Coated citric acid particles

Abstract

The objective is to provide citric acid particles that have a slow rate of leaching into water and do not contain any undissolved components, when manufacturing foods with high moisture content. [Solution] Coated citric acid particles comprising citric acid particles and a coating that covers the surface of the citric acid particles, wherein the coating consists of at least an emulsifier and a water-soluble excipient, the HLB value of the emulsifier is 8.0 to 20.0, the water-soluble excipient is a polysaccharide, and the content ratio of the emulsifier and the water-soluble excipient is 6 to 99% by mass relative to the coated citric acid particles.

Description

Technical Field

[0001] The present invention relates to coated citric acid particles.

Background Art

[0002] Conventionally, citric acid has been used as one of the acidulants that impart acidity to foods. Examples of foods to which acidity is imparted by the addition of citric acid include, for example, soft drinks (flavored water, carbonated beverages, fruit juice beverages, milk-based beverages, tea beverages, sports beverages, nutritional drinks, jelly beverages, vinegar beverages, etc.) and powdered soft drinks (powdered juice, instant juice, tea mixes, etc.), alcoholic beverages (chuhai, cocktails, etc.), frozen desserts (sorbet, ice cream, lacto ice, etc.), dairy products (yogurt, cheese, etc.), milk beverages, jams, confectionery (tablets, capsule confectionery, film confectionery, candy, chewing gum, gummies, jelly, etc.), processed foods (fermented foods, milk processed products, seasonings, frozen foods, retort foods, canned foods, instant foods, etc.), pickled foods (umeboshi, fukujinzuke, rakkyo, tsubo-zuke, harihari-zuke, shiba-zuke, takuan, bettarazuke, pickles, kimchi, etc.), seasonings (sauce, ketchup, dressing), and the like.

[0003] Since this citric acid has a very high dissolution rate in water, when added to jelly or protein beverages, it has been a problem that unnecessary reactions occur with other food components during food production. For example, in the production of jelly, there is a problem that citric acid inhibits the reaction between Ca ions and pectin and does not gel, and in the production of protein beverages, there is a problem that the protein aggregates.

[0004] Therefore, for example, in Patent Document 1, a crystalline or powdery acidulant powder at room temperature is intimately mixed with a lipid powder having a melting point of 40 ° C or higher as a coating agent, and the lipid powder is uniformly coated on the entire surface of the acidulant, thereby coating the surface of the organic acid with powdery oil.

[0005] Furthermore, Patent Document 2 discloses coating with calcium citrate, that is, using citric acid as a calcium salt.

[0006] Furthermore, Patent Document 3 discloses a coated powder having a coating layer on the surface of the powder, which is a film material for forming particulate coated powder, containing an oil (A) having a solid fat content of 20-100% at 35°C and a melting point of 40-70°C, an emulsifier (B), and a water-soluble excipient (C), wherein the oil (A) content is 40-75% by mass, the emulsifier (B) content is 2.5-13% by mass, and the water-soluble excipient (C) content is 22.5-45% by mass, the endothermic peak temperature of differential scanning calorimetry is 40-70°C, and the average particle size is 10-150 μm. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 08-116909 [Patent Document 2] Japanese Patent Publication No. 2021-187772 [Patent Document 3] Japanese Patent Publication No. 2019-176790 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, the above-mentioned conventional technology had the following problems. Patent Document 1 states that when used with foods containing a high moisture content, the dispersion is poor, and the floating or undissolved oils used for coating can negatively affect the appearance and texture of the food. In Patent Document 2, the effect may be insufficient, and the appearance of the food may be impaired due to undissolved calcium salts. Patent Document 3 uses oils and fats, and when added to food, there is a risk that the oils and fats may precipitate if the balance with water-soluble components is disrupted.

[0009] Therefore, when citric acid is used in foods with high moisture content, the manufacturing process requires two conflicting properties: a slow leaching rate of citric acid, and no undissolved components remaining in the finished food.

