TWI869449B - Powdery food preservative composition and method for preserving food products - Google Patents

Abstract

Provided is a powdery food preservative composition comprising an ascorbic acid compound, an acetate and pullulan, wherein

the weight loss on drying (Xa) of the composition after the composition is dried for 12 hours at 45℃ and a relative humidity of 20% RH is -0.1 to 0.1%,

the weight loss on drying (Xb) of the composition after the composition is dried for 4 hours at a temperature of 120℃ is 0.05 to 0.5%, and

the color difference (ΔYI) between the yellowness (YIa) determined after the composition is stored in a 50 mL sealed glass container with a lid at a temperature of 45℃ for 2 weeks and the yellowness (YIb) determined after the composition is stored at a temperature of 0℃ for 2 weeks is less than 14.

Description

Powdered quality preservative and quality preserving method

The present invention relates to a powdered quality preserving agent, which mainly has an antibacterial effect and a discoloration inhibiting effect on food, and contains ascorbic acid. In addition, the present invention relates to a method for preserving the quality of food, which enhances the antibacterial effect (bacteriostatic action) and discoloration inhibiting effect on food.

In the food industry, various countermeasures have been adopted to improve the shelf life of food. Among them, the method of maintaining by adding a pH adjuster is a well-known representative method and is adopted by a variety of foods. However, when the pH is reduced to a level that can ensure sufficient shelf life by adding a pH adjuster, the food will have an unnatural sour taste. In addition, when vegetables, especially green vegetables such as beans, green peas, podded peas, and edamame, are used in boiled green vegetables, there is also a problem of discoloration and fading due to the decrease in pH. The commercial value of boiled green vegetables that have discolored or faded will be significantly reduced.

As a means of preventing such vegetables from discoloring or fading, a method of using sodium ascorbate has been proposed (Patent Documents 1 to 3).

In addition, ascorbic acid or sodium ascorbate is widely used as an antioxidant component in the processing of fruits, vegetables, livestock meat, etc., but it is known that it is an unstable substance that decomposes or discolors due to the influence of moisture, oxygen, acid, alkali, etc. during storage. Therefore, a method for improving the stability of conventional ascorbic acid is proposed.

Patent document 4 proposes a method of coating L-ascorbic acid and its salts with fats to stabilize them, but the production process requires a lot of labor and there are problems such as reduced solubility in water and difficulty in application to non-heated foods.

Patent document 5 proposes a method of stabilizing vitamin C by adding chlorogenic acid. However, chlorogenic acid has a bitter or sour taste, so its impact on the taste of food cannot be ignored.

Patent document 6 proposes a composition containing ascorbic acid and containing protamine or its salt as a stabilizer. However, since protamine has a unique smell, its effect on the taste of food cannot be ignored.

Patent document 7 proposes a vitamin C-containing composition containing vitamin C and erythritol, but erythritol has a unique sweet taste and is easy to recrystallize, and its impact on the taste and physical properties of food cannot be ignored.

However, even with these methods, the coloring inhibition of ascorbic acid is still insufficient. In particular, in food long-lasting enhancers containing various organic acids or their salts, the coloring during storage will be obvious, and a unique odor will be generated as the coloring progresses.

Therefore, it is desired to have a quality preservative that has little effect on the taste or flavor of food, has antibacterial effect and discoloration inhibition effect, and has excellent stability in inhibiting the coloring of ascorbic acid.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 08-056610

[Patent Document 2] Japanese Patent Publication No. 08-308523

[Patent Document 3] Japanese Patent Publication No. 2015-000018

[Patent Document 4] Japanese Patent Publication No. 53-127819

[Patent Document 5] Japanese Patent Publication No. 06-009603

[Patent Document 6] Japanese Patent Publication No. 06-247854

[Patent Document 7] Japanese Patent Publication No. 09-095447

The purpose of the present invention is to provide a quality preservative that has little effect on the taste or flavor of food, has antibacterial effect and discoloration inhibition effect, and has excellent stability in that the coloring and generation of odor of the quality preservative are suppressed.

