JPS5910777B2 - Frozen protein production method - Google Patents

Description

[Detailed description of the invention] This invention relates to a method for producing frozen proteins.

In 1977, the United States, Canada, the Soviet Union, EC countries, Japan, and other countries successively established their own 200-nautical-mile fishing zones, and the world's fishing industry is said to have entered the 200-nautical-mile era.

As a result, in Japan, the supply of frozen surimi, especially walleye, has decreased considerably, and at the same time the price has increased, and there is an urgent need to develop and supply alternative raw materials for frozen surimi.

Conventionally, as an alternative raw material of this kind, isolated soybean protein powder has been used, which is obtained by heat-treating a soybean protein extract (usually 4-8% solids content) to increase its viscoelasticity and then spray-drying it. However, in this era of expensive fuel resources, not only is the cost of heating and spray drying protein extracts high, but the disadvantage is that it is not possible to increase supply without expanding spray drying equipment, which requires a large investment of capital. was there.

However, the quality of frozen fish surimi requires excellent viscoelasticity, a high white color, and a small amount of dripping after thawing. Switching from spray drying means to freezing means poses challenges.

First of all, freezing generally promotes protein denaturation, but among vegetable proteins, soybean glycinin is said to be more susceptible to freezing denaturation than wheat gluten, and in the case of soybean proteins, irreversible spongy tissue formation can occur. It is difficult to return to the original paste state after freezing and thawing.

Second, although it is said that heat treatment of soybean protein extract improves its viscoelasticity, it has also been reported that when soybean protein extract is heat treated at 80°C or higher and then frozen or refrigerated, it undergoes significant denaturation due to freezing. Therefore, it was considered impossible to obtain a product that retains excellent heating gel-forming ability by cutting curd from a heat-treated soybean protein extract and storing it in a frozen state. .

Thirdly, the soybean protein extract is subjected to a combination of alkali treatment (pH 11 or higher) and heat treatment (nearly neutral, 80°C or higher) to extract curd from the heat-treated soybean protein extract and freeze it. Although there are proposals to solve the drawbacks of these methods, such methods not only have the disadvantage of significantly reducing product whiteness due to the use of strong alkali, but also the need to remove even some of the alkaline odor, making it difficult to The drawback is that it requires washing with water to neutralize and remove salt, and there is a high possibility of secondary contamination due to bacteria after heating.

etc. The present inventor, while researching a method for producing frozen protein from soybean protein raw materials as an alternative to frozen fish surimi,
Soybean protein is heat-treated using a special method.

In other words, heating is not performed in the state of the extract, but at a concentration of solids that is similar to surimi, and optimally, a certain function value defined by the heating temperature and heating time is By heat treatment under specific conditions lower than those normally used for extracts, freezing with excellent viscoelasticity, color tone (whiteness), and non-drip properties can be achieved. They completed the present invention by discovering that protein products can be obtained at extremely low heating costs and that addition of fats and oils has further improvement effects.

The present invention will be explained in detail below.

In the present invention, purified soybean protein acid precipitated curd is substantially neutralized to a solid content of 15% or more, and optimally the function log (seconds) + 6.0 5 log (temperature This is a method for producing frozen protein, which basically consists of heat treatment, cooling, and freezing so that the value indicated by °C is within the range of 13.0 to 14.2.

A purified acid-precipitated soybean protein curd can be obtained by a known method for producing isolated soybean protein or concentrated soybean protein.

In other words, proteins are extracted from soybeans or low-denatured defatted soybeans with water, a dilute aqueous alkaline solution, a neutral salt aqueous solution, etc., and the pH is adjusted to around the isoelectric point of the protein by acidification, with or without removing insoluble materials (Okara components). The curd that has been adjusted and precipitated at °C is subjected to water washing, dialysis, membrane separation, strong dehydration, etc. to remove as many soluble components as possible.

The curd used in the present invention is not based on a coagulant containing an alkaline earth metal salt, but is based on acid precipitation.

If the curd is made from an alkaline earth metal salt, the protein will be significantly denatured by freezing, making it impossible to obtain a viscoelastic product.

