Discoloration inhibitor for processed vegetables and fruits and method for inhibiting discoloration of processed vegetables and fruits

Abstract

To provide a discoloration inhibitor for a vegetable / fruit processed product capable of inhibiting discoloration of a vegetable / fruit processed product, and a method for inhibiting discoloration of a vegetable / fruit processed product.SOLUTION: Provided are a discoloration inhibitor for a vegetable / fruit processed product, containing at least one or more constituents selected from a maltobionic acid and a maltobionic acid salt, and a method for inhibiting discoloration of a vegetable / fruit processed product, including a step of mixing of a discoloration inhibitor for a vegetable / fruit processed product to a vegetable or a fruit. The maltobionic acid salt is preferably a maltobionic acid calcium or a maltobionic acid magnesium.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an agent for inhibiting discoloration of processed vegetable and fruit products and a method for inhibiting discoloration of processed vegetable and fruit products. [Background technology]

[0002] Agricultural products such as vegetables and fruits are processed in various ways for the purposes of flavoring and preservation, but the color of the ingredients easily fades due to processing (treatment) such as heating and drying. Because food color plays a major role in palatability, coloring agents are sometimes used to adjust the color to a more desirable level. However, in recent years, health-conscious consumers have begun to avoid additives such as coloring agents. For this reason, various methods have been investigated to prevent the discoloration of processed vegetable and fruit products.

[0003] For example, methods proposed for improving the color tone of vegetables include soaking chlorophyll-containing vegetables in a ferulic acid-containing aqueous solution and a calcium-containing aqueous solution (see Patent Document 1), and adding polyphenol-containing substances or rice bran enzymatic hydrolyzates to eggplant (see Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-165712 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-259488 Summary of the Invention [Problem to be solved by the invention]

[0005] However, other methods are desired that can suppress discoloration of processed vegetables and fruits and increase their commercial value.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a discoloration inhibitor for processed vegetables and fruit products that can inhibit discoloration of processed vegetables and fruit products, a method for inhibiting discoloration of processed vegetables and fruit products, and processed vegetables and fruit products. [Means for solving the problem]

[0007] The present inventors have discovered that maltobionic acid and maltobionate can inhibit discoloration of processed vegetable and fruit products, and have completed the present invention. More specifically, the present invention provides the following.

[0008] (1) A discoloration inhibitor for processed vegetables and fruits, comprising at least one component selected from maltobionic acid and maltobionate salts.

[0009] (2) The discoloration inhibitor for processed vegetable and fruit products according to (1), wherein the maltobionate is calcium maltobionate or magnesium maltobionate.

[0010] (3) A method for inhibiting discoloration of processed vegetables and fruit products, comprising the step of blending the discoloration inhibitor for processed vegetables and fruit products described in (1) or (2) with vegetables or fruit products.

[0011] (4) A processed vegetable or fruit product containing the color fading inhibitor for processed vegetable or fruit products described in (1) or (2). [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a discoloration inhibitor for processed vegetables and fruit products that can suppress discoloration of processed vegetables and fruit products, a method for suppressing discoloration of processed vegetables and fruit products, and processed vegetables and fruit products in which discoloration is suppressed. DETAILED DESCRIPTION OF THE INVENTION

[0013] Specific embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the object of the present invention. Note that duplicated explanations may be omitted as appropriate, but this does not limit the gist of the invention.

[0014] <Anti-fading agent for processed vegetables and fruits> The discoloration inhibitor for processed vegetable and fruit products of the present invention (hereinafter also referred to as "discoloration inhibitor of the present invention") contains at least one component selected from maltobionic acid and maltobionate salts. Processed vegetables and fruits are processed vegetables or fruits. Processing methods include cutting, heating, freezing, drying, soaking in a liquid, or a combination of these.

[0015] Heating includes boiling, cooking, simmering, etc. The heating conditions are not particularly limited, but the lower limit of the heating temperature is, for example, 80°C, preferably 85°C, and more preferably 95°C. The upper limit of the heating temperature is, for example, 130°C, preferably 120°C, and more preferably 110°C. The lower limit of the heating time is, for example, 2 minutes, preferably 4 minutes, more preferably 8 minutes, and the upper limit of the heating time is, for example, 40 minutes, preferably 30 minutes, more preferably 20 minutes.