As a result of intensive research to solve the above-mentioned problems, the inventors of this case found that the above-mentioned problems can be solved by formulating polytriglucose in a preparation containing ascorbic acid in a manner that satisfies specific conditions, thereby completing the present invention.

That is, the present invention provides a powdered quality retainer containing ascorbic acid, acetate and polytriglucose, wherein the drying loss (Xa) of the quality retainer after drying for 12 hours at a temperature of 45°C and a relative humidity of 20%RH is -0.1 to 0.1%, and the drying loss (Xb) after drying for 4 hours at a temperature of 120°C is 0.05 to 0.5%, and the color difference (ΔYI) between the yellowness (YIa) of the quality retainer sealed in a 50mL glass bottle with a cap after being stored at a temperature of 45°C for 2 weeks and the yellowness (YIb) after being stored at a temperature of 0°C for 2 weeks is less than 14.

In addition, the present invention provides a method for maintaining food quality, which comprises immersing food in a solution in which the powdered quality preserving agent is dissolved, or mixing the solution with raw materials. In addition, the present invention provides a method for stabilizing a powdered quality preserving agent, which comprises mixing powdered polytriglucose in a powdered quality preserving agent containing ascorbic acid and acetate.

The present invention is described in detail below.

In the present invention, "quality maintenance" refers to achieving both the increase in the shelf life of the added object and the suppression of discoloration.

The ascorbic acid and acetate used in the powdered quality preservative of the present invention are not particularly limited, but commercially available food additives can be used.

Examples of ascorbic acid include L-ascorbic acid, sodium L-ascorbate, calcium L-ascorbate, potassium L-ascorbate, ammonium L-ascorbate, monoethanolamine L-ascorbate, diethanolamine L-ascorbate, isoascorbic acid, sodium isoascorbate, calcium isoascorbate, potassium isoascorbate, ammonium isoascorbate, monoethanolamine L-ascorbate, diethanolamine L-ascorbate, etc. Among them, sodium L-ascorbate is preferred because of its excellent solubility in water, excellent dispersibility in food, and excellent discoloration inhibition effect.

The above-mentioned ascorbic acid can be used in either anhydride or hydrate form, or two or more types can be used in combination.

The average particle size (D ₅₀ ) of the ascorbic acid is preferably 50 to 250 μm, more preferably 80 to 240 μm, and even more preferably 100 to 230 μm. When the average particle size is less than 50 μm, the coloring of the quality retaining agent tends to proceed, and when it exceeds 250 μm, segregation tends to occur easily.

Examples of acetate salts include sodium acetate, potassium acetate, calcium acetate, etc. Among them, sodium acetate is preferred because of its excellent solubility in water, excellent dispersibility in food, and excellent antibacterial effect.

The above-mentioned acetic acid salt may be used in the form of either an anhydride or a hydrate, or may be used in combination of two or more.

The average particle size (D ₅₀ ) of the acetic acid salt is preferably 150 to 350 μm, more preferably 180 to 320 μm, and even more preferably 200 to 300 μm. When the average particle size is less than 150 μm, the coloring of the quality retaining agent tends to proceed, and when it exceeds 350 μm, segregation tends to occur easily.

In the powdered quality-preserving agent of the present invention, the mixing ratio of ascorbic acid and acetate is not particularly limited and can be adjusted within the range of 1:99 to 99:1 according to the purpose. However, from the perspective of balancing the antibacterial effect and the discoloration inhibition effect, the mixing ratio is preferably 5:95 to 95:5, more preferably 10:90 to 90:10, more preferably 15:85 to 85:15, and even more preferably 20:80 to 80:20.

The ratio of ascorbic acid and acetate to the total weight of the powdered quality-keeping agent is preferably 40 to 99 weight%, more preferably 45 to 95 weight%, and even more preferably 50 to 90 weight%. When the total ratio of ascorbic acid and acetate to the total weight of the powdered quality-keeping agent is less than 40 weight%, the antibacterial effect or discoloration inhibition effect tends to be insufficient. When it exceeds 99 weight%, the coloration inhibition effect of the quality-keeping agent is low, and the effect on the taste of food tends to be greater.

