because dextrose-delta-lactone becomes just generation effect of gluconic acid after heating.Precipitation color after washing shoals, and aqueous solution color is darker, and this may remove wash-out such as the sugar of some co-precipitation, protein, saponin.Detect through HPLC, the main component in the precipitation is Genistoside and daidzin.
Based on above-mentioned discovery, the invention provides dextrose-delta-lactone as the purposes of flocculation agent with the acquisition isoflavone precipitation, especially obtain the purposes of soybean isoflavones or Radix Puerariae isoflavone.
In purposes according to the present invention, adding dextrose-delta-lactone to concentration is 0.05~0.3% (w/v), and preferred concentration is 0.15% (w/v).
In purposes according to the present invention, preferably in process, heat with the dextrose-delta-lactone flocculation, Heating temperature is preferably 75 ℃~95 ℃, most preferably is 90 ℃.
In purposes according to the present invention, preferably after with the dextrose-delta-lactone flocculation, wash isoflavone precipitation with water.In a preferred embodiment, wash isoflavone precipitation with water 1~4 time.
Another favourable part of the present invention is to use dextrose-delta-lactone as flocculation agent, and once flocculation just brings up to more than 30% (w/w) content of soybean isoflavones in general extractive.
Another favourable part of the present invention is can make dextrose-delta-lactone remain in the soybean isoflavones hardly by washing, and the more important thing is the content that can progressively improve soybean isoflavones glycosides in the throw out, the purity of the much more beans isoflavone aglycones of washing times is high more.
Embodiment
Below specify all respects of the present invention and feature by preferred embodiment.It should be appreciated by those skilled in the art that these embodiment just are used for illustration purpose, and do not limit the scope of the invention.Protection scope of the present invention only is subjected to the restriction of claims.Under the condition that does not deviate from claims scope.Those skilled in the art can carry out various modifications and improvement to various aspects of the present invention, and these modifications and improvement also belong to protection scope of the present invention.
In addition, unless it should be noted that and specialize, below among the embodiment used various materials and reagent all be material and reagent commonly used in this area, can obtain by conventional commercial sources; Method therefor is and well known to a person skilled in the art ordinary method.In addition, unless specialize, the percentage composition of material is w/w per-cent, i.e. % (w/w).
Embodiment 1
Get soybean isoflavones medicinal extract 200g (containing solid substance 72%), add water 280g and make that to contain solid substance be 30%.Other takes by weighing dextrose-delta-lactone 0.75g, adds 10ml water, and heating makes dissolving, slowly adds in the medicinal extract liquid under constantly stirring, placed 30 minutes, centrifugal (3500rpm/min), abandoning supernatant must precipitate (wetting) 8.64g.Behind 60 ℃ of following drying under reduced pressure, get dry extract 2.16g.Measuring isoflavone content is Genistoside 18.5%, daidzin 5.6%, and 1.5%, three kind of isoflavone aglycone total content of daidzin is 25.6%.
Embodiment 2
Get soybean isoflavones medicinal extract 200g (containing solid substance 72%), add water 280g and make that to contain solid substance be 30%.Other takes by weighing dextrose-delta-lactone (foodstuff additive GB7657-87, purchase in chemical plant, Xianju, Zhejiang Dongxing) 0.75g, add 10ml water, heating makes dissolving, slowly adds in the medicinal extract under constantly stirring, after being incubated 60 minutes under 90 ℃, be placed into room temperature, centrifugal (3500rpm/min), abandoning supernatant must precipitate (wetting) 9.02g.Behind 60 ℃ of following drying under reduced pressure, get dry extract 2.35g.Measuring isoflavone content is Genistoside 24.5%, daidzin 7.5%, and 1.8%, three kind of isoflavone aglycone total content of daidzin is 33.8%.
Embodiment 3
Get soybean isoflavones medicinal extract 200g (containing solid substance 72%), add water 280g and make that to contain solid substance be 30%.Other takes by weighing dextrose-delta-lactone (foodstuff additive GB7657-87, purchase in chemical plant, Xianju, Zhejiang Dongxing) 0.25g, add 10ml water, heating makes dissolving, slowly adds in the medicinal extract under constantly stirring, after being incubated 60 minutes under 90 ℃, be placed into room temperature, centrifugal (3500rpm/min), abandoning supernatant must precipitate (wetting) 3.11g.Behind 60 ℃ of following drying under reduced pressure, get dry extract 0.75g.Measuring isoflavone content is Genistoside 21.0%, daidzin 7.1%, and 1.5%, three kind of isoflavone aglycone total content of daidzin is 29.6%.