[0010] Therefore, the present invention aims to provide citric acid particles that have a slow rate of leaching into water and do not contain any undissolved components when used in the production of foods with a high moisture content. [Means for solving the problem]

[0011] The above problems are solved by the present invention as described below. In other words, the present invention (1) is a coated citric acid particle having citric acid particles and a coating that covers the surface of the citric acid particles, The coating consists of at least an emulsifier and a water-soluble excipient. The emulsifier has an HLB value of 8.0 to 20.0, and the water-soluble excipient is a polysaccharide. The proportion of the emulsifier and the water-soluble excipient is 6 to 99% by mass relative to the coated citric acid particles. This invention provides coated citric acid particles characterized by the following:

[0012] Furthermore, the present invention (2) provides coated citric acid particles of (1), characterized in that the water-soluble excipient is a thickening polysaccharide.

[0013] Furthermore, the present invention (3) provides coated citric acid particles of (1) characterized in that the content ratio of the water-soluble excipient to the emulsifier (water-soluble excipient / emulsifier) ​​is 1.8 to 33.

[0014] Furthermore, the present invention (4) provides coated citric acid particles of (1) characterized in that they are for use as an acidulant.

[0015] Furthermore, the present invention (5) provides a coated citric acid particle composition characterized by containing the coated citric acid particles of (1). [Effects of the Invention]

[0016] According to the present invention, when producing a food with a high water content, it is possible to provide citric acid particles with a slow elution rate of citric acid into water and no remaining dissolved components.

Mode for Carrying Out the Invention

[0017] The coated citric acid particles of the present invention are coated citric acid particles having citric acid particles and a coating covering the surface of the citric acid particles. The coating consists of at least an emulsifier and a water-soluble excipient. The HLB value of the emulsifier is 8.0 to 20.0, and the water-soluble excipient is a polysaccharide. The content ratios of the emulsifier and the water-soluble excipient are 6 to 99% by mass based on the coated citric acid particles. The coated citric acid particles are characterized by the above.

[0018] The coated citric acid particles of the present invention are coated citric acid particles having citric acid particles and a coating covering the surface of the citric acid particles. That is, the coated citric acid particles of the present invention are citric acid particles whose surfaces are covered with a coating. In the coated citric acid particles of the present invention, it is preferable that the entire surface of the citric acid particles is covered with the coating, but a portion where the coating does not exist may be present on a part of the surface of the citric acid particles as long as the effects of the present invention are not impaired.

[0019] The citric acid particles of the coated citric acid particles of the present invention are not particularly limited as long as they are usually used for food addition. The average particle diameter of the citric acid particles in the coated citric acid particles is 500 to 1000 μm, more preferably 650 to 850 μm.

[0020] The coating of the coated citric acid particles of the present invention comprises at least an emulsifier and a water-soluble excipient. Examples of the coating include a two-layer coating composed of an emulsifier layer present in a layered manner on the surface of citric acid and a water-soluble excipient layer present in a layered manner on the surface of the emulsifier layer. Further, examples of the coating include a coating composed of a mixture of an emulsifier and a water-soluble excipient that covers the surface of citric acid.

[0021] The coating contains an emulsifier as a constituent component. By including an emulsifier as a constituent component in the coating, the dissolution rate of citric acid in water can be slowed down during the production of high-moisture foods.

[0022] The HLB value of the emulsifier constituting the coating is 8.0 to 20.0, preferably 8.2 to 17.0. When the HLB value of the emulsifier is within the above range, in food products, there is no undissolved residue or extremely little undissolved residue, and no problem of undissolved residue occurs in the food.

[0023] In the present invention, the HLB value is a value obtained as follows. HLB = 20(1 - S / A) (In the formula, S: saponification value of the ester, A: neutralization value of the fatty acid)

[0024] The viscosity of the emulsifier at 25°C is preferably 5 to 200 Pa·s, more preferably 8 to 190 Pa·s. When the viscosity of the emulsifier is within the above range, the effect of slowing down the dissolution rate of citric acid in water during the production of high-moisture foods is enhanced.

[0025] Examples of the emulsifier include polyglycerol fatty acid ester, glycerol fatty acid ester, sucrose fatty acid ester, lecithin, etc. Among these, as the emulsifier, polyglycerol fatty acid ester is preferable in that it has a high effect of slowing down the dissolution rate of citric acid in water during the production of high-moisture foods.

