JP7651271B2 - Syneresis inhibitor using powdered oil - Google Patents

Description

The present invention relates to a syneresis inhibitor using powdered oils and fats.

Tofu and processed meat foods have a problem with dehydration during processing (especially when cooked) and during distribution and storage. Furthermore, in recent years, they are often distributed frozen and thawed before consumption, which can cause problems such as dehydration and a deterioration in texture when thawed, and improvements were needed.

The techniques described in Patent Documents 1 to 4 are known as methods for suppressing syneresis, but Patent Documents 1 and 2 produce an off-flavor derived from the formulation. Patent Documents 3 and 4 use thickeners and hardened oils, which makes the texture hard. Therefore, there is room for improvement in the methods for suppressing syneresis.

International Publication No. 2017/104807 JP 2016-103992 A JP 2014-076041 A International Publication No. 2018/174204

The present invention was made in consideration of the above circumstances, and aims to provide a technology that imparts cold thawing resistance and syneresis suppression effects to tofu, processed meat foods, etc.

To solve the above problems, the syneresis inhibitor of the present invention contains dry powdered oil and fat, and is characterized in that the median diameter of the oil-in-water emulsion obtained by redissolving the powdered oil and fat is 0.3 to 2.0 μm.

The syneresis inhibitor of the present invention imparts cold thawing resistance and syneresis inhibition effects to tofu, processed meat foods, etc.

The present invention is described in detail below.

In the present invention, the oils and fats used in the powdered oils and fats of the syneresis inhibitor are not particularly limited, but examples thereof include palm oil, palm kernel oil, coconut oil, rapeseed oil, soybean oil, cottonseed oil, corn oil, sunflower oil, rice oil, safflower oil, olive oil, sesame oil, shea butter, monkey fat, mango oil, illipe fat, cacao butter, lard, beef tallow, milk fat, butter oil, fractionated oils thereof, processed oils (those that have been subjected to one or more of the following processes: hardening and transesterification), etc. These oils and fats may be used alone or in combination of two or more.

In the present invention, the powdered oil or fat preferably contains an excipient. Examples of excipients include proteins or their hydrolyzates, carbohydrates, etc.

Examples of proteins include milk protein, soy protein, wheat protein, pea protein, fava bean protein, whole milk powder, skim milk powder, whey powder, buttermilk powder, collagen, gelatin, etc. Examples of protein hydrolysates include peptides obtained by hydrolyzing proteins by enzymatic digestion, etc. These may be used alone or in combination of two or more. Among these, milk protein or its hydrolysates are preferred.

Examples of milk proteins include caseins such as acid casein, rennet casein, sodium caseinate, and potassium caseinate, as well as whey protein, milk protein concentrate, and total milk protein. Examples of milk protein hydrolyzates include milk peptides obtained by hydrolyzing milk proteins by enzymatic digestion or the like. Among these, non-micellar products such as sodium caseinate, potassium caseinate, whey protein, milk peptides, and acid casein are preferred in terms of improving emulsion stability.

The amount of protein or its hydrolyzate is not particularly limited, but taking into consideration the viscosity of the emulsion before powderization, etc., it is preferably 0.5 to 10% by mass, more preferably 1 to 8% by mass, and even more preferably 2 to 6% by mass, based on the total amount of powdered oil.

Examples of carbohydrates include monosaccharides such as glucose, fructose, galactose, and mannose, disaccharides such as lactose, sucrose, maltose, and trehalose, oligosaccharides, dextrins (corn, cassava, rice, potato, sweet potato, wheat, etc., such as starch syrup, powdered syrup, maltodextrin, cyclodextrin, roasted dextrin, branched cyclodextrin, and resistant dextrin), and starches (potato starch, corn starch, and waxy corn starch). , wheat starch, rice starch, sweet potato starch, tapioca starch, mung bean starch, sago starch, etc.), thickening polysaccharides (pullulan, gum arabic, xanthan gum, tragacanth gum, gellan gum, guar gum, locust bean gum, tamarind seed gum, carrageenan, agar, LM pectin, HM pectin, methylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose, etc.), indigestible carbohydrates, sugar alcohols, etc. These may be used alone or in combination of two or more.

