Thermally inhibited starches and flours and process for their production

The present invention relates to heat-suppressed starch and flowers and methods for producing the same. This heat-suppressed starch and flower can be used in place of the chemically crosslinked starch and flower currently used in food and in the manufacture of industrial products.

The prior art teaches that starch can be heated for a variety of purposes, for example, for drying, evaporating off-flavors, imparting smoke flavor or dextrinization, as indicated by the following literature: There is.

U.S. Pat. No. 4,303,451, approved by Seidel et al. December 1, 1981, heats waxy maize starch at natural pH in the range 120-200 ° C to remove wood odors and improve texture by pregelatinization. Is disclosed.

Japanese Publication No. 61-254602, December 11, 1986, states that waxy maize starch and waxy maize starch derivatives are heated at a temperature of 100 to 200 ° C to provide starch having emulsifying properties to replace arabic rubber. It is disclosed. In this step, the starch is heated in the presence of water, preferably under acidic conditions of pH 4.0 to 5.0 to hydrolyze the starch to obtain emulsifying properties.

U.S. Pat. No. 4,303,452 discloses a smoke treatment of waxy maize starch to increase gel strength and impart a smoked flavor. In order to eliminate the acidity of smoke and to obtain a final starch product with a pH of 4-7, the pH of the starch is raised to the range 9-11 before smoking. The preferred water content of starch in smoke is 10-20%.

These documents disclose heating starch for a variety of purposes, but how they are suppressed without the use of heating to make suppressed starch or the use of chemical reagents. It does not disclose whether to make starch.

When natural starch granules are dispersed in water and heated, they hydrate and swell at about 60 ° C and reach a peak viscosity between 65 and 95 ° C. This increase in viscosity is a desired property in many food and industrial applications, and it derives from the physical attraction or frictional force between the highly swollen granules. However, swollen hydrated starch granules are quite brittle. When the starch slurry is kept at a temperature of 92-95 ° C, the starch granules begin to break and the viscosity begins to break down. Extreme pH shearing conditions also tend to disintegrate and fragment the granules, which causes the starch polymer to dissociate and begin to dissolve, leading to a sharp drop from the original high viscosity.

It is known that both swelling and decrease in viscosity of starch granules can be suppressed by treating starch with a chemical reagent that introduces intermolecular cross-linking between starch molecules. This cross-linking reinforces the associative hydrogen bonds that bind the granules together, suppresses the swelling of the starch granules, and, as a result, suppresses the disintegration and fragmentation of the granules. Because of this suppression, crosslinked starch is also called suppressed starch.

Chemically crosslinked starch is used in many applications where a stable and viscous starch paste is required, so if natural or modified starch behaves similarly to chemically crosslinked starch without the use of chemicals. If it can be suppressed, it will be advantageous in reducing price, time and use of chemicals.

The starches and flowers of the present invention are heat-suppressed in a method that results in starches or flowers with the characteristics of chemically crosslinked starches without the addition of chemical reagents. When these heat-suppressed starches and flowers are dispersed in water at 92-95 ° C and pH 3 as 5-6.3% anhydrous solids, they exhibit the characteristic properties of suppressed starches: ie, parenchyma. Perfectly suppressed starches and flowers will withstand gelatinization; highly suppressed starches and flowers will gelatinize only to a certain degree and will show a continuous increase in viscosity, It will not reach peak viscosities; moderately suppressed starches and flowers will show lower peak viscosities and lower percentage reductions compared to the same unsuppressed starches; and slightly Starch and flowers suppressed by will show a slight increase in peak viscosity and a lower percentage decrease in percentage compared to control starch; the property.

In general, heat-suppressing methods dehydrate granular starch or flowers to anhydrous or substantially anhydrous (for the purposes herein, this means a water content of less than 1% by weight), and then this. It comprises the steps of heat-treating anhydrous or substantially anhydrous starch or flower at a temperature and time effective for suppression. Both the dehydration and heat treatment steps are carried out under conditions where decomposition or hydrolysis of starch or flower is avoided.

The starch or flower may be dehydrated and heated at its natural pH (generally in the range of pH 5.0 to pH 6.5), or the pH of the starch or flower may be raised from the beginning to above neutral.

Neutral as used herein means to include a pH value range around pH and to include from about pH 6.5 to about pH 7.5.

