Powdered quality maintenance agent and quality maintenance method

Abstract

The object of the present invention is to provide a quality retainer with little effect on the taste and flavor of food, antibacterial effect and discoloration inhibition effect, and excellent stability of inhibiting the quality retainer from coloring and odor. A powdered quality retainer is provided, which is a powdered quality retainer containing ascorbic acid, acetate and pullulan, wherein the drying loss (Xa) of the quality retainer when dried for 12 hours at a temperature of 45°C and a relative humidity of 20%RH is 0.1~0.1%, and the drying loss (Xb) when dried for 4 hours at a temperature of 120°C is 0.05~0.5%, and the color difference (ΔYI) of the yellowness (YIa) of the quality retainer sealed in a glass bottle with a cover of 50mL after being stored for 2 weeks at a temperature of 45°C and the yellowness (YIb) after being stored for 2 weeks at a temperature of 0°C is less than 14.

Description

Technical Field

[0001] The present invention mainly relates to a powdered quality-maintaining agent containing ascorbic acid which has an antibacterial effect and a discoloration-inhibiting effect on food. In addition, the present invention also relates to a method for maintaining the quality of food by improving the antibacterial effect and the discoloration-inhibiting effect on food. Background Art

[0002] In the field of food, various countermeasures have been adopted to improve the preservability of food. Among them, preservation by adding a pH adjusting agent is known as a representative method and has been used for various foods. However, when preserving by adding a pH adjusting agent, if the pH is reduced to a degree that can ensure sufficient preservability, there is a problem that the food presents an unnatural sour taste. In addition, in the case of boiled green vegetables obtained by boiling vegetables, particularly green vegetables such as kidney beans, green peas, pea pods, and edamame, there is also a problem of promoting discoloration and fading due to pH reduction. The commercial value of the boiled green vegetables that have discolored or faded is significantly reduced.

[0003] As a method for preventing such discoloration or fading of vegetables, a method using sodium ascorbate has been proposed (Patent Documents 1 to 3).

[0004] In addition, ascorbic acid or sodium ascorbate is widely used as an antioxidant component when processing fruits, vegetables, livestock meat, etc., but it is known that it is an unstable substance that decomposes or discolors during storage due to the influence of water, oxygen, acid, alkali, etc. Therefore, methods for improving the stability of ascorbic acid have been proposed.

[0005] Patent Document 4 proposes a stabilization method based on coating L-ascorbic acid and its salts with fats and oils, but there are problems such as difficulty in preparation, reduced solubility in water, and difficulty in application to non-heated foods.

[0006] Patent Document 5 proposes a stabilization method by blending chlorogenic acid into vitamin C. However, since chlorogenic acid has astringent or sour taste, its influence on the taste of food cannot be ignored.

[0007] Patent Document 6 proposes an ascorbic acid-containing composition blended with protamine or a salt thereof as a stabilizer. However, since protamine has a unique odor, its influence on the taste of food cannot be ignored.

[0008] Patent Document 7 proposes a vitamin C-containing composition containing vitamins C and erythritol. However, erythritol not only has a unique sweet taste but also easily recrystallizes, and its influence on the taste and physical properties of food cannot be ignored.

[0009] However, even these methods cannot fully suppress the coloration of ascorbic acid, and in particular, in food preservability improving agents containing various organic acids or their salts, the coloration during storage is remarkable, and a unique odor is generated as the coloration progresses.

[0010] Therefore, there is a demand for a quality retaining agent that has little influence on the taste and flavor of food, has an antibacterial effect and a discoloration suppressing effect, and is excellent in stability in suppressing the coloring of ascorbic acid.

