KR20060037153A - A preparation method of enzyme-resistant starch using extrusion process - Google Patents

Abstract

The present invention relates to a method for producing enzyme-resistant starch using an extrusion molding method, and more particularly, to a method for producing enzyme-resistant starch using an extrusion molding method, water content, barrel temperature, screw rotation speed, citric acid, vitamin C Optimized various factors such as extrusion molding process such as addition of organic acid, storage and drying conditions after extrusion molding, and number of extrusion molding, and maximized yield of enzyme resistance starch by introducing new extrusion molding process by injection of carbon dioxide gas. The present invention relates to a method for producing high efficiency and economic enzyme starch.

Extrusion method, enzyme resistance starch, carbon dioxide injection

Description

A preparation method of enzyme-resistant starch using extrusion process

1 is a diagram showing the screw arrangement of the experimental twin-axial co-extrusion molding machine (THK 31T, Inchen Machinery, Korea) used to prepare the extruded enzyme resistance starch in the present invention.

Figure 2 is a diagram of the analysis method of enzyme resistance starch using the phosphate buffer solution used in the present invention.

Figure 3 is a diagram of the analysis method of enzyme resistance starch using Mes-Tris buffer solution used in the present invention.

4 is a graph showing the change in RS yield of extruded wheat starch according to the water content and barrel temperature (60 ~ 80 ℃).

5 is a graph showing the change in RS yield of extruded wheat starch according to moisture content and barrel temperature (50 ~ 110 ℃).

The present invention relates to a method for producing enzyme-resistant starch using an extrusion molding method, and more particularly, to a method for producing enzyme-resistant starch using an extrusion molding method, water content, barrel temperature, screw rotation speed, citric acid, vitamin C Optimized various factors such as extrusion molding process such as addition of organic acid, storage and drying conditions after extrusion molding, and number of extrusion molding, and maximized yield of enzyme resistance starch by introducing new extrusion molding process by injection of carbon dioxide gas. The present invention relates to a method for producing high efficiency and economic enzyme starch.

Since the 1980s, starch has been recognized as not only a simple energy source but also a resource that can contribute to the health of humankind. From this point of view, research on the production process and functional effects on starch, which is an enzyme-resistant starch (RS) resistant to starch degrading enzymes present in the human digestive system, has begun (Englist et al. , Classification and measurement of nutritionally important starch fractions, Eur. J. Clin. Nutri. 46 (2): 33-40, 1992). Enzyme-resistant starch has many similarities in terms of nutrition with undigested fiber in human small intestine, but physical functions such as texture, viscoelasticity, cohesiveness, water absorption, water solubility, and color are different from non-digestible nutrients in human body including fiber. Many can be added to existing foods. In other words, it will be a material that can be applied not only to foods with similar properties such as breads, hamburgers, snacks, pasta, grain expanded foods, expanded snacks, soups, yogurts, beverages, and functional foods, but also to the development of new innovative foods. Brown et al., The use of high maize starch in the preparatuin of nutritional foods, Food Australia 52 (1,2): 22-26, 2000.

Resistant starch has been around since similarity. Starch produced through dry milling, which is a structural separation method, and wet milling, which is a separation of components, and wet milling, which are not easily separated by enzymes, are completely dehydrated. Unstarched starch also belongs to the category of resistance starch. Research on modified starch (RS-4) formed by crosslinking between starch (RS-3) and hydroxyl group of starch by forming crystals by repeating gelatinization and aging of starch, At this time, the raw material uses a lot of high amylose corn starch.

RS-3, produced through gelatinization and aging, is an undigested starch that resists human enzymes by forming crystals during heating and cooling storage at 125 ° C. In order to improve the yield of enzyme-resistant starch, a study was conducted to increase the yield of enzyme-resistant starch by adding nonvolatile organic acid, citric acid, lactic acid, etc., to induce partial degradation of starch chain. A paper was published that the yield of enzyme-resistant starch was improved by the addition of organic acid and the yield of enzyme-resistant starch of the extruded extruded molding at 120-130 ℃ under pressure.

Starch is gelatinized when heated under appropriate moisture and temperature conditions. When it is cooled, recrystallization of starch forms a crystalline form of Form B. This series of processes is called aging, and the crystallization of amylose formed by aging is RS-. 3 is called. Therefore, factors related to aging of starch may affect the enzyme resistance starch content. That is, the type of starch, amylose content, moisture content, heat-cooled recovery, heating temperature, and additives may affect RS-3 production. Processes known as physical treatment methods for increasing RS-3 include extrusion, annealing, and moisture-heat treatment, among which extrusion molding can be continuously mass-produced.

In the related art, Korean Laid-Open Patent Publication No. 2000-4816 discloses an additional method of enzymatic resistance starch content using an extrusion molding method. However, the prior art simply extrudes starch having a water content of 10 to 50% (w / w) at 80 to 150 ° C., and further heats the extruded starch at 100 to 150 ° C. without any comparative treatment. In addition, the extruded starch is a method characterized in that it is left for a certain time at -10 ~ -20 ℃, extrusion molding such as the optimum water content and temperature to maximize the yield of enzyme-resistant starch Process variables have not been studied at all.