[0016] The drying conditions are not particularly limited, and drying may be performed without heating, or may be performed with heating. When heating is performed, the lower limit of the drying temperature is, for example, 40°C, preferably 55°C, and more preferably 70°C. The upper limit of the drying temperature is, for example, 100°C, preferably 90°C, and more preferably 80°C. The lower limit of the drying time is, for example, 30 minutes, preferably 1 hour, more preferably 3 hours, and the upper limit of the drying time is, for example, 10 hours, preferably 8 hours, more preferably 6 hours.

[0017] The freezing conditions are not particularly limited, but the lower limit of the freezing temperature is, for example, −40° C., preferably −35° C., and more preferably −30° C. The upper limit of the freezing temperature is, for example, −5° C., preferably −10° C., and more preferably −20° C. The lower limit of the freezing time is, for example, 30 minutes, preferably 1 hour, more preferably 3 hours, and the upper limit of the freezing time is, for example, 10 hours, preferably 8 hours, more preferably 6 hours.

[0018] The conditions for immersion in the immersion liquid are not particularly limited, but the lower limit of the immersion time is, for example, 15 minutes, preferably 1 hour, more preferably 1 day, and the upper limit of the immersion time is, for example, 20 days, preferably 15 days, more preferably 10 days.

[0019] Specific examples of processed vegetable and fruit products for which the discoloration inhibitor of the present invention inhibits discoloration include those provided in a raw state, such as cut fruit; those that are heat-processed, such as simmered dishes, jams, purees, boiled vegetables, and seasoned rice (e.g., sweet potato rice); those that are heated and then frozen, such as blanched vegetables; those that are hot-air dried or freeze-dried, such as dried fruits; and those that are pickled for long periods, such as pickles.

[0020] Vegetables and fruits used as raw materials for processed vegetables and fruits (i.e., vegetables and fruits to be processed) include, but are not limited to, vegetables and fruits containing polyphenols, carotenoids, or chlorophyll. Examples of polyphenols include flavonoids. Specific examples of vegetables and fruits used as raw materials for processed vegetables and fruits include cabbage, purple cabbage, lettuce, komatsuna, spinach, kale, chrysanthemum, chives, lettuce, parsley, basil, chives, snow peas, edamame, shishito peppers, zucchini, broccoli, cauliflower, carrots, okra, bitter melon, pumpkin, edamame, avocado, paprika, bell peppers, mizuna, bok choy, kale, coriander, sprouts, tomyo, shiso, and edamame. These include sesame, purple sweet potato, red turnip, radish, onion, asparagus, celery, peas, green beans, eggplant, sweet potato, potato, tomato, black beans, adzuki beans, apple, pear, strawberry, grape, blueberry, raspberry, blackberry, bilberry, prune, acai, black currant, haskap, peach, cherries, mandarin orange, orange, iyokan, persimmon, melon, banana, kiwi fruit, pomegranate, yuzu, chestnut, and prune.

[0021] (Maltobionic acid and its salts) The discoloration inhibitor of the present invention contains at least one component selected from maltobionic acid and maltobionate salts, which may be used alone or in combination of two or more. In this way, by including maltobionic acid or maltobionate, discoloration of processed fruit and vegetable products during processing such as heating and drying, and during storage, can be suppressed, as will be shown in the Examples below. Note that, in this specification, "discoloration" means a lightening of color (discoloration) or discoloration.

[0022] (Principle of vegetable fading) The anti-fading effect of the present invention is believed to be due to the fact that maltobionic acid and maltobionate limit or stabilize the activity of polyphenols, carotenoids, and chlorophyll found in vegetables and fruits. Polyphenols include isoflavones found in soybeans and soybean flour, quercetin found in onions, apples, and shallots, anthocyanins (e.g., anthocyanins) found in red wine, blueberries, and black beans, sesamin found in sesame seeds, theaflavin found in black tea, hesperidin found in yuzu, Satsuma mandarins, and lemons, luteolin found in bell peppers, chrysanthemum daisy, and celery, naringin found in grapefruit and hassaku oranges, tannins found in lotus root, chlorogenic acid found in prunes, plums, burdock, and coffee, and mumefural found in ume plums. Carotenoids include lycopene, α-carotene, β-carotene, lutein, zeaxanthin, and β-cryptoxanthin. Examples of chlorophyll include chlorophyll a, chlorophyll b, chlorophyll c, and chlorophyll d.