[0026] Polyglycerin fatty acid esters are esterification products of polyglycerin, which is polymerized glycerin, and fatty acids. Polyglycerin fatty acid esters used as emulsifiers in coatings have an HLB value of 8.0 to 20.0, preferably 8.2 to 17.0. Examples of polyglycerin fatty acid esters include decaglycerin caprate, diglycerin caprate, tetraglycerin laurate, hexaglycerin laurate, decaglycerin laurate, decaglycerin myristate, tetraglycerin stearate, hexaglycerin stearate, and decaglycerin stearate. When using polyglycerin fatty acid esters as emulsifiers in coatings, it is preferable that they are esterification products of polyglycerin with 1 to 12 polymerization units of glycerin and a fatty acid with 4 to 16 carbon atoms, as this enhances the effect of slowing the elution rate of citric acid into water during the production of foods with high water content. Furthermore, the polyglycerol fatty acid ester used as an emulsifier in the coating is more preferably an esterification product of polyglycerol having 2 to 11 polymerization units of glycerol and a fatty acid having 6 to 14 carbon atoms. This is preferable because it has a greater effect in slowing down the rate at which citric acid dissolves into water during the production of foods with high moisture content, as well as providing greater stability during storage. Storage stability refers to being less susceptible to moisture absorption, deliquescension, and caking in humid environments.

[0027] The coating contains a water-soluble excipient as a component. Because the coating contains a water-soluble excipient as a component, the rate of citric acid dissolution into water can be slowed during the production of foods with high moisture content, and there is little to no undissolved residue in the food product, thus preventing problems with undissolved residue in the food.

[0028] Water-soluble excipients are powdered polysaccharides that are soluble in water. A water-soluble excipient is considered soluble in water if its solubility in 100g of water at 25°C is 3.0g or more.

[0029] The average particle size of the water-soluble excipient is preferably 30 to 120 μm, more preferably 45 to 90 μm. In this invention, the average particle size of the water-soluble excipient is measured using CAMSIZER X2 (X-Jet) (manufactured by Verder Scientific).

[0030] Examples of water-soluble excipients include thickening polysaccharides. By using thickening polysaccharides as water-soluble excipients that make up the coating, the effect of slowing down the rate at which citric acid dissolves into water is enhanced when manufacturing foods with high moisture content. Examples of thickening polysaccharides used as water-soluble excipients that make up the coating include xanthan gum, tamarind seed gum, locust bean gum, gellan gum, pectin, carrageenan, guar gum, gum arabic, alginic acid, alginate, karaya gum, succinoglycan, curdlan, cellulose derivatives (hydroxypropyl methylcellulose, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, ethylcellulose, hydroxypropylcellulose), pregelatinized starch, modified starch, and dextrin. Of these, xanthan gum, hydroxymethylcellulose, and methylcellulose are preferred as thickening polysaccharides used as water-soluble excipients constituting the coating, as they are highly effective in slowing down the rate at which citric acid dissolves into water when manufacturing foods with high moisture content. Xanthan gum is more preferred because, in addition to being highly effective in slowing down the rate at which citric acid dissolves into water when manufacturing foods with high moisture content, it also provides greater stability during storage.

[0031] In the coated citric acid particles of the present invention, the content ratio of the emulsifier and the water-soluble excipient is 6 to 99% by mass, preferably 8 to 60% by mass, and more preferably 9 to 22% by mass, relative to the coated citric acid particles. If the content ratio of the emulsifier and the water-soluble excipient is less than the above range, the effect of slowing the rate of citric acid dissolution into water cannot be obtained when manufacturing foods with high moisture content. If it exceeds the above range, the relative amount of citric acid becomes too small, making it difficult to obtain the effect of adding citric acid. Furthermore, in the coated citric acid particles of the present invention, by adjusting the content ratio of the emulsifier and the water-soluble excipient, the amount of coating on the citric acid particles changes, and the rate of citric acid dissolution into water can be adjusted when manufacturing foods with high moisture content.