From the viewpoint of sufficiently increasing emulsifiability, the lower limit of the carbohydrate content is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more, based on the total mass of the powdered oil or fat. The upper limit of the carbohydrate content is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less, based on the total mass of the powdered oil or fat.

In the present invention, an emulsifier can be blended with the powdered oil or fat. The emulsifier is not particularly limited as long as it is for food use, and examples thereof include lecithin, saponin, glycerin fatty acid ester, organic acid glycerin fatty acid ester, polyglycerin fatty acid ester, polyglycerin condensed ricinoleic acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, propylene glycol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, calcium stearoyl lactylate, sodium stearoyl lactylate, and processed starch (etherified carboxymethyl starch, hydroxypropyl starch, esterified starch phosphate, sodium starch octenylsuccinate, starch acetate, moist heat treated starch, acid treated starch, cross-linked starch, gelatinized starch, etc.). These may be used alone or in combination of two or more.

From the viewpoint of emulsion stability, the lower limit of the emulsifier content is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1.0% by mass or more, based on the total mass of the powdered oil and fat. From the viewpoint of flavor and solubility of the powdered oil and fat, the upper limit of the emulsifier content is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, based on the total mass of the powdered oil and fat.

The HLB value of the emulsifier is preferably 10 or less, from the viewpoint of easily obtaining an oil-in-water emulsion suitable for drying. Here, the HLB value indicates the molecular weight of the hydrophilic group portion in the total molecular weight of the surfactant, and can be calculated by the Griffin formula (Atlas method).

When an emulsifier is added to powdered oils and fats, the oil-soluble emulsifier is usually added to the oil phase, and the water-soluble emulsifier is added to the water phase. Antioxidants, colorants, flavors, etc. may be added to the oil and water phases as appropriate.

In the present invention, the powdered oil is a dry type powdered oil obtained by drying an oil-in-water emulsion, and when added to water, it becomes the original oil-in-water emulsion, and the oil droplets are redispersed. The median diameter of the redissolved oil-in-water emulsion is 0.3 to 2.0 μm, preferably 0.5 to 1.3 μm. Within this range, it has excellent cold thawing resistance and syneresis suppression effect for tofu and processed meat foods. If the median diameter is too small, the oil does not act well on starch and protein, and the effect of the oil is not fully exerted. If the median diameter is too large, the dispersibility of the oil droplets decreases, the emulsification of the oil-in-water emulsion becomes unstable, and the syneresis suppression effect is not fully obtained.

In the present invention, it is preferable that the oil-in-water emulsion obtained by redissolving the powdered oil has a skewness represented by formula (A) of -1 to 1.

歪度（わいど）：分布の形状が正規分布からどれだけ離れているかを表す指標。分布が左に偏れば正の値、正規分布であれば０、分布が右に偏れば負の値をとる。

Skewness: An index that indicates how far the shape of a distribution is from a normal distribution. If the distribution is skewed to the left, it is a positive value, if it is a normal distribution, it is 0, and if the distribution is skewed to the right, it is a negative value.

The skewness is preferably between 0 and 1, and more preferably between 0 and 0.5.

When the skewness represented by formula (A) is between -1 and 1, the product has excellent cold thawing resistance and syneresis inhibition effect for tofu, processed meat foods, etc. As the skewness increases, the proportion of small particles increases. If the skewness is too large, the oil and fat will not act as effectively on the starch and protein, and the effect of the oil and fat will not be fully exerted. As the skewness decreases, the proportion of large particles increases. If the skewness is too small, the emulsion of the oil-in-water emulsion will become unstable, and the syneresis inhibition effect will not be fully achieved.

In the present invention, it is preferable that the standard deviation of the particle size of the oil-in-water emulsion obtained by redissolving the powdered oil or fat is 0.3 or less.
Standard deviation: A value that indicates the degree of dispersion of data. It is calculated by taking the positive square root of the variance. The more the data is concentrated around the mean value, the smaller the value will be (the minimum value is 0), and the more spread out the data is from the mean value, the larger the value will be.