Preferably, this method raises the pH of the starch to above neutral, dehydrates the starch to anhydrous or substantially anhydrous, and cools the anhydrous or substantially anhydrous starch above 100 ° C. Consists of a step of heat treatment over an effective period of time to serve the suppressed starch in.

By varying the conditions of this method, such as the initial pH of the starch or flower, the dehydration and heat treatment temperatures, and the heat treatment time, the suppression level can be varied to provide various viscous properties of the starch or flower. Since the parameters of the dehydration and heat treatment method can be correlated with the particular equipment used for dehydration and heat treatment, the choice of equipment will also be a factor in controlling the suppression level.

In one embodiment, the dehydration and heat treatment steps are performed simultaneously. This step step may be carried out as part of a series of steps involving the extraction of starch or flowers from plant material.

The heat-suppressed starches and flowers of the present invention are granules and can be derived from any natural resource. This natural resource includes bananas, corn, pea, potatoes, sweet potatoes, burley, whit, rice, sago, amaranth, tapioca, soybean gum, waxy maize, waxy rice, waxy burley, waxy potato, waxy soybean gum, starch containing high amylose, etc. It is possible. Suitable starches are waxy starches such as waxy maize, waxy rice, waxy potatoes, waxy saw gum and waxy burley. Unless otherwise specified, reference to starch herein is meant to include its corresponding flower. Reference to starch means that it also includes protein-containing starch, which is an endogenous protein as well as additional proteins derived from animal or plant resources, such as zein, albumin and soybean proteins.

Natural starch as used herein refers to those found in nature. The starch may be natural starch or modified by enzyme, thermal or acid conversion, oxidation, phosphorylation, etherification (particularly hydroxyalkylation), esterification, and chemical cross-linking.

In the first step of this method for achieving heat suppression, the starch is dehydrated at a time and temperature sufficient to make it anhydrous or substantially anhydrous. In the second step, this anhydrous or substantially anhydrous starch is heat treated for a time and temperature sufficient to suppress it.

When starch is exposed to heating in the presence of water, acid hydrolysis or decomposition of starch can occur. Hydrolysis or degradation will interfere with or prevent inhibition. Therefore, the conditions for the hydrolysis of starch need to be chosen so that the inhibition will overcome the hydrolysis or decomposition. Any condition that meets this criterion is available, but a suitable condition consists of dehydration at low temperature or raising the pH of the starch prior to dehydration. This suitable condition consists of a combination of low temperature and neutral to basic pH.

Preferably, the temperature at which the starch is dehydrated is kept below 125 ° C, and more preferably at a temperature of 100-120 ° C, or within that temperature range. The dehydration temperature may be less than 100 ° C, but temperatures above 100 ° C may be more effective in removing water.

A suitable pH is 7 or higher, generally pH 7.5 to 10.5, preferably 8 to 9.5, and most preferably greater than pH 8. At pH higher than 12, it becomes easier to gelatinize. Therefore, pH adjustment below 12 is more effective.

To adjust the pH, granule starch is slurried in water or other aqueous medium, generally at a ratio of 1.5-2.0 parts water to 1.0 part starch, and the pH is added with any suitable base. Raise by. A buffer, such as sodium phosphate, may be used to maintain pH if necessary. The starch is then dehydrated and dried, or directly dried to a moisture content of 2-6%. Such a drying procedure is distinct from the steps of a heat suppression step in which the starch is dehydrated to an anhydrous state. On the other hand, powdered starch is sprayed with a solution of base until the starch reaches the desired pH, or an alkaline gas, such as NH.₃May be injected into starch.

For food applications, food grade bases suitable for use in the pH adjustment phase are, but are not limited to, sodium hydroxide, sodium carbonate, sodium pyrophosphate, ammonium orthorate, disodium orthophosphate, triphosphate. Contains sodium, calcium carbonate, calcium hydroxide, potassium carbonate and potassium hydroxide, as well as any other base approved for food use under the Food and Drug Administration Act or other food regulation laws. .. Bases not approved under these regulations may also be utilized provided that they are washed away from the starch and therefore the final product is consistent with good manufacturing practices for food applications. A suitable food grade base is sodium carbonate. It should be noted that the texture and viscosity advantages of the heat suppression process tend to increase with increasing pH, but higher pH tends to increase the browning of starch during the heat treatment process.

If starch is not used for food, any effective or suitable inorganic or organic base that can increase the pH of starch may be used.

