How processed coconut milk is made

Abstract

The purpose of the present invention is to provide a processing technique whereby the flavor of a coconut milk can be improved. According to this method of manufacturing a processed coconut milk, said method comprising a step for treating a coconut milk with a protein deamidase, the flavor of the coconut milk can be improved.

Description

[Technical Field]

[0001] The present invention relates to a processing technology that can improve the flavor of coconut milk, and more specifically, the present invention relates to a method for producing processed 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 dairy ingredients have long been widely enjoyed, with a wide variety of products available. In these products, the flavor of milk (milkiness) is an important factor in determining palatability, and consumers tend to prefer products with a strong milkiness. For this reason, various processing methods have been proposed to enhance the milkiness of beverages containing dairy ingredients. Examples include adding sucralose to a milk-containing beverage (Patent Document 1), adding a seasoning obtained by processing yeast extract and dextrin (Patent Document 2), and adding a dextrin component containing xylitol and reduced dextrin (Patent Document 3). It is also known that beverages other than milk-containing beverages have a milky flavor. For example, it is known that a palm kernel extract with an enhanced milkiness can be obtained by solvent extraction of the endosperm of palm kernels followed by removal of aroma components (Patent Document 4).

[0003] On the other hand, there is a growing movement to substitute milk and beverages containing milk ingredients with plant-based milks in order to avoid the risk of lactose intolerance and / or milk allergies, as well as to respond to the diversifying tastes of consumers today.

[0004] Among plant-based milks, coconut milk is a staple ingredient in tropical cuisine, particularly in Southeast Asia. For this reason, coconut milk has long been available commercially as canned or frozen products. Coconut milk is rich in minerals such as potassium, iron, and magnesium, and is cholesterol-free. Its nutritional value has garnered attention, and with growing awareness of health and beauty, it is rapidly becoming popular outside of Southeast Asia.

[0005] Coconut milk generally has a composition of about 10 to 30% fat and oil, a few to 30% solids, and the remainder water, and is usually an oil-in-water white liquid (Patent Document 5). In order to solve problems such as the formation of precipitates, separation of lipid components, and floating oil when coconut milk is used in foods and beverages, coconut milk beverages using sucrose fatty acid esters in which 70% or more by weight of the fatty acids are saturated fatty acids with 16 to 22 carbon atoms and an HLB value of 5 to 16 (Patent Document 6), and coconut milk-containing foods and beverages containing glycerin fatty acid esters and sodium caseinate (Patent Document 5) have been proposed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-42021 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-4673 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-94131 [Patent Document 4] Japanese Patent Application Laid-Open No. 2015-181354 [Patent Document 5] Japanese Patent Application Laid-Open No. 2003-325147 [Patent Document 6] Japanese Patent Application Publication No. 8-256743 Summary of the Invention [Problem to be solved by the invention]

[0007] Although processing methods have been proposed to improve the physical properties of coconut milk based on its characteristic composition and properties, processing technologies to improve its flavor have not been explored. The flavors of coconut milk include the aroma, sweetness, and milkiness of the original ingredients, which are the driving force behind its popularity as a dairy substitute. However, considering the potential for coconut milk to become more widely used in the future, technologies that can improve (i.e., enhance) the flavors of coconut milk, such as the aroma, sweetness, and / or milkiness of the original ingredients, are desirable in order to respond to the diversifying flavor preferences of consumers.

[0008] Therefore, the present invention aims to provide a processing technique that can improve the flavor of coconut milk. [Means for solving the problem]

[0009] As a result of extensive research, the present inventors have found that the flavor of coconut milk can be improved by treating coconut milk with protein deamidating enzyme, which was not previously known to have an effect of improving the taste of vegetable milk. That is, the present invention provides the following aspects.