The polytriglucose used in the powdered quality-maintaining agent of the present invention is a polysaccharide produced by microorganisms and has a structure of glucose polymerization. Therefore, the molecular weight of polytriglucose is not fixed, and there are various types of polytriglucose. In the present invention, any type of polytriglucose can be used, but the one commonly sold on the market as a food additive or a pharmaceutical additive can be used.

In addition, the average particle size (D ₅₀ ) of the polytriglucose is preferably 100 to 300 μm, more preferably 130 to 270 μm, and even more preferably 150 to 250 μm. When the average particle size is less than 100 μm, segregation tends to occur, and when it exceeds 300 μm, the coloring of the quality retaining agent tends to proceed.

The ratio of polytriglucose can be appropriately adjusted to correspond to the ratio of the above-mentioned ascorbic acid and acetate. However, due to the coloring inhibition effect of ascorbic acid and the reduced impact on the physical properties of food, the ratio is preferably 1 to 10% by weight, more preferably 1.5 to 8% by weight, and even more preferably 2 to 7% by weight relative to the total weight of the powdered quality retainer.

The ascorbic acid, acetate and polytriglucose in the powdered quality retainer of the present invention have different water contents, and the water contents will also change with the different environments in which the materials are stored. Therefore, after preparing the powdered quality retainer, the drying loss (Xa) and drying loss (Xb) are measured. According to the measurement results, the mixing ratio of the materials is appropriately adjusted to adjust the drying loss. The drying loss can be calculated from the weight before and after drying using the following calculation formula.

Drying loss (%) = ((weight before drying - weight after drying) / weight before drying) × 100

The drying loss (Xa) is calculated from the weight before drying by measuring the weight before drying, drying for 12 hours at a temperature of 45°C and a relative humidity of 20%RH, and measuring the weight after drying. The drying loss (Xa) can be -0.1 to 0.1%, preferably -0.05 to 0.08%, and more preferably 0 to 0.07%.

The drying loss (Xb) is calculated from the weight before drying and after drying at 120°C for 4 hours. The weight after drying is measured and the above calculation formula is used to calculate the weight before and after drying. The drying loss (Xb) can be 0.05 to 0.5%, preferably 0.06 to 0.4%, and more preferably 0.07 to 0.35%.

Either the drying loss (Xa) or the drying loss (Xb) must be adjusted within the above range. By setting both within the above range, the coloring of the quality-preserving agent during storage can be suppressed.

Therefore, in the powdered quality retainer of the present invention, the coloration suppression effect must be further confirmed. Specifically, the powdered quality retainer sealed in a 50 mL glass bottle with a cap is adjusted so that the color difference (ΔYI) between the yellow chromaticity (YIa) after being stored at a temperature of 45°C for 2 weeks and the yellow chromaticity (YIb) after being stored at a temperature of 0°C for 2 weeks does not reach 14. The color difference (ΔYI) is preferably less than 12, and more preferably less than 11.

In the present invention, the yellow chromaticity can be measured by using a measuring instrument generally known to a person of ordinary skill in the technical field to which the invention belongs. The measuring instrument is not particularly limited as long as it can measure the yellow chromaticity, but examples thereof include a spectrophotometer (e.g., SE7700 (manufactured by Nippon Denshoku Industries Co., Ltd.)), a colorimetric colorimeter (e.g., ZE6000 (manufactured by Nippon Denshoku Industries Co., Ltd.)), etc. The powdered quality retaining agent of the present invention uses a colorimetric colorimeter ZE6000 (manufactured by Nippon Denshoku Industries Co., Ltd.) to obtain the yellow chromaticity (YIa), yellow chromaticity (YIb) and color difference (ΔYI) by the yellow chromaticity (YI) measurement method specified in ASTM D 1925.