After dehydration, the starch is heat treated for a time effective to suppress it and at a temperature or temperature range. A suitable heat range is a temperature or temperature range above 100 ° C. For practical purposes, the upper limit of the heat treatment temperature is usually around 200 ° C, at which highly suppressed starch can be obtained. Generally, the heat treatment is performed at 120 to 180 ° C, preferably 140 to 160 ° C, and more preferably 160 ° C. The time and temperature profile will depend on the desired level of inhibition.

For most industrial applications, the dehydration and heat treatment steps are continuous and accomplished by thermal application of starch starting from ambient temperature. In most cases, the water will be expelled before the temperature reaches about 125 ° C, and the starch will be anhydrous or substantially anhydrous. If the starch reaches anhydrous or substantially anhydrous and continues to be heated, some level of inhibition will be achieved as soon as or even before the final heat treatment temperature is reached. Usually, at such an initial suppression level, the peak viscosity is higher than that of the suppression level reached by the longer heat treatment time, however there will be a greater reduction in viscosity from the peak viscosity. As the heat treatment continues, the peak viscosity decreases, but the decrease in viscosity decreases.

The pH is adjusted above pH 8 to achieve suppression when moisture is present during the heat treatment step, and especially when the heat treatment step is carried out at high temperatures.

Starch resources, dehydration conditions, heating time and temperature, initial pH, and the presence or absence of water during the treatment phase are all variable factors that affect the degree of inhibition that can be achieved. All of these factors are interrelated, and the tests of the examples show that various variable factors influence the regulation of inhibition levels, as well as the regulation of texture and viscosity properties of the inhibitory product.

These starches can be suppressed individually or multiple ones at the same time. These starches may be suppressed in the presence of other materials or ingredients that do not interfere with the heat suppression process or alter the properties of the starch product.

The process steps may be carried out under normal pressure, vacuum or pressurization and may be accomplished using any means known to those of skill in the art, however, a preferred method is dry heating in the atmosphere or in an inert aerobic environment. Depends on application.

Following the heat treatment step, the starch may be screened to select the desired particle size, slurried in water and washed, filtered, then dried or otherwise purified. The pH may be adjusted as desired. In particular, the pH may be readjusted to the natural pH of the starch. The heat-suppressed starch may be pregelatinized to disintegrate the granules after this heat-suppressing step.

This heat suppression step is used for other starch reactions used to modify starch for commercial use, such as heating or acid conversion, oxidation, phosphorylation, etherification (especially hydroxyalkylation), esterification and Can be used with chemical cross-linking. Usually, these modifications are performed before the starch is heat-suppressed, but may be performed after the fact.

Dehydration and heat treatment equipment can be industrial ovens such as conventional ovens, microwave ovens, dextrinizers, fluidized layer reactors and dryers, mixers and blenders with heaters, and other types of heaters, but this. The device is required to have a vent to the air to prevent water buildup and settling on the oven. Preferably, the device is equipped with a means for removing water vapor from the device, such as a vacuum device or blower that expels air from the device's headspace, or is flowing a fluid gas. The heat treatment step may be accomplished in the same equipment as the dehydration step, and most conveniently is continuous with the dehydration step. When the dehydration step is continuous with the heat treatment step, and especially when the dehydration and heat treatment device is a fluidized bed reaction reactor or dryer, the dehydration step is performed at the same time as the device is brought to the final heat treatment temperature.

Excellent heat-suppressed starch with a high viscosity of 0 or a low percentage drop is obtained in a fluidized bed reactor in less time than can be achieved using other conventional heating ovens. .. Suitable fluid gases are air and nitrogen. For safety reasons, it is preferable to use a gas containing less than 12% oxygen.

Conventional ovens can be used to provide good heat suppression products that are acceptable for a wide range of applications. The temperature of this device should be adjusted to 120-180 ° C, preferably 140-160 ° C, and most preferably about 160 ° C to obtain a heat-suppressed starch product. At a temperature of 160 ° C, the heating step is preferably carried out for 3.5 to 4.5 hours. Depending on the precise temperature selected, batch size, pH, choice of starch or flower to use, and other factors, the heating step may be carried out for about 1-20 hours.

