Method of manufacturing processed coconut milk

Abstract

An object of the present application is to provide a processing technique capable of improving the flavor of coconut milk. According to the manufacturing method of processed coconut milk, the flavor of coconut milk can be improved, the manufacturing method comprising a step of treating coconut milk with a protein deamidase.

Description

Technical Field

[0001] This invention relates to processing techniques that can improve the flavor of coconut milk, and more specifically, to a method for processing coconut milk, a flavor improver for coconut milk, and a method for improving the flavor of coconut milk. Background Technology

[0002] Beverages containing milk and milk-based ingredients have long been widely popular, resulting in a wide variety of products. Among these products, the flavor (milky texture) of milk is a crucial factor in creating deliciousness, and there is a trend towards products with a strong milky texture being favored by consumers. Therefore, various processing methods have been proposed to enhance the milky texture of beverages containing milk-based ingredients. For example, methods for adding sucralose to milk-containing beverages are known (Patent Document 1), methods for adding flavorings obtained by processing yeast extract and dextrin (Patent Document 2), and methods for adding xylitol and dextrin components containing reduced dextrin (Patent Document 3), etc. It should be noted that the presence of a milky flavor is known in beverages other than those containing milk. For example, it is known that by solvent extraction of the endosperm of coconut fruit followed by removal of aroma components, a coconut fruit extract with enhanced milky texture can be obtained (Patent Document 4).

[0003] On the other hand, for beverages containing milk and milk ingredients, there has been a movement to use plant-based milk as a substitute, based on the perspectives of avoiding the risks of lactose intolerance and / or milk allergy, and in response to the diversification of consumer preferences in recent times.

[0004] Coconut milk is a common ingredient in tropical cuisine, particularly in Southeast Asia. As a result, it has long been commercially available as canned and frozen products. Its nutritional value, including being rich in minerals such as potassium, iron, and magnesium, and being cholesterol-free, has garnered attention, and with increasing awareness of beauty and health, it is rapidly gaining popularity beyond Southeast Asia.

[0005] Coconut milk typically consists of approximately 10-30% oil, a few percent-30% solids, and the remainder is water, usually presenting as a white, water-in-oil emulsion liquid (Patent Document 5). Regarding coconut milk, to address issues such as sedimentation, lipid separation, and oil flotation when used in food and beverage products, patent documents have been proposed, including coconut milk beverages containing sucrose fatty acid esters with 70% or more of the fatty acids being saturated fatty acids with 16-22 carbon atoms and an HLB of 5-16 (Patent Document 6), and coconut milk-containing food and beverage products containing glycerol fatty acid esters and sodium caseinate (Patent Document 5). Existing technical documents Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-42021 Patent Document 2: Japanese Patent Application Publication No. 2011-4673 Patent Document 3: Japanese Patent Application Publication No. 2013-94131 Patent Document 4: Japanese Patent Application Publication No. 2015-181354 Patent Document 5: Japanese Patent Application Publication No. 2003-325147 Patent Document 6: Japanese Patent Application Publication No. 8-256743 Summary of the Invention The technical problem that the invention aims to solve

[0007] Regarding coconut milk, processing methods have been proposed to improve its physical properties based on its characteristic composition and characteristics, but processing techniques to improve its flavor have not been studied. The flavors inherent in coconut milk include the aroma, sweetness, and milky texture of the raw material itself, which support its popularity as a substitute for milk beverages. On the other hand, given the potential for further expansion of coconut milk's popularity, it is desirable to develop techniques that can improve (i.e., enhance) the aroma, sweetness, and / or milky texture of the coconut milk raw material itself in order to address the diversification of consumer flavor preferences.

[0008] Therefore, the purpose of this invention is to provide a processing technique that can improve the flavor of coconut milk. Means for solving technical problems

[0009] The inventors conducted in-depth research and discovered that treating coconut milk with a protein deamidase, whose flavor-enhancing effect on plant-based milk is unknown, can improve the flavor of coconut milk. That is, the present invention provides an invention according to the method described below.