[0011] Prior art literature

[0012] Patent Literature

[0013] Patent Document 1: Japanese Patent Application Laid-Open No. 08-056610

[0014] Patent Document 2: Japanese Patent Application Laid-Open No. 08-308523

[0015] Patent Document 3: Japanese Patent Application Publication No. 2015-000018

[0016] Patent Document 4: Japanese Patent Application Laid-Open No. 53-127819

[0017] Patent Document 5: Japanese Patent Application Laid-Open No. 06-009603

[0018] Patent Document 6: Japanese Patent Application Laid-Open No. 06-247854

[0019] Patent document 7: Japanese Patent Application Laid-Open No. 09-095447. Summary of the invention

[0020] Problems to be solved by the invention

[0021] The object of the present invention is to provide a quality preservative having little effect on the taste and flavor of food, having an antibacterial effect and a discoloration suppressing effect, and having excellent stability in suppressing the generation of coloration and odor in the quality preservative.

[0022] Means of solving problems

[0023] The present inventors have conducted intensive studies to solve the above problems and have found that the above problems can be solved by blending pullulan so that the water content in a preparation containing ascorbic acid satisfies specific conditions, thereby completing the present invention.

[0024] That is, the present invention provides a powdered quality-preserving agent, which is a powdered quality-preserving agent containing ascorbic acid, acetate and pullulan, wherein the drying loss (Xa) of the quality-preserving agent when dried for 12 hours in an environment of a temperature of 45°C and a relative humidity of 20%RH is -0.1 to 0.1%, and the drying loss (Xb) when dried for 4 hours in an environment of a temperature of 120°C is 0.05 to 0.5%, and the color difference (ΔYI) between the yellowness (YIa) of the quality-preserving agent sealed in a 50 mL glass bottle with a cover after being stored in an environment of a temperature of 45°C for 2 weeks and the yellowness (YIb) after being stored in an environment of a temperature of 0°C for 2 weeks is less than 14.

[0025] The present invention also provides a method for maintaining the quality of food, characterized in that the food is immersed in a solution in which the powdered quality preserving agent is dissolved, or mixed with raw materials. The present invention also provides a method for stabilizing a powdered quality preserving agent, characterized in that powdered pullulan is mixed with a powdered quality preserving agent containing ascorbic acid and acetate. DETAILED DESCRIPTION

[0026] The present invention is described in detail below.

[0027] In the present invention, "quality maintenance" means that both the storage stability of the added object can be improved and the discoloration can be suppressed.

[0028] In the specification and claims, the term "food" refers to any type of food material or processed food that can be sold on the market, whether processed or not.

[0029] In the specification and claims, the term "ascorbic acid" means ascorbic acid, its salts or esters. The ascorbic acid and acetate used in the powdery quality retaining agent of the present invention are not particularly limited, and commercially available products as food additives can be used.

[0030] Ascorbic acid, there can be exemplified 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 erythorbate, diethanolamine erythorbate, etc. Among them, sodium L-ascorbate is preferred because of its excellent solubility in water, dispersibility in food, and discoloration suppressing effect.

[0031] Among the above-mentioned ascorbic acids, both anhydrides and hydrates may be used, and two or more kinds may be used in combination.

[0032] In addition, the average particle size (D 50) is preferably 50 to 250 μm, more preferably 80 to 240 μm, and further preferably 100 to 230 μm. When the average particle size is less than 50 μm, the quality retaining agent tends to be colored, and when it exceeds 250 μm, segregation tends to occur easily.

[0033] Examples of the acetate include sodium acetate, potassium acetate, calcium acetate, etc. Among them, sodium acetate is preferred because of its excellent solubility in water, dispersibility in food, and antibacterial effect.

[0034] Of the above-mentioned acetates, both anhydrides and hydrates may be used, and two or more thereof may be used in combination.

[0035] In addition, the average particle size (D 50 ) is preferably 150 to 350 μm, more preferably 180 to 320 μm, and further preferably 200 to 300 μm. When the average particle size is less than 150 μm, the quality retaining agent tends to be colored, and when it exceeds 350 μm, segregation tends to occur easily.