These studies were mainly carried out outside the country, and in Korea, only some of them were conducted in the Department of Food and Nutrition, Chonnam National University and the Department of Food Science and Technology, Kongju National University. However, the studies at home and abroad have not been conducted in a systematic manner according to moisture content, temperature distribution of barrel, screw rotation speed, and amount of organic acid added. Therefore, it was necessary to optimize the process variables that significantly affect the yield through the study of extrusion process and enzyme resistance starch yield.

On the other hand, the study on the formation of enzyme-resistant starch by storing the luxury corn starch extrudates at -2 ℃ ~ room temperature was partly carried out in the Department of Food Science and Nutrition, Chonnam National University. However, like the above extrusion molding process, the crystallization kinetics are controlled by controlling the humidity and the drying rate in addition to the basic storage period and the significant factors depending on the temperature, the size of the extrudate and the storage conditions (temperature and duration) of the extrudate. There is a need for a study to increase the yield of enzyme resistance starch in a short time by increasing the reaction rate constant through analysis of kinetics.

Extrusion molding process by injection of critical carbonic acid or carbonic acid is the process of minimizing the destruction of nutrients that are unstable to heat and inflating by injecting carbonic acid gas into the pore forming agent instead of the existing moisture to control the texture by controlling the internal pores of the extrudate. Its applications in food processing are very broad, including minimizing the breakdown rate of vitamin C, producing dairy-enhanced extruded products, and studying thermal and physical properties (Ryu et al., 1995-2002). Therefore, if the extrusion molding process by the carbon dioxide injection is applied to the production of enzyme-resistant starch, the control of drying rate and crystal formation rate through pore formation at high moisture content, maximization of enzyme-resistant starch formation, breaking force of extrudate by pore formation Although there are many advantages compared to the existing process, such as reduction of the grinding energy requirement of the extrudate through reduction, so far no research has been attempted to apply the extrusion molding process by the carbon dioxide injection to the enzyme-resistant starch production at home and abroad.

Therefore, in view of the above, the present inventors have found that the yield of enzyme resistance starch according to the extrusion molding process variable, the crystal formation rate according to the process variable after extrusion molding, and the enzyme resistance starch by the injection of carbon dioxide gas with additives to improve the production of enzyme resistance starch. Through researches on production process development, we tried to provide a method for producing enzyme-resistant starch by applying high-efficiency and economical extrusion process.

An object of the present invention is to produce an enzyme-resistant starch using the extrusion molding method, the water content, barrel temperature, screw rotation speed, extrusion process parameters such as the addition of organic acid, storage and drying conditions after extrusion molding, number of extrusion molding, etc. By optimizing various influence factors and introducing a new extrusion molding process by injecting carbon dioxide, it is possible to provide a more efficient method for producing enzyme-resistant starch.

Hereinafter, the configuration and operation of the present invention will be described in detail.

The present invention provides an optimal production method of enzyme-resistant starch using the extrusion molding method according to the above object.

The present invention is a method for producing enzyme-resistant starch using the extrusion molding method, the starch is citric acid, at a barrel temperature of 95 ~ 110 ℃, water content 30 ~ 40% (w / w), screw rotation speed of 250 ~ 350 rpm It is characterized by extruding by adding any one selected from vitamin C, thermostable liquefied enzyme or high amylose.

At this time, the barrel temperature of 95 ~ 110 ℃, water content 30 ~ 40% (w / w) and screw rotation speed of 250 ~ 350 rpm conditions are the optimum conditions during extrusion molding to maximize the yield of the enzyme resistance starch, The yield of enzyme-resistant starch can be further increased by adding any one selected from citric acid, vitamin C, thermostable liquefied enzyme or high amylose.

In the above, additives such as citric acid, vitamin C, thermostable liquefied enzyme, and high amylose are preferably added in an amount of 0.1% to 10.0% based on the starch weight.

In another aspect, the present invention is characterized in that the starch extruded under the above conditions are stored and dried for 6 hours to 3 days at a temperature of 0 ℃ ~ 80 ℃, moisture content 50 ~ 70% (w / w) All.

In this regard, Korean Patent Laid-Open Publication No. 2000-4816 discloses a method for producing enzyme-resistant starch, characterized in that the extruded starch is heated at a temperature of 100-150 ° C. and left at a constant time at −10 to −20 ° C. However, the present invention further goes above that by optimizing the extrusion process parameters as described above, the upper limit of the storage and drying temperature of the extruded starch can be up to 80 ° C, and the starch can be accelerated to the maximum. There is a big difference in the fact that the content of starch during storage and drying is 50 ~ 70% (w / w) for the first time.

The present invention also provides a method for producing enzyme-resistant starch, characterized by injecting carbon dioxide gas or critical carbonic acid in addition to the storage and drying conditions after extrusion and extrusion molding as described above.