Embodiment 4
Get soybean isoflavones medicinal extract 200g (containing solid substance 72%), add water 280g and make that to contain solid substance be 30%.Other takes by weighing dextrose-delta-lactone (foodstuff additive GB7657-87, purchase in chemical plant, Xianju, Zhejiang Dongxing) 1.5g, add 10ml water, heating makes dissolving, slowly adds in the medicinal extract under constantly stirring, after being incubated 60 minutes under 90 ℃, be placed into room temperature, centrifugal (3500rpm/min), abandoning supernatant must precipitate (wetting) 10.51g.Behind 60 ℃ of following drying under reduced pressure, get dry extract 2.53g.Measuring isoflavone content is Genistoside 23.2%, daidzin 7.5%, and 1.7%, three kind of isoflavone aglycone total content of daidzin is 32.4%.
Embodiment 5
Get Radix Puerariae isoflavone medicinal extract 200g (containing solid substance 72%), add water 280g and make that to contain solid substance be 30%.Other takes by weighing dextrose-delta-lactone 1.2g, adds 10ml water, and heating makes dissolving, slowly adds in the medicinal extract liquid under constantly stirring, placed 30 minutes, centrifugal (3500rpm/min), abandoning supernatant must precipitate (wetting) 7.86g.Behind 60 ℃ of following drying under reduced pressure, get dry extract 1.25g.With the puerarin is that reference substance is 50.5% with UV method mensuration root of kudzu vine total isoflavone content.
Embodiment 6
Present embodiment checking flocculation after washing number of times is to the influence of isoflavones purity.
Take by weighing and obtain the soybean isoflavones crude extract after flocculating by aforementioned condition, add the water washing of 10 times of amounts at every turn, centrifugal (3500r/min) precipitates 60 ℃ of drying under reduced pressure, measures isoflavone content, result's following (table 2):
Table 2 washing experimental result
Washing times | 0 | 1 | 2 |
Experiment number | 1 | 2 | 3 | 1 | 2 | 3 | 1 | 2 | 3 |
Precipitate the total isoflavone content (%) of dried cream amount (mg) genistin (%) daidzin (%) daidzin (%) | 388.1 26.08 4.95 1.20 32.23 | 404.1 24.89 5.16 1.25 31.30 | 393.8 25.62 4.86 1.22 31.70 | 206.5 35.36 5.72 1.35 42.43 | 172.6 41.75 6.64 1.45 49.84 | 190.2 40.55 6.51 1.52 48.58 | 107.1 54.42 8.51 1.56 64.49 | 103.8 55.41 8.72 1.60 65.73 | 105.1 54.93 8.64 1.55 65.12 |
Table 2 (continuing) washing experimental result
Washing times | 3 | 4 | 5 |
Experiment number | 1 | 2 | 3 | 1 | 2 | 3 | 1 | 2 | 3 |
Precipitate dried cream amount (mg) | 69.8 | 68.7 | 70.4 | 41.6 | 39.5 | 40.3 | 26.2 | 24.7 | 24.9 |
The total isoflavone content (%) of genistin (%) daidzin (%) daidzin (%) | 59.02 10.90 1.52 71.44 | 59.48 11.46 1.49 72.43 | 60.88 11.78 1.41 74.07 | 68.05 14.24 1.40 83.69 | 69.20 14.83 1.41 85.44 | 68.76 14.68 1.37 84.81 | 70.83 14.88 1.38 87.09 | 71.03 15.02 1.36 87.41 | 69.58 14.98 1.40 85.96 |
From above experimental result as can be seen, three parallel tests show, flocculation postprecipitation soybean isoflavones total content about about 30%, wash soybean isoflavones total content about about 45% one time, soybean isoflavones total content about about 65% behind the washing secondary, it is about about 72% to wash three soybean isoflavones total contents, and it is about about 84% to wash four soybean isoflavones total contents, washes soybean isoflavones total content about about 86% five times.The 5th time how much washing purity substantially no longer rises, but sample loss is more, so preparation technology of the present invention is advisable with interior to wash four times, how much soybean isoflavones purity is according to demand, definite washing obtains the soybean isoflavones product of different stage several times, such as, the soybean isoflavones product of needs 30% purity, the after drying that can directly flocculate gets final product; Need the soybean isoflavones product of 40% purity, can wash an after drying and get final product; The soybean isoflavones product that needs 50% purity, the product and the washing product once that can wash secondary with water are blent; Need the soybean isoflavones product of 60% purity, can wash the secondary after drying and get final product; Need the soybean isoflavones product of 70% purity, can wash three after drying and get final product; Need the soybean isoflavones product of 80% purity, can wash four after drying and get final product.