Among the components that are soluble at pH near the isoelectric point, salts are included.
If the whey protein is present, it tends to be a factor that promotes freeze denaturation in the subsequent heating step, and if the whey protein is not sufficiently removed, the viscoelasticity tends to decrease.

The purified curd is then approximately neutralized.

That is, pn is preferably 6 to 8.5, preferably 6.5 to 7.5.

If the pH is lower than 6, it not only exhibits a sour taste but also becomes susceptible to denaturation, making it difficult to heat uniformly at temperatures exceeding 100°C without flocculation of fibrous substances, or causing freezing and loss of viscoelasticity. easy.

Furthermore, when the pH is about 9 or higher, it exhibits an alkaline odor and taste, so it must be neutralized eventually, and even after neutralization and washing with water, the alkaline odor remains and is susceptible to secondary contamination by bacteria after heating.

Furthermore, if the pH becomes higher than 11, the whiteness will drop significantly, making it unsuitable for replacing frozen surimi.If heated in that state, the γ-amino group of lysine will be blocked and effective lysine will decrease, resulting in a loss of nutrients. The alkaline odor remains even after neutralization and washing with water.

Various additives can be added to the purified curd or curd neutralized product to further improve the physical properties of the frozen protein.

The present inventor has discovered that when oil is added to purified curd or curd neutralized product to emulsify it, the physical properties of the product obtained by heating, cooling, or freezing do not deteriorate, but are even clearly improved, especially in the salted state. I got a surprising finding.

That is, unlike the case of many other fish and livestock meats, the viscoelasticity and jelly strength of soybean protein tend to decrease when oil or salt is added. By adding and emulsifying it, even in a salted state, viscoelasticity and jelly strength comparable to those in an unsalted state can be obtained.

The addition of oil and fat also has the effect of improving the whiteness and flavor of the product.

These effects are greatest when the amount of fat added is 25 to 40% of the curd solids.

For emulsification, a so-called silent cutter, mixer, high-pressure homogenizer, etc. can be used, and an emulsifier may be added if necessary.

In addition, sugars and polyhydric alcohols are known as freeze denaturation inhibitors for frozen ground fish meat, but they are also effective in preventing freeze denaturation in the production of frozen proteins, and are effective in preventing products with good viscoelasticity. Contribute to obtaining.

These are preferably used in an amount of 5 to 10% based on the curd neutralized product.

Types of sugar include sucrose, glucose, manoletose, maltotriose, raffinose, etc. When using reducing sugars, care must be taken not to cause browning reactions.

Starches have similar effects, but care must be taken as adding too much will increase the viscosity of the curd neutralized product and make it difficult to work with.

Polyhydric alcohols such as glycerin, ethylene glycol, globylene glycol, sorbitol, etc. are used,
Water retention agents with relatively small molecular weights are most effective, and water retention agents such as citric acid, monosodium glutamate, and polymerized phosphoric acid can also be added as they have the effect of somewhat improving the physical properties of the product.

Furthermore, depending on the intended use of the frozen protein, it is possible to add flavors and the like that are required at °C, but unlike the spray drying method, the present invention has the advantage that the possibility of scattering during the manufacturing process is extremely low.

The various additives mentioned above have almost the same effect when added to the neutralized curd at any stage before freezing, but if they are added after heating and before freezing, the possibility of secondary contamination increases.

The neutralized curd, with or without the addition of fats, oils, sugars, polyhydric alcohols, and other additives, is uniformly heat-treated at 70 to 160°C with a solids content of 15% or more.

This treatment makes it possible to obtain a product that retains good viscoelasticity by thawing and kneading even though it is later frozen.

Due to the heat treatment with a high solids content,
Compared to heating soybean protein extract, heat resources per protein can be saved (i.e., the amount of heat required to heat the same weight of curd neutralized product and extract at the same temperature and for the same time is equivalent) ), but also has the surprising effect of requiring less heat per unit weight of the curd neutralized product compared to the amount of heat per unit weight of soy protein extract conventionally required to impart viscoelasticity. It is.