[0010] Item 1. A method for producing processed coconut milk, comprising treating coconut milk with protein deamidating enzyme. Item 2. The production method according to Item 1, wherein the protein deamidating enzyme is used in an amount of 0.1 U or more per 1 g of soluble solids in the coconut milk. Item 3. A flavor improver for coconut milk, containing protein deamidase. Item 4. The flavor improving agent according to Item 3, wherein the flavor improvement is an enhancement of sweetness. Item 5. The flavor improving agent according to Item 3 or 4, wherein the flavor improvement is an enhancement of milkiness. Item 6. The flavor improving agent according to any one of Items 3 to 5, wherein the flavor improvement is an enhancement of coconut aroma. Item 7. A method for improving the flavor of coconut milk, comprising the step of treating coconut milk with protein deamidating enzyme to obtain coconut milk with improved flavor. Item 8. The flavor improving method according to Item 7, wherein the coconut milk having improved flavor is coconut milk having enhanced sweetness. Item 9. The flavor improving method according to Item 7 or 8, wherein the coconut milk having improved flavor is coconut milk having an enhanced milky taste. Item 10. The flavor improving method according to any one of Items 7 to 9, wherein the coconut milk having improved flavor is coconut milk having an enhanced coconut aroma. [Effects of the Invention]

[0011] According to the present invention, a processing technique is provided that can improve the flavor of coconut milk. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1. Manufacturing method of processed coconut milk The method for producing processed coconut milk of the present invention is characterized by comprising a step of treating coconut milk with protein deamidating enzyme. The method for producing processed coconut milk of the present invention is described in detail below.

[0013] 1-1. Coconut milk Coconut is the solid endosperm of the mature fruit of the coconut palm, and coconut milk may be any ordinary coconut milk, and may be prepared by squeezing a slurry of crushed coconut. A specific example of a method for preparing coconut milk is a method in which crushed and / or shredded endosperm or copra (dried endosperm of the mature fruit) of a raw coconut is ground in water to prepare a coconut slurry, and then the coconut slurry is strained.

[0014] The soluble solid content of coconut milk is, for example, 1 to 10% by weight, preferably 1.5 to 9.5% by weight, and the protein content of coconut milk is, for example, 0.3 to 2% by weight, preferably 0.5 to 1.5% by weight.

[0015] 1-2. Protein deamidase The protein deamidase used in the present invention is not particularly limited in type or origin, as long as it is an enzyme that degrades amide group-containing side chains of proteins without cleaving peptide bonds or cross-linking proteins. Examples of protein deamidases include protein deamidases derived from the genera Chryseobacterium, Flavobacterium, Empedobacter, Sphingobacterium, Aureobacterium, or Myroides, as disclosed in Japanese Patent Laid-Open Nos. 2000-50887, 2001-218590, and WO 2006 / 075772, and protein glutaminases derived from the Chryseobacterium genus. These protein deamidases may be used alone or in combination.

[0016] Among these protein deamidating enzymes, from the viewpoint of further enhancing the flavor improving effect of coconut milk, protein deamidating enzymes derived from the genus Chryseobacterium are preferred, protein glutaminases derived from the genus Chryseobacterium are more preferred, and protein glutaminase derived from the species Chryseobacterium proteolyticum is even more preferred.

[0017] Protein deamidase can be prepared from a culture medium of a microorganism from which the above-mentioned protein deamidase is derived. Specific preparation methods include methods of recovering protein deamidase from the culture medium or cells of the above-mentioned microorganism. For example, when a protein deamidase-secreting microorganism is used, the cells can be recovered from the culture medium in advance by filtration, centrifugation, or the like, as necessary, and the enzyme can then be separated and / or purified. When a protein deamidase-nonsecreting microorganism is used, the cells can be recovered from the culture medium in advance by pressure treatment, ultrasonic treatment, or the like, as necessary, and the enzyme can then be separated and / or purified. The enzyme can be separated and / or purified by any known protein separation and / or purification method, without any particular limitation, and examples of the method include centrifugation, UF concentration, salting out, and various chromatography methods using ion exchange resins, etc. The separated and / or purified enzyme can be powdered by a drying method such as freeze-drying or vacuum drying, or can be powdered using an appropriate excipient and / or drying aid in the drying method. Alternatively, the isolated and / or purified enzyme can be liquefied by adding an appropriate additive and sterilizing by filtration.

[0018] Commercially available protein deamidating enzymes can also be used, and a preferred example of a commercially available protein glutaminase is "Amano" 500 manufactured by Amano Enzyme Inc.

