RU2810087C1 - Method for producing high amylose potato starch - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: method for producing high-amylose potato starch involves preparing an aqueous suspension from native potato starch and ultrasonic treatment. In this case, a 4% aqueous suspension is prepared from starch at a temperature of 34-37°C. The resulting suspension is stirred for 3 minutes and treated with ultrasound at a frequency of 22 ± 1.65 kHz and a power of 409.5 W for 10 minutes at a temperature of 34–37°C. Then it is centrifuged at a speed of 6000 rpm for 10 minutes and dried at a temperature of 30-40°C up to humidity 17-20%.

EFFECT: expanding the scope of methods for producing high-amylose starch, which has an increased degree of resistance due to ultrasonic exposure, which can be used in food methods.

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Description

The invention relates to the food industry, and more specifically to methods for producing modified starches with an increased proportion of amylose fraction based on ultrasonic exposure.

The present invention can be used as a method for obtaining a functional ingredient in food system technologies (confectionery, bakery, dairy, meat and others).

A generalized scheme of the process of isolating starch from starch-containing raw materials is known, shown in Fig .

Modification of starches used for the food industry is carried out using known methods: chemical, physical and enzymatic, which, as a rule, change the technological properties and consumer characteristics (viscosity, gelatinization, texture, hydrophilic properties) in different ways.

As a rule, in most of the approaches used, changes in the properties of the fractional composition, in particular, the presence of the proportion of resistant starch, are not observed. This fraction determines the functional properties of food systems.

Resistant starch (RS), defined as resistant to digestion in the human small intestine, is a type of dietary fiber, providing a lower glycemic index in foods containing it. In fact, during the modification process, the amylose fraction of starch increases, not only quantitatively, but also qualitatively, due to the rearrangement of the molecule. It has been established that RS, upon reaching parts of the large intestine, forms butyrates (butyric acid), thereby reducing the pH level, reducing the risk of inflammation, and, as a result, the risk of developing colorectal cancer. An important property of RS. for food systems technology is its high thermal stability.

All resistant (resistant starches) are systematized, taking into account the degree of their availability for digestion, into five types:

1. RS1 - is not physically available for digestion, mainly because it is surrounded by cell walls or other tissues that prevent contact and reaction with enzymes. RS1 is unstable, and fine grinding or deep processing destroys its structure; it is usually found in partially ground grains, seeds or tubers.

2. RS2 refers to native starch with a compact structure, the granules of which are relatively dehydrated. RS2 is densely packed radially within raw starch granules, limiting access to digestive enzymes and most amylases. RS2 is found in raw potatoes, peas and green bananas.

3. RS3 consists of retrograde starches, which are basically recrystallized amylose obtained after cooking and cooling starchy foods. RS3 refers to physically modified starches, which are mainly formed through the process of gelatinization and retrogradation during food processing and production.

4. RS4 generally refers to a chemically modified starch with an altered molecular structure that contains new chemical linkages rather than α-(1-4)- or α-(1-6)-glycosidic linkages and thus exhibits increased resistance to amylolytic enzymes.

5. RS5 is an amylose-lipid complex that forms a helical structure that prevents the breakdown of amylose. Lipids bind to the amylose in the starch granule, preventing its expansion and providing resistance to enzymatic hydrolysis. Such amylose-lipid complexes are usually formed from starches with high amylose content.

To enhance the resistance of starches, various substances that are rich in lipids are added, which allows the formation of a complex of amylose with lipids, forming a structure that includes the RS5 type of resistant starch.

Another way to increase the resistance of native starches is to add cell wall substances to native starch, resulting in RS1 type resistance.

These known methods for producing resistant starch products are described by the authors of patent RU 2759286 C1. Where flax seeds and/or flaxseed powder and/or flaxseed mucilage extract are used as a substance that increases the resistance of native starches. In this case, mechanical mixing is carried out for 1-5 minutes at 1000-3000 rpm. With subsequent single extrusion processing on a single- or twin-screw extrusion unit at a temperature of 100-140°C, screw rotation speed 50-100 rpm, die diameter - 1-6 mm, followed by crushing in a hammer crusher to particles of size 0. 1-1.0 mm, sifting through a sieve with holes no more than 1.0 mm and carrying out magnetic separation using permanent magnets, while the thickness of the product layer is 6-8 mm, and the speed of passage of the layer through magnets is no more than 0.5 m/s. This invention makes it possible to develop a resistant starch product. The disadvantage of this method is the change in the nutritional value of the starch product due to the use of excipients.