Optimally, a function (hereinafter simply referred to as F value) F
A product exhibiting optimal viscoelasticity and non-dripping properties can be obtained by heat treatment within the range of = log (seconds) + 6.05 log (temperature °C) within the range of 13.6 ± 0.6. It is.

If the above function value exceeds 14.2, the frozen and thawed product lacks uniformity and has poor viscoelasticity;
．． When it is smaller than 0, the effect of heat treatment is small and viscoelasticity is hardly imparted, and drips are generated.

Incidentally, the above function value required to impart viscoelasticity to a soybean protein extract (solid content: 7%) is around 15.

If the solids content is less than 15%, not only will there be no heat energy saving effect as described above, but since it is in a liquid state, it cannot be handled in the same way as frozen surimi unless it is re-sedimented after heating or dried. However, in the present invention, after heating, cooling, freezing, and thawing, the product can be used in the same manner as minced fish immediately.

In the present invention, if there is no loss due to scattering when adding water, which is the case when using powder obtained by spray drying, there is no need to make efforts to eliminate clumps.

As long as the solids content is 15% or more, any content may be used as long as the protein can be kept in a liquid state and uniform heating is possible, but 30% or less is usually suitable due to mechanical constraints.

This heat treatment requires that the curd neutralized product be heated uniformly.

If excessive heating occurs locally, partial freeze denaturation occurs during freezing, which is thought to increase the overall freeze denaturation, making it impossible to obtain a product that retains viscoelasticity.

In the present invention, since the solid content during heating is high, such a phenomenon is likely to occur, so special attention must be paid to the heating method.

Specifically, stirring is performed at a relatively high speed while blowing steam, blowing a steam flow large enough to stir or flow the curd neutralized product, and making it flow through a thin pipe in the heating medium. The measures enable homogeneous heating, and the equipment includes a high-speed cutter for cheese melting, a heat exchanger,
Ejuctor, autoclave, votator, onrator, etc. can be used.

When the heating temperature is 70°C or lower, the effect of the heat treatment is small and it takes a long time, and when the heating temperature is 160°C or higher, instantaneous heating is difficult and excessive heating is unavoidable.

It is most effective to reduce the number of bacteria by keeping the odor within this range or at a temperature of 100'C or higher.In that case, direct or indirect heating while flowing through a thin pipe can be used for a short time. It's suitable.

The heat-treated curd neutralized product is then cooled and frozen.

As a cooling method, vacuum cooling is the most preferred because it provides a product with improved flavor, increases cooling efficiency, and makes it easy to control the function value within a range.

The present inventor has discovered that the heat-treated curd neutralized product contains glucono delta-lactone (GDL) at a temperature of 55°C or higher during the cooling process.
It has been found that the strength of the jelly can be significantly increased when it is frozen as is or after neutralization.

Although the reason for this is not clear, the effect is small if GDL is added at a temperature of 55° C. or lower, or if the amount added per solid curd is 0.5% or less.

Freezing should be carried out quickly through the temperature range of -1 to -3°C.

If it passes through a temperature range of -1 to -3°C for a long time, it becomes a spongy tissue after freezing and cannot maintain excellent viscoelasticity when thawed.

The frozen protein thus obtained has excellent viscoelasticity, color tone (whiteness), and non-dripping properties, and can be used in the same way as frozen surimi, fish paste products, livestock meat paste products, and can be used in microwave It can be used for many purposes, such as puffing and drying to make confectionery.

The mode of use of the frozen protein according to the present invention includes not only kneading it with frozen minced fish meat but also adding powdered separated protein and water.

The present invention will be explained below with reference to Examples.

Example 1 10 times the amount of dilute alkali aqueous solution was added to low denatured defatted soybeans,
After extracting the protein and removing okara components and adding acid, the resulting curd was washed twice with water, dehydrated, and then adjusted to pH 7. 0
(solids concentration 18.5%).

Each 10 kg of this curd neutralized product was heat treated under various conditions (
For heating at 100°C or higher, the mixture was flowed through a pipe with an inner diameter of 4 in a coil heat exchanger, and the heating time was adjusted by adjusting the flow rate.