[0036] The mixing ratio of ascorbic acid and acetate in the powdered quality retaining agent of the present invention is not particularly limited and can be adjusted within the range of 1:99 to 99:1 according to the purpose. However, from the viewpoint of achieving a good balance between the antibacterial effect and the discoloration inhibitory effect, it is preferably 5:95 to 95:5, more preferably 10:90 to 90:10, further preferably 15:85 to 85:15, and further preferably 20:80 to 80:20.

[0037] The sum of the ratios of ascorbic acid and acetate relative to the total weight of the powdered quality retaining agent is preferably 40 to 99% by weight, more preferably 45 to 95% by weight, and still more preferably 50 to 90% by weight. If the sum of the ratios of ascorbic acid and acetate relative to the total weight of the powdered quality retaining agent is less than 40% by weight, the antibacterial effect or discoloration inhibitory effect tends to be insufficient, and if it exceeds 99% by weight, the coloration inhibitory effect of the quality retaining agent tends to be reduced, and the influence on the taste of the food tends to be greater.

[0038] The pullulan used in the powdered quality retainer of the present invention is a polysaccharide produced by microorganisms, and has a structure formed by the polymerization of glucose. Therefore, the molecular weight of pullulan is not fixed, and there are various pullulans. In the present invention, any pullulan can be used, and products commercially available as food additives or pharmaceutical additives can generally be used.

[0039] In addition, the average particle size (D 50) is preferably 100 to 300 μm, more preferably 130 to 270 μm, and further preferably 150 to 250 μm. When the average particle size is less than 100 μm, segregation tends to occur easily, and when it exceeds 300 μm, the quality retaining agent tends to be colored.

[0040] The proportion of pullulan can be appropriately adjusted according to the ratio of ascorbic acid and acetate, but in order to reduce the influence of the coloring inhibitory effect of ascorbic acid and the physical properties of food, it 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 retaining agent.

[0041] Since the ascorbic acid, acetate and pullulan used as the materials of the powdered quality retainer of the present invention not only have different water contents, but also the water contents vary depending on the environment in which the materials are stored, the drying loss (Xa) and the drying loss (Xb) are measured after the powdered quality retainer is prepared, and the blending ratio of the materials is appropriately adjusted based on the measurement results, thereby adjusting the drying loss. The drying loss can be calculated from the weight before and after drying by the following calculation formula.

[0042] Loss on drying (%) = ((weight before drying - weight after drying) / weight before drying) × 100

[0043] The drying loss (Xa) is calculated 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 weight before and after drying is calculated by the above calculation formula. The drying loss (Xa) can be -0.1 to 0.1%, preferably -0.05 to 0.08%, and more preferably 0 to 0.07%.

[0044] The drying loss (Xb) is calculated by measuring the weight before drying, drying at 120°C for 4 hours, and measuring the weight after drying, from the weights before and after drying using the above calculation formula. The drying loss (Xb) may be 0.05 to 0.5%, preferably 0.06 to 0.4%, and more preferably 0.07 to 0.35%.

[0045] Both the loss on drying (Xa) and the loss on drying (Xb) need to be adjusted to the above ranges. By adjusting both to the above ranges, the coloring of the quality retaining agent during storage can be suppressed.

[0046] Therefore, in the powdered quality retainer of the present invention, it is also necessary to confirm that the coloring inhibition effect is exerted. Specifically, the powdered quality retainer sealed in a 50 mL glass bottle with a lid is adjusted so that the color difference (ΔYI) between the yellowness (YIa) 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. The color difference (ΔYI) is preferably less than 12, and more preferably less than 11.

[0047] In the present invention, the yellowness can be measured using a measuring device generally known to those skilled in the art. As the measuring device, there is no particular limitation as long as it is a device that can measure the yellowness, and 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 powdery quality retaining agent of the present invention uses a colorimetric colorimeter ZE6000 (manufactured by Nippon Denshoku Industries Co., Ltd.) to determine the yellowness (YIa), yellowness (YIb) and color difference (ΔYI) by the yellowness (YI, yellow index) measurement method specified in ASTM D 1925.