In one particular embodiment, the inert thermostable starch adjusts the pH of natural granular starch with a water content of 0-12 wt% to a pH higher than 8.0 by the addition of a base, then at 120-180 ° C. It is made by heating for 1 to 20 hours. As mentioned earlier, moisture is expelled during this heating, and the heat treatment step is carried out with anhydrous or substantially anhydrous starch or flower. On an industrial scale using a conventional oven, heating for 4-5 hours may be required to equilibrate the starch temperature to 160 ° C before performing the heating step.<u style="single">Determining the characteristics of suppression by texture</u> Starch or flower with a low to moderate degree of inhibition will exhibit constant texture properties when heated to disperse and gelatinize in an aqueous medium. In the following examples, these samples are determined to be suppressed when the heat gelatinized slurry of the sample exhibits a non-adhesive, smooth texture.<u style="single">Suppression characterization by lavender data</u> The characteristics of the heat-suppressed starch are determined in detail by referring to the measured value of its viscosity after being dispersed in water and gelatinized. The device used to measure the viscosity is VISCO / Amylo / GRAPH (manufactured by CW Brabender instruments, Inc., Hackensack, NJ). VISCO / Amylo / GRAPH records the torque required to balance the viscosities that occur when starch slurries are subjected to a programmed heating cycle. For unsuppressed starch, the cycle usually begins with an increase in viscosity at about 60-70 ° C, the development of peak viscosities in the range 65-95 ° C, and the starch to a high temperature of usually 92-95 ° C. It undergoes an arbitrary decrease in viscosity when maintained. This record is an arbitrary unit of measure expressed in lavender units (BU) and consists of a curve that tracks the viscosity throughout the heating cycle.

Suppressed starch will show a lavender curve that is different from the curve with the same unsuppressed starch (hereafter, control starch). At low levels of suppression, the suppressed starch will reach a peak viscosity slightly higher than the peak viscosity of the control, and there will be no reduction in% decrease in viscosity compared to the control. As the degree of inhibition increases, the peak viscosity and the decrease in viscosity decrease. At high levels of inhibition, the rate of gelatinization and the swelling rate of the granules decreased, the peak viscosity disappeared, and upon prolonged heating, the lavender traces drew an ascending curve, suggesting a slow, continuous increase in viscosity. At very high levels of inhibition, the starch granules are no longer gelatinized, and the lavender curve remains flat.<u style="single">Sample preparation</u> All starch and flowers used were provided as granules and, unless otherwise noted, by the National Starch and Chemical Company in Bridgewater, NJ.

Controls for the test sample were derived from the same natural resources as the test sample and were either unmodified or modified as the test sample and at the same pH unless otherwise noted.

All starches or flowers in both the test and control samples were individually prepared and tested.

For the pH of the sample, starch or flower is slurried in water with a solid content of 30-40%, then a sufficient amount of 5% sodium carbonate solution is added until the desired pH is reached.

All samples were spray-dried or flush-dried (without viscous) to approximately 2-15% moisture as is customary in the industry.

The control sample was not further dehydrated or heat treated.

The pH of the samples before and after the heat suppression step was measured with a sample consisting of 1 part of anhydrous starch or flower, paired with 4 parts of water.

Except when characterizing a conventional oven or dextrinizer, test samples were dehydrated and heat treated in a fluidized bed reactor model No. FDR-100 manufactured by Procedyne Corporation in New Brunswick, NJ. The cross-sectional area of the fluidized bed reactor was 0.05 square meters. The height of the starting layer was 0.3 to 0.8 meters, but it is usually 0.77 meters. Unless otherwise noted, the fluid gas was air and used at a speed of 5-15 m / min. The sidewalls of the reactor were heated with hot oil, and the fluid gas was heated with an electric heater. Samples were placed in the reactor and then either introduced with fluidized gas or loaded with fluidized gas. No difference was observed in the samples in the order of loading. The sample was brought to 125 ° C from ambient temperature until anhydrous and then heated to a specific heat treatment temperature. When the treatment temperature was 160 ° C, the time required to reach that temperature was within 3 hours.

The water level of the sample at the final heating temperature was set to 0% unless otherwise specified. A portion of the sample was taken and tested for inhibition at the temperature and time shown in the table.

