Method for regulating starch retrogradation by utilizing linear sugar chain with medium-high polymerization degree

Abstract

The invention discloses a method for regulating starch retrogradation by utilizing a medium-high polymerization degree linear sugar chain, and belongs to the technical field of physical modified starch. According to the method disclosed by the invention, linear sugar chains with medium and high polymerization degrees, such as maltohexaose, maltoheptaose, maltooctasaccharide and glucan with the average polymerization degree of 9, 21 and 34, are added into starch. In the starch retrogradation process, sugar chain molecules form hydrogen bonds with water or starch chains or are entangled with amylopectin chains, so that crystallization of amylose and amylopectin is interfered or promoted, and the purpose of regulating and controlling the starch retrogradation property is achieved. Therefore, the starch retrogradation is effectively regulated and controlled by adding the medium-high polymerization degree linear sugar chain, and the method has important significance in food industrial manufacturing.

Description

Technical Field

[0001] The invention relates to a method for regulating starch retrogradation by utilizing linear sugar chains with medium and high polymerization degrees, and belongs to the technical field of physically modified starch. Background Art

[0002] Natural starch is a semi-crystalline polymer macromolecule, mainly composed of amylose and highly branched amylopectin. When starch is gelatinized, starch granules will change from an ordered crystalline state to a disordered state. During the cooling process, amylose and amylopectin will recombine into an ordered structure, which is called starch retrogradation. Starch retrogradation can be divided into short-term retrogradation and long-term retrogradation. Short-term retrogradation is mainly based on the crystallization of amylose, which takes hours; long-term retrogradation is mainly based on the recrystallization of amylopectin, which takes days. Starch is an important food raw material. Due to the retrogradation phenomenon, starch foods will become harder, less elastic and less flavorful during storage, and thus have a shorter shelf life. At the same time, this phenomenon is an indispensable processing technology in the processing and application of traditional gel foods. For example, in the production process of starch gel foods such as vermicelli, jelly, and fresh wet rice noodles, moderate retrogradation significantly improves the structure and sensory quality of the product. Therefore, taking effective means to regulate starch retrogradation can improve the nutritional value and functionality of food, improve the structure and sensory quality of food, and is of great significance in food industry manufacturing.

[0003] At present, the methods for regulating starch retrogradation mainly include physical method, chemical method and bio-enzyme method. The main advantage of physical method is that it is simple to operate and easy to apply in industrial production. In previous studies, the small molecule sugars that control starch retrogradation are mostly some relatively rare sugars, such as inulin, trehalose, and Artemisia polysaccharide. The structural unit of maltooligosaccharide is the same as that of starch, and the structure of glucan is similar to that of starch. In addition, some maltooligosaccharides and glucans can be mass-produced industrially, which is cheap and easy to obtain. Therefore, using them to modify starch and regulate starch retrogradation has certain industrial production and commercial value. Summary of the invention

[0004] In order to solve the above problems, the present invention adds linear sugar chains with medium and high polymerization degrees to starch, such as maltohexaose, maltoheptaose, maltooctaose and glucans with average polymerization degrees of 9, 21 and 34. During the starch retrogradation process, the sugar chain molecules form hydrogen bonds with water or starch chains, or entangle with amylopectin chains, thereby interfering with or promoting the crystallization of amylose and amylopectin, thereby achieving the purpose of regulating the starch retrogradation properties.

[0005] The first object of the present invention is to provide a method for regulating starch retrogradation, wherein the method comprises adding linear sugar chains with medium or high polymerization degrees into starch to regulate its retrogradation properties.

[0006] In one embodiment of the present invention, the method is to disperse the linear sugar chains with medium and high polymerization degrees into water, add starch, mix well, heat for gelatinization, and cool for storage.

[0007] In one embodiment of the present invention, the regulating starch retrogradation includes promoting or inhibiting starch retrogradation.

[0008] In one embodiment of the present invention, the medium-high degree of polymerization linear sugar chain is maltooligosaccharide or glucan with a DP between 6-35.

[0009] In one embodiment of the present invention, the medium-to-high degree of polymerization linear sugar chain is maltohexaose, maltoheptaose, maltooctaose, or glucan with an average degree of polymerization of 9, 21, or 34.

[0010] In one embodiment of the present invention, the method comprises adding one or more linear sugar chains simultaneously.