Another known method for producing resistant phosphorylated starch (RU 2771048 C1), which involves treating starch with sodium tripolyphosphate. A 50 g sample of starch is dispersed in distilled water by stirring for 60 minutes at a temperature of 25°C. Then an aqueous solution of sodium tripolyphosphate (2 ml) is added dropwise to the stirred suspension, adjusted with a 0.5 N HCl solution to pH 6 and stirred for another hour. After sedimentation, the suspension is washed from acid four times with distilled water and once with ethanol. The supernatant suspension is centrifuged using a benchtop centrifuge at 7000 rpm for one minute and the resulting precipitate is dried to constant weight at 40°C. The invention is aimed at developing phosphorylated starch with a low glycemic index of products, which characterizes the gradual release of glucose over a long time. The disadvantage of this method can be considered the use of chemicals when modifying starch, which affects the environmental friendliness of this product, which also limits its use in some products, including specialized and functional ones.

Another method for producing starch enriched with resistant starch (patent RU 2544058 C2) involves treating amylose-rich starch with an amylose content of 40% or more by acid treatment in an aqueous solution of inorganic acid. In this case, the acid treatment is carried out under reaction conditions specified by the ratio expressions. The disadvantage of this method is the complexity of the process, as well as the use of chemicals.

The closest in essence is the method for producing modified starch, which was patented by scientists E.P. Tyurev, S.V. Zverev, O.V. Tsygulev. (patent No. RU 2078087). This method of producing starch includes pre-treatment of native starch and the formation of a starch extruder, wherein the pre-treatment is carried out with a solution of starch paste or gelatin, and the starch extruder is subjected to secondary heating using an IR emitter as a heat source. In this case, a 0.3 - 0.7% aqueous solution of starch paste or gelatin is used, and secondary heating is carried out at a temperature of 15-18 ° C. However, the technological parameters of this method do not allow increasing the resistant properties of native starches.

The technical task and technical result of the proposed invention is to expand the arsenal of methods for producing high-amylose starch, which has an increased degree of resistance due to ultrasonic exposure, which can be used in food system technologies (confectionery, bakery, dairy, meat and others).

The technical problem and result of the proposed method is achieved due to the fact that the method for producing high-amylose potato starch includes the preparation of an aqueous suspension from native potato starch and its ultrasonic treatment, while a 4% aqueous suspension is prepared from starch at a temperature of 34-37 ° C, the resulting suspension stirred for 3 minutes and treated with ultrasound with a frequency of 22 ± 1.65 kHz and a power of 409.5 W for 10 minutes at a temperature of 34-37 ° C, then it is centrifuged at a speed of 6000 rpm for 10 minutes and dried at temperature 30-40°C to humidity 17-20%.

Based on the use of low-frequency ultrasound (USV) to modify starch, with variations in duration and power, cavitation effects are observed, which cause erosion and the formation of pores on the surface of starch granules, and this in turn leads to the destruction of α-1,6 bonds, while there is an increase in the content of the amylose fraction, which directly related to the amount of resistant starch.

It has been experimentally established that:

- with ultrasonic treatment for more than 10 minutes (at a power of 409.5 W), α-1,6-bonds are destroyed and the crystal structure is destroyed, and the size of starch granules changes, since part of the released amylose goes into solution, a micronization effect will take place here ;

- with USV for less than 10 minutes (at a power of 409.5 W) it does not give the effect of increasing the starch grain in volume, while α-1,6-bonds are not destroyed, no structural changes are observed in the starch grain, therefore it is not advisable.