The powdered quality-maintaining agent of the present invention may further contain a pH adjuster. As the pH adjuster, those confirmed to be usable as food additives can be used except ascorbic acid and acetate. Preferred pH adjusters can be selected from the group consisting of citric acid, fumaric acid, apple acid, succinic acid, adipic acid, lactic acid, tartaric acid, gluconic acid, phytic acid, propionic acid, butyric acid, phosphoric acid, hypophosphorous acid and phosphorous acid, or sodium salts, potassium salts, calcium salts and ammonium salts thereof. Among them, from the perspective of high water solubility or little effect on food taste, it is more preferred to select one or more of the group consisting of citric acid, trisodium citrate, monosodium fumarate and malic acid, and particularly preferred is citric acid, trisodium citrate and/or monosodium fumarate.

The amount of the pH adjuster added is not particularly limited, but it is preferably adjusted so that the pH of a 4 wt% aqueous solution is 6.3 to 6.9, more preferably 6.4 to 6.8, and even more preferably 6.5 to 6.7. When the pH is less than 6.3, the discoloration inhibition effect of vegetables tends to decrease, and when it exceeds 6.9, the antibacterial effect tends to decrease.

The powdered quality preservative of the present invention can further contain sodium chloride and/or potassium chloride because the above-mentioned ascorbic acid, acetate, and pH adjuster reduce the impact on food taste. Sodium chloride is more preferred from the perspective of discoloration inhibition effect and excellent taste. The amount of sodium chloride and/or potassium chloride added is not particularly limited and can be determined by considering the impact on taste when applying the powdered quality preservative.

The preparation of the powdered quality retainer of the present invention does not require any special operation, and the above ingredients can be mixed. In addition, for the purpose of improving the physical properties and stability of the preparation, a shaping agent such as dextrin or an anti-caking agent such as micro-particle silicon dioxide may be contained.

The packaging form of the powdered quality retainer of the present invention is not particularly limited. After preparation, it can be filled into bags or containers of appropriate materials. For example, when filled into a packaging bag, the material is preferably a plastic packaging material with low water vapor permeability, such as polyethylene, polyethylene terephthalate, polypropylene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, and vapor-deposited film. Among these packaging materials, polyethylene, aluminum vapor-deposited film, and silicon dioxide vapor-deposited film are more preferred. In addition, these packaging materials can be single-layer films or multi-layer films.

There is no particular limitation on the timing of applying the powdered quality preservative of the present invention. For example, when applied to boiled green vegetables, it can be applied before or after boiling the green vegetables, or during boiling. The application method of the powdered quality preservative of the present invention can be exemplified by: boiling green vegetables in a boiling liquid with powder added, adding powder to the boiling liquid after boiling green vegetables, adding powder to a seasoning liquid such as seasoning and sprinkling it on boiled green vegetables, sprinkling powder directly on boiled green vegetables, soaking boiled green vegetables in a solution in which a powdered quality preservative is dissolved, and spraying or applying the solution on the green vegetables. In addition, other application methods can be exemplified by: when applied to stuffings, mixing with the raw materials of the stuffings.

The method for maintaining the quality of food of the present invention can be a method of dissolving the powdered quality preservative of the present invention in a solution of a solvent and impregnating the food. In the impregnation liquid, the powdered quality preservative is preferably dissolved in 2 to 7% by weight, more preferably 3 to 5% by weight, relative to the solvent. When it is less than 2% by weight, the discoloration inhibition effect and antibacterial effect are insufficient, and thus it is not good. When it exceeds 7% by weight, the effect on taste becomes greater, and thus it is not good.

The pH of the solution in which the powdered quality preservative of the present invention is dissolved is 6.3 to 6.9, preferably 6.4 to 6.8, and particularly preferably 6.5 to 6.7. Examples of solvents include water and a mixture of water and ethanol. As long as the pH of the solution is within the above range, it can also be dissolved in a seasoning liquid containing nucleic acid-based liquid seasonings, soy sauce-based liquid seasonings, and other seasonings, and then used together with food seasoning. The powdered quality preservative of the present invention also includes dissolving the above-mentioned components in an appropriate solvent or seasoning liquid and providing it as a solution.

The temperature and soaking time of the soaking liquid are not particularly limited, preferably 10 to 120 minutes at 0 to 15°C, and more preferably 30 to 90 minutes at 0 to 10°C. The amount of soaking liquid is not particularly limited as long as it can soak the vegetables to be processed, and the standard is about twice the weight of the vegetables.