As such, when carbon dioxide or critical carbonic acid is injected into the barrel during the extrusion molding process, pores are formed in the extrudate that does not cause swelling at 80 ° C. or lower, thereby making it easier to crush the dried extrudate. As the grinding efficiency of the dry extrudate increases, the yield of enzyme-resistant starch is also greatly improved.

This extrusion molding process of starch through the injection of carbonic acid gas or critical carbonic acid is provided for the first time in the world in this invention, at this time, it is preferable to inject carbonic acid gas or critical carbonic acid at 8 to 12 atm.

The present invention is also a method for further improving the yield of enzyme-resistant starch in extrusion molding starch by injection of carbon dioxide gas or critical carbonic acid, characterized in that the processing of microwaves during storage and drying of the extruded starch do. At this time, as the number of microwave treatment increases, the yield of enzyme-resistant starch increases.

Finally, the present invention provides a method for producing enzyme-resistant starch, characterized in that the number of extrusion molding of starch twice in the above-mentioned extrusion molding and storage and drying conditions. Repeated production of enzyme-resistant starch under optimal extrusion molding conditions and storage and drying conditions of extruded moldings yields significantly higher yields of enzyme-resistant starch than single extrusion.

On the other hand, the materials and experimental procedures used in the present invention are as follows.

1. Material

Starch for the production of extruded enzyme-resistant starch is a general corn starch with 13% water content (w / w, below), 28% amylose content (Samyang Genex), 14% water content, and 27% amylose content corn (Doosan Co., Ltd.) and wheat starch having a water content of 14.2% and an amylose content of 15.5% were used.

2. Extrusion molding process

The production of the extrusion enzyme resistance starch was used for the experimental twin-axial coextrusion machine (THK 31T, Inchen Machinery, Korea), the screw arrangement is shown in FIG. The screw diameter was 3.0 cm, the length and diameter ratio (L / D ratio) was 25: 1, and the injection hole was used as a circular diameter of 3mm. The temperature control of the barrel was controlled by using a heater and cooling water.

Extrusion process variables include barrel temperature, moisture content and screw rotation speed. Barrel temperatures range from 80/70/60/40 ℃ to 130/120/80/40 ℃ (1/2/3/4 barrel). In the range, the water content was 20 to 40% range, the screw rotation speed was performed in the 250 to 350 rpm range, respectively.

The raw material injection amount was fixed at 157.8 g / min at 20 rpm of the raw material feeder screw rotation speed. In order to increase the crystallization of the starch chain of the extruded extruded product, the extruded enzyme was stored at a storage temperature of 0 to 80 ° C. and then dried by hot air drying to dry the extruded product with a water content of 8% or less and then pulverized with a small household grinder. Resistant starch powder was sampled and analyzed.

3. Enzyme Resistance Starch Analysis Method

(1) Enzyme Resistance Starch Yield Using Phosphate Buffer

The enzyme resistance starch production rate was analyzed as shown in Figure 2 by modifying the enzyme weight method (AOAC, 1990). That is, 0.5 g (db) of the sample is mixed with 25 mL of phosphate buffer solution (pH 6.0) and 0.05 mL of heat-stable α-amylase, and reacted for 30 minutes in a 100 ° C constant-temperature water bath, and cooled at room temperature. It was. The cooled sample was adjusted to pH 7.5 by adding 0.275N NaOH, and then 0.05 mL of a 50 mg dilute solution of protease was added to 1.0 mL of phosphate buffer solution (pH 6.0). Cooled. 0.325N HCl was added to adjust the pH to 4.3, then 0.15 mL of amyloglucosidase was added thereto, reacted at 60 ° C. for 30 minutes, cooled to room temperature, diluted with 80% alcohol, and celite (celite). ) The filtered residue was dried and quantified by using a glass filter to which 0.5 g was added. The ratio of the residue to the weight of the sample was expressed.

Yield yield of enzyme-resistant starch (%) = weight of insoluble residue after drying / weight of sample × 100

(2) Enzyme Resistance Starch Yield Using Mes-Tris Buffer

The yield of enzyme resistance starch using Mes-Tris buffer was analyzed by the same procedure as in FIG. 3. That is, 1 g of an extruded enzyme resistance starch sample, 40 mL of, Mes-Tris buffer solution (pH 8.2) and 0.1 mL of heat stable alpha amylase were mixed. The mixture was reacted for 15 minutes after 5 minutes of preheating in a constant temperature water bath at 100 ° C. and then cooled at room temperature.

0.1 mL of a solution diluted with 50 mg of protease in 1 mL of Mes-Tris buffer (pH 8.2) was added to the cooled sample, stirred for 30 minutes at 60 ° C in a constant temperature water bath, and then 5 mL of 0.567 N HCl was added to pH 4.6. Corrected. 0.1 mL of amyloglucosidase was added to the calibrated sample solution, and the reaction was stirred for 3 minutes at 60 ° C. in a constant temperature water bath, followed by cooling at room temperature. After adding 95% ethanol to 80% total alcohol concentration in the cooled sample solution, it was left to stand for 1 hour, and 0.5 g of celite was covered with a glass filter. The insoluble residue obtained by vacuum suction filtration was 95% ethanol and 78% acetone. After washing, the insoluble residue was calculated by quantifying the weight of the insoluble residue after drying in an oven at 105 ° C. and substituting the following equation.