These samples were tested for inhibition using the following lavender procedure.<u style="single">Lavender procedure</u> Unless otherwise noted, the following lavender procedure was used. All samples except corn, tapioca and waxy rice flowers were slurried in an amount of distilled water sufficient to make an anhydrous starch slurry with a solid content of 5%. Corn, tapioca and waxy rice flowers were slurried at 6.3% anhydrous solids. The pH was adjusted to pH 3.0 with sodium citrate citrate buffer and the slurry was placed in a sample cup of lavender VISCO / Amylo / GRAPH with a 350 cm / g cartridge. The starch slurry was rapidly heated to 92 ° C and kept for 10 minutes. The peak viscosity and the viscosity 10 minutes after the peak viscosity were recorded in lavender units (BU). The percent decrease in viscosity was calculated according to the following formula:

<maths num="1"><img file="JP4891007B2_D0001.tif" /></maths>

The "peak" is the peak viscosity in lavender units, and the "(peak +10')" is the viscosity in lavender units 10 minutes after the peak viscosity.

When the peak viscosity was not reached, i.e. when the data showed an ascending curve or a flat curve, the viscosity at 92 ° C and the viscosity 30 minutes after reaching 92 ° C were recorded.

Using data from the Brabender curve, suppression was performed during the Brabender heating cycle when the suppression was dispersed in water at pH 3 at 92-95 ° C with a solid content of 5-6.3%. , (I) No or almost no increase in viscosity (indicating that the starch was suppressed and did not gelatinize or strongly tolerated gelatinization); (ii) Continuously increasing viscosity without peak viscosity (Standing Highly suppressed and gelatinized to a certain degree); (iii) Low peak viscosity and low percent decrease in viscosity compared to controls (showing moderate suppression); or (iv) It was determined that there was inhibition when a slight increase in peak viscosity and a lower percentage decrease (indicating a low level of inhibition) compared to the control were shown.

In the first three cases, the indicated moisture is the moisture in the starch before the dehydration and heat treatment steps. As mentioned above, starch becomes anhydrous or substantially anhydrous when it is heated from ambient temperature to heating temperature. Example 1 This example illustrates the preparation of the starch of the present invention from commercially available granular waxy maize starch by the heat treatment method of the present invention.

The process conditions and their effects on the viscosity and texture of waxy maize starch are shown in Tables I and II below.

To obtain a thermostable non-stick thickener, a sample of granular starch was slurried in 1.5 parts of water and the pH of the slurry was adjusted to 5% Na₃CO₃It was adjusted by the addition of a solution, then the slurry was stirred for 1 hour, then filtered, dried and ground. A dry starch sample (150 g) was placed in an aluminum foil pan (4 × 5 × 1.5 ) and heated in a conventional oven under the conditions described in Tables I and II. Lavender viscosity measurements showed that the most thermostable starch was obtained by heating at 160 ° C and at least 8.0 pH for about 3.5-6.0 hours.

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^a. All samples were commercial samples of granular waxy maize starch obtained from the National Starch Chemical Company in Bridgewater, NJ.^b. The unmodified control was commercially available granular waxy maize starch obtained from the National Starch Chemical Company in Bridgewater, NJ.^c. The modification control was commercially available crosslinked (phosphorus oxychloride treated) granule waxy maize starch obtained from the National Starch Chemical Company in Bridgewater, NJ.^d. Samples were cooked by slurping 7.0 g of starch (12% water) in 91 ml of neutral pH water and then heating this starch slurry in a boiling water bath for 20 minutes.^e. The low temperature evaluation was carried out at 25 ° C.

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^a. See Table I for sample details.^b. In the lavender procedure, a sample containing anhydrous starch with a solid content of 5.4% dispersed in water was rapidly heated to 50 ° C, then the heat was raised to 95 ° C at 1.5 ° C per minute. And it was kept at that temperature for 20 minutes. Example 2 This example illustrates that various starches can be treated by the methods of the invention to provide non-adhesive thickeners with properties similar to chemically crosslinked starches.

The process conditions and their effects on the viscosity and texture of waxy burley, tapioca, VO hybrid and waxy rice starch are shown in Tables III and IV below.

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^a. The tapioca starch sample was a commercially available granular starch obtained from the National Starch Chemical Company in Bridgewater, NJ. The waxy barley starch sample was a commercially available granular starch obtained from Alko, Finland. The waxy rice starch sample was a commercially available granular starch obtained from Mitsubishi Corpoaition in Japan.^b. Samples were made into a 7.5 g starch 20 slurry with 12% water content in 100 ml of water and then cooked by heating this starch slurry in a boiling water bath for 20 minutes.

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^a. The VO hybrid starch sample was granular starch obtained from the National Starch Chemical Company in Bridgewater, NJ.^b. Samples were cooked by slurrying 7.5 g of starch with 12% water content in 100 ml of water and then heating this starch slurry in a boiling water bath for 20 minutes.