[0048] The powdered quality retainer of the present invention may also contain a pH adjusting agent. As a pH adjusting agent, any substance other than ascorbic acid and acetate that is confirmed to be used as a food additive may be used. As a preferred pH adjusting agent, one or more selected from 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 may be cited. Among them, from the viewpoint of high water solubility or small effect on the taste of food, more preferably selected from citric acid, trisodium citrate, monosodium fumarate and malic acid, particularly preferably citric acid, trisodium citrate and / or monosodium fumarate.

[0049] The amount of the pH adjuster added is not particularly limited, and 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 further preferably 6.5 to 6.7. If the pH is lower than 6.3, the discoloration inhibitory effect of vegetables tends to decrease, and if it exceeds 6.9, the antibacterial effect tends to decrease.

[0050] In order to reduce the influence of the above-mentioned ascorbic acid, acetate, and pH adjuster on the taste of food, the powdered quality preservative of the present invention may also contain sodium chloride and / or potassium chloride. From the viewpoint of the discoloration inhibition effect and the particularly excellent taste, sodium chloride is more preferred. There is no particular restriction on the amount of sodium chloride and / or potassium chloride added, and it can be determined by considering the influence on the taste when the powdered quality preservative is used.

[0051] The powdered quality retaining agent of the present invention can be prepared without any special operation, and only the above-mentioned components need to be mixed. In addition, in order to improve the physical properties and stability of the preparation, an excipient such as dextrin or an anti-caking agent such as fine-particle silicon dioxide may be contained.

[0052] The packaging form of the powdered quality retainer of the present invention is not particularly limited, and can be filled in a bag or container of a suitable material after preparation. For example, when filled in a packaging bag, as its material, a plastic packaging material with low water vapor permeability is preferred, and polyethylene, polyethylene terephthalate, polypropylene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride and vapor-deposited film can be exemplified. Among these packaging materials, polyethylene, aluminum vapor-deposited film, and silicon oxide vapor-deposited film are more preferred. In addition, these packaging materials can be monolayer films or laminated films.

[0053] There is no particular restriction on the timing of applying the powdered quality preservative of the present invention. For example, if it is applied to boiled green vegetables, it can be applied before or after the green vegetables are boiled, or during the boiling process. As the application method of the powdered quality preservative of the present invention, for example, the following methods can be cited: boil green vegetables with a boiling liquid added with powder, add powder to the boiling liquid after boiling the green vegetables, add powder to a seasoning liquid such as dressing and apply it to boiled green vegetables, apply powder directly to boiled green vegetables, immerse boiled green vegetables in a solution dissolved with a powdered quality preservative, spray and apply the solution to the green vegetables, etc. In addition, as other application methods, for example, if it is applied to fillings, a method of mixing it with the raw materials of the fillings can be cited.

[0054] As a method for maintaining the quality of food of the present invention, there can be cited a method of immersing food in a solution obtained by dissolving the powdered quality preserving agent of the present invention in a solvent. The impregnation liquid is prepared by dissolving preferably 2 to 7% by weight, more preferably 3 to 5% by weight of the powdered quality preserving agent relative to the solvent. If it is less than 2% by weight, the discoloration inhibition effect and antibacterial effect are insufficient, so it is not preferred, and if it exceeds 7% by weight, the influence on the taste becomes greater, so it is not preferred.

[0055] 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 the solvent include water and a mixture of water and ethanol; as long as the pH of the solution is within the above range, the powdered quality preservative can be dissolved in a seasoning liquid containing a nucleic acid-based liquid seasoning, a soy sauce-based liquid seasoning, and the like, and used for seasoning food at the same time. The powdered quality preservative of the present invention also includes a substance provided in the form of a solution in which the above-mentioned components are dissolved in an appropriate solvent or seasoning liquid.

[0056] The temperature and immersion time of the immersion liquid are not particularly limited, but are preferably about 10 to 120 minutes at 0 to 15° C., and more preferably about 30 to 90 minutes at 0 to 10° C. The amount of the immersion liquid is not particularly limited as long as it is an amount sufficient to immerse the vegetables to be treated, but as a standard, it is about twice the weight of the vegetables.