[0011] In one embodiment of the present invention, the addition amount of the linear sugar chain with medium to high polymerization degree is 2%-10% (w / w).

[0012] In one embodiment of the present invention, the amount of water added is 0.5-1.5 mL for every 100 mg of sugar chain and starch.

[0013] In one embodiment of the present invention, the starch is specifically corn starch, potato starch, tapioca starch, sweet potato starch, pea starch, wheat starch, rice starch, mung bean starch, red bean starch, lotus seed starch or chestnut starch.

[0014] In one embodiment of the present invention, the method of adding sugar chains to starch includes adding sugar chains before starch gelatinization or adding sugar chains during starch gelatinization.

[0015] In one embodiment of the present invention, in the method, the temperature during starch gelatinization is controlled at 90-100° C., and the heating time is 30-90 min.

[0016] In one embodiment of the present invention, the stirring speed during starch gelatinization in the method is 300-1000 r / min.

[0017] In one embodiment of the present invention, the storage condition in the method is 1-10° C. for 3-7 days.

[0018] In one embodiment of the present invention, the method is to disperse glucan with an average degree of polymerization of 34 into water, add wheat starch, mix evenly, stir and heat for gelatinization, and store at 4°C for 3 days; the amount of glucan added is 2% (w / w); the stirring and heating gelatinization conditions are temperature 95°C, rotation speed 500r / min, and constant temperature heating for 60min.

[0019] In one embodiment of the present invention, the method is to disperse maltoheptaose in water, add wheat starch, mix evenly, stir and heat for gelatinization, and store at 4°C for 7 days; the amount of maltoheptaose added is 2% (w / w); the stirring and heating gelatinization conditions are temperature 95°C, rotation speed 500r / min, and constant temperature heating for 60min.

[0020] The second object of the present invention is to provide a method for promoting starch retrogradation.

[0021] In one embodiment of the present invention, the method comprises dispersing glucan with an average degree of polymerization of 21-34 into water, adding starch, stirring and heating for gelatinization after mixing evenly, and storing at 1-10°C for 2-5 days. The amount of glucan added is 2-5% (w / w); the stirring and heating gelatinization conditions are a temperature of 90-100°C, a rotation speed of 300-1000 r / min, and constant temperature heating for 30-90 minutes.

[0022] The third object of the present invention is to provide a modified starch prepared by the above method.

[0023] The fourth object of the present invention is to provide an application of the modified starch in the preparation of starch foods.

[0024] In one embodiment of the present invention, the starchy foods include steamed bread, bread and rice noodles.

[0025] The fifth object of the present invention is to provide an application of the above method for regulating starch retrogradation in regulating starch retrogradation.

[0026] Beneficial effects:

[0027] The method of the present invention mixes linear sugar chains with medium and high polymerization degrees with starch. Sugar chain molecules interfere with or promote starch crystallization at the molecular level by forming hydrogen bonds with water molecules and starch chains, or forming entanglements with amylopectin chains, thereby achieving the purpose of regulating starch retrogradation. Sugar chains with different polymerization degrees all have a certain regulating effect on starch retrogradation. The one with the best inhibition effect of retrogradation is added with 2% maltoheptaose, and the retrogradation effect is reduced by 48.2% at 7 days; and the one with the best promotion effect of retrogradation is added with glucan with an average polymerization degree of 34, and the recovery effect is increased by 61.3% at 3 days. Long-chain sugar molecules guide the linear starch molecules to form helices, which has a significant promoting effect on starch retrogradation. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0029] The materials involved in the following examples are as follows:

[0030] Wheat starch was purchased from Hangzhou Prostar Starch Co., Ltd.; maltohexaose, maltoheptaose and maltooctaose were purchased from Caberson Chemical Technology Co., Ltd., UK; dextran with average polymerization degree of 9, 21 and 34 was purchased from Shanghai Aladdin Reagent (Shanghai) Co., Ltd.

[0031] The method for determining the retrogradation properties of starch involved in the following examples is as follows:

[0032] The retrogradation properties of starch are characterized by the retrogradation enthalpy of starch. The determination method is to use a differential scanning calorimeter (DSC) to determine the retrogradation properties of all samples under ultrapure nitrogen. Mix 2 to 4 mg of starch sample and 2 times deionized water (w / w) in an aluminum pan and then seal it. The sealed aluminum pan is equilibrated at room temperature for 12 hours. The aluminum pan containing the sample is then heated from 30°C to 100°C at a rate of 10°C / min, and an empty aluminum pan is used as a control. The enthalpy value (ΔH) is calculated based on the DSC curve using the Muse working software.