The standard deviation is preferably 0.26 or less, and more preferably 0.20 or less. A standard deviation of 0.30 or less provides excellent cold thawing resistance and syneresis suppression effect for tofu, processed meat foods, etc. The smaller the standard deviation, the narrower and more uniform the particle size distribution becomes, resulting in a more stable emulsification of the oil-in-water emulsion.

In the present invention, the oil powder preferably has an oil content of more than 45% by mass, and the ratio of the total amount of emulsifier and protein or hydrolyzate thereof to the oil is 0.06 or more. Within this range, the oil content is excellent in cold thawing resistance and syneresis suppression effect for tofu and processed meat foods. From this viewpoint, the oil content is more preferably 60% by mass or more. There is no particular upper limit, but in consideration of the emulsion stability of the oil-in-water emulsion, it is, for example, 80% by mass or less. In addition, the ratio of the total amount of emulsifier and protein or hydrolyzate thereof to the oil is more preferably 0.08 or more, and even more preferably 0.12 or more. There is no particular upper limit, but in consideration of the viscosity of the oil-in-water emulsion not being excessively increased, it is, for example, preferably 0.30 or less, and more preferably 0.25 or less.

In the present invention, the powdered oil preferably has a ratio of emulsifier to oil of 0.015 or more. Within this range, the powdered oil has excellent cold thawing resistance and syneresis suppression effect for tofu and processed meat foods. In particular, the flavor of tofu is improved, and the binding property of processed meat foods is improved. From this perspective, the ratio of emulsifier to oil is more preferably 0.025 or more, and even more preferably 0.040 or more. There is no particular upper limit, but taking into consideration flavor and the like, for example, a ratio of 0.200 or less is preferable, and 0.170 or less is more preferable.

In the present invention, the powdered oil preferably has a ratio of protein or its hydrolysate to the oil of 0.043 or more. Within this range, the effect of inhibiting syneresis in tofu, processed meat foods, etc. is excellent. From this viewpoint, the ratio of protein or its hydrolysate to the oil is more preferably 0.046 or more. There is no particular upper limit, but in consideration of the fact that the viscosity of the oil-in-water emulsion is not excessively increased, it is preferably 0.080 or less, and more preferably 0.070 or less.

In the present invention, the powdered oil preferably has a ratio of emulsifier to protein or its hydrolysate of 2.0 or more. Within this range, the texture of tofu, processed meat foods, etc. is improved, and the syneresis suppression effect is also improved. From this viewpoint, the ratio of emulsifier to protein or its hydrolysate is more preferably 2.5 or more. There is no particular upper limit, but in consideration of the fact that the viscosity of the oil-in-water emulsion is not excessively increased, it is preferably 4.0 or less, more preferably 3.5 or less.

An example of a method for producing the syneresis inhibitor of the present invention is described below.

Powdered oils and fats can be obtained by adding an oil phase containing the above-mentioned oils and fats to an aqueous phase containing excipients, stirring and emulsifying with a homomixer or the like, and then homogenizing with a homogenizer or the like to produce an oil-in-water emulsion, which is then dried and powdered.

The oil-in-water emulsion can be dried and powdered using spray drying or freeze drying, and the dried powdered oil obtained by spray drying or freeze drying is used.

An oil-in-water emulsion can be prepared by mixing an aqueous phase containing an excipient with an oil phase containing an oil. For example, it can be prepared by the following emulsification and homogenization steps.

In the emulsification process, the above-mentioned raw materials are placed in the stirring tank of the emulsifier and stirred and mixed. The blending ratio of the raw materials, including fats and oils, excipients, and water, is not particularly limited, but can be, for example, within the range of 50 to 200 parts by weight of water per 100 parts by weight of the total amount of fats and oils and excipients.

These blending procedures are not particularly limited, but for example, the excipients can be dispersed in water at room temperature and then stirred under heating, or the excipients can be dispersed in heated water, stirred until completely dissolved, and then heated and dissolved fats and oils can be added dropwise while stirring with a homomixer to emulsify.