[0010] Item 1. A method for processing coconut milk, comprising the step of treating coconut milk with a protein deamidase. Item 2. The manufacturing method according to Item 1, wherein more than 0.1 U of the protein deamidase is used relative to 1 g of the soluble solids content of the coconut milk. Item 3. A flavor enhancer for coconut milk, comprising a protein deamidase. Item 4. The flavor enhancer according to Item 3, wherein the flavor enhancement is an enhancement of sweetness. Item 5. The flavor enhancer according to item 3 or 4, wherein the flavor enhancement is an enhancement of the milky feel. Item 6. The flavor enhancer according to any one of items 3 to 5, wherein the flavor enhancement is an enhancement of coconut aroma. Item 7. A method for improving the flavor of coconut milk, comprising: The process of treating coconut milk with protein deamidase to obtain coconut milk with improved flavor. Item 8. The flavor improvement method according to Item 7, wherein the flavor-improved coconut milk is coconut milk with enhanced sweetness. Item 9. The flavor improvement method according to Item 7 or 8, wherein the flavor-improved coconut milk is coconut milk with enhanced milkiness. Item 10. The flavor improvement method according to any one of items 7 to 9, wherein the flavor-improved coconut milk is coconut milk with enhanced coconut aroma. Invention Effects

[0011] According to the present invention, a processing technique that can improve the flavor of coconut milk can be provided. Detailed Implementation

[0012] 1. Methods for processing coconut milk The method for manufacturing processed coconut milk according to the present invention is characterized by including a step of treating the coconut milk using a protein deamidase. The method for manufacturing processed coconut milk according to the present invention will be described in detail below.

[0013] 1-1. Coconut milk Coconut milk is the solid endosperm of the mature fruit of the coconut tree. Any common type of coconut milk will suffice, typically prepared by pressing the pulp from crushed coconut flesh. A specific method for preparing coconut milk can be as follows: crushing and / or finely slicing the endosperm of a mature coconut fruit or dried coconut endosperm (copra) in water to prepare a coconut pulp, followed by filtering the coconut pulp.

[0014] As a soluble solids component of coconut milk, for example, 1 to 10% by weight, preferably 1.5 to 9.5% by weight, and as a protein component of coconut milk, for example, 0.3 to 2% by weight, preferably 0.5 to 1.5% by weight.

[0015] 1-2. Protein deamidases As for the protein deamidase used in this invention, there are no particular limitations on its type and source, as long as it is an enzyme that does not involve peptide bond cleavage and protein cross-linking and exhibits the function of decomposing the amide-containing side chains of proteins. Examples of protein deamidases include those disclosed in Japanese Patent Application Publication No. 2000-50887, Japanese Patent Application Publication No. 2001-218590, and International Patent Publication No. 2006 / 075772, which are derived from the genera *Chryseobacterium*, *Flavobacterium*, *Empedobacter*, *Sphingobacterium*, *Aureobacterium*, or *Myroides*, as well as protein glutaminase derived from the genus *Chryseobacterium*. These protein deamidases can be used alone or in combination.

[0016] Among these protein deamidases, from the viewpoint of further improving the flavor of coconut milk, protein deamidases derived from the genus *Chlorella* are preferred, protein glutaminases derived from the genus *Chlorella* are more preferred, and protein glutaminases derived from *Chlorella utilis* are even more preferred.

[0017] Protein deamidases can be prepared from the culture medium of microorganisms that serve as the source of the aforementioned protein deamidases. Specific preparation methods include recovering protein deamidases from the culture medium or bacterial cells of these microorganisms. For example, when using protein deamidase-secreting microorganisms, the bacterial cells can be recovered from the culture medium beforehand by filtration, centrifugation, etc., and the enzyme can then be separated and / or purified. Alternatively, when using non-secreting protein deamidase microorganisms, the bacterial cells can be recovered from the culture medium beforehand, and the enzyme can be exposed by pressure treatment, ultrasonic treatment, etc., after the bacterial cells are broken up, and then the enzyme can be separated and / or purified. Known protein separation and / or purification methods can be used without particular limitation, such as centrifugation, UF concentration, salting out, and various chromatographic methods using ion exchange resins. The separated and / or purified enzymes can be powdered by freeze-drying, vacuum drying, or other drying methods. Furthermore, powdering can also be achieved using appropriate excipients and / or drying aids in these drying methods. In addition, isolated and / or purified enzymes can also be liquefied by adding appropriate additives and then filtration sterilization.