[0023] Discoloration of vegetables and fruits occurs due to pigment destabilization caused by heat and light, enzymatic reactions, and other factors. For example, chlorophyll, the green pigment in cabbage, is stabilized by binding with metal ions such as magnesium, but discoloration occurs when the metal ions are released during processing such as heating. Furthermore, processed vegetables and fruits served raw, such as cut apples, experience significant browning reactions due to polyphenols and enzymes. Furthermore, polyphenols such as chlorogenic acid contained in sweet potatoes and other vegetables can turn black when they bind with iron ions. On the other hand, maltobionic acid and its salts have the effect of increasing the solubility stability of metal ions. This is thought to be because maltobionic acid has one carboxyl group and multiple hydroxyl groups, which interact with metal ions. For this reason, it is speculated that maltobionic acid and maltobionate salts exert a discoloration-inhibiting effect by limiting or stabilizing the activity of polyphenols, carotenoids, and chlorophyll contained in vegetables and fruits, thereby suppressing the reactivity of metal ions in processed vegetable and fruit products (for example, binding with iron ions) and suppressing the release (release) of metal ions from pigments.

[0024] For example, when processed vegetable and fruit products are cut fruits obtained by immersing cut fruits in a liquid containing the discoloration inhibitor of the present invention, by using the discoloration inhibitor of the present invention, the color tone after 24 hours of storage at room temperature is ΔE 0.01, compared to when the product is not immersed in a liquid containing the discoloration inhibitor of the present invention (no maltobionic acid or maltobionate salt is added). ab * is 5 or more. ab * ) are identified by the method shown in the examples.

[0025] Furthermore, when vegetables are heated, they soften and their texture deteriorates, but the discoloration inhibitor of the present invention can also inhibit the softening of vegetables due to heating.

[0026] Furthermore, while conventionally known discoloration inhibitors may impart fruit juice flavors or sweetness, the maltobionic acid and maltobionate salts contained in the discoloration inhibitor of the present invention as discoloration inhibitor components have a weak taste intensity themselves, and therefore the discoloration inhibitor of the present invention can inhibit the discoloration of processed vegetable and fruit products without imparting or imparting almost no unnecessary flavors such as fruit juice flavors or sweetness.

[0027] Maltobionate salts include mineral salts of maltobionic acid. The minerals are not particularly limited as long as they can be incorporated into foods. Specific examples of maltobionate salts include calcium maltobionate, magnesium maltobionate, sodium maltobionate, potassium maltobionate, and iron maltobionate.

[0028] The maltobionic acid and maltobionate may be in the form of maltooligosaccharide oxide, starch syrup oxide, powdered syrup oxide or dextrin oxide.

[0029] Maltobionic acid and maltobionate salts may be in the form of a liquid (such as a syrup) or a powder.

[0030] (Method of producing maltobionic acid and its salts) Maltobionic acid and maltobionate salts can be produced according to conventional methods. Examples of methods for producing maltobionic acid include (1) a method in which starch hydrolysates are oxidized by chemical oxidation, and (2) a method in which a starch hydrolysate is reacted with a microorganism or oxidase capable of oxidizing oligosaccharides. Among the above, method (2) includes, for example, a method in which an oxidase is extracted from a microorganism capable of oxidizing oligosaccharides, such as Acremonium chrysogenum, and the enzyme is allowed to act.

[0031] A salt of maltobionic acid and a divalent mineral can be produced, for example, by adding a mineral (salt) to maltobionic acid. For example, calcium maltobionate can be produced by adding a calcium source such as calcium carbonate to a maltobionic acid solution in a molar ratio of 2:1 and dissolving it. The calcium source used in this case is not particularly limited as long as it is edible calcium, and may be, for example, either a natural material (eggshell powder, coral powder, bone powder, shell powder, etc.) or a chemically synthesized product (calcium carbonate, calcium chloride, etc.).