In the homogenization step, the emulsion obtained in the emulsification step is fed to a pressure homogenizer to reduce the size of the oil droplets. For example, a commercially available pressure homogenizer can be used to homogenize the emulsion at a pressure of about 10 to 250 kgf/ ^cm2 to reduce the size of the oil droplets.

Next, when the emulsion is dried and powdered by spray drying, the homogenized emulsion is fed to the inlet of a spray dryer using a high-pressure pump, and high-temperature hot air is blown in and sprayed from above into the tank of the spray dryer. The spray-dried powder is deposited at the bottom of the tank. As the spray dryer, for example, a spray dryer that uses an atomizer method or a nozzle method can be used.

Next, the spray-dried powder is removed from the tank of the spray dryer and then cooled with cold air while being transported in a vibrating fluidized bed, etc., to produce powdered oils and fats. Note that a heat sterilization process, etc., can also be added as appropriate.

The syneresis inhibitor of the present invention contains the dry-type powdered oil described above, and the median diameter of the oil-in-water emulsion obtained by redissolving the powdered oil is 0.3 to 2.0 μm.

The processed food of the present invention contains the syneresis inhibitor of the present invention described above. Processed foods are foods produced by various processing and cooking using agricultural products, livestock products, and marine products as raw materials, and examples of such foods include soybean processed foods such as tofu, meat processed foods such as hamburger steaks, gelled foods, egg processed foods, nursing care foods, baby foods, side dishes, frozen foods, and chilled foods. Methods for incorporating the syneresis inhibitor into meat processed foods include directly kneading the meat to incorporate the syneresis inhibitor, blending the syneresis inhibitor into pickling liquid or batter liquid and immersing ingredients in the liquid, and directly injecting pickling liquid into the meat. From the viewpoint of effectively inhibiting syneresis, the method of directly kneading the meat to incorporate the syneresis inhibitor is particularly preferred.

The syneresis inhibitor of the present invention has excellent cold thawing resistance and syneresis inhibition effect, and can be suitably used for tofu, meat kneading, gelling food, egg processed food, etc. Examples of meat kneading include hamburger steak and meatballs. Examples of tofu include tofu itself, as well as processed tofu foods (grilled tofu, fried tofu, deep-fried tofu, fried tofu, tofu steak, tofu hamburger steak), etc. Examples of gelling food include jelly, etc. Examples of egg processed food include tamagoyaki, omelettes, scrambled eggs, chawanmushi, pudding, etc. When used for tofu, the texture is very smooth, the whiteness is high, the smoothness and richness are excellent, and the grassy smell is reduced. When used for meat kneading, there is little loss of heat and shrinkage after baking, and the softness is excellent. When used in jellies, they have a high whiteness and a soft texture, and are smooth and rich. The amount of the syneresis inhibitor of the present invention added is not particularly limited, but for example, for meat kneading, it is 3 to 10% by mass based on the total amount of processed meat foods, for tofu, it is 1.5 to 10% by mass based on the total amount of tofu, and for jelly, it is 3 to 10% by mass based on the total amount of jelly. When added as a high-calorie jelly, the syneresis inhibitor effect is further enhanced by adding 10% by mass or more based on the total amount of jelly. Powdered oils and fats contain almost no water, so compared to when the same amount of oil and fat is added to processed foods in the form of an oil-in-water emulsion, there is no increase in syneresis due to an increase in water content, and workability during processing is also good.

The syneresis inhibitor of the present invention can also be suitably used in nursing care foods and baby foods. Examples of nursing care foods include swallowing foods, chopped foods, blender foods, soft foods, etc. When the syneresis inhibitor of the present invention is used in nursing care foods, the smoothness and ease of assembly are improved. The amount of the syneresis inhibitor of the present invention added is not particularly limited, but for nursing care foods, the range of 3 to 20% by mass of the entire nursing care food can be exemplified.