Another aspect of the food quality preservation method of the present invention is to mix the powdered quality preservative of the present invention with the raw materials of the food. The amount of the powdered quality preservative added to the food is preferably 0.1 to 5% by weight, and more preferably 0.3 to 3% by weight, relative to the total weight of the food. When it is less than 0.1% by weight, the discoloration inhibition effect and antibacterial effect are insufficient, and thus it is not good. When it exceeds 5% by weight, the effect on taste becomes greater, and thus it is not good.

The method for stabilizing the powdered quality retainer of the present invention may include mixing a powdered quality retainer containing ascorbic acid and acetate with powdered polytriglucose, but is not limited thereto.

The food used in the present invention can be vegetables such as green vegetables, diced vegetables, boiled green vegetables, vegetable soups, etc.; vegetable side dishes such as potato salad, stew, and aemono; fruits such as diced fruits; fruit jams, fruit sauces, etc.; curry bread or meat bun fillings, sandwich fillings, etc.; fish cakes, bamboo shoots, etc. The store sells a wide variety of food products, including fish slices, half slices (Hanpen), fish ham, fish sausage, etc.; livestock meat products, including ham, sausage, bacon, hamburger meat, meatballs, etc.; fried products, including croquettes, pork chops, fried chicken, fried fish, chicken nuggets, etc.; rice products, including fried rice and steamed rice; noodles, including Chinese noodles, Italian noodles, udon noodles, buckwheat noodles, etc.; cream products, including custard sauce, whipped cream, flower paste, etc.; pastries, including Nagasaki cake, sponge cake, Japanese sweet steamed buns, stuffing, etc.; fruit juice drinks, vegetable drinks, carbonated drinks, tea drinks, etc., and other refreshing drinks. Among them, vegetables, processed vegetable products, vegetable side dishes, fruits, processed fruit products, and stuffings are preferred, and green vegetables containing chlorophyll, cut vegetables, and boiled green vegetables are particularly preferred. The effect can be expected to be greater for green vegetables of the leguminous family such as beans, peas, sweet snap beans, and edamame.

The food to which the powdered quality preservative of the present invention is applied by any method can be provided directly or after additional conditioning and/or seasoning. The food, which is directly or after conditioning and/or seasoning, can also be frozen and provided as a frozen food.

The following presents embodiments and comparative examples to further illustrate the present invention, but the present invention is not limited to these embodiments.

[Implementation example]

Test examples 1 to 15

Screening test for anti-coloring materials:

Prepare the preparations shown in Tables 1-1 to 1-3. 40 g of each prepared preparation was placed in a 50 mL glass bottle with a cap and stored at 0°C and 45°C for 1 month in a thermostat with a freezer (MIR-554-J manufactured by PHC Co., Ltd.). The degree of coloration of each preparation after storage was visually observed and evaluated according to the following evaluation criteria. In addition, the odor of each preparation after storage was confirmed and evaluated according to the following evaluation criteria. The evaluation results of coloration and odor are presented in Tables 1-1 to 1-3. In addition, the following materials were used to prepare each preparation.

‧ Anhydrous L-ascorbic acid sodium (average particle size (D ₅₀ ): 155 μm, manufactured by Weisheng Pharmaceutical Co., Ltd.)

‧Anhydrous sodium acetate (average particle size (D ₅₀ ): 276 μm, manufactured by Mitsubishi Chemical Co., Ltd.)

‧Polytriglyceride (average particle size (D ₅₀ ): 233 μm, manufactured by Hayashibara Co., Ltd.)

‧Dextrin I (Max1000EX-C (DE: 7.0 to 9.0), manufactured by Songgu Chemical Industry Co., Ltd.)

‧Dextrin II (Pinedex (registered trademark) # 2 (DE: 10.0 to 12.0), manufactured by Songgu Chemical Industry Co., Ltd.)

‧Dextrin III (Cluster Dextrin (registered trademark) (DE: less than 5), manufactured by Glico Nutrition Foods Co., Ltd.)