[0032] In the coated citric acid particles of the present invention, the ratio of water-soluble excipient to emulsifier (water-soluble excipient / emulsifier) ​​(mass ratio) is preferably 1.8 to 33, more preferably 2.0 to 30. Having the water-soluble excipient to emulsifier in the coating within this range enhances the effect of slowing the rate of citric acid elution into water during the production of foods with high moisture content.

[0033] The average particle size of the coated citric acid particles of the present invention is 500 to 1500 μm, more preferably 650 to 1300 μm. In this invention, the average particle size of the coated citric acid particles is measured using CAMSIZER X2 (X-Jet) (manufactured by Verder Scientific).

[0034] The coated citric acid particles of the present invention may optionally contain anti-caking agents such as tricalcium phosphate, fine silicon dioxide, calcium lactate, and calcium carbonate.

[0035] In the present invention, the fact that the surface of the citric acid particles is coated with a coating can be confirmed by determining the elution rate of citric acid as shown below. <Measurement of dissolution rate> First, 0.2 g of coated citric acid particles are added to 100 mL of deionized water and stirred with a magnetic stirrer at 1000 rpm to completely dissolve the coated citric acid particles in the deionized water. Next, the concentration of citric acid in the aqueous solution is measured using high-performance liquid chromatography (HPLC), and the amount of citric acid per gram of coated citric acid is determined from this concentration. Next, 1.0 g of coated citric acid particles are added to 400 mL of deionized water while stirring with a magnetic stirrer at 25°C and 350 rpm. The aqueous solution is sampled 5 seconds after the addition of the coated citric acid particles. Then, the concentration of citric acid in the sampled aqueous solution is measured using high-performance liquid chromatography (HPLC), and the amount of citric acid eluted per 1 g of coated citric acid is determined from this concentration. Next, the dissolution rate (%) is calculated using the following formula. Citric acid elution rate (%) = (Amount of citric acid eluted per gram of coated citric acid / Amount of citric acid per gram of coated citric acid) × 100 <Determining whether or not there is a covering> If the elution rate of citric acid determined by the above method is 65.0% or less, it is determined that the surface of the citric acid particles is coated with a coating material.

[0036] The elution rate of citric acid in the coated citric acid particles of the present invention is 65.0% or less, and preferably between 0.1% and 50.0%.

[0037] The coated citric acid particles of the present invention may be obtained by any manufacturing method.

[0038] One method for producing coated citric acid particles according to the present invention (1) is to first place citric acid particles and an emulsifier in a mixing container or mixing device, and stir-mix them while heating to 70-80°C to obtain a stirred mixture of citric acid particles and emulsifier, and then add a water-soluble excipient to the stirred mixture of citric acid particles and emulsifier, and stir-mix them while heating to 50-80°C to obtain coated citric acid particles.

[0039] Furthermore, (2) a method for producing coated citric acid particles according to the present invention is to place citric acid particles, an emulsifier, and a water-soluble excipient into a mixing container or mixing device, and stir-mix them while heating to 70-80°C to obtain coated citric acid particles.

[0040] The citric acid particles used in the methods (1) and (2) for producing coated citric acid particles of the present invention are not particularly limited as long as they are commonly used as food additives. The average particle size of the citric acid particles used in the methods (1) and (2) for producing coated citric acid particles of the present invention, that is, the citric acid particles before coating, is 500 to 1000 μm, more preferably 650 to 850 μm. On the other hand, if the average particle size of the citric acid particles is less than the above range, a uniform coating will not be formed or the coated citric acid particles will aggregate. If it exceeds the above range, segregation will easily occur when mixed with other powder components in food products. In the present invention, the average particle size of the citric acid particles is measured using CAMSIZER X2 (X-Jet) (manufactured by Verder Scientific).

[0041] The emulsifier used in the methods (1) and (2) for producing coated citric acid particles of the present invention is an emulsifier with an HLB value of 8.0 to 20.0, preferably 8.2 to 17.0. Because the HLB value of the emulsifier is within the above range, there is little to no undissolved residue in the food product, preventing problems with undissolved residue in the food.