Yield yield of enzyme-resistant starch (%) = weight of insoluble residue after drying / weight of sample × 100

Hereinafter, the structure of the present invention will be described in more detail with reference to Examples.

Example 1 Optimization of Enzyme Resistance Starch Production by Extrusion from Corn Starch

1. Yield of Starch Resistance by Extrusion Process Variables

In order to determine the optimum condition to improve the yield of enzyme-resistant starch (hereinafter referred to as RS) to the maximum, barrel temperature and water content, which are extrusion process variables affecting RS yield in the first step, and extrusion After molding, the RS yield was analyzed according to storage temperature and drying temperature to induce crystallization of the internal starch chain.

The raw material used was corn corn starch with 13% moisture content and 28% amylose content produced by Samyang Genex Co., Ltd., and the extrusion process parameters were barrel temperature 80 ℃ and 100 ℃, water content 20% (w / w) and 40% (w / w), the screw rotation speed 250rpm, the raw material injection amount was fixed at 157.8 g / min (raw material feeder screw rotational speed 20rpm).

Further, the starch extruded under the above extrusion molding conditions were stored for 2 days at a storage temperature of 25 ° C. and then dried at 100 ° C. for 2 hours, dried at 80 ° C. for 6 hours, and then dried at 100 ° C. for 2 hours. RS yields were measured by grinding the samples each having a water content of 5% (w / w) or less. The results are shown in Table 1 below.

Changes in RS Yield According to Extrusion Process Parameters (pH 6.0 Phosphate Buffer) Extrusion Process Variables Moisture control and drying RS yield (%) Barrel Temperature (℃) Water content (% (w / w)) 80 20 2 days at 25 ℃ 5.72 80 20 6 hours at 80 ℃ 4.01 80 40 2 days at 25 ℃ 7.01 80 40 6 hours at 80 ℃ 4.91 100 20 2 days at 25 ℃ 5.02 100 20 6 hours at 80 ℃ 4.96 100 40 2 days at 25 ℃ 5.13 100 40 6 hours at 80 ℃ 5.72

As can be seen in Table 1, the RS yield was more increased at the barrel temperature of 80 ° C. than at 100 ° C., and the water content increased from 20% (w / w) to 40% (w / w) in the extruded molding. Yield was high. In addition, the storage temperature after extrusion in this experiment did not significantly affect the RS yield. However, in order to use enzyme-resistant starch as a food intermediate material, drying is necessary because the grinding process is necessary. If the storage temperature is low, the drying time required for drying increases, which increases the production cost of enzyme-resistant starch. It was concluded that 80 ° C was better than 25 ° C.

2. RS yield according to storage temperature and drying temperature

The extruded product after extrusion of general corn starch produced by Doosan Corporation (water content 14%, amylose content 27%) at barrel temperature 110 ℃, water content 35% (w / w), screw rotation speed 250 rpm Was stored and dried at various temperatures to examine the RS yield according to storage temperature and drying temperature in more detail. First stored for 8 hours at a storage temperature of 25 ℃ and then dried for 4 hours and 8 hours at a drying temperature of 60 ℃ to adjust the moisture content to 10% (w / w) or less and then pulverized. In addition, the RS yield was analyzed by pulverizing the extrudate dried for 4 hours and 8 hours at 70 ℃ and 110 ℃ to perform storage and drying at the same time. The results are shown in Table 2 below.

Changes in RS Yield of Extruded Corn Starch by Storage and Drying Temperatures Storage and drying conditions RS yield (%) Storage and drying temperature (℃) Drying time 25 ^* 4 8.29 25 ^** 8 9.45 70 4 8.70 70 8 11.81 110 4 10.42 110 8 9.68

^* , ^** : Store at 25 ℃ and then dry for 4 hours and 8 hours at 60 ℃

Experimental results As can be seen in Table 2, as shown in the experiment for the extrusion molding process variable setting in 1. The significant difference in the RS yield was not seen depending on the storage temperature. That is, the RS yield tended to increase as the drying time increased from 4 hours to 8 hours at storage temperatures of 25 ℃ and 70 ℃, but the RS yield increased even if drying time increased from 4 hours to 8 hours at 110 ℃. It wasn't. Therefore, from the above results, it was confirmed that the storage and drying temperatures were most suitable up to 80 ° C.

3. Addition of Thermostable Limease (Thermamyl) and RS Yield

To the corn starch produced by Samyang Genex Co., Ltd. (13% water content, 28% amylose content) was added 3% of thermylyl (heat-stable α-amylase), a heat stable starch dehydrogenase, based on the starch weight. After extrusion molding, the RS yield was analyzed to examine the effect of the addition of thermostable liquefied enzyme. At this time, the barrel temperature was fixed at 95 ℃ to minimize the inactivation of the enzyme, the water content was adjusted to 25% (w / w), 30% (w / w), 35% (w / w).