‧Dextrin IV (CAVAMAX (registered trademark) W7 Food, manufactured by Cyclochem Co., Ltd.)

‧Xanthan gum: (Xanthan gum C/made by Omiya Food Industry Co., Ltd.)

‧Trehalose (produced by Linyuan Co., Ltd.)

‧Fumaric acid (produced by Kawasaki Chemical Industries, Ltd.)

‧Adipic acid (produced by Asahi Kasei Chemicals Co., Ltd.)

‧Citric acid (produced by Showa Chemical Industry Co., Ltd.)

‧Monosodium fumarate (manufactured by Kawasaki Chemical Industries, Ltd.)

‧Sodium citrate (manufactured by Iwata Chemical Industry Co., Ltd.)

‧Ferulic acid (manufactured by Chikuno Food Industry Co., Ltd.)

‧Alanine (produced by Musashino Chemical Research Institute Co., Ltd.)

[Evaluation criteria for coloring]

○: Compared with Test Example 1 stored at 45°C for 1 month, coloring is suppressed

△: Same as test example 1 stored at 45°C for 1 month

×: Compared with Test Example 1 stored at 45°C for 1 month, there is coloration

[Evaluation criteria for odor]

○: Same as Test Example 1 which was stored at 0℃ for 1 month

×: Compared with Test Example 1 which was stored at 0℃ for 1 month, there is a strange smell.

單位：重量% [Table 1-1]

Unit: Weight%

單位：重量% [Table 1-2]

Unit: Weight%

單位：重量% [Table 1-3]

Unit: Weight%

Examples 1 to 11 and Comparative Examples 1 to 9

Preparation of powdered quality maintenance agent:

Preparations A to T of the compositions shown in Tables 2-1 to 2-4 were prepared (the numerical values showing the ratios of the components in the table are in weight %). In addition, the materials used in the preparation of each preparation were the same as those in the above test examples.

Determination of loss on drying:

2 g of the prepared preparations A to T were placed in a weighing bottle and placed in a constant temperature desiccator (MOV-202 manufactured by Sanyo Electric Co., Ltd.) set at 45°C (relative humidity 20% RH) at room temperature 25°C and relative humidity 60% RH for 12 hours. Similarly, the bottles were dried in a vacuum desiccator (VO-32D manufactured by Toyo Seisakusho Co., Ltd.) set at 120°C at room temperature 25°C and relative humidity 60% RH for 4 hours. The weight loss was calculated from the weight before and after drying at each temperature and was defined as the drying loss. The test results of the drying loss (Xa) after drying for 12 hours at a temperature of 45°C and a relative humidity of 20% RH and the drying loss (Xb) after drying for 4 hours at a temperature of 120°C are shown in Tables 2-1 to 2-4.

Determination of color difference:

40 g of each of the prepared preparations A to T were placed in a 50 mL glass bottle with a cap and stored at 0°C and 45°C for 2 weeks in a thermostat with a freezer (MIR-554-J manufactured by PHC Co., Ltd.). The yellowness of the preparations after storage was measured using a colorimeter ZE6000 (manufactured by Nippon Denshoku Industries Co., Ltd.) according to the yellowness (YI) measurement method specified in ASTM D1925. The color difference (ΔYI) was calculated by subtracting the yellowness (YIb) of the preparation stored at 0°C from the yellowness (YIa) of the preparation stored at 45°C. The color difference measurement results are shown in Tables 2-1 to 2-4.

[Table 2-1]

[Table 2-2]

[Table 2-3]

[Table 2-4]

Compared with the preparation of the comparative example, the powdered quality maintenance agent of the present invention has a smaller color difference (ΔYI), and the coloring from sodium L-ascorbate is suppressed.

Example 12

Determination of drying loss and color difference of preparations:

The drying loss (Xa, Xb) and color difference (ΔYI) of the preparations shown in Table 3 were measured by the same method as in the above-mentioned embodiment. The results are shown in Table 3. In addition, the following materials were used in the preparation of each preparation.

‧Anhydrous sodium acetate (average particle size (D ₅₀ ): 276 μm, manufactured by Mitsubishi Chemical Co., Ltd.)

