A kind of preparation method of high amylose starches
Technical field
The present invention relates to starch conversion technical field, in particular to a kind of preparation method of high amylose starches.
Background technique
Starch is one of living resources the most abundant in nature, and source is very extensive, can be by corn, sweet potato, wild
It extracts and obtains in the amyloid substance such as acorn nut and pueraria lobata.As a kind of important renewable substance, starch food, papermaking,
It is widely applied in the industry such as weaving, pharmacy, petroleum.
Starch can be divided into amylose and amylopectin by molecular structure point.It forms sediment in high amylose starches containing higher straight chain
Powder ratio has the characteristics that PhastGel, high-gel strength, high rigidity and high structural stability, in packaging material for food, low
The fields such as fat foods, food additives, medical treatment and pharmacy are all widely used.However, directly being extracted from amyloid crops
Starch be mostly amylopectin, and be mainly at present butanol method by the technique that amylopectin is converted into high amylose starches, process
Relatively complicated, this causes in the market, and high amylose starches price is costly.
Summary of the invention
In view of this, it is an object of that present invention to provide a kind of preparation methods of high amylose starches.Gao Zhi provided by the invention
The preparation method of chain starch is easy to operate, low in cost, can effectively improve the content of amylose in starch.
In order to achieve the above-mentioned object of the invention, the present invention the following technical schemes are provided:
The present invention provides a kind of preparation methods of high amylose starches, comprising the following steps:
(1) starch is mixed with water, obtains starch milk;
(2) starch milk is subjected to twin-screw extrusion, obtains high amylose starches.
Preferably, the starch is cornstarch, wheaten starch, sorghum starch, sweet potato starch, wild acorn starch and Pueraria lobota
One or more of root starch.
Preferably, the dosage of water is the 10~15% of starch quality in the step (1).
Preferably, the time mixed in the step (1) is 30~40min.
Preferably, the Heating Zone Temperature of the twin-screw extrusion is 90~95 DEG C.
Preferably, the screw speed of the twin-screw extrusion is 800~1600r/min.
The present invention provides a kind of preparation method of high amylose starches, the present invention first mixes starch with water, obtains starch
Cream, then starch milk is subjected to twin-screw extrusion, obtain high amylose starches.The present invention utilizes the high temperature generated when twin-screw extrusion high
Pressure makes the molecular structure of starch change, and chain rupture occurs for starch molecule branch to improve the content of amylose in starch.
In addition, preparation method provided by the invention is easy to operate, it is low in cost, it is easy to accomplish industrialized production.Embodiment the result shows that,
The mass content of amylose is 38% or more in the high amylose starches obtained using the method for the present invention, compared to untreated
The content of starch, amylose is obviously improved.
Specific embodiment
The present invention provides a kind of preparation methods of high amylose starches, comprising the following steps:
(1) starch is mixed with water, obtains starch milk;
(2) starch milk is subjected to twin-screw extrusion, obtains high amylose starches.
The present invention mixes starch with water, obtains starch milk.In the present invention, the starch be preferably cornstarch, it is small
One or more of wheat starch, sorghum starch, sweet potato starch, wild acorn starch and pueraria starch.The present invention is to the shallow lake
The source of powder does not have special requirement, uses the starch of this field conventional commercial.
In the present invention, the dosage of the water is preferably the 10~15% of starch quality, more preferably 12~14%;It is described
The mixed time is preferably 30~40min, more preferably 32~36min;In the present invention, the mixed mode is preferably stirred
Mix mixing.The present invention does not have special requirement to the rate of the stirring, can stir evenly starch and water.
After obtaining starch milk, the starch milk is carried out twin-screw extrusion by the present invention, obtains high amylose starches.In the present invention
In, the Heating Zone Temperature of the twin-screw extrusion is preferably 90~95 DEG C, and more preferably 90~93 DEG C;The twin-screw extrusion
Screw speed is preferably 800~1600r/min, more preferably 1000~1400r/min, most preferably 1200r/min;The present invention
Twin-screw extrusion is carried out using double screw extruder well known to those skilled in the art.
In the present invention, it is rotated along with screw rod, starch milk is extruded;When starch milk passes through the heating of double screw extruder
Qu Shi, the high temperature and pressure that heating zone generates are gelatinized starch, and the molecular structure of starch can also change correspondingly at this time, starch point
Chain rupture can occur for sub- branch, so that the content of amylose rises in starch;Spray orifice of the last starch milk from double screw extruder
It squeezes out, starch milk is contacted with air at this time, and into relatively low pressure area, meeting instantaneous expansion is dry, obtains high amylose starches solid.
After obtaining high amylose starches solid, the present invention preferably crushes the high amylose starches solid.The present invention couple
The mode of the crushing does not have special requirement, can crush high amylose starches solid to be powdered, of the invention real
It applies in example, it is preferable to use pulverizer crushes the high amylose starches solid.
It is described in detail below with reference to preparation method of the embodiment to high amylose starches provided by the invention, but not
They can be interpreted as limiting the scope of the present invention.
Embodiment 1
Commercially available cornstarch 6000g is weighed, this starch is detected using ultraviolet spectrophotometer method, through detecting,
The mass content of amylose is 27% in this starch, and the mass content of amylopectin is 73%.
Above-mentioned cornstarch is divided into 3 parts, every part with the water mixing 40min of 200g, respectively in 800r/min, 1200r/
Twin-screw extrusion is carried out under the screw speed of min and 1600r/min, wherein the Heating Zone Temperature of double screw extruder is disposed as
90 DEG C, obtained high amylose starches solid is respectively labeled as sample 1, sample 2, sample 3, and using pulverizer will sample 1,
Sample 2, sample 3 are crushed.
Test sample 1, sample 2 are distinguished using ultraviolet spectrophotometer method, amylose and amylopectin contains in sample 3
Amount, acquired results are listed in Table 1 below.
Under 1 different screw of table in starch amylose and amylopectin mass content
As shown in Table 1, using preparation method provided by the invention, when screw speed is 800~1600r/min, double spiral shells
The mass content of amylose after bar squeezes out in starch mutually less carries out the sample of twin-screw extrusion up to 46% or more,
Its amylose content is obviously improved.
Embodiment 2
Commercially available wheaten starch 6000g is weighed, this starch is detected using ultraviolet spectrophotometer method, through detecting,
The mass content of amylose is 27% in this starch, and the mass content of amylopectin is 73%.
Above-mentioned wheaten starch is divided into 3 parts, every part with the water mixing 40min of 300g, be respectively 90 in Heating Zone Temperature
DEG C, 93 DEG C, carry out twin-screw extrusion under conditions of 95 DEG C, wherein the screw speed of double screw extruder is disposed as 1200r/
Obtained high amylose starches solid is respectively labeled as sample 4, sample 5, sample 6 by min, and using pulverizer will sample 4,
Sample 5, sample 6 are crushed.
Test sample 4, sample 5 are distinguished using ultraviolet spectrophotometer method, amylose and amylopectin contains in sample 6
Amount, acquired results are listed in Table 2 below.
At a temperature of 2 different heating area of table in starch amylose and amylopectin mass content
As shown in Table 2, using preparation method provided by the invention, when the Heating Zone Temperature of double screw extruder is 90~95
DEG C when, the mass content of the amylose after twin-screw extrusion in starch mutually less carries out twin-screw and squeezes up to 38% or more
Sample out, amylose content are obviously improved.
The above is only a preferred embodiment of the present invention, it is noted that for the ordinary skill people of the art
For member, various improvements and modifications may be made without departing from the principle of the present invention, these improvements and modifications are also answered
It is considered as protection scope of the present invention.