In addition, in order to examine the effect of preconditioning, the moisture content of starch was adjusted to 35% (w / w) before extrusion molding, and then stored in a refrigerator for 12 hours to sufficiently diffuse moisture into the starch particles. Next, extrusion was carried out while adding thermamil. At this time, the drying conditions of the extrusion molded product was analyzed by grinding the hot-air dried sample for 6 hours at 80 ℃.

As a result, as shown in Table 3, the RS yield was 4.22 for the sample extruded at 35% water (w / w) with the addition of thermylyl, a thermostable liquefied enzyme (starch). It increased significantly from% to 7.13%. In addition, when the same enzyme content was added, when the water content was 25% (w / w) and 30% (w / w), the RS yield was 5.15% and 5.13%, but the water content was 35%. In the case of (w / w), the RS yield increased significantly to 7.13%. On the other hand, RS yield did not increase by preliminary moisture control.

Changes in RS Yield due to Enzyme Treatment and Difference in Water Content (pH 6.0 Phosphate Buffer) Extrusion Process Variables Reserve Moisture Control RS yield (%) Barrel Temperature (℃) Moisture content (% (w / w)) Add Thermamil (Thermamyl) 95 25 adding - 5.15 95 30 adding - 5.13 95 35 No addition - 4.22 95 35 adding - 7.13 95 35 No addition 12 hours 3.64 95 35 adding 12 hours 3.98

4. RS yield according to vitamin C addition

Vitamin C aqueous solution breaks down starch chains with weak acids. Since the RS yield increases when a nonvolatile organic acid such as citric acid is added to increase the RS yield, a change in RS yield was determined by adding 3% of vitamin C to corn starch based on the starch weight. At this time, the water content was fixed at a barrel temperature of 90, 110 and 130 ° C. at 35% (w / w) and a screw rotation speed of 250 rpm.

As a result, as shown in Table 4 below, when vitamin C was added, the RS yield decreased at 6.42%, 4.69%, and 4.52% at barrel temperatures 90, 110, and 130 ° C, respectively, and barrel temperature 90 The highest RS yield was 6.42% at ℃.

Yield Changes of Extruded Corn Starch RS with Vitamin C (pH 6.0 Phosphate Buffer) Barrel Temperature (℃) RS yield (%) 90 6.42 110 4.69 130 4.52

[Example 2: Optimization of Enzyme Resistance Starch Production Using Extrusion Molding Method from Wheat Starch]

1. RS yield of wheat starch according to the number of extrusion molding

In the production method of enzyme-resistant starch using high amylose corn starch, the crystallization of corn starch at high temperature and then repeated several times to increase the crystal yield due to the increase of the bonds between the starch chains and increase the RS yield. Continue to repeat. In the production process of starch-resistant starch starch by extrusion molding process, extrusion molding was performed to repeat gelatinization (melting) and cooling, and then water molding and dry extruding molding were coarsely pulverized, and extrusion molding was repeated. Was reviewed.

As a result, as shown in Table 5, extrusion starch was extruded under the extrusion temperature of barrel temperature 115 ℃, water content 40% (w / w), screw rotation speed 250 rpm, extrusion molding by varying the drying conditions The RS yield of one extrudate was 2.88%, but the RS yield increased to 3.3-3.4% when the extrusion was repeated twice under the same conditions.

In addition, since the one-time extruded wheat starch was not easy to insert into the raw material inserter during extrusion molding, newly extruded 50% of the primary extrudate and 50% of the raw wheat starch were extruded, and in this case, the obtained RS The yields showed the same RS yield when compared to the sample extruded again from the primary extrudate when stored at 25 ° C. and 45 ° C. except the storage temperature of 80 ° C.

Therefore, it can be seen from the above results that the RS yield can be further improved by repeatedly extruding the enzyme-resistant starch production process using the extrusion molding process, and the first extrusion molded product is stored at an optimal storage temperature for aging. When accelerated and then again extruded under the same conditions, it was expected that the RS yield could be greatly improved.

Changes in RS Yield of Extruded Wheat Starch According to the Number of Extrusions (Mes-Tris Buffer) Extrusion Process Variables Reserve Moisture Control RS yield (%) Extrusion Cycles Barrel Temperature (℃) Moisture content (% (w / w)) One 115 40 6 hours at 80 ℃ 2.88 2 115 40 12 hours at 45 ℃ 3.33 2 115 40 24 hours at 25 ℃ 3.41 2 ^* 115 40 6 hours at 80 ℃ 2.67 2 ^* 115 40 12 hours at 45 ℃ 3.59 2 ^* 115 40 24 hours at 25 ℃ 3.37

2 ^* : 2nd extrusion by mixing 50% of one time extruded product and 50% of raw wheat starch

2. RS yield according to extrusion process

Screw rotation speed 250 rpm, storage temperature for the change of RS yield of wheat starch according to barrel temperature (60, 70, 80 ℃) and water content (25, 30, 35% (w / w)) of extrusion process RS yield was stored for 3 days at 0 ° C. and dried at 80 ° C.