[0032] (Other ingredients) The agent for inhibiting discoloration of processed vegetable and fruit products of the present invention may contain any component within a range that does not impair the effects of the present invention. Examples of such optional ingredients include water, flavorings, thickeners, sweeteners (sugar, isomerized sugar, glucose, fructose, high-fructose corn syrup, glucose-fructose corn syrup, honey, starch syrup, powdered syrup, maltodextrin, sorbitol, maltitol, reduced starch syrup, maltose, trehalose, brown sugar, etc.), dietary fiber, protein (milk, soybeans, beef extract, chicken extract, pork extract, fish extract, gelatin, etc.), acidulants (organic acids such as citric acid, acetic acid, lactic acid, malic acid, and tartaric acid), minerals (calcium, magnesium, iron, potassium, zinc, copper, etc.), amino acids (arginine, valine, leucine, isoleucine, etc.), spices (garlic, ginger, sesame, chili pepper, wasabi, Japanese pepper, and myoga, etc.), emulsifiers, enzymes, functional ingredients, preservatives, stabilizers, antioxidants, and vitamins. The amounts of these components added can be adjusted appropriately depending on the effect to be achieved.

[0033] Since the discoloration inhibitor of the present invention can sufficiently inhibit discoloration of processed vegetables and fruits, the discoloration inhibitor of the present invention may or may not contain a conventional discoloration inhibitor or coloring agent for processed vegetables and fruits. Conventional discoloration inhibitors for processed vegetables and fruits include ascorbic acid and alum.

[0034] The color fading inhibitor for processed vegetable and fruit products of the present invention may or may not contain components used in conventional methods for producing processed vegetable and fruit products, such as pH adjusters and organic acids.

[0035] (How to use) The method of using the discoloration inhibitor of the present invention is not particularly limited and can be appropriately selected depending on the type of processed vegetable or fruit product, etc. For example, the discoloration inhibitor of the present invention is brought into contact with vegetables or fruits during, before, or after processing of the vegetables or fruits by the following method. When the processed vegetable or fruit product is boiled, blanched, freeze-dried, or the like, the vegetable is boiled or heated in water to which the discoloration inhibitor of the present invention has been added. When processed vegetables and fruits are simmered dishes, jams, purees, cooked rice, etc., the discoloration inhibitor of the present invention is mixed with the vegetables and fruits. When the processed vegetable or fruit product is pickled, the discoloration inhibitor of the present invention is added to the pickling liquid. When the processed vegetable or fruit product is cut fruit or dried fruit, the cut fruit is immersed in water to which the discoloration inhibitor of the present invention has been added.

[0036] The amount of the discoloration inhibitor of the present invention used is not limited as long as it is an amount that can exert a discoloration inhibitory effect. For example, the discoloration inhibitor of the present invention is used so that the total amount of maltobionic acid and maltobionate is preferably 0.05 parts by weight or more, more preferably 3 parts by weight or more, per 100 parts by weight of vegetables or fruits. Furthermore, the discoloration inhibitor of the present invention is blended so that the total amount of maltobionic acid and maltobionate is preferably 70 parts by weight or less, more preferably 40 parts by weight or less, per 100 parts by weight of vegetables or fruits. When the amount is 0.05 parts by weight or more, the discoloration inhibitory effect of processed vegetables and fruit products is easily achieved, while when the amount is 70 parts by weight or less, the discoloration inhibitory effect of processed vegetables and fruit products is adequate. In addition, in the case of processed vegetable and fruit products such as simmered dishes, jams, purees, and cooked rice, which are obtained by manufacturing methods that do not include a process for removing the used discoloration inhibitor, the entire amount of maltobionic acid or maltobionate used may be contained in the processed vegetable and fruit products produced.

[0037] Processed vegetable and fruit products produced using the color-fading inhibitor of the present invention may be sterilized and packed into containers as needed. The method and order of sterilization and packing are not particularly limited.

[0038] When vegetable and fruit processed products produced using the discoloration inhibitor of the present invention are packed into containers, examples of containers include plastic products such as polyethylene terephthalate (PET) (retort pouch containers, plastic bottles, etc.), metal products such as steel and aluminum (cans, etc.), and paper cartons.