For heating below 100°C, steam was blown in a vacuum cutter manufactured by Stefan AG, West Germany, at 1400 rpm.
) and stirred in a Stephan cutter at -65
The mixture was brought to 0 wHg, cooled to 55°C, placed in a polyethylene bag to a thickness of 4 cIft, frozen at -40°C overnight, and then stored at -20°C.

The frozen protein that had been stored for two weeks was thawed, kneaded, and packed into a saran tube with an inner diameter of 221 nJIt.
A product was prepared by heating at 0° C. for 40 minutes and water-cooling at 20° C., and the viscoelasticity was measured by a four-fold test and the jelly strength was measured using an Okada jelly strength meter, and the results were as shown in Table 1.

All those with an F value within the range of 13.6 ± 0.6 show good viscoelasticity, have strong jelly strength and are flexible; on the other hand, those that have not been subjected to ℃ heat treatment are casing heated. Shape retention was not observed in Yotsuko either.

In addition, when heated at 100° C. for 4 seconds, a large amount of drips flowed out during thawing, and water retention was poor.

Those heated at 100°C for 300 seconds and 600 seconds are
Although there was little dripping during thawing, when the frozen protein was compressed, water leaked out, and a spongy tissue was observed, resulting in freeze denaturation.

Example 2 A neutralized curd product obtained in the same manner as in Example 1 (pH 7.
12. Solids content 18.7%) 10Kg of soybean oil 800%
Emulsified in cutter with or without addition of v;

As in Example 1, the flow rate was 1 in the pipe between the inner diameters of 4 and
7 By passing it through 3crIL/see, the product temperature 1
Heat for 14 seconds at 11”C and vacuum step-660
The mixture was cooled to 53° C. under a vacuum of mHr, further water-cooled to 20° C., and frozen in the same manner as in Example 1.

After 2 weeks of frozen storage, thaw and knead the soybean oil-added plots as they are, and add soybean oil to the non-additive plots at the same ratio as the additive-added plots and knead them at ℃.
Table 2 shows that the viscoelasticity and jelly strength, etc. of both the thawed product (adding 2.5 parts of salt to the thawed product) and the unsalted state are shown in Table 2. was clearly improved, and the improvement effect was especially remarkable when salt was added.

Example A curd neutralized product (pH 7.12) obtained in the same manner as in Example 1
, solids content 18.7%), add 500 V of sugar and 560 V of soybean oil to 10 Kg, emulsify it, and pass this through the pipe at 155 crn/see in the same manner.
℃ for 25.2 seconds (F value 13.7), cooled in the same way,
Frozen.

On the other hand, as a control, low-denatured defatted soybeans were extracted with a dilute alkaline aqueous solution, and okara components were removed (solid content: 6.5
%) and alkali treatment (processed at 60°C for 30 minutes at pH 12.6), then at pH 7. 5 and heat treated (90'C for 20 minutes, F value 14.9), acid precipitated by adding hydrochloric acid, dehydrated to a solid content of 20%, washed with water, and then diluted with sodium hydroxide solution. Add “C p H 7.2
After adjusting the solid content to 18.8%, it was frozen in the same manner.

The frozen soybean protein of the present invention was thawed and kneaded, and the frozen soybean protein of the control was thawed. Sugar 50 per K4
F. Soybean oil 569° C. was added and kneaded, the casing was heated and the physical properties were compared, and the results shown in Table 3 were obtained.

Compared to the control, the product according to the present invention has physical properties that are the same or higher than that even though it requires a very small amount of heat capacity. )
, which was preferred as a frozen surimi substitute.

Example 4 A neutralized curd product was obtained in the same manner as in Example 1 except that it was dehydrated to a solid content of 22.1%, and this was heated at 100°C for 30 seconds while blowing steam directly in an onlator. After that,
It was continuously cooled to 40°C using a jacketed onrator and frozen in the same manner as in Example 1.

When we measured the physical properties of the product frozen for 4 weeks, the viscoelasticity was AA, the jelly strength was 140V, and the deflection was 29.
It was a bummer.