[0042] The viscosity of the emulsifier at 25°C is preferably 5 to 200 Pa·s, more preferably 8 to 190 Pa·s. Having the viscosity of the emulsifier within this range provides a coating that effectively slows down the rate at which citric acid dissolves into water during the production of foods with high water content.

[0043] Examples of emulsifiers include polyglycerol fatty acid esters, glycerol fatty acid esters, sucrose fatty acid esters, and lecithin. Of these, polyglycerol fatty acid esters are preferred as emulsifiers because they provide a coating that is highly effective in slowing down the rate at which citric acid dissolves into water when manufacturing foods with high water content.

[0044] Polyglycerin fatty acid esters are esterification products of polyglycerin, which is polymerized glycerin, and fatty acids. Polyglycerin fatty acid esters used as emulsifiers have an HLB value of 8.0 to 20.0, preferably 8.2 to 17.0. Examples of polyglycerin fatty acid esters include decaglycerin caprate, diglycerin caprate, tetraglycerin laurate, hexaglycerin laurate, decaglycerin laurate, decaglycerin myristate, tetraglycerin stearate, hexaglycerin stearate, and decaglycerin stearate. It is preferable that the polyglycerin fatty acid ester is an esterification product of polyglycerin with 1 to 12 polymerization units of glycerin and a fatty acid with 4 to 16 carbon atoms, as this provides a coating that effectively slows the rate of citric acid elution into water during the production of foods with high water content. Furthermore, it is preferable that the polyglycerol fatty acid ester is more preferably an esterification product of polyglycerol having 2 to 11 polymerization units of glycerol and a fatty acid having 6 to 14 carbon atoms, as this enhances the effect of slowing the rate of citric acid elution into water during the production of foods with high moisture content, and also provides a coating that offers high stability during storage.

[0045] The water-soluble excipient used in the methods (1) and (2) for producing coated citric acid particles of the present invention is a powdered polysaccharide that is soluble in water. The average particle size of the water-soluble excipient is preferably 30 to 120 μm, more preferably 45 to 90 μm. When the average particle size of the water-soluble excipient is within the above range, a coating is obtained that is highly effective in slowing down the rate at which citric acid dissolves into water when manufacturing foods with high moisture content. On the other hand, if the average particle size of the water-soluble excipient is less than the above range, handling during manufacturing becomes difficult due to powder scattering, and if it exceeds the above range, a uniform coating cannot be formed or the coated citric acid particles aggregate.

[0046] Examples of water-soluble excipients include thickening polysaccharides. By using thickening polysaccharides as water-soluble excipients, a coating can be obtained that is highly effective in slowing down the rate at which citric acid dissolves into water during the production of foods with high moisture content. Examples of thickening polysaccharides used as water-soluble excipients that make up the coating include xanthan gum, tamarind seed gum, locust bean gum, gellan gum, pectin, carrageenan, guar gum, gum arabic, alginic acid, alginate, karaya gum, succinoglycan, curdlan, cellulose derivatives (hydroxypropyl methylcellulose, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, ethylcellulose, hydroxypropylcellulose), pregelatinized starch, modified starch, and dextrin. Of these, xanthan gum, hydroxypropyl methylcellulose, and methylcellulose are preferred as thickening polysaccharides used as water-soluble excipients because they provide a coating that is highly effective in slowing down the rate at which citric acid dissolves into water when manufacturing foods with high moisture content. Xanthan gum is more preferred because, in addition to being highly effective in slowing down the rate at which citric acid dissolves into water when manufacturing foods with high moisture content, it provides a coating that is highly stable during storage.

[0047] In the methods (1) and (2) for producing coated citric acid particles of the present invention, the ratio of water-soluble excipient to emulsifier (water-soluble excipient / emulsifier) ​​(mass ratio) is preferably 1.8 to 33, more preferably 2.0 to 30. By having the ratio of water-soluble excipient to emulsifier within the above range, it is possible to form a coating that slows down the rate at which citric acid dissolves into water when producing foods with a high moisture content.