The results of viscosity and texture evaluation indicate that a non-adhesive, heat-stable starch thickener can be prepared from waxy burley, VO hybrid, tapioca and waxy rice starch by the method of the present invention. The degree of inhibition (non-adhesive thickening property in the cooked aqueous dispersion) increased as the heat treatment time was extended. Example 3 This example illustrates the effects of temperature and pH and starch moisture content on the viscosity and texture of treated starch.<u style="single">Part A:</u> A 20.4% water-containing waxy maize starch sample (100 g) was placed in an oven at 100 ° C for 16 hours in a glass jar with a lid and heated. Under the same conditions, the second sample was heated for 4 hours, and the third sample was heated for 7 hours. The viscosity and texture of the product was compared to the Granular Waxy Maze Starch Control with 12.1% Moisture using the cooking evaluation method in Table I of Example 1. The results are shown in Table V below.

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^a. Samples were obtained from the National Starch Chemical Company in Bridgewater, NJ.^b. The step was performed at pH 5.2.^c. See Table III for cooking conditions.

These results showed that the water added during this step resulted in a product that was as sticky and undesired as untreated control starch.<u style="single">Part B:</u> A sample (900 g) of commercially available granular waxy maize starch (obtained from the National Starch Chemical Company in Bridgewater, NJ) was placed in a 10 × 15 × 0.75 aluminum tray and placed in an oven at 15,30. Heated at 180 ° C for 45 and 60 minutes. The pH of the starch was not adjusted and remained at about 5.2 during the heating process. The viscosity and texture of the sample were evaluated by the method of Example 1.

As shown in Table VI below, the pH 5.2 sample featured an undesired sticky texture similar to that of unheat-treated Waxy Maze Starch Control.

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^a. The pH is not adjusted from that of natural waxy maize starch (pH = 5.2), and Samples 1-4 correspond to starch processed by the process of US Pat. No. 4,303,451 (no pH adjustment).^b. See Table III for cooking conditions.

Therefore, the combination of selection factors, including pH, water content and type of natural starch, determines whether the method of the present invention can produce the desired non-adhesive thermostable starch thickener.

The heat-suppressed starches and controls of the following examples are prepared as described above and defined by texture properties or by association with data obtained from the lavender curve using the procedure described above. Example 4 Tapioca, Waxy Maze and Waxy Rice Flower: Tracing of Suppression by Lavender Procedure Samples of tapioca starch, waxy maize starch and waxy rice flowers with pH 9.4-9.6 were dehydrated to less than 1% water content at temperatures below 125 ° C and equilibrated to 160 ° C, then thermal reactor (horizontal). Heated at 160 ° C in a tank with a double ribbon jacket. The heat treatment time of the sample was in the range of 3 to 6 hours.

Samples were evaluated for inhibition according to the Bubender procedure above, and the results are shown in the table below. Dehydrated and heated starches and flowers exhibited reduced viscosity compared to dehydrated and unheated controls. This inhibition correlates with the brittle, non-stick texture in the cooled product.

<tables num="7"><img file="JP4891007B2_D0008.tif" /></tables>

Example 5 Waxy Maze: Effect of Initial pH and Heating Time The effect of initial pH and heat treatment time on the level of inhibition levels on samples of waxy maize starch at natural pH (about 6.0) and pH 7.5, pH 8.5 and pH 9.5 was evaluated and the data in the table below were evaluated. Is shown. This data shows that starches with different levels of suppression reflected by fluctuations in percent decrease in viscosity are obtained at different heating times and initial pH, and that higher suppression is obtained at higher pH values and longer heating times. Show that it can be done. Furthermore, comparing the shortened heat treatment times in this example using a fluidized bed reactor with the heat treatment times in hours in Examples 4 and 5, a fluidized bed was used rather than possible in a standard thermal reactor or oven. It can be seen that a suppressed starch with a higher peak viscosity can be obtained in a much shorter time.

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Example 6 Waxy Maze: Effect of Heating Temperature and Time The effect of heat treatment temperature and time on the level of inhibition on waxy maize starch at pH 9.5 was evaluated and the results are shown in the table below. This data shows that suppression samples are obtained at heat treatment temperatures of 100-200 ° C, with further suppression at higher temperatures or at lower temperatures for longer periods of time. Starch samples heated at 200 ° C were highly suppressed (rising curve) or completely suppressed (not gelatinized).