[0039] <Methods for preventing discoloration of processed vegetables and fruits> The method of the present invention for inhibiting discoloration of processed vegetable and fruit products (hereinafter also referred to as the "discoloration inhibition method of the present invention") includes a step of blending the above-mentioned discoloration inhibitor for processed vegetable and fruit products of the present invention with vegetables or fruits.

[0040] In the discoloration suppression method of the present invention, the timing and amount of the discoloration suppressant of the present invention to be added to vegetables or fruits can be appropriately selected depending on the type of food and the degree of discoloration suppression to be achieved, and are not particularly limited. For example, the conditions listed in the above section <Discoloration suppressant for processed vegetables and fruits> can be used.

[0041] <Processed vegetables and fruits, including color retardants for processed vegetables and fruits> The processed vegetable and fruit products of the present invention are processed using the above-mentioned color fading inhibitor for processed vegetable and fruit products of the present invention, and contain the color fading inhibitor for processed vegetable and fruit products of the present invention. The processed vegetable and fruit products of the present invention are processed using the color retarder for processed vegetable and fruit products of the present invention, and therefore color retardation during processing of vegetables and fruits such as heating, drying, etc. Furthermore, since the processed vegetable and fruit products of the present invention contain the color retarder for processed vegetable and fruit products of the present invention, discoloration of the processed vegetable and fruit products during storage is inhibited. Therefore, the processed vegetable and fruit products of the present invention can maintain a favorable appearance from the time of processing through storage. For example, discoloration is suppressed even when stored for 20 hours or more at room temperature or in an unsealed state, which are conditions that can easily cause discoloration. Furthermore, since the maltobionic acid and maltobionate salts contained as discoloration inhibitor components in the discoloration inhibitor of the present invention have a weak taste intensity themselves, vegetable and fruit processed products can be produced that have little or no extraneous tastes such as fruit juice flavor or sweetness due to the discoloration inhibitor.

[0042] The amount of the discoloration inhibitor of the present invention contained in processed vegetable and fruit products is not particularly limited, and is selected appropriately depending on the type of processed vegetable and fruit product, the color tone to be achieved, etc.

[0043] The content of maltobionic acid and maltobionate can be calculated using the HPAED-PAD method (pulsed amperometric detector, CarboPac PA1 column). The measurement conditions for the HPAED-PAD method are as follows. Elution: 35℃, 1.0ml / min Sodium hydroxide concentration: 100 mM Sodium acetate concentration: 0 min - 0 mM, 5 min - 0 mM, 55 min - 40 mM [Example]

[0044] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0045] <Test 1: Boiled vegetables: Broccoli> Boiled vegetables were prepared using the following ingredients and the color was evaluated.

[0046] (material) Maltobionic acid syrup (70% maltobionic acid by mass, 30% water by mass): manufactured by Sanei Sugar Chemical Co., Ltd. Calcium maltobionate (powder): Sanei Sugar Chemical Co., Ltd. Salt: Produced by the Salt Industry Center Calcium carbonate: Sankyo Seifun Co., Ltd.

[0047] (Preparation of boiled vegetables) Commercially available broccoli was used to prepare blanched vegetables in the following manner. (1) Maltobionic acid syrup, calcium maltobionate, salt, and calcium carbonate in the amounts specified in Table 1 were added to water in the amounts specified in Table 1, and the mixture was heated to a boil. (2) Broccoli, divided into small florets, was placed in boiling water, heated for 10 minutes, then removed and immediately cooled in ice water for 1 minute. (3) After draining the water, check the color visually and measure the ΔE value below. ab * The evaluation was carried out based on the following criteria.

[0048] In addition, the color tone of blanched vegetables prepared in the same manner as in (1) to (3) was also evaluated, except that the heating time was changed from 10 minutes to 3 minutes.