[0048] In the methods (1) and (2) for producing coated citric acid particles of the present invention, the amounts of citric acid particles, emulsifiers, and water-soluble excipients used are adjusted so that the total amount of emulsifiers and water-soluble excipients added is 6 to 99% by mass, preferably 8 to 60% by mass, and more preferably 9 to 22% by mass, relative to the total amount of citric acid particles, emulsifiers, and water-soluble excipients added.

[0049] The coated citric acid particles of the present invention are used as acidulants.

[0050] Furthermore, the coated citric acid particles of the present invention are suitably used in applications where citric acid is added to water or components with a high moisture content. For example, the coated citric acid particles of the present invention are used in instant jelly powder, protein drinks, powdered beverages, and powdered soft drinks. The coated citric acid particles of the present invention can adjust the citric acid elution rate when adding citric acid to water or components with a high moisture content.

[0051] The coated citric acid particle composition of the present invention is characterized by containing the coated citric acid particles of the present invention.

[0052] The coated citric acid particle composition of the present invention may optionally contain anti-caking agents such as tricalcium phosphate, fine silicon dioxide, calcium lactate, and calcium carbonate.

[0053] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the examples shown below. [Examples]

[0054] (Examples 1-5, Comparative Examples 1-3) <Manufacturing of coated citric acid particles> Citric acid particles and an emulsifier were placed in a beaker and stirred with a spatula while being heated in a 75°C constant temperature bath until a uniform mixture was achieved. Next, a water-soluble excipient was added while being heated in a 75°C constant temperature bath, and stirred with a spatula to obtain coated citric acid particles.

[0055] <Making Jelly> Each coated citric acid particle and other components were weighed out as shown in Table 1, mixed in a bag, and a mixed powder was obtained. Next, 80g of tap water was added to a 200mL beaker, and the mixed powder was added while stirring with a magnetic stirrer at 1000rpm for 15 seconds. After mixing was complete, the solution was transferred to a plastic cup and allowed to stand to observe the gel formation process. The degree of gel formation was determined according to the following criteria.

[0056] A: The entire body gels and becomes self-supporting. B: The entire thing gels, and it stands on its own but is soft. C: The entire structure gels, but it is weak and does not stand on its own, or it is in the form of crushed jelly. D: Partially gels, but the proportion of aqueous solution is high. E: Does not gel, remains in aqueous solution

[0057] [Table 1]

[0058] <Preparing protein drinks> In a 450mL protein shaker, 40g of whey protein powder, 3.0g of cocoa powder, and 0.40g of antifoaming agent were added, and then citric acid or coated citric acid particles were added and mixed to a total amount equivalent to 2.0g of citric acid. Next, 357g of tap water at 20-25°C was added, the lid was closed, and the mixture was shaken vigorously up and down 120 times. After letting it stand for at least 1 minute, the mixture was shaken vigorously up and down again 120 times. After mixing was complete, the mixture was allowed to stand and its dispersion state was observed. The amount of clumps formed by the reaction between the protein components and citric acid was determined according to the following criteria.

[0059] A: The amount of clumping is less than 10% compared to the case of citric acid. B: Compared to the case of citric acid, the amount of clumping is 10% to less than 30%. C: Compared to citric acid, the amount of clumping is 30% to less than 50%. D: Compared to the case of citric acid, the amount of clumping is 50% to less than 80%. E: Compared to citric acid, the amount of clumping is 80% or more or equivalent.

[0060] <Evaluation of storage stability> Citric acid or coated citric acid particles and sodium bicarbonate were dried overnight in a desiccator. Then, 5 g of sodium bicarbonate and the dried coated citric acid particles were placed in a resealable bag so that the total amount equivalent to the amount of citric acid was 5 g. The bag was immediately sealed, and the total weight was measured using a precision balance to obtain the weight before the reaction. Next, I shook the resealable bag to mix the powder inside. After stirring, the contents were left in the opened resealable bag and stored in a desiccator at 40°C and 75% RH for 7 days. After 7 days, the resealable bag was removed, sealed, and its weight was measured using a precision balance. This was considered the post-reaction weight, and the difference in weight before and after the reaction was converted into the amount of gas generated. Based on the converted amount of gas generated, the ratio of the amount of gas generated to the amount of gas generated in the case of citric acid was determined and judged according to the following criteria.