[0057] As another embodiment of the method for maintaining the quality of food of the present invention, a method of mixing the powdered quality preservative of the present invention with the raw materials of the food can be cited. The amount of the powdered quality preservative added to the food is preferably 0.1 to 5% by weight, more preferably 0.3 to 3% by weight relative to the total weight of the food. If it is less than 0.1% by weight, the discoloration inhibition effect and the antibacterial effect are insufficient, so it is not preferred. If it exceeds 5% by weight, the effect on the taste becomes greater, so it is not preferred.

[0058] Examples of the method for stabilizing the powdery quality-maintaining agent of the present invention include a method of mixing powdery pullulan with a powdery quality-maintaining agent containing ascorbic acids and acetate, but the present invention is not limited thereto.

[0059] The food used in the present invention can be used for vegetables such as green vegetables and cut vegetables, vegetable processed products such as boiled green vegetables and vegetable soup, vegetable side dishes such as potato salad, stew, mixed vegetables, fruits such as cut fruits, fruit processed products such as jam and fruit sauce, fillings such as curry bread or steamed buns, sandwich ingredients, etc., fish cakes, fish rolls (bamboo rolls), fish and sweet potato cakes, fish ham, fish sausages, etc., livestock meat products such as ham, sausage, bacon, hamburger beef patties, meatballs (minced balls), fried products such as croquettes, fried pork cutlets, fried chicken, fried fish, karaage (Karaage), etc., rice such as fried rice and vegetable rice, noodles such as Chinese noodles, pasta, udon noodles, soba noodles, custard cream, whipped cream, flower sugar paste (flower paste), etc. Paste) and other creams, Nagasaki cake (castella), sponge cake, steamed bread, bean paste and other desserts, fruit drinks, vegetable drinks, carbonated drinks, tea drinks and other refreshing drinks and other foods. Among them, vegetables, vegetable processed products, vegetable side dishes, fruits, fruit processed products, fillings are preferred, and green vegetables containing chlorophyll, cut vegetables, and cooked green vegetables are particularly preferred. Green vegetables of the leguminous family such as kidney beans, green peas, pea pods, and edamame can be expected to have a better effect.

[0060] The food to which the powdered quality retaining agent of the present invention is applied by any method may be provided as it is, or may be provided after being re-cooked and / or seasoned. The food as it is or after being cooked and / or seasoned may be frozen and provided as a frozen food.

[0061] The present invention will be further described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Example

[0062] Test Examples 1 to 15

[0063] Screening test for anti-staining materials

[0064] The preparations shown in Tables 1-1 to 1-3 were prepared. 40 g of each prepared preparation was placed in a 50 mL glass bottle with a lid and stored at 0°C and 45°C for 1 month in a thermostat with a refrigerator (manufactured by PHC Corporation: MIR-554-J). For each preparation after storage at 45°C, the degree of coloration was visually observed and evaluated according to the following evaluation criteria. In addition, for each preparation after storage at 0°C, the odor was confirmed and evaluated according to the following evaluation criteria. The evaluation results of coloration and odor are shown in Tables 1-1 to 1-3. It should be noted that the following materials were used in the preparation of each preparation.

[0065] · Anhydrous L-Sodium Ascorbate (average particle size (D 50 ): 155μm, manufactured by Weisheng Pharmaceutical Co., Ltd.

[0066] ·Sodium acetate anhydrous (average particle size (D 50 ): 276μm, manufactured by Mitsubishi Chemical Corporation)

[0067] ·Pullulan (average particle size (D 50 ): 233μm, manufactured by Hayashihara Co., Ltd.)

[0068] Dextrin I (Max1000EX-C (DE: 7.0~9.0), manufactured by Matsutani Chemical Industry Co., Ltd.)

[0069] Dextrin II (Pinedex (registered trademark) #2 (DE: 10.0~12.0), manufactured by Matsutani Chemical Industry Co., Ltd.)