[0033] Embodiment 1:

[0034] Disperse 30mg and 75mg of maltohexaose into 15mL ultrapure water, add 1470mg or 1425mg of wheat starch (i.e., 2% / 5% maltohexaose), mix well and put into a magnetic stirrer, set the temperature to 95℃ and the speed to 500r / min. Heat at a constant temperature for 60min to gelatinize. After cooling, divide it into two parts, store them at 4℃ for 3d and 7d respectively, dry and grind them through a 100-mesh sieve.

[0035] Embodiment 2:

[0036] Disperse 30mg and 75mg of maltoheptaose into 15mL ultrapure water, add 1470mg or 1425mg of wheat starch (i.e., the amount of maltoheptaose added is 2% / 5%), mix well and put into a magnetic stirrer, set the temperature to 95℃ and the speed to 500r / min. Heat at a constant temperature for 60min to gelatinize. After cooling, divide it into two parts, store them at 4℃ for 3d and 7d respectively, dry and grind them through a 100-mesh sieve.

[0037] Embodiment 3:

[0038] Disperse 30mg and 75mg of maltooctaose into 15mL ultrapure water, add 1470mg or 1425mg of wheat starch (i.e., maltooctaose added in an amount of 2% / 5%), mix well and put into a magnetic stirrer, set the temperature to 95°C and the speed to 500r / min. Heat at a constant temperature for 60min to gelatinize. After cooling, divide it into two equal parts, store it at 4°C for 3d and 7d respectively, dry it, grind it and pass it through a 100-mesh sieve.

[0039] Embodiment 4:

[0040] Disperse 30mg and 75mg of glucan with an average degree of polymerization of 9 into 15mL of ultrapure water, add 1470mg or 1425mg of wheat starch (i.e., the addition amount of glucan with an average degree of polymerization of 9 is 2% / 5%), mix well and put into a magnetic stirrer, set the temperature to 95℃ and the speed to 500r / min. Heat at a constant temperature for 60min to gelatinize. After cooling, divide it into two equal parts, store them at 4℃ for 3d and 7d respectively, dry and grind them through a 100-mesh sieve.

[0041] Embodiment 5:

[0042] Disperse 30mg and 75mg of glucan with an average degree of polymerization of 21 into 15mL of ultrapure water, add 1470mg or 1425mg of wheat starch (i.e., the addition amount of glucan with an average degree of polymerization of 21 is 2% / 5%), mix well and put into a magnetic stirrer, set the temperature to 95℃ and the speed to 500r / min. Heat at a constant temperature for 60min to gelatinize. After cooling, divide it into two equal parts, store them at 4℃ for 3d and 7d respectively, dry and grind them through a 100-mesh sieve.

[0043] Embodiment 6:

[0044] Disperse 30mg and 75mg of glucan with an average degree of polymerization of 34 into 15mL ultrapure water, add 1470mg or 1425mg of wheat starch (i.e., the addition amount of glucan with an average degree of polymerization of 34 is 2% / 5%), mix well and put into a magnetic stirrer, set the temperature to 95℃ and the speed to 500r / min. Heat at a constant temperature for 60min to gelatinize. After cooling, divide it into two equal parts, store it at 4℃ for 3d and 7d respectively, dry and grind it through a 100-mesh sieve.

[0045] Comparative Example 1:

[0046] Dissolve 1500 mg wheat starch in 15 mL ultrapure water, mix well and put into a magnetic stirrer, set the temperature to 95°C and the speed to 500 r / min. Heat at a constant temperature for 60 minutes to gelatinize. After cooling, store at 4°C for 3 days, dry and grind to pass through a 100-mesh sieve.

[0047] Comparative Example 2:

[0048] Dissolve 1500 mg wheat starch in 15 mL ultrapure water, mix well and put into a magnetic stirrer, set the temperature to 95°C and the speed to 500 r / min. Heat at a constant temperature for 60 minutes to gelatinize. After cooling, store at 4°C for 7 days, dry and grind through a 100-mesh sieve.