[0061] A: Compared to the case of citric acid, the amount of gas generated is between 0% and less than 15%. B: Compared to the case of citric acid, the amount of gas generated is 15% to less than 20%. C: Compared to the case of citric acid, the amount of gas generated is 20% to less than 30%. D: Compared to the case of citric acid, the amount of gas generated is 30% to less than 40%. E: Compared to the case of citric acid, the amount of gas generated is 40% to less than 50%. F: Compared to the case of citric acid, the amount of gas generated is 50% or more.

[0062] <Measurement of citrate elution rate> First, 0.2 g of coated citric acid particles were added to 100 mL of deionized water and stirred with a magnetic stirrer at 1000 rpm to completely dissolve the coated citric acid particles in the deionized water. Next, the concentration of citric acid in the aqueous solution was measured using high-performance liquid chromatography (HPLC), and the amount of citric acid per gram of coated citric acid was determined from this concentration. Next, 1.0 g of coated citric acid particles were added to 400 mL of deionized water while stirring with a magnetic stirrer at 25°C and 350 rpm. The aqueous solution was sampled 5 seconds after the addition of the coated citric acid particles. Then, the concentration of citric acid in the sampled aqueous solution was measured using high-performance liquid chromatography (HPLC), and the amount of citric acid eluted per 1 g of coated citric acid was determined from this concentration. Next, the dissolution rate (%) was calculated using the following formula. Citric acid elution rate (%) = (Amount of citric acid eluted per gram of coated citric acid / Amount of citric acid per gram of coated citric acid) × 100 • Column: SHISEIDO CAPCELLPACK C 18 4.6mm ID*250mm • Eluent: 2% by weight diammonium hydrogen phosphate, pH 2.0 ·Flow rate: 0.65mL / min • Sample injection volume: 2 μL

[0063] [Table 2]

[0064] <Citric acid particles> • Citric acid: Anhydrous citric acid L, manufactured by Fuso Chemical Industries, Ltd., average particle size 754 μm <Emulsifier> • Emulsifier 1: Decaglycerin laurate, Poem J-0021, manufactured by Riken Vitamin Co., Ltd., HLB value 15.5, viscosity at 25℃ 146 Pa·s • Emulsifier 2: Decaglycerin monocaplate, SY Glister MCA750, manufactured by Sakamoto Pharmaceutical Co., Ltd., HLB value 16.1, viscosity at 25℃ 63 Pa·s • Emulsifier 3: Diglycerin monocaprate, SY Glister MCA150, manufactured by Sakamoto Pharmaceutical Co., Ltd., HLB value 8.7, viscosity at 25℃ 10 Pa·s <Water-soluble excipients> • Water-soluble excipient 1: Xanthan gum, Grinsted Xanthan Clear 80, Danisco Japan, average particle size 82 μm • Water-soluble excipient 2: Hydroxypropyl methylcellulose (HPMC), Metroze SFE-4000, manufactured by Shin-Etsu Chemical Co., Ltd., average particle size 54 μm • Water-soluble excipient 3: Methylcellulose, Metrose MCE-4, manufactured by Shin-Etsu Chemical Co., Ltd., average particle size 52 μm • Water-soluble excipient 4: Reduced palatinose, reduced palatinose PNP, manufactured by DM Mitsui Sugar Co., Ltd.

Claims

1. Coated citric acid particles comprising citric acid particles and a coating that covers the surface of the citric acid particles, The coating consists of at least an emulsifier and a water-soluble excipient. The emulsifier has an HLB value of 8.0 to 20.0, and the water-soluble excipient is a polysaccharide. The content ratio of the emulsifier and the water-soluble excipient is 6 to 99% by mass relative to the coated citric acid particles. Coated citric acid particles characterized by the following.

2. The coated citric acid particles according to claim 1, characterized in that the water-soluble excipient is a thickening polysaccharide.

3. The coated citric acid particles according to claim 1, characterized in that the content ratio of the water-soluble excipient to the emulsifier (water-soluble excipient / emulsifier) ​​is 1.8 to 33.

4. Coated citric acid particles according to claim 1, characterized in that they are for use as an acidulant.

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