[0070] Dextrin III (Cluster Dextrin (registered trademark) (DE: less than 5), manufactured by Glico Nutrition Co., Ltd.)

[0071] ·Dextrin IV (CAVAMAX (registered trademark) W7 Food, manufactured by CycloChem Co., Ltd.)

[0072] · Xanthan gum: (Xanthan gum C / manufactured by Omiya Grain Industry Co., Ltd.)

[0073] ·Trehalose (manufactured by Hayashihara Co., Ltd.)

[0074] Fumaric acid (manufactured by Kawasaki Chemical Industries, Ltd.)

[0075] ·Adipic acid (manufactured by Asahi Kasei Chemical Co., Ltd.)

[0076] ·Citric acid (Showa Chemical Industry Co., Ltd.)

[0077] ·Monosodium fumarate (manufactured by Kawasaki Chemical Industries, Ltd.)

[0078] ·Sodium citrate (manufactured by Iwata Chemical Industry Co., Ltd.)

[0079] ·Ferulic acid (produced by Chikuno Food Industry Co., Ltd.)

[0080] · Alanine (manufactured by Musashino Chemical Laboratories, Ltd.).

[0081] [Evaluation criteria for coloring]

[0082] ○: Coloration was suppressed compared to Test Example 1 when stored at 45°C for 1 month

[0083] △: Equivalent to that of Test Example 1 stored at 45°C for 1 month

[0084] ×: Colored compared with Test Example 1 after storage at 45°C for one month.

[0085] [Evaluation criteria for odor]

[0086] ○: Equivalent to Test Example 1 stored at 0°C for 1 month

[0087] ×: There is a strange smell compared with Test Example 1 stored at 0°C for one month.

[0088] [Table 1-1]

[0089]

[0090] [Table 1-2]

[0091]

[0092] [Table 1-3]

[0093]

[0094] Examples 1 to 11 and Comparative Examples 1 to 9

[0095] Preparation of powdered quality maintenance agent

[0096] Preparations A to T having the compositions shown in Tables 2-1 to 2-4 were prepared (the numerical values ​​indicating the ratios of the components in the tables are in weight %). It should be noted that the materials used to prepare the preparations were the same as those in the above-mentioned test examples.

[0097] Determination of loss on drying

[0098] 2 g of the prepared preparations A to T were placed in a weighing bottle, placed in a constant temperature dryer (MOV-202 manufactured by Sanyo Electric Co., Ltd.) set at 45°C (relative humidity 20% RH) in a room with a room temperature of 25°C and a relative humidity of 60% RH, and dried for 12 hours. Similarly, dried for 4 hours in a vacuum dryer (VO-32D manufactured by Toyo Seisakusho Co., Ltd.) set at 120°C in a room with a room temperature of 25°C and a relative humidity of 60% RH. The reduction rate was calculated from the weight before and after drying at each temperature as the drying loss. The measurement results of the drying loss (Xa) when dried for 12 hours in an environment with a temperature of 45°C and a relative humidity of 20% RH and the drying loss (Xb) when dried for 4 hours in an environment with a temperature of 120°C are shown in Tables 2-1 to 2-4.

[0099] Determination of color difference

[0100] 40 g of each of the prepared preparations A to T was placed in a 50 mL glass bottle with a lid and stored at 0°C and 45°C for 2 weeks in a thermostat with a refrigerator (manufactured by PHC Co., Ltd.: MIR-554-J). For the preparations after storage, the yellowness was measured by the yellowness (YI) measurement method specified in ASTM D 1925 using a colorimetric colorimeter ZE6000 (manufactured by Nippon Denshoku Industries Co., Ltd.). 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.

[0101] [Table 2-1]

[0102]

[0103] [Table 2-2]

[0104]

[0105] [Table 2-3]

[0106]

[0107] [Table 2-4]

[0108]

[0109] The powdered quality-maintaining agent of the present invention has a smaller color difference (ΔYI) than the preparation of the comparative example, and can suppress coloration derived from sodium L-ascorbate.