The product obtained in Example 1 by heating at 100° C. for 30 seconds and then vacuum cooling was superior to this product in that it had extremely less soybean odor.

Example 5 A curd neutralized product (pH 7.13) obtained in the same manner as in Example 1
, solids content 18.5%) and 10 kg of sugar or corn starch (with or without the addition of 1 kg of sugar or 100 v of cornstarch), and then soybean oil so. y was added and emulsified in a cutter.

These flow through pipes with an inner diameter of 4 mm at a flow rate of 1 to 6, respectively.
By passing it through at 6 cm/see, the product temperature can be reduced to 110℃1.
After heating for 4.3 seconds, a frozen protein was produced in the same manner as in Example 1. The physical properties after 2 weeks of cryopreservation were as shown in Table 4.
It was as follows.

In addition, 10 kg of curd neutralized product was mixed with 8-yang raw gluten (pH 6.80, solids content 30.1%) and kneaded. When a frozen protein was produced in the same manner, the physical properties were as follows.

f Rute7 combination area AA l 199r 30m Example 6 Curd neutralized product obtained at °C in the same manner as Example 1 (pH 7.13
, solids content 18.5%) with palm oil 480V added,
After emulsifying with a Stephan cutter (trade name), steam was blown into the same cutter and the temperature was 90°C while stirring at 140 rpm.
Heated at ℃.

This was cooled to 55°C in a state of -650 vunH f/ in the same cutter, but when GDL15S' was dissolved in a small amount of water in advance, the temperature of the heated neutralized product was 65°C during cooling. I decided to add it or not when it reached that point.

The pH of the GDL-added area was adjusted to 7.20 before freezing.

The physical properties of the frozen and thawed products are shown in Table 5, and the jelly strength and deflection were well improved by the addition of GDL.

Application example 1 A thawed kneaded product of frozen protein obtained by adding 50% of second grade frozen surimi to the oil and fat of Example 2 in the following standard formulation, or a commercially available powdered isolated soybean protein obtained by adding 4 times the amount of water. When a nusage was produced in place of the mixed wire, the results shown in Table 6 were obtained.

Products using frozen protein had almost the same evaluation as products using powdered isolated protein.

Standard composition> Pork meat 61.5 Grade 2 surimi 15.0 Pork fat 5.0 Water 10.0 Starch 7.0 Sugar. Salt. Seasoning 1.5 Application Example 2 In the following standard formulation, 25 parts of C2 grade frozen surimi were substituted in the same manner as in Application Example 1, and fried dumplings were produced, and the results shown in Table 7 were obtained.

Standard combination> 2nd grade surimi 68.5% water
20.5 starch
6.8% salt, sucrose, glucose, MSG 4.2 The color tone is slightly different, but this is thought to be due to the presence of oil and fat in the frozen protein, but there is no problem in terms of commercial value.

Claims (1)

[Claims] 1. A purified acid-precipitated soybean protein curd is substantially neutralized to have a solid content of 15% or more, uniformly heated at 70 to 160°C, cooled, and frozen. A method for producing frozen proteins. The value of 21og (seconds) + 6.0510g (temperature °C) is 1
The method for producing a frozen protein according to claim 1, wherein the frozen protein is heat-treated so as to be within the range of 3.6±0.6. 3 In a method in which purified acid-precipitated soybean protein curd is substantially neutralized to have a solid content of 15% or more, uniformly heated at 70 to 160°C, cooled, and frozen, the curd before heating or in the curd A method for producing frozen protein, which is characterized by adding oil and fat to a protein and emulsifying it. 4 In a method in which purified acid-precipitated soybean protein curd is substantially neutralized to a solid content of 15% or more, uniformly heated at 70 to 160°C, cooled, and frozen, the curd before heating or in the curd A method for producing frozen proteins characterized by adding sugars or polyhydric alcohols to a protein. 5 The purified acid-precipitated soybean protein curd is approximately neutralized to a solid content of 15% or more, heat-treated uniformly at 70 to 160°C, cooled, and glucono delta-lactone is added at 55°C or less during cooling. , a method for producing a frozen protein characterized by freezing.