The syneresis inhibitor of the present invention can be blended with one or more starches selected from starches obtained from any raw material (corn, rice, wheat, beans, potatoes, sweet potatoes, tapioca) and processed starches. The syneresis inhibitor of the present invention can further improve the cold thawing resistance and syneresis inhibitory effect by using starches in combination with dry powdered oils and fats. The amount of starches to be added can be, for example, a ratio of starches to dry powdered oils and fats in the range of 0.02 to 60.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.
<Preparation of syneresis inhibitor>
The oils and fats shown in Tables 2 and 4 were added with an emulsifier (processed starch was added to the water phase) and heated to 60°C to obtain an oil phase. The protein or its decomposition product and carbohydrates shown in the table were added to water (about 20°C) in an amount equal to the powdered oil composition shown in the table and heated to 60°C to obtain an aqueous phase. The aqueous phase and the oil phase were mixed and emulsified, and then homogenized at a pressure of 150 kgf/ ^cm2 using a pressure homogenizer to obtain an oil-in-water emulsion as an emulsion. The obtained emulsion was spray-dried at a flow rate of 25 ml/min using a nozzle-type spray dryer to obtain a syneresis inhibitor (powdered oil) with a water content of 1.5% (spray drying conditions: inlet temperature 210°C). The median diameter and standard deviation of the particle diameter of the oil-in-water emulsion obtained by redissolving the obtained dry powdered oil were measured using a laser diffraction particle size distribution analyzer (SALD-2300, manufactured by Shimadzu Corporation). The skewness is calculated from the particle size distribution obtained by the above measurement according to the above formula (A), and can be easily calculated using a spreadsheet software (for example, Microsoft Excel, etc.).
It should be noted that Comparative Example 2 is an oil-in-water emulsion (not spray-dried), and the median diameter and standard deviation of particle diameter are values measured after homogenization.

<Preparation of frozen tofu>
1. Dissolve the modified starch, reduced starch hydrolysate, and magnesium chloride in water.
2. Add soy milk and stir.
3. Add the syneresis inhibitor and mix until uniform (soy milk liquid).
4. Dispense 50 ml into each container.
5. Steam for 15 minutes, turn off the heat and leave to steam for 15 minutes.
6. After cooling, flash freeze.

After freezing overnight, the product was thawed at room temperature and the amount of water released was measured, the cross-section was observed, the whiteness was measured, and a sensory evaluation was performed. A rating of △ or higher was deemed to have resolved the issue.

[Amount of separated water]
A 4 g portion was cut from the center of the tofu and placed on filter paper to measure the amount of water absorbed after 3 hours at 20° C. The amount of water absorbed by the filter paper was evaluated as the amount of water separated from the tofu according to the following criteria.
◎: The amount of water released is less than 0.25 g. ○: The amount of water released is 0.25 g or more and less than 0.27 g. △: The amount of water released is 0.27 g or more and less than 0.29 g. ×: The amount of water released is 0.29 g or more.

[Cross-section state]
The state of the cross section of the tofu was visually observed and evaluated according to the following criteria.
: The texture is very smooth.
◯: The texture is slightly rough.
△: Rough texture is observed.
×: The texture is significantly rough.

[Whiteness]
The soy milk obtained in the frozen tofu production step 3 was measured with a spectrophotometer, and the Hunter whiteness index was calculated and evaluated according to the following criteria. The higher the whiteness index value, the whiter the tofu.
○: Hunter whiteness is 79.0 or more △: Hunter whiteness is 78.0 or more and less than 79.0 ×: Hunter whiteness is less than 78.0

A panel of 20 people tasted each type of tofu and rated it on a scale of 10 for "smoothness," "richness," and "green flavor," with a reference example with no added syneresis inhibitor given a standard score of 5 points, and the average score was calculated. The closer to 10 points the "smoothness" and "richness" were felt to be stronger than the reference example, the closer to 10 points the score was given to the "green flavor," and the closer to 10 points the weaker the "green flavor" was felt to be compared to the reference example.