[0018] Commercially available products can also be used as protein deamidases. As a preferred example of a commercially available product, the protein glutaminase "AMANO" 500 manufactured by Amano Enzyme Co., Ltd.

[0019] The potency of protein deamidase is not particularly limited, but examples include 50-1000 U / g, 100-900 U / g, 200-800 U / g, preferably 300-700 U / g, more preferably 400-600 U / g, and even more preferably 450-550 U / g.

[0020] There is no particular limitation on the amount of protein deamidase used. For example, 1 U or more can be used relative to 1g of coconut protein. From the viewpoint of further improving the flavor of coconut milk, 5 U or more is preferred, 10 U or more is more preferred, 20 U or more is even more preferred, 100 U or more is still more preferred, 200 U or more is even more preferred, and 240 U or more or 250 U or more is particularly preferred. There is no particular limitation on the upper limit of the range of coconut protein used relative to the protein deamidase, such as 5000 U or less, 2000 U, 1000 U, 500 U or less, or 300 U or less. Furthermore, regarding the amount of protein deamidase used, as relative to 1g of soluble solids in coconut milk, examples include 0.1U or more. From the viewpoint of further improving the flavor of coconut milk, examples include 0.5U or more, more preferably 1U or more, further preferably 5U or more, further preferably 10U or more, even more preferably 20U or more or 30U or more, particularly preferably 40U or more or 100U or more, and most preferably 120U or more. There is no particular limitation on the upper limit of the range of soluble solids in coconut milk relative to 1g of protein deamidase used; examples include 4000U or less, 3000U or less, 2000U or less, 1000U or less, 500U or less, 300U or less, or 200U or less. Furthermore, regarding the amount of protein deamidase used, relative to 100 mL of coconut milk, examples include 1 U or more. From the viewpoint of further improving the flavor of coconut milk, examples include 5 U or more, more preferably 10 U or more, further preferably 20 U or more, even more preferably 100 U or more, even more preferably 200 U or more, and particularly preferably 250 U or more. There is no particular limitation on the upper limit of the range of the amount of protein deamidase used relative to 100 mL of coconut milk; examples include 5000 U or less, 2000 U or less, 1000 U or less, or 500 U or less.

[0021] Regarding the activity of protein deamidases, benzyloxycarbonyl-L-glutamine-glycine (Z-Gln-Gly) was used as the substrate, and the amount of enzyme that releases 1 μmol of ammonia within 1 minute was defined as 1 unit (1U).

[0022] 1-5. Reaction conditions, etc. In the process of treating coconut milk with protein deamidase, a coconut milk composition containing coconut milk and protein deamidase is prepared by adding protein deamidase to the above-mentioned coconut milk. By keeping the coconut milk composition under heating, an enzymatic treatment reaction (i.e., a reaction that improves the flavor of coconut milk) can be carried out.

[0023] There is no particular limitation on the heating temperature (enzyme treatment reaction temperature) of the coconut milk composition. Those skilled in the art can determine it appropriately based on the optimal temperature for using the enzyme. Examples include 40-70°C, preferably 50-70°C, more preferably 55-65°C, and even more preferably 58-62°C.

[0024] There is no particular limitation on the enzyme treatment reaction time for the coconut milk composition, as long as it is appropriately determined according to the scale of the composition, for example, 0.5 hours or more, preferably 1 hour or more. There is no particular limitation on the upper limit of the enzyme treatment reaction time range, for example, 24 hours or less, 12 hours or less, 8 hours or less, 6 hours or less, 4 hours or less, or 2 hours or less.

[0025] The enzyme treatment reaction can be terminated by enzyme inactivation treatment using high heat. Examples of enzyme inactivation treatment temperature include 85°C or higher, preferably 90°C or higher, and examples of enzyme inactivation treatment time include 5 to 25 minutes, preferably 10 to 20 minutes.