[0110] Example 12

[0111] Determination of drying loss and color difference of preparations

[0112] 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 examples. The results are shown in Table 3. The following materials were used in the preparation of each preparation.

[0113] ·Sodium acetate anhydrous (average particle size (D 50 ): 276μm, manufactured by Mitsubishi Chemical Corporation)

[0114] · Anhydrous L-Sodium Ascorbate (average particle size (D 50 ): 155μm, manufactured by Weisheng Pharmaceutical Co., Ltd.

[0115] ·Sodium chloride (manufactured by Nippon Salt Manufacturing Co., Ltd.)

[0116] · Trisodium citrate (manufactured by Iwata Chemical Industry Co., Ltd.)

[0117] ·Monosodium fumarate (manufactured by Fuso Chemical Industry Co., Ltd.)

[0118] ·Pullulan (average particle size (D 50 ): 233μm, manufactured by Hayashihara Co., Ltd.).

[0119] Experiment on the inhibition of discoloration of boiled beans

[0120] 8 g of the preparation shown in Table 3 was dissolved in 200 g of tap water to prepare a 4 wt % aqueous solution. After commercially available frozen kidney beans were boiled in 1% salt water for 1 minute and 30 seconds, the liquid was drained and immersed in the prepared aqueous solution at 4 ° C for 60 minutes. The kidney beans were taken out from the immersion liquid, and 5 g of each was placed in a sterilized polyethylene bag for bacterial inspection and sealed to make a sample. The sample was stored in a thermostat at 25 ° C under 1000 lx irradiation for 2 days. The general bacterial count of the sample after storage was determined and evaluated according to the following antibacterial effect evaluation criteria. The hue change of the sample after storage was observed visually and evaluated according to the following discoloration inhibition effect evaluation criteria (visual). In addition, the colorimetric colorimeter ZE6000 (manufactured by Nippon Denshoku Industries Co., Ltd.) was used to measure the brightness L* value, hue a* value (green ⇔ red), and hue b* value (blue ⇔ yellow) of the boiled kidney beans just after preparation and after storage. When the value immediately after preparation is indicated by the suffix p, and the value after storage is indicated by the suffix q, ΔE* as the comprehensive color difference is calculated by the following formula.

[0121] (Formula) ΔE*=[(L*qL*p) 2 +(a*qa*p) 2 +(b*qb*p) 2 ] 1 / 2

[0122] It should be noted that ΔE* represents the difference in the numerical values ​​of L*, a*, and b* immediately after preparation and after storage, and is evaluated according to the following discoloration inhibition effect evaluation criteria (color difference ΔE*). In addition, the taste of kidney beans immediately after being taken out of the immersion liquid was evaluated according to the following taste evaluation criteria.

[0123] [Evaluation criteria for antibacterial effect]

[0124] ○: General bacterial count (CFU / g) < 10 3

[0125] △: 10 3 ≤General bacterial count (CFU / g)<10 4

[0126] ×: 10 4 ≤General bacterial count (CFU / g).

[0127] [Evaluation criteria for discoloration suppression effect (visual inspection)]

[0128] ○: Compared with no treatment, discoloration is suppressed

[0129] ×: No discoloration suppressing effect compared with no treatment.

[0130] [Evaluation criteria for discoloration suppression effect (color difference ΔE*)]

[0131] The smaller the value of ΔE*, the less the change from immediately after preparation, and the higher the discoloration suppression effect. The value of ΔE* is preferably 12 or less, and more preferably 11 or less.

[0132] [Taste quality evaluation criteria]

[0133] ○: Almost no odor, preferred

[0134] △: Slightly odorous, but preferred

[0135] ×: Has a strange smell, not preferred

[0136] [Table 3]

[0137]

[0138] The powdered quality-preserving agent of the present invention can maintain the color tone at the time of preparation even after storage for 2 weeks, does not generate any odor, and exhibits excellent antibacterial effect and discoloration suppressing effect on kidney beans.