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Example 7 Waxy Maze: Effect of Moisture and pH Waxy maze starch with an initial pH of 9.5 was evaluated for suppression in the presence of 1 to 2 samples by weight% of water by injecting saturated air into the chamber of the fluidized bed reactor. The results are shown in the table below and show that heat treatment of starch under anhydrous or substantially anhydrous conditions is more strongly suppressed than heat treatment in the presence of moisture (for anhydrous samples). Note the low percentage of viscosity reduction).

<tables num="10"><img file="JP4891007B2_D0011.tif" /></tables>

<tables num="11"><img file="JP4891007B2_D0012.tif" /></tables>

Example 8 Corn Starch: Effect of pH and heating time at 160 ° C The effects of initial pH and heat treatment time at 160 ° C on the suppression levels of corn starch samples at natural pH and initial pH 9.5 were evaluated and the results are shown in the table below. This data shows that very high levels of inhibition (notice the increase in viscosity) are obtained at basic pH compared to natural pH, and stronger inhibition is obtained with longer heat treatment times.

<tables num="12"><img file="JP4891007B2_D0013.tif" /></tables>

Example 9 Potato Starch: Effect of pH The effect of initial pH on the level of inhibition on samples of potato starch at natural pH and initial pH 9.5 was evaluated and the results are shown in the table below.

Lavender data at natural pH suggested that starch degradation, rather than suppression, occurred as the heat treatment proceeded. This example shows that heat suppression can be correlated with both pH and starting starch. In this case, it was revealed that the heat suppression of potato starch was more dependent on pH than other starches (for example, waxy maize). Therefore, the conditions required for dehydration of potato starch and effective heat suppression are more stringent to avoid hydrolysis and decomposition.

However, dehydration and heat treatment in the basic pH range provided suppressed starch that remained highly viscous, and heat treatment times longer than 90 minutes provided highly suppressed starch, as indicated by the ever-increasing viscosity. ..

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Example 10 Waxy Maze with Endogenous Protein Effect of protein, time and temperature Protein presence and heat treatment for inhibition on samples of Waxy Maze containing 3.95% endogenous protein and adjusted to pH 8.5 and 9.5, and samples containing 1.52% endogenous protein and adjusted to pH 7.5 and 9.5. The effects of time and temperature are evaluated and the results are shown in the table below. This data showed that the presence of protein resulted in higher levels of inhibition than reached in protein-free samples. The results also show that protein levels, pH and heat treatment time and temperature all have independent and cumulative suppression level effects, and therefore suppression increases with increasing protein, pH, time and temperature.

<tables num="15"><img file="JP4891007B2_D0016.tif" /></tables>

<tables num="16"><img file="JP4891007B2_D0017.tif" /></tables>

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Example 11 Waxy Maze Replaced with Propylene Oxide: Effect of etherification and pH Waxy maze samples reacted with 7 and 3 wt% propylene oxide at natural pH and pH 9.5 were evaluated for inhibition and the results are shown in the table below.

This data shows that the substituted starch (in this case, etherified starch) is heat-suppressed by this method, and higher suppression can be achieved at higher pH.

In addition to propylene oxide, other suitable etherifying agents known and used in the art can be used to ethereate starch before and after heat suppression. Typical etherifying agents are acrolein, epichlorohydrin and combinations of epichlorohydrin and propylene oxide.

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Example 12 Waxy Maze Substituted with Acetyl Group: Esterification and pH effect Waxy maze samples at natural pH and pH 8.5 reacted with 1 wt% acetic anhydride were evaluated for inhibition and the results are shown in the table below.

This data shows that substituted starch (in this case esterified starch) can be suppressed to varying degrees and more strongly at higher pH.

In addition to acetic anhydride, other common esterifying agents known and used in the art can be used to esterify starch before and after heat suppression. Typical esterifying agents are acetic anhydride, acetic anhydride in combination with adipic anhydride, orthophosphoric acid-sodium, 1-octyl succinic anhydride, 1-octyl succinic anhydride in combination with aluminum sulfate, phosphorus oxychloride. , A combination of phosphorus oxychloride and either acetic anhydride or vinyl acetate, sodium trimetaphosphate, a combination of sodium trimetaphosphate and sodium tripolyphosphate, succinic anhydride and vinyl acetate.