[0026] After enzyme treatment, the coconut milk composition is subjected to post-processing such as filtration as needed to obtain processed coconut milk (i.e., coconut milk with improved flavor).

[0027] 2. Flavor enhancers for coconut milk and methods for improving the flavor of coconut milk. As described above, protein deamidases can improve the flavor of coconut milk. Therefore, the present invention also provides a flavor improver for coconut milk and a method for improving the flavor of coconut milk.

[0028] The flavor enhancer for coconut milk of the present invention is characterized by containing a protein deamidase. In the present invention, "flavor enhancement" includes "enhancement of sweetness", "enhancement of milkiness" and / or "enhancement of coconut aroma".

[0029] The method for improving the flavor of coconut milk according to the present invention is characterized by comprising a step of treating coconut milk with a protein deamidase to obtain coconut milk with improved flavor. Similarly, "improved flavor" includes "enhanced sweetness," "enhanced milkiness," and / or "enhanced coconut aroma."

[0030] It should be noted that "sweetness" refers to one of the five common tastes. According to the present invention, even if the coconut milk is unsweetened, the sweetness of the raw material can be enhanced. In addition, "milky texture" refers to a milky flavor, which is known to exist in beverages without milk components. "Coconut aroma" refers to the unique sweet aroma of coconut as a raw material, which is known to be presented by lactones (γ-nonanolactone, massosia lactone, wine lactone).

[0031] Regarding the flavor enhancers and methods for improving the flavor of coconut milk mentioned above, the types and amounts of ingredients used are as shown in the "1. Manufacturing method of processed coconut milk" section above. Example

[0032] The present invention will be specifically described below with examples, but the present invention is not to be construed as being limited to the following examples.

[0033] The protein deamidase (protein glutaminase) used in the following test examples was a protein glutaminase derived from *Chlorella vulgaris* (protein glutaminase "AMANO" 500; titer 500 U / g). The activity of the protein deamidase was determined by the following method.

[0034] (1) Add 0.1 ml of an aqueous solution containing protein deamidase to 1 ml of 0.2 M phosphate buffer (pH 6.5) containing 30 mM Z-Gln-Gly, incubate at 37 °C for 10 minutes, then add 1 ml of 0.4 M TCA solution to stop the reaction. As a blank, add 1 ml of 0.4 M TCA solution to 1 ml of 0.2 M phosphate buffer (pH 6.5) containing 30 mM Z-Gln-Gly, then add 0.1 ml of an aqueous solution containing protein deamidase, and incubate at 37 °C for 10 minutes. (2) The amount of ammonia produced in the reaction solution was determined using an Ammonia-test Wako (Fujifilm and Koichi Chemical Co., Ltd.) instrument. The ammonia concentration in the reaction solution was determined from a standard curve showing the relationship between ammonia concentration and absorbance (630 nm) prepared using ammonia standard solution (ammonium chloride). (3) The amount of enzyme that generates 1 μmol of ammonia within 1 minute is defined as 1 unit (1U). The activity of the protein deamidase is calculated using the following mathematical formula. In the formula, the reaction solution volume is 2.1, the enzyme solution volume is 0.1, and Df is the dilution factor of the enzyme solution. In addition, 17.03 is the molecular weight of ammonia.

[0035] Enzyme activity (U / mL) = Ammonia concentration in reaction solution (mg / L) × (1 / 17.03) × (Reaction solution volume / Enzyme solution volume) × (1 / 10) × Df

[0036] Experimental Example 1 (1) Preparation of coconut milk Mix 2 cups of coconut strips (finely sliced ​​dried coconut endosperm) with 4 cups of water and blend for 2 minutes to prepare coconut pulp. Filter the coconut pulp using a filter bag to prepare coconut milk. The prepared coconut milk is then blended while stirring. The soluble solids content of the coconut milk is approximately 1–8% by weight (approximately 2% by weight in the coconut milk used in this experiment), and the protein content of the coconut milk, calculated from the protein content of coconut, is approximately 1% by weight.