[0049] (Color evaluation) Using a color difference meter (small colorimeter / whiteness meter NW-12 Nippon Denshoku Industries), the L of each sample was measured. * , a * , b * The color difference ΔL was measured based on the measured value of Comparative Example 1-1 after heating for 3 minutes. * , Δa * , Δb * That is, the L of each sample was calculated. * , a * , b * The value obtained by subtracting the measured value in Comparative Example 1-1 with a heating time of 3 minutes from the value obtained by subtracting the measured value from the value obtained by * , Δa * , Δb * ΔL * , Δa * , Δb * Using the following formula 1, ΔE ab * The difference in color tone from the standard was quantified. * is the brightness * and b * represents chromaticity. (Formula 1)ΔE ab * =((Δa * ) 2 +(Δb * ) 2 +(ΔL * ) 2 ) 1 / 2 In this test, the category without fading was used as the standard (heating time of 3 minutes in Comparative Example 1-1), so ΔE ab * The smaller the value, the more the fading is suppressed. ab * When ΔE was 5 or more, fading was clearly visible to the naked eye, ab * A value of less than 5 was judged to have a fading suppression effect.

[0050] [Table 1]

[0051] As shown in Table 1, when the heating time was 3 minutes, both the Examples and Comparative Examples maintained a vivid green color, but changes in color fading were observed as the heating time was extended. When salt, which is used as a color fixative, was added (Comparative Example 1-2) or when calcium carbonate was added (Comparative Example 1-3), color fading was confirmed after 10 minutes of heating, and softening was more advanced than when no additive was added (Comparative Example 1-1). On the other hand, when maltobionic acid syrup or calcium maltobionate was added (Examples), color fading and softening were suppressed.

[0052] <Test 2: Lightly Pickled Eggplant A> Salted eggplants were prepared using the following ingredients and the color was evaluated.

[0053] (material) Calcium maltobionate (powder): manufactured by Sanei Saccharification Co., Ltd. Salt: Produced by the Salt Industry Center Calcium lactate: Fuso Chemical Co., Ltd.

[0054] (Preparing lightly pickled eggplant) Lightly pickled eggplant was prepared using commercially available eggplants in the following manner. (1) Cut the eggplant into 4 equal parts lengthwise and cut into 3cm wide pieces. (2) The saline solution, calcium maltobionate, and calcium lactate in the amounts shown in Table 2 were mixed to prepare an immersion solution. (3) The cut eggplant was placed in the soaking liquid (2) and stored in a refrigerator (4°C) for one week. (4) After one week, the specimens were removed and the color was evaluated.

[0055] Using Comparative Example 2-1 as a standard, the ΔE of each sample was evaluated in the same manner as in the above (color tone evaluation). ab *In this study, the standard was Comparative Example 2-1, in which fading was confirmed, so ΔE ab * The larger the value, the more the fading is suppressed.

[0056] [Table 2]

[0057] As shown in Table 2, it was confirmed that calcium maltobionate can suppress discoloration even in processed foods that are in contact with moisture for long periods of time, such as pickles.

[0058] <Test 3: Lightly Pickled Eggplant B> Salted eggplants were prepared using the following ingredients and the color was evaluated.

[0059] (material) Maltobionic acid syrup (70% maltobionic acid by mass, 30% water by mass): manufactured by Sanei Sugar Chemical Co., Ltd. Magnesium maltobionate (powder): Sanei Toka Co., Ltd. Salt: Produced by the Salt Industry Center Maltose monohydrate: Fujifilm Wako Pure Chemical Industries, Ltd. Calcium carbonate: Sankyo Seifun Co., Ltd.

[0060] Lightly pickled eggplant was prepared in the same manner as described above (Preparation of lightly pickled eggplant).

[0061] Using Comparative Example 2-1 as a standard, the ΔE of each sample was evaluated in the same manner as in the above (color tone evaluation). ab * In this study, the standard was Comparative Example 2-1, in which fading was confirmed, so ΔE ab * The larger the value, the more the fading is suppressed.

[0062] [Table 3]

[0063] As shown in Table 3, the anti-fading effect was confirmed when maltobionic acid or magnesium maltobionate was used. The anti-fading effect was also confirmed when combined with ingredients containing other minerals, such as calcium carbonate. Furthermore, the anti-fading effect was not observed when maltose, a disaccharide like maltobionic acid, was added, demonstrating that the anti-fading effect is specific to maltobionic acid and maltobionate salts.

[0064] <Test 4: Heat-treated sweet potato> Heat-treated sweet potatoes were prepared using the following ingredients and their color was evaluated.