The technology for implementing this method is as follows. A 4.0% aqueous suspension at a temperature of 34-37°C is prepared from potato starch. Next, the resulting suspensions were treated with ultrasound in a cooling jacket (to prevent heating of aqueous suspensions above the specified temperatures and swelling of starch grains) for 10 minutes at a power of 409.5 W, on an acoustic source of elastic vibrations - an ultrasonic device "Volna", model UZTA-0.63/22-OM, operating at a frequency of 22 ± 1.65 kHz and an output power of no more than 630 W. A 4.0% aqueous starch suspension without RAS treatment was taken as a control sample to compare the properties of the proposed method for producing high-amylose starch. Table 1 shows the modification parameters of potato starch obtained by the proposed method.

Example 1. 4.0 grams of native potato starch is placed in a vessel, 100 ml of prepared (purified) water is poured at a temperature of 34-37 ° C and mechanically stir for 3 minutes. The resulting 4.0% aqueous suspension is treated with ultrasound on a Volna device, model UZTA-0.63/22-OM, at a frequency of 22 ± 1.65 kHz with a power of 409.5 W for 10 minutes with temperature control - 34-37 °C (to prevent heating of aqueous suspensions and swelling of starch grains). RAS-treated suspensions were centrifuged at 6000 rpm for 10 min. Then they were dried at a temperature of 30 - 40 ° C, to a moisture content of 17-20%, the moisture content of a commercial product. To study the effect of RAS, amylose was isolated from the resulting modified starch using differential scanning spectrophotometry (Table 1).

Example 2. 4.0 grams of native potato starch is placed in a vessel, 100 ml of prepared (purified) water is poured at a temperature of 34-37 ° C and mechanically stir for 3 minutes. The resulting 4.0% aqueous suspension is treated with ultrasound on a Volna device, model UZTA-0.63/22-OM, at a frequency of 22 ± 1.65 kHz and an exposure power of 630 W for 10 minutes with temperature control at 34-37° C (to prevent heating of aqueous suspensions and swelling of starch grains). Processed The RAS suspension was centrifuged at 6000 rpm for 10 min. Then it was dried at a temperature of 30-40°C, to a moisture content of 17-20%, the moisture content of a commercial product. To study the effect of RAS, amylose was isolated from the resulting modified starch using differential scanning spectrophotometry (Table 1).

All declared parameters of the process for obtaining modified starch (concentration of starch suspension, ultrasonic treatment modes (time, power, temperature), other modes of the method were selected experimentally from the conditions that ensure the most effective implementation of the starch modification process to obtain a technical result (Table 1).

Table 1 - Potato starch modification parameters Sample name Indicators Temperature,
°C Particle size range, microns Amylose content, 625 nm RAS time 5 min,
power 630 W 34.5±0.3 45.26…29.59 0.1590 RAS time 10 min,
power 630 W 35.8±0.2 49.63…30.23 0.4100 RAS time 15 min,
power 630 W 36.5±0.3 46.08…23.22 0.4000 RAS time 5 min, power 409.5 W 34.1±0.1 44.75…24.96 0.1856 RAS time 10 min,
power 409.5 W 34.9±0.2 48.79…33.53 0.4290 RAS time 15 min, power 409.5 W 36.8±0.2 44.75…24.96 0.3900 Control 34.0±0.2 37.64…25.19 0.1430

The starch is dried to a moisture content of 17-20%. This is necessary to ensure optimal conditions for storing the finished product. The above examples prove that the modification of starch using the proposed method using ultrasonic ultrasound at a power of 409.5 W and an exposure time of 10 minutes. (Table 1) makes it possible to triple the content of the amylose fraction of potato starch compared to the control.

Claims (1)

A method for producing high-amylose potato starch, including the preparation of an aqueous suspension from native potato starch and its ultrasonic treatment, wherein a 4% aqueous suspension is prepared from the starch at a temperature of 34-37°C, the resulting suspension is stirred for 3 minutes and treated with ultrasonication at a frequency of 22 ± 1.65 kHz power 409.5 W for 10 minutes at a temperature of 34-37 ° C, then it is centrifuged at a speed of 6000 rpm for 10 minutes and dried at a temperature of 30-40 ° C to a moisture content of 17-20% .