The evaluation panel that evaluated the flavor below prepared 20 sets of tofu with different textures and flavors, performed a one-to-two test (a duo-trio test in which three samples are presented for two types of samples, one of which is presented as a standard sample and participants are asked to select the one that matches the standard sample), and selected participants with a correct answer rate of 70% or higher. When conducting the evaluation, the entire panel discussed the matter and adjusted the characteristics of each evaluation item so that each panelist had a common understanding. In addition, to eliminate panel bias in the sensory evaluation and increase the accuracy of the evaluation, the test section numbers and contents of the samples were not disclosed to the panelists, and the samples were presented randomly.

[Sensory evaluation of tofu (smoothness)]
◎: Average value of "smoothness" is more than 7.5 points ○: Average value of "smoothness" is more than 6 points and less than 7.5 points △: Average value of "smoothness" is more than 5 points and less than 6 points ×: Average value of "smoothness" is less than 5 points

[Sensory evaluation of tofu (richness)]
◎: Average value of "Body" is over 8 points ○: Average value of "Body" is over 6 points and under 8 points △: Average value of "Body" is over 5 points and under 6 points ×: Average value of "Body" is under 5 points

[Sensory evaluation of tofu (grainy smell)]
◎: Average score of "green smell" is over 8 points. ○: Average score of "green smell" is over 6 points and under 8 points.
△: The average score for "green smell" is more than 5 points and less than 6 points. ×: The average score for "green smell" is less than 5 points.

The results of the above measurements and evaluations are shown in Table 2.

<Preparation of hamburger steak>
1. Combine breadcrumbs and milk.
2. Mix ground beef, ground pork, salt, and oil until uniform.
3. Add 1, sautéed onion, egg, black pepper, and nutmeg to 2 and mix until evenly combined.
4. Divide into 100g portions and deflate 20 times. Shape into circles by hand.
5. Bake at 180°C.

[Burning rate]
The amount of drip was calculated from the weight difference before and after baking, and the baking loss rate (%) was calculated from the amount of drip relative to the weight before baking. The baking loss rate was evaluated as the amount of water syneresis before and after baking. The lower the baking loss rate, the more water syneresis is suppressed.
Burning loss rate (%) = (weight before burning - weight after burning) / weight before burning x 100 (%)
◎: Burning rate is less than 12%. ○: Burning rate is 12% or more and less than 16%. △: Burning rate is 16% or more and less than 20%. ×: Burning rate is 20% or more.

[Shrinkage rate]
The volume before and after baking was measured using a laser volume meter Volscan (Stable Micro Systems), the shrinkage rate (%) was calculated, and evaluated according to the following criteria. The greater the amount of water syneresis before and after baking, the higher the shrinkage rate, so the lower the shrinkage rate, the more water syneresis is suppressed.
◎: Shrinkage rate is less than 5%. ○: Shrinkage rate is 5% or more but less than 8%. △: Shrinkage rate is 8% or more but less than 12%. ×: Shrinkage rate is 12% or more.

[Softness]
Using a texture analyzer EZ-SX200N (manufactured by Shimadzu Corporation), the load (N) was measured under conditions of 50% compression and 1 mm/sec, and evaluated according to the following criteria: ⊚: The force applied during compression was 16 N or less ◯: The force applied during compression was 16 N or more but less than 17 N △: The force applied during compression was 17 N or more but less than 20 N ×: The force applied during compression was 20 N or more

The results of the above measurements and evaluations are shown in Table 4.

Next, using the syneresis inhibitor (powdered oil) and oil-in-water emulsion in the formulations shown in Table 5, hamburger dough was prepared in the same manner as above with the formulations shown in Table 6, and the differences in moldability and shape retention between the powdered oil and the oil-in-water emulsion were evaluated in terms of the following items.
[Moldability (workability)]
The ease of forming the dough by hand was evaluated according to the following criteria.
○: The dough is well bonded and easy to gather. △: It is easy to gather, but falls apart when force is applied. ×: The dough is not well bonded and is difficult to gather.