As a result, as shown in Table 6, the RS yield of the extruded wheat starch according to the barrel temperature and the moisture content was generally high at the barrel temperature of 80 ℃, in the case of the moisture content significant RS yield according to the content change Did not show a difference. In general, as the water content increases, the chain mobility during starch gel aging increases the aging degree, but in this experiment, the RS yield was not increased in the high moisture content.

On the other hand, at a barrel temperature of 60 ° C., the lower the water content, the higher the RS yield. After starch was gelatinized, amylose recombination increased due to the aging process, which increased the enzyme resistance starch content (type 3) or lowered the degree of gelatinization. The starch was believed to be retained.

Changes in RS Yield of Extruded Wheat Starch According to Extrusion Process Variables (Mes-Tris Buffer) Barrel Temperature (℃) Screw speed (rpm) Storage and drying conditions Temperature (℃) / hour (day) Moisture content (% (w / w)) RS yield (%) 60 250 0 ℃ / 3 days 25 4.40 30 3.55 35 2.84 70 250 0 ℃ / 3 days 25 2.86 30 2.34 35 2.88 80 250 0 ℃ / 3 days 25 3.90 30 2.96 35 3.74

On the other hand, Figure 4 is a three-dimensional graph showing the RS yield according to the moisture content and the temperature of the barrel, the highest RS yield at 35% moisture (w / w), barrel temperature 80 ℃, but the maximum RS yield in the experimental range The optimum moisture content and barrel temperature could not be found. RS yield decreased with increasing barrel temperature from 60 ° C to 70 ° C in the water content range of 25% (w / w) to 35% (w / w) and then increased as the yield increased from 70 ° C to 80 ° C. Showed.

Therefore, there was a need for experiments to determine the optimum extrusion process parameters by widening the barrel temperature and moisture range. Accordingly, the water content ranged from 10% (w / w) to 40% (w / w) and the barrel temperature was increased at 50 ° C. It is shown in Figure 5 the change in RS yield according to widening to 110 ℃ range.

As a result, as can be seen in Figure 5, the moisture content was increased to 40% (w / w) and the maximum RS yield in the range of the barrel temperature is 95 ℃ to 110 ℃.

3. Citric acid addition and RS yield

In order to investigate the RS yield of the extruded wheat starch according to the addition of citric acid, the content of citric acid powder at the barrel temperature of 110 ° C., water content of 40% (w / w), and screw rotation speed of 250 rpm was 2.5%, 5.0 based on the starch weight. The change of RS yield at the time of addition at% and 10.0% was examined.

As a result, as shown in Table 7, the RS yield of the extruded wheat starch tended to increase as the amount of citric acid increased, and the RS yield was highest when dried for 6 hours at a storage temperature of 80 ° C.

Changes in RS Yield of Extruded Wheat Starch by Addition of Citric Acid (Mes-Tris Buffer) Barrel Temperature (℃) Screw speed (rpm) Storage condition Moisture content (% (w / w)) Citric acid content (%) RS yield 110 250 80 ℃ / 6 hours 40 2.5 4.92 5.0 5.04 10.0 6.66 110 250 45 ℃ / 12 hours 40 2.5 3.36 5.0 4.47 10.0 4.77 110 250 25 ℃ / 24 hours 40 2.5 4.47 5.0 4.39 10.0 4.85

4. Screw rotation speed, moisture content and RS yield

Adjust the screw rotation speed to 250 rpm and 350 rpm at the barrel temperature of 60 ℃, adjust the water content to 25% (w / w) and 35% (w / w), and extrude the wheat starch to improve its RS yield. Comparative analysis. At this time, in order to increase RS yield, high amylose corn starch (Himaize) was added as much as 10% based on the starch weight. Also, pores were formed in the extrudates that did not cause swelling at a barrel temperature of 80 ° C. or lower to improve RS yield. In order to improve the grinding efficiency of the dry extrudate, 10 atm of CO ₂ gas was injected into the barrel during the extrusion process.

As a result, as shown in Table 8 below, the RS yield of the extruded wheat starch was increased when the water content and the screw rotation speed were increased from 25% (w / w) to 35% (w / w) and 250 rpm to 350 rpm, respectively. There was a slight increase, and RS yield was markedly increased when high amylose was added by 10% based on the starch weight, compared to the unadded sample. This resulted in an increase in RS yield due to increased starch chains by macrodegradation with increasing screw rotational speed, suggesting that amylose is very important for the production of enzyme-resistant starch.

In addition, it was found that when CO ₂ gas is injected into the barrel during the extrusion process, pores are formed in the extrudate and the breakage force of the extrudate is reduced, thereby facilitating crushing. Accordingly, CO ₂ gas is injected into the starch. The extrusion was expected to improve the grinding efficiency of the dry extrusion molding to reduce the grinding cost.