[0037] (2) Enzyme treatment PG (protein glutaminase) was added in the amounts shown in Table 1, and the reaction was carried out at 60°C for 1 hour or 2 hours. Enzyme inactivation was then performed at 90°C for 15 minutes to obtain processed coconut milk (Examples 1-4). Alternatively, processed coconut milk was prepared without PG addition and enzyme treatment at 60°C, but only after treatment at 90°C for 15 minutes (Comparative Example 1). Furthermore, chickpea milk or soy milk (i.e., soybean milk) was used instead of coconut milk, and the same procedures were followed as in Comparative Examples 1 and 4 to prepare processed chickpea milk (soluble solids content of approximately 7% by weight, protein content of approximately 3.3% by weight) or processed soy milk (Comparative Examples 2-5).

[0038] (3) Evaluation Sensory evaluations were conducted on the obtained processed coconut milk, processed chickpea milk, and processed soy milk (collectively referred to as "processed plant-based milk") regarding pH (25°C) and flavor (sweetness, milkiness, and raw material aroma). The results are shown in Table 1.

[0039] <Sensory evaluation of sweetness> For sweetness, the evaluation is based on the sweetness of untreated processed plant-based milk, using the following criteria as a benchmark. -: No enhancement of sweetness confirmed. +: Enhanced sweetness ++: The sweetness is further enhanced.

[0040] <Sensory evaluation of milky texture> For the milky texture (milky flavor), the evaluation is based on the milky texture of untreated processed plant-based milk, using the following criteria as a benchmark. -: No enhancement of milky feel confirmed. +: Enhanced milky feel

[0041] <Sensory evaluation of the fragrance of the raw materials> The aroma of the raw materials (coconut aroma in the case of coconut milk processing, chickpea aroma in the case of chickpea milk processing, and soybean aroma in the case of soy milk processing) is evaluated based on the aroma of raw materials for processed plant-based milk that has not undergone PG treatment, using the following criteria as a benchmark. -: No enhancement of the raw material fragrance was confirmed. +: Enhanced fragrance of raw materials

[0042] [Table 1]

[0043] As shown in Table 1, the treatment of coconut milk with protein glutaminase (Examples 1-4) showed an enhanced sweetness, milkiness, and coconut aroma compared to the case without protein glutaminase treatment (Comparative Example 1), indicating a particularly significant improvement in flavor. On the other hand, in the cases of chickpea milk and soy milk (Comparative Examples 2 and 3, Comparative Examples 4 and 5), the treatment with protein glutaminase did not enhance sweetness, milkiness, or raw material aroma, and no improvement in flavor was observed.

Claims

1. A method for processing coconut milk, comprising the step of treating coconut milk with a protein deamidase, wherein, The protein deamidase is used at a rate of 10 U or more relative to 1 g of the soluble solids content of the coconut milk.

2. The manufacturing method according to claim 1, wherein, The protein deamidase is used at a rate of 20 U or more per 1 g of soluble solids relative to the coconut milk.

3. The use of protein deamidase as a flavor enhancer for coconut milk, characterized in that, Coconut milk was treated with protein deamidase to obtain coconut milk with improved flavor. The protein deamidase is used at a rate of 10 U or more relative to 1 g of the soluble solids content of the coconut milk.

4. The use according to claim 3, wherein, The flavor improvement is an enhancement of sweetness.

5. The use according to claim 3, wherein, The flavor improvement is an enhancement of the milky feel.

6. The use according to claim 3, wherein, The flavor improvement is an enhancement of the coconut aroma.

7. A method for improving the flavor of coconut milk, comprising: The process of treating coconut milk with protein deamidase to obtain coconut milk with improved flavor. The protein deamidase is used at a rate of 10 U or more relative to 1 g of the soluble solids content of the coconut milk.

8. The flavor improvement method according to claim 7, wherein, The improved coconut milk is coconut milk with enhanced sweetness.

9. The flavor improvement method according to claim 7, wherein, The improved coconut milk has an enhanced milky feel.

10. The flavor improvement method according to claim 7, wherein, The improved coconut milk is coconut milk with enhanced coconut flavor.

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