Claims

1. A powdered quality-preserving agent, which is a powdered quality-preserving agent containing ascorbic acid, acetate and pullulan, wherein: The drying loss Xa of the quality retaining agent 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 retaining agent sealed in a 50 mL glass bottle with a cover after being stored for 2 weeks at a temperature of 45°C and the yellowness YIb of the quality retaining agent stored for 2 weeks at a temperature of 0°C is less than 14, The total weight of the ascorbic acid and the acetate is 40 to 99% by weight relative to the total weight of the powdered quality retaining agent. The ratio of pullulan is 1 to 10% by weight relative to the total weight of the powdery quality-maintaining agent.

2. The powdery quality retaining agent according to claim 1, wherein The drying loss Xa is -0.05-0.08%, the drying loss Xb is 0.06-0.4%, and the color difference ΔYI is less than 12.

3. The powdery quality retaining agent according to claim 1, wherein The ascorbic acid is at least one selected from L-ascorbic acid, sodium L-ascorbate, calcium L-ascorbate, potassium L-ascorbate, ammonium L-ascorbate, L-ascorbic acid monoethanolamine, L-ascorbic acid diethanolamine, erythorbic acid, sodium erythorbate, calcium erythorbate, potassium erythorbate, ammonium erythorbate, erythorbic acid monoethanolamine and erythorbic acid diethanolamine.

4. The powdery quality retaining agent according to claim 1, wherein The acetate is one or more selected from the group consisting of sodium acetate, potassium acetate and calcium acetate.

5. The powdery quality retaining agent according to claim 1, wherein The mixing ratio of ascorbic acid to acetate is 1:99 to 99:

1. The powdery quality-maintaining agent according to claim 1 , further comprising a pH adjuster.

7. The powdery quality retaining agent according to claim 6, wherein The pH adjuster is one or more selected from 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, phosphorous acid, and sodium salts, potassium salts, calcium salts, and ammonium salts thereof.

8. The powdery quality retaining agent according to claim 1, The drying loss Xa is -0.05 to 0.08%, the drying loss Xb is 0.06 to 0.4%, and the color difference ΔYI is less than 12; wherein the ascorbic acid is at least one selected from L-ascorbic acid, sodium L-ascorbate, calcium L-ascorbate, potassium L-ascorbate, ammonium L-ascorbate, L-ascorbic acid monoethanolamine, L-ascorbic acid diethanolamine, erythorbic acid, sodium erythorbate, calcium erythorbate, potassium erythorbate, ammonium erythorbate, erythorbate monoethanolamine and erythorbate diethanolamine; wherein the acetate is one or more selected from the group consisting of sodium acetate, potassium acetate and calcium acetate; The mixing ratio of ascorbic acid to acetate is 1:99 to 99:1; and The powdered quality retainer further contains a pH adjuster, wherein the pH adjuster is one or more selected from 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, phosphorous acid, and their sodium salts, potassium salts, calcium salts, and ammonium salts.

9. A method for maintaining the quality of food, the method comprising immersing the food in a solution in which the powdered quality maintaining agent according to any one of claims 1 to 8 is dissolved.

10. The quality maintenance method according to claim 9, wherein: The food is one or more selected from green vegetables, cooked green vegetables, cut vegetables and cut fruits.

11. A method for maintaining the quality of food, the method comprising mixing the powdered quality maintaining agent according to any one of claims 1 to 8 with a raw material of the food.

12. The quality maintenance method according to claim 11, wherein: The food is one or more selected from vegetable side dishes, fruit processed products and fillings.

13. A method for stabilizing a powdered quality-maintaining agent, characterized in that: Powdered pullulan is mixed with a powdered quality-maintaining agent containing ascorbic acid and acetate. The total weight of the ascorbic acid and the acetate is 40 to 99% by weight relative to the total weight of the powdered quality retaining agent. The ratio of pullulan is 1 to 10% by weight relative to the total weight of the powdery quality-maintaining agent.

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