‧ Anhydrous L-ascorbic acid sodium (average particle size (D ₅₀ ): 155 μm, manufactured by Weisheng Pharmaceutical Co., Ltd.)

‧Sodium chloride (produced by Nippon Salt Manufacturing Co., Ltd.)

‧Trisodium citrate (manufactured by Iwata Chemical Industry Co., Ltd.)

‧Monosodium fumarate (manufactured by Fuso Chemical Industries, Ltd.)

‧Polytriglyceride (average particle size (D ₅₀ ): 233 μm, manufactured by Hayashibara Co., Ltd.)

Boiled beans discoloration inhibition test:

紅色)、色相b^*值(藍色

黃色)。將剛製造後的值附註p，保存後的值附註q來顯示時，藉由下式算出整體的色差ΔE^*。 Dissolve 8 g of the preparation shown in Table 3 in 200 g of tap water to prepare a 4 wt% aqueous solution. Boil commercially available frozen kidney beans in 1% salt water for 1 minute and 30 seconds, drain, and soak in the prepared aqueous solution at 4°C for 60 minutes. Take the kidney beans out of the soaking liquid, put them into sterilized plastic bags for bacteria inspection at 5 g each and seal them as samples. The samples are kept in a thermostat at 25°C under 10001x irradiation for 2 days. Determine the general bacterial count of the sample after maintenance and evaluate it according to the following antibacterial effect evaluation standard. Visually observe the color change of the sample after maintenance and evaluate it according to the following color change inhibition effect evaluation standard (visual). In addition, the brightness L ^* value and hue a ^* value (green) of the boiled beans just after production and after storage were measured using a colorimeter ZE6000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

Red), hue b ^* value (blue

Yellow). When the value immediately after manufacturing is annotated with p and the value after storage is annotated with q and displayed, the overall color difference ΔE ^* is calculated using the following formula.

(Formula) ΔE ^* = [(L ^* qL ^* p) ² + (a ^* qa ^* p) ² + (b ^* qb ^* p) ² ] ^1/2

ΔE ^* represents the difference between the values of L ^* , a ^* , and b ^* immediately after production and after storage, and was evaluated according to the following discoloration suppression effect evaluation criteria (color difference ΔE ^* ). Furthermore, the taste of kidney beans immediately after being taken out of the soaking liquid was evaluated according to the following taste evaluation criteria.

[Criteria for evaluating antibacterial effects]

○: General bacterial count (CFU/g) <10 ³

△: 10 ³ ≦ General bacterial count (CFU/g) < 10 ⁴

×: 10 ⁴ ≦ General bacterial count (CFU/g)

[Evaluation criteria for discoloration suppression effect (visual inspection)]

○: Has a discoloration suppression effect compared to no treatment

×: No discoloration suppression effect compared to no treatment

[Evaluation criteria for discoloration suppression effect (color difference ΔE ^* )]

The smaller the value of ΔE ^* is, the less the change from immediately after production is, and the higher the discoloration suppression effect is. The value of ΔE ^* is preferably 12 or less, and more preferably 11 or less.

[Taste quality evaluation criteria]

○: Almost no odor, better

△: There is a slight odor, slightly better

×: There is a strange smell, not good

[Table 3]

The powdered quality preservative of the present invention still maintains the color of the preparation after being stored for 2 weeks, does not produce any peculiar smell, etc., and exhibits excellent antibacterial and discoloration inhibition effects on kidney beans.

Claims (13)