[0065] (material) Maltobionic acid syrup (70% maltobionic acid by mass, 30% water by mass): manufactured by Sanei Sugar Chemical Co., Ltd. Calcium maltobionate (powder): manufactured by Sanei Saccharification Co., Ltd. Citric acid (anhydrous): Fuso Chemical Co., Ltd. Calcium lactate: Fuso Chemical Co., Ltd.

[0066] (Preparation of heat-treated sweet potatoes) Commercially available sweet potatoes were used to prepare heat-treated sweet potatoes by the following method. (1) Cut the sweet potato into 1cm cubes and soak it in water. (2) 1000g of water was brought to a boil, 200g of cut sweet potato was added, and the mixture was heated for 2 minutes to perform a blanching process. (3) Various aqueous solutions of maltobionic acid syrup, calcium maltobionic acid, citric acid, and calcium lactate in the amounts shown in Table 4 were mixed with blanched sweet potato (blanched sweet potato) and vacuum-packed. (4)(3) was steam-heated in a steam convection oven (TANICO) at 100°C for 30 minutes, then immediately cooled in ice water for 20 minutes and stored frozen (-25°C) for one month. (5)(4) was thawed at room temperature and the color was evaluated.

[0067] Using Comparative Example 4-1 as a standard, the ΔE of each sample was evaluated in the same manner as in the above (color tone evaluation). ab * In this study, the standard was Comparative Example 4-1, in which fading was confirmed, so ΔE ab * The larger the value, the more the fading is suppressed.

[0068] [Table 4]

[0069] As shown in Table 4, it was confirmed that the color turned black when no additives were added, or when citric acid or calcium lactate was added. On the other hand, when maltobionic acid or calcium maltobionate was added, the color turned black and the bright yellow color was maintained.

[0070] <Test 5: Sweet potato rice> Sweet potato rice was prepared using the following ingredients and the color was evaluated.

[0071] (material) Calcium maltobionate (powder): manufactured by Sanei Saccharification Co., Ltd. Sake: King Brewery Co., Ltd. Mirin: Kikkoman Corporation Salt: Produced by the Salt Industry Center

[0072] (Preparation of sweet potato rice) Sweet potato rice was prepared using commercially available sweet potatoes and polished rice (Akita Komachi) using the following method. (1) Cut the sweet potato into 1cm cubes and soak it in water. (2) 150 g of raw rice was washed and transferred to a rice cooker. The sake, mirin, salt seasonings, calcium maltobionate, and water in the amounts listed in Table 5 were added and mixed lightly, and then cooked in a rice cooker. (3) After cooking, the rice was lightly mixed with a rice paddle, and the rice was steamed for 1 hour with the heat setting turned off, after which the color was evaluated.

[0073] Using Comparative Example 5-1 as a standard, the ΔE of each sample was evaluated in the same manner as in the above (color tone evaluation). ab * In this study, Comparative Example 5-1 was used as the faded standard, so ΔE ab * The larger the value, the more the fading is suppressed.

[0074] [Table 5]

[0075] As shown in Table 5, the addition of calcium maltobionate prevented the sweet potatoes in the sweet potato rice from turning black, maintaining their bright yellow color.

[0076] <Test 6: Cut Apple> Cut apples were prepared using the following ingredients and evaluated for color.

[0077] (material) Calcium maltobionate (powder): manufactured by Sanei Saccharification Co., Ltd.

[0078] (Preparation of cut apples) Commercially available apples were used to prepare cut apples in the following manner. (1) Cut the apple into 5mm thick ginkgo slices. (2) After mixing calcium maltobionate and water in the amounts shown in Table 6, the apples from (1) were added and soaked for 30 minutes. (3) After draining the liquid, the color was evaluated after storing at room temperature for 24 hours.

[0079] Using Comparative Example 6-1 as a standard, the ΔE of each sample was evaluated in the same manner as in the above (color tone evaluation). ab * In this study, the comparative example 6-1, in which discoloration was confirmed, was used as the standard, so ΔE ab * The larger the value, the more the fading is suppressed.

[0080] [Table 6]

[0081] As shown in Table 6, it was confirmed that adding calcium maltobionate suppressed browning of cut apples, indicating that maltobionic acid and maltobionate salts can also control enzyme-mediated color changes.