Changes in RS Yield with Screw Rotation Speed and Water Content (Mes-Tris Buffer) Barrel Temperature (℃) Screw speed (rpm) Moisture content (% (w / w)) Add high amylose (% (w / w)) CO ₂ injection (atm) RS yield (%) 60 250 25 10 10 5.18 350 5.37 250 35 5.19 350 6.87

5. Storage and drying conditions and RS yield

(1) moisture content and RS yield

In order to investigate the change of RS yield according to moisture content during storage and drying conditions after extrusion of starch, the extrusion conditions were changed to water content of 30% (w / w), screw rotation speed of 250 rpm, barrel temperature of 60 ℃ and 90 ℃. After extruded wheat starch by fixation, the water content of the extruded product was sprayed at 50-70% (w / w) by spraying water on the extruded product, and then refrigerated at 0 ° C. for 3 days to investigate RS yield. It was.

As a result, as shown in Table 9, the RS yield increased significantly as the moisture content increased during storage and drying, in particular, extrusion temperature of barrel temperature 90 ℃, screw rotation speed 250 rpm, water content 30% (w / w) The RS yield of wheat starch extrudates produced at 70% (w / w) of moisture and storage and drying conditions was the highest at 5.01%. This phenomenon is believed to increase the yield of enzyme-resistant starch by actively promoting recrystallization by increasing the fluidity between amylose chains as storage moisture is increased.

(2) Citric acid addition and storage and drying moisture content and RS yield

Changes in RS yield with citric acid addition and storage drying during extrusion were investigated. To this end, the extrusion molding conditions were fixed at a barrel temperature of 100 ° C., water content of 40% (w / w), and screw rotation speed of 250 rpm, and the content of citric acid powder was added at 0%, 2.0%, and 3.0% based on the starch weight. After preparing the extruded product, the RS yield of the extruded wheat starch was investigated by spraying distilled water onto the extruded product during storage of the extruded product to adjust the water content to 60% (w / w).

As a result, as shown in Table 9, the RS yield was greatly increased in the case of the sample stored by spraying distilled water during storage and drying the extruded extrudate, the RS yield was increased by the addition of citric acid during extrusion molding . The maximum RS yield was 6.78% in the sample with 3% citric acid added and sprayed during storage and drying to adjust the water content of the extrudate to 60% (w / w).

Changes in RS Yield of Extruded Wheat Starch According to Moisture Content during Citric Acid Addition and Storage Drying (Mes-Tris Buffer) Barrel Temperature (℃) Extrusion Moisture Content (% (w / w)) Citric acid addition amount (%) Storage temperature / period Storage dry moisture content (% (w / w)) RS yield (%) 100 40 - 0 ℃ / 3 days 60 4.25 100 40 - 0 ° C 3 days - 2.52 100 40 - 80 ℃ / 6 hours 60 3.43 100 40 - 80 ℃ / 6 hours - 1.90 100 40 2.0 0 ℃ / 3 days 60 5.46 100 40 2.0 0 ℃ / 3 days - 2.54 100 40 2.0 80 ℃ / 6 hours 60 4.22 100 40 2.0 80 ℃ / 6 hours - 1.72 100 40 3.0 0 ℃ / 3 days 60 7.72 100 40 3.0 0 ℃ / 3 days - 5.30 100 40 3.0 80 ℃ / 6 hours 60 6.78 100 40 3.0 80 ℃ / 6 hours - 3.33

6. CO2 ₂ Injection and RS yield

Extrusion molding process by injecting carbon dioxide and critical carbonic acid is a process for using as a pore-forming agent to form pores by injecting carbonic acid gas or critical carbonic acid at 100 ° C. or lower to reinforce nutrients that are unstable to heat. However, when carbonic acid gas was applied to the production process of enzyme-resistant starch using the extrusion molding process as described above, it was possible to solve the problem of producing enzyme-resistant starch by applying the conventional extrusion molding process to date. That is, the production of enzyme-resistant starch by the extrusion molding process is essential, so the pores of the extruded product collapsed after storage and drying, and the strength thereof was very high. When injected into the barrel, pores were formed in the internal structure of the extrudate, so that the dry extrudate could be easily crushed.

In addition, when carbonic acid gas and water are injected into the extruder barrel, carbonic acid reacts with water to generate carbonic acid, and as a result, RS yield is remarkable when an organic acid such as citric acid is added. As a result, the RS yield can be improved by injecting carbon dioxide gas and organic acid.

Therefore, in this experiment, after the injection of carbon dioxide gas during extrusion, the RS yield was analyzed according to the values of various extrusion process variables. In other words, the yield change of RS was determined by the diameter of the injection hole 3.0mm, carbon dioxide injection pressure about 10 atm, barrel temperature 80 ~ 100 ℃ according to moisture content of dough, microwave drying, citric acid addition and high amylose corn starch. The experiment was performed as follows.

(1) moisture content and RS yield

RS production yield of wheat starch by carbon dioxide injection at 30, 35 and 40% (w / w) was tested. The produced extrudate was easily pulverized by forming pores through carbon dioxide injection. Particularly, when the carbon content was not injected at 40% (w / w) of water content, the extrudate was very hard to grind, but when the carbon dioxide was injected, the grinding was easy.