A powdered quality preservative contains ascorbic acid, acetate and polytriglucose, wherein the quality preservative has a drying loss (Xa) of -0.1 to 0.1% when dried for 12 hours at a temperature of 45°C and a relative humidity of 20%RH, and a drying loss (Xb) of 0.05 to 0.5% when dried for 4 hours at a temperature of 120°C. The quality preservative is sealed in a 50mL glass bottle with a cap. The color difference (△YI) between the yellowness (YIa) of the quality-preserving agent after being stored at a temperature of 45°C for 2 weeks and the yellowness (YIb) after being stored at a temperature of 0°C for 2 weeks is less than 14, wherein the total ratio of ascorbic acid and acetate is 40 to 99% by weight relative to the total weight of the powdered quality-preserving agent, and the ratio of polytriglucose is 1 to 10% by weight relative to the total weight of the powdered quality-preserving agent. The powdered quality maintenance agent as described in claim 1, wherein the drying loss (Xa) is -0.05 to 0.08%, the drying loss (Xb) is 0.06 to 0.4%, and the color difference (△YI) is less than 12. The powdered quality retaining agent as described in claim 1 or 2, wherein the ascorbic acid is selected from one or more of the group consisting of L-ascorbic acid, sodium L-ascorbate, calcium L-ascorbate, potassium L-ascorbate, ammonium L-ascorbate, monoethanolamine L-ascorbic acid, diethanolamine L-ascorbic acid, isoascorbic acid, sodium isoascorbate, calcium isoascorbate, potassium isoascorbate, ammonium isoascorbate, monoethanolamine L-ascorbic acid, and diethanolamine isoascorbic acid. A powdered quality retainer as described in claim 1 or 2, wherein the acetate is selected from one or more of the group consisting of sodium acetate, potassium acetate, and calcium acetate. A powdered quality retaining agent as described in claim 1 or 2, wherein the mixing ratio of ascorbic acid and acetate is 1:99 to 99:1. The powdered quality maintenance agent as described in claim 1 or 2 further contains a pH adjuster. The powdered quality retainer as described in claim 6, wherein the pH adjuster is selected from one or more of the group consisting of citric acid, fumaric acid, apple acid, succinic acid, adipic acid, lactic acid, tartaric acid, gluconic acid, phytic acid, propionic acid, butyric acid, phosphoric acid, hypophosphorous acid and phosphorous acid, or their sodium salts, potassium salts, calcium salts and ammonium salts. A powdered quality-maintaining agent as described in claim 1, wherein the loss on drying (Xa) is -0.05 to 0.08%, the loss on drying (Xb) is 0.06 to 0.4%, the color difference (△YI) is less than 12, and the ascorbic acid is selected from L-ascorbic acid, sodium L-ascorbate, calcium L-ascorbate, potassium L-ascorbate, ammonium L-ascorbate, monoethanolamine L-ascorbic acid, diethanolamine L-ascorbic acid, isoascorbic acid, sodium isoascorbate, calcium isoascorbate, potassium isoascorbate, ammonium isoascorbate, monoethanolamine L-ascorbic acid, One or more of the group consisting of isoascorbic acid diethanolamine, the acetate is one or more of the group consisting of sodium acetate, potassium acetate, and calcium acetate, and the mixing ratio of ascorbic acid and acetate is 1:99 to 99:1. The powdered quality retainer further contains a pH adjuster, and the pH adjuster is one or more of the group consisting of citric acid, fumaric acid, malic acid, succinic acid, adipic acid, lactic acid, tartaric acid, gluconic acid, phytic acid, propionic acid, butyric acid, phosphoric acid, hypophosphorous acid, and phosphorous acid, or their sodium salts, potassium salts, calcium salts, and ammonium salts. A method for maintaining food quality, comprising immersing the food in a solution containing a powdered quality maintaining agent as described in any one of claims 1 to 8. The quality maintenance method as described in claim 9, wherein the food is selected from one or more of the group consisting of green vegetables, boiled green vegetables, cut vegetables, and cut fruits. A method for maintaining food quality, comprising mixing the powdered quality maintaining agent described in any one of claim 1 to 8 with the raw materials of the food. The quality maintenance method as described in claim 11, wherein the food is selected from one or more of the group consisting of vegetable side dishes, fruit processed products, and fillings. A method for stabilizing a powdered quality-preserving agent comprises mixing powdered polytriglucose with a powdered quality-preserving agent containing ascorbic acid and acetate, wherein the total ratio of ascorbic acid and acetate is 40 to 99% by weight relative to the total weight of the powdered quality-preserving agent, and the ratio of polytriglucose is 1 to 10% by weight relative to the total weight of the powdered quality-preserving agent.