[0049] The retrogradation enthalpy of the modified starch was measured according to the method for measuring the retrogradation properties of starch. The results are shown in Tables 1 and 2.

[0050] Table 1 Regeneration enthalpy of different modified starch samples after short-term storage (3d)

[0051]

[0052]

[0053] Table 2 Regeneration enthalpy of different modified starch samples after long-term storage (7 days)

[0054]

[0055] From the data analysis of Table 1 and Table 2, it can be seen that the examples all have a regulating effect on the retrogradation of wheat starch. Among them, Example 6 has the most obvious promoting effect, with the retrogradation enthalpy increased by 61.3%, and Example 2 has the most obvious inhibitory effect, with the retrogradation enthalpy reduced by 48.2%.

[0056] The regulation effect of linear sugar chains with different polymerization degrees is different. The retrogradation enthalpy of samples in Example 1 and Example 2 shows the following rules: 2% 3d retrogradation enthalpy increases, 2% 7d retrogradation enthalpy decreases; 5% 3d retrogradation enthalpy decreases, 5% 7d retrogradation enthalpy decreases. The samples in Examples 3, 4, and 5 show an increase in 3d retrogradation enthalpy and a decrease in 7d retrogradation enthalpy. This is because when the polymerization degree of sugar chains is between 6 and 20, sugar molecules increase the regional concentration as solutes, promote short-term retrogradation of starch, and form hydrogen bonds with starch molecules at the same time, thereby delaying long-term retrogradation. The retrogradation enthalpy of sample 6 in Example 3d increases, the retrogradation enthalpy of 2% 7d increases slightly, and the retrogradation enthalpy of 5% 7d decreases. When the polymerization degree of sugar chains is higher, long-chain sugar molecules act as the backbone to promote the formation of helices by linear starch molecules, promote short-term retrogradation, but hinder the binding of branched molecular chains, inhibiting the long-term retrogradation of starch.

[0057] Therefore, adding 2% maltoheptaose reduced the retrogradation effect by 48.2% at 7 days, while adding glucan with an average degree of polymerization of 34 increased the retrogradation effect by 61.3% at 3 days. The long-chain sugar molecules guided the linear starch molecules to form a spiral, which significantly promoted the retrogradation of starch. The above results show that the treatment of different medium and high degree of polymerization linear sugar chains can significantly regulate the retrogradation of starch.

[0058] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with the technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be

[0059] The definition in the claims shall prevail.

Claims

1. A method for regulating starch retrogradation, characterized in that: The method comprises adding linear sugar chains with medium or high polymerization degrees to starch, heating and gelatinizing after uniform mixing, and regulating the retrogradation property thereof; the regulating starch retrogradation comprises promoting or inhibiting starch retrogradation.

2. The method according to claim 1, characterized in that The medium-high degree of polymerization linear sugar chain is maltooligosaccharide or glucan with a DP between 6-35.

3. The method according to claim 1, characterized in that The method comprises adding one or several linear sugar chains thereof at the same time, and the added ratio of the sugar chains is 2%-10% (w / w).

4. The method according to claim 1, characterized in that: The starch is specifically corn starch, potato starch, tapioca starch, sweet potato starch, pea starch, wheat starch, rice starch, mung bean starch, red bean starch, lotus seed starch or chestnut starch.

5. The method according to claim 1, characterized in that Adding sugar chains to starch includes adding sugar chains before starch gelatinization and adding sugar chains during starch gelatinization.

6. The method according to claim 1, characterized in that During starch gelatinization, the temperature is controlled at 90-100°C and the heating time is 30-90 minutes.

7. A method for promoting starch retrogradation, characterized in that: The method comprises the following steps: dispersing glucan with an average degree of polymerization of 21-34 into water, adding starch, stirring and heating for gelatinization after mixing, and storing the mixture at 1-10°C for 2-5 days; the amount of glucan added is 2-5% (w / w); and the stirring and heating gelatinization conditions are 90-100°C and constant temperature heating for 30-90 minutes.

8. A modified starch prepared by the method according to any one of claims 1 to 7.

9. The use of the modified starch according to claim 8 in the preparation of starchy foods, characterized in that: The starchy foods include steamed bread, bread and rice noodles.

10. Use of the method for regulating starch retrogradation according to any one of claims 1 to 7 in regulating starch retrogradation.

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