[Shape retention]
The dough condition when the formed dough types were arranged on a tray was visually evaluated according to the following criteria.
○: No sagging even after 5 minutes of standing at room temperature after molding. △: Maintains shape immediately after standing, but sagging occurs within 5 minutes. ×: Loses shape immediately after standing.

The results of the above measurements and evaluations are shown in Table 6.

As shown in Table 6, when hamburgers were made using the powdered oil of Example 8 and the oil-in-water emulsion of Comparative Example 2, the dough did not bond well and did not retain its shape when made using the oil-in-water emulsion, but the dough bonded well and had good shape retention when made using the powdered oil, demonstrating that the powdered oil is useful not only for syneresis suppression but also for workability.

<Preparation of nursing care food (blended food)>
The blended diet was prepared according to the following procedure.
1. Combine all ingredients according to the formula in Table 7 and blend in a mixer until it becomes a paste.
2. Heat to 90°C for 3 minutes.
3. Place 50 g in each container and cool at room temperature.
4. After cooling, quickly freeze and store at -20°C for one week.

[Amount of separated water]
50 g of the prepared frozen blended food was left at room temperature for 3 hours, the amount of water released was measured, and the food was evaluated according to the following criteria.
◎: The amount of water released is less than 0.50 g. ○: The amount of water released is 0.50 g or more and less than 0.60 g. ×: The amount of water released is 0.60 g or more.

As shown in Table 8, it was confirmed that the amount of syneresis was suppressed in the blended diets containing the syneresis inhibitors of Examples 1 and 3 to 8.

<Preparing frozen tamagoyaki>
Frozen omelets were prepared according to the following procedure.
1. Combine all ingredients in a bowl.
2. Add oil to an egg cooker and heat it until the surface temperature reaches 150℃.
3. Pour one-third of the total amount of batter mixed in 1 into 2, and roll it up once cooked.
4. Pour in another third of the batter and roll it up once it's cooked through.
5. Pour in the remaining batter and roll it up once cooked.
6. After slowly cooling at room temperature for 60 minutes, quickly freeze and store at -20°C for 3 days.

[Separation rate]
The amount of drip was calculated from the weight difference between before freezing and after 2 hours of thawing at room temperature, and the rate of water separation (%) was calculated from the amount of drip relative to the weight before freezing. The rate of water separation was evaluated as the amount of water separation before and after cold thawing. The lower the rate of water separation, the more water separation was suppressed.
◎: The amount of water release is less than 2.0%. ○: The amount of water release is 2.0% or more and less than 4.0%. △: The amount of water release is 4.0% or more and less than 6.0%. ×: The amount of water release is 6.0% or more.

As shown in Table 9, it was confirmed that the amount of syneresis was suppressed in the omelet containing the syneresis inhibitor of Example 2. It was also confirmed that the amount of syneresis was further suppressed in the syneresis inhibitor of Example 2-2, which is a form in which potato starch is added to the syneresis inhibitor of Example 2 (powdered oil).

Claims (8)

A syneresis inhibitor that contains dry powdered oil and fats, and in which the median diameter of the oil-in-water emulsion obtained by redissolving the powdered oil and fats is 0.3 to 2.0 μm. The syneresis inhibitor according to claim 1, wherein the standard deviation of the particle size of the oil-in-water emulsion is 0.30 or less. The syneresis inhibitor according to claim 1 or 2, wherein the powdered oil has an oil content of more than 45% by mass, and the ratio of the total amount of emulsifier and protein or its hydrolyzate to the oil is 0.06 or more. The syneresis inhibitor according to any one of claims 1 to 3, wherein the powdered oil has an emulsifier to oil ratio of 0.015 or more. The syneresis inhibitor according to any one of claims 1 to 4, wherein the powdered oil has a ratio of protein or its decomposition product to oil of 0.043 or more. The syneresis inhibitor according to any one of claims 1 to 5, wherein the powdered oil has a ratio of emulsifier to protein or its hydrolyzate of 2.0 or more. The syneresis inhibitor according to any one of claims 1 to 6, which is for tofu. The syneresis inhibitor according to any one of claims 1 to 6, which is used for kneading livestock meat.