The increase in RS yield with increasing water content was the same in the extrusion process through carbon dioxide injection as in the conventional general process (see Table 10). However, RS yield did not increase through carbon dioxide injection alone.

Changes in RS Yield of Carbon Dioxide Injection Extruded Wheat Starch According to Water Content (Mes-Tris Buffer) Water content (% (w / w)) Storage and drying condition CO ₂ injection (atm) RS yield (%) 30 80 ℃ / 6 hours 10 1.88 35 80 ℃ / 6 hours 10 2.35 40 80 ℃ / 6 hours 10 2.05

(2) microwave drying and RS yield

When storing the extrudate produced through the injection of carbon dioxide gas was experimented to improve the RS yield by microwave treatment. As a result, it was found that the RS yield is improved through the microwave treatment as shown in Table 11 below. In addition, the RS yield was further increased when the microwave treatment was repeated.

Changes in RS Yield of Carbon Dioxide Injection Extruded Wheat Starch by Microwave Treatment (Mes-Tris Buffer) Moisture content (% (w / w)) Storage and drying condition Microwave count CO ₂ gas injection (stm) RS yield (%) 35 80 ℃ / 6 hours One 10 2.75 35 80 ℃ / 6 hours 2 10 3.02

(3) citric acid addition and RS yield

In order to examine the RS yield of the extruded wheat starch according to the addition of citric acid in the enzymatic resistance starch manufacturing process using the injection molding process by injection of carbon dioxide gas, barrel temperature 90 ℃, water content 40% (w / w), screw rotation speed At 250 rpm, the content of citric acid powder was added at 0.5% and 1.0% based on the starch weight, and the change in RS yield was analyzed.

As a result, as shown in Table 12, the amount of citric acid added was 0.5% in the extrusion process using carbon dioxide injection, unlike the general extrusion process in which the RS yield of the extruded starch increased as the amount of citric acid increased. As the ratio increased from (w / w) to 1.0% (w / w), the RS yield tended to decrease. This may be due to the small difference in the amount of citric acid added at 0.5% or the effect of carbon dioxide injection.

Changes in RS Yield of Carbon Dioxide Injection Extruded Wheat Starch by Addition of Citric Acid (Mes-Tris Buffer) Moisture content (% (w / w)) Storage and drying condition Citric acid addition amount (%) CO ₂ gas injection (atm) RS yield (%) 40 80 ℃ / 6 hours 0.5 10 5.02 40 80 ℃ / 6 hours 1.0 10 3.84

(4) high amylose addition and RS yield

In order to examine the change of RS yield according to the addition of high amylose in the extrusion process through the injection of carbon dioxide gas, the high amylose was starch based on starch weight at a barrel temperature of 60 ° C, water content of 35% (w / w), and screw rotation speed of 350 rpm. After extrusion by adding 10%, the RS yield was compared with the RS yield of the sample without high amylose.

As a result, as shown in Table 13, when the 10% by weight of high amylose was added based on the starch weight, the RS yield was significantly increased compared to the sample not added. This means that amylose is very important for the production of enzyme resistant starch.

Changes in RS Yield of Carbon Dioxide Injection Extruded Wheat Starch with High Amylose Addition (Mes-Tris Buffer) Barrel temperature (℃) Moisture content (% (w / w)) Screw rotation speed Goamylose CO ₂ gas injection (atm) RS yield (%) 60 35 350 No addition 10 5.39 adding 6.87

As described above in detail through the above examples, the present invention is an extrusion molding process such as water content, barrel temperature, screw rotation speed, citric acid, addition of organic acids such as vitamin C, etc. It is possible to maximize the yield of enzyme-resistant starch by optimizing various factors that can affect the production of enzyme starch, such as parameters, storage and drying conditions of extruded products after extrusion, number of extrusion moldings, and new introduction of carbon dioxide injection. It is a very useful invention in the food processing industry because it provides a high efficiency and economical enzyme resistance starch production method.

Claims (5)

In the production method of enzyme-resistant starch by using the extrusion molding method, Starch is extruded by adding any one selected from citric acid, vitamin C, thermostable liquefied enzyme or high amylose under conditions of barrel temperature 95 ~ 110 ℃, water content 30 ~ 50% (w / w), screw rotation speed 250 ~ 350rpm Method for producing enzyme-resistant starch, characterized in that the molding. The method for producing enzyme-resistant starch according to claim 1, wherein the extruded starch is stored and dried for 6 hours to 3 days under conditions of 0 to 80 DEG C and a water content of 30 to 70% (w / w). . 3. The production method of enzyme-resistant starch according to claim 1 or 2, wherein extrusion is performed by injection of carbon dioxide gas or critical carbonic acid. 4. The method for producing enzyme-resistant starch according to claim 3, wherein the extruded starch is stored and dried by microwave treatment. 3. The production method of enzyme resistant starch according to claim 1 or 2, wherein the number of extrusion molding is performed twice.

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