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<tables num="22"><img file="JP4891007B2_D0023.tif" /></tables>

Example 13 POCL₃Waxi Maze cross-linked with: Crosslinking and pH effects POCL at 0.02% by weight₃Waxy maze samples of natural pH and pH 9.5 crosslinked by are evaluated for inhibition and the results are shown in the table below. The data show a decreasing viscosity, and increasing the heat treatment time almost eliminates the decrease in viscosity, suggesting that crosslinked starch can be further suppressed by this method. The data also show that increasing pH further increases inhibition.

<tables num="23"><img file="JP4891007B2_D0024.tif" /></tables>

Example 14 Waxy Maze: Fluid N₂ NH₃ Preparation of starch pH in fluidized bed by spraying A waxy maze sample with an initial water content of 10.9% was introduced into a fluidized bed reactor with a nitrogen fluidized gas containing the concentrations shown in the table. These samples were evaluated for the effect of ammonia gas on suppression levels. Comparing the results with those obtained in Example 5 at pH 9.5, it can be seen that ammonia gas is effective in increasing the pH of starch and inhibiting hydrolysis, but hydrolysis and inhibition. Direct pH adjustment of starch was not effective in promoting starch.

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Example 15 Waxi Maze: Na₂CO₃Adjustment of pH in the fluidized bed by spraying Waxy maze samples were introduced into a fluidized bed reactor and sprayed with a 25% sodium carbonate solution, and at the same time a fluidized gas was introduced to raise the pH. The sample was then raised from ambient temperature to 160 ° C within 3 hours and kept at 160 ° C for the time shown in the table.

Samples were evaluated for suppression. This data shows that this technique is effective in raising the pH of a sample to prevent acid hydrolysis and promote suppression.

<tables num="26"><img file="JP4891007B2_D0027.tif" /></tables>

Example 16 Waxy Maze: Effect of Fluid Gas For waxy maze samples at pH 9.5 fluidized with nitrogen gas and air, the effect of the fluid gas on suppression levels was evaluated. Samples are tested for suppression, and data show that higher suppression rates can be achieved when air is used as the fluid gas compared to nitrogen.

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Example 17 Effect of high amylose content Samples of high amylose-containing starch (Hylon V) at natural pH and pH 9.5 were evaluated for their effect on suppression of high amylose content. High levels of amylose required the use of pressurized visco / amylo / Graph (CWBrabender, Hackensack, NJ) to obtain the lavender curve. Samples were slurried with 10% starch solids, heated to 120 ° C and kept for 30 minutes. This data shows that inhibition was obtained only in high pH samples.

<tables num="28"><img file="JP4891007B2_D0029.tif" /></tables>

Example 18 Waxy Maze and Tapioca: Substitution Samples of waxy maze and tapioca starch were slurried in 1.5 parts of water. The slurry was placed in a hot water bath at 52 ° C, stirred and equilibrated over 1 hour. Concentrated HCl was added to 0.8% of the weight of this sample. This sample was transformed at 52 ° C for 1 hour. The pH was then adjusted to 5.5 with sodium carbonate and then to pH 8.5 with sodium hydroxide. This sample was collected by filtration and air dried (approximately 11% moisture). A 50 g amount of starch was placed in an aluminum tray, covered and placed in a forced draft oven at 140 ° C for 5.5 hours. This starch was evaluated for inhibition and the results are shown in the table below, indicating that this method of converted starch can be thermally suppressed.

<tables num="29"><img file="JP4891007B2_D0030.tif" /></tables>

Example 18 Use of natural pH heat-suppressed waxy maze in foods This example describes the preparation of a barbecue sauce containing heat-suppressed waxy maize starch (TI starch) at natural pH (pH 6) that has been heat-treated at 160 ° C for 150 minutes. The ingredients in% by weight are:

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The sauce was heated to 85 ° C, kept for 15 minutes and cooled to room temperature overnight. This sauce had a smooth, non-sticky texture.<u style="single">Description of use</u> Granular heat-suppressed starch prepared by this method can be used in foods or industrial products using chemically crosslinked starch. The main advantage of these starches is that they have the inhibitory properties of chemically crosslinked starches, without the use of chemical reagents. A further advantage is that these heat-suppressed starches and flowers are substantially sterilized by the heat-suppressing treatment and remain sterile when properly stored. It is also advantageous in that when starch having natural ligation-dissolving stability is heat-suppressed by this method, the heat-suppressed starch remains freeze-dissolving stability.