[0082] <Test 7: Dried Apple> Dried apples were prepared using the following ingredients and evaluated for color.

[0083] (material) Calcium maltobionate (powder): manufactured by Sanei Saccharification Co., Ltd.

[0084] (Preparation of dried apples) Commercially available apples were used to prepare dried apples in the following manner. (1) Cut the apple into 5mm thick ginkgo slices. (2) After mixing calcium maltobionate and water in the amounts shown in Table 6, the apples from (1) were added and soaked for 30 minutes. (3) After draining, the color tone was evaluated after drying with hot air at 75°C for 5 hours.

[0085] Using Comparative Example 7-1 as a standard, the ΔE of each sample was evaluated in the same manner as in the above (color tone evaluation). ab * In this study, the comparative example 7-1, in which discoloration was confirmed, was used as the standard, so ΔE ab * The larger the value, the more the fading is suppressed.

[0086] [Table 7]

[0087] As shown in Table 7, it was confirmed that adding calcium maltobionate suppressed browning of dried apples.

[0088] <Test 8: Boiled cabbage> Boiled cabbage was prepared using the following ingredients and the color was evaluated.

[0089] (material) Calcium maltobionate (powder): manufactured by Sanei Saccharification Co., Ltd.

[0090] (Preparing boiled cabbage) Boiled cabbage was prepared using commercially available cabbage in the following manner. (1) Cut the cabbage into 2cm cubes. (2) Calcium maltobionate and water in the amounts shown in Table 7 were mixed and then heated to a boil. (3) The cut cabbage was added to (2) and heated for 4 minutes, then cooled in ice water for 2 minutes. (4) After draining the water, the color was evaluated.

[0091] Using Comparative Example 8-1 as a standard, the ΔE of each sample was evaluated in the same manner as in the above (color tone evaluation). ab * In this study, the comparative example 8-1, in which discoloration was confirmed, was used as the standard, so ΔE ab * The larger the value, the more the fading is suppressed.

[0092] [Table 8]

[0093] As shown in Table 8, the addition of calcium maltobionate prevented the discoloration of boiled cabbage and maintained its vivid green color.

[0094] <Test 9: Freeze-dried cabbage> Freeze-dried cabbage was prepared using the following ingredients and its color was evaluated.

[0095] (material) Calcium maltobionate (powder): manufactured by Sanei Saccharification Co., Ltd.

[0096] (Preparation of freeze-dried cabbage) Using the boiled cabbage from Test 8, freeze-dried cabbage was prepared in the following manner. (1) Boiled cabbage was frozen and then freeze-dried. (2) After freeze-drying, the cabbage was poured over with an equal amount of hot water (90°C) and rehydrated for 3 minutes. (3) After draining the water, the color was evaluated.

[0097] Using Comparative Example 9-1 as a standard, the ΔE of each sample was evaluated in the same manner as in the above (color tone evaluation). ab * In this study, the comparative example 9-1, in which discoloration was confirmed, was used as the standard, so ΔE ab * The larger the value, the more the fading is suppressed.

[0098] [Table 9]

[0099] As shown in Table 9, it was confirmed that the addition of calcium maltobionate maintained the vivid green color of freeze-dried cabbage.

Claims

1. Contains at least one component selected from maltobionic acid and maltobionate salts, A discoloration inhibitor for processed vegetable and fruit products, which is formulated so that the total amount of maltobionic acid and maltobionate is 0.05 parts by mass or more per 100 parts by mass of vegetables or fruits.

2. A discoloration inhibitor for processed vegetable and fruit products, comprising at least one component selected from maltobionic acid and maltobionate salts, and not containing honey.

3. The discoloration inhibitor for processed vegetable and fruit products according to claim 1 or 2, wherein the maltobionate is calcium maltobionate or magnesium maltobionate.

4. A method for suppressing discoloration of processed vegetable and fruit products, comprising a step of blending the discoloration inhibitor for processed vegetable and fruit products according to any one of claims 1 to 3 with vegetables or fruits so that the total amount of maltobionic acid and maltobionate is 0.05 parts by mass or more per 100 parts by mass of the vegetables or fruits.

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