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

[0020] The amount of protein deamidase used is not particularly limited, but may be, for example, 1 U or more per 1 g of coconut protein, and from the viewpoint of further enhancing the flavor-improving effect of coconut milk, preferably 5 U or more, more preferably 10 U or more, even more preferably 20 U or more, still more preferably 100 U or more, even more preferably 200 U or more, and particularly preferably 240 U or more or 250 U or more. The upper limit of the amount of protein deamidase used per 1 g of coconut protein is not particularly limited, but may be, for example, 5000 U or less, 2000 U, 1000 U, 500 U or less, or 300 U or less. The amount of protein deamidase used is, for example, 0.1 U or more per gram of soluble solids in coconut milk, and from the viewpoint of further enhancing the flavor-improving effect of coconut milk, is preferably 0.5 U or more, more preferably 1 U or more, even more preferably 5 U or more, even more preferably 10 U or more, still more preferably 20 U or more or 30 U or more, particularly preferably 40 U or more, 100 U or more, and most preferably 120 U or more. The upper limit of the amount of protein deamidase used per gram of soluble solids in coconut milk is not particularly limited, and examples include 4000 U or less, 3000 U or less, 2000 U or less, 1000 U or less, 500 U or less, 300 U or less, or 200 U or less. Furthermore, the amount of protein deamidase used per 100 mL of coconut milk may be, for example, 1 U or more, and from the viewpoint of further enhancing the flavor-improving effect of coconut milk, preferably 5 U or more, more preferably 10 U or more, even more preferably 20 U or more, still more preferably 100 U or more, even more preferably 200 U or more, and particularly preferably 250 U or more. The upper limit of the amount of protein deamidase used per 100 mL of coconut milk is not particularly limited, and examples include 5000 U or less, 2000 U or less, 1000 U or less, and 500 U or less.

[0021] Regarding the activity of protein deamidase, one unit (1 U) is defined as the amount of enzyme that liberates 1 μmol of ammonia per minute using benzyloxycarbonyl-L-glutaminylglycine (Z-Gln-Gly) as a substrate.

[0022] 1-3. Reaction conditions, etc. In the step of treating coconut milk with protein deamidating enzyme, protein deamidating enzyme is added to the coconut milk to prepare a coconut milk composition containing coconut milk and protein deamidating enzyme, and the coconut milk composition is maintained in a heated state to allow the enzyme treatment reaction (i.e., the reaction that improves the flavor of coconut milk) to proceed.

[0023] The heating temperature (enzyme treatment reaction temperature) of the coconut milk composition is not particularly limited and can be determined appropriately by a person skilled in the art depending on the optimal temperature of the enzyme used, etc., but examples include 40 to 70°C, preferably 50 to 70°C, more preferably 55 to 65°C, and even more preferably 58 to 62°C.

[0024] The enzyme treatment reaction time for the coconut milk composition is not particularly limited and may be determined appropriately depending on the preparation scale of the composition, etc., but may be, for example, 0.5 hours or more, preferably 1 hour or more. The upper limit of the range of the enzyme treatment reaction time is not particularly limited, but may be, 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. The enzyme inactivation treatment temperature is, for example, 85°C or higher, preferably 90°C or higher, and the enzyme inactivation treatment time is, for example, 5 to 25 minutes, preferably 10 to 20 minutes.

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

[0027] 2. Coconut milk flavor improver and method for improving coconut milk flavor As described above, protein deamidase can improve the flavor of coconut milk. Therefore, the present invention also provides an agent for improving the flavor of coconut milk and a method for improving the flavor of coconut milk.

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

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

[0030] "Sweetness" is one of the five general tastes. According to the present invention, even if coconut milk is unsweetened, the sweetness of the material can be enhanced. "Milkiness" is a milk-like flavor that is known to be present even in beverages that do not contain dairy ingredients. "Coconut aroma" is the sweet aroma unique to the raw material coconut, and is known to be exhibited by lactones (γ-nonalactone, massoialactone, and wine lactone).

[0031] In the coconut milk flavor improver and coconut milk flavor improving method described above, the types and amounts of ingredients used are as described in the section "1. Method for producing processed coconut milk." [Example]

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

[0033] The protein deamidase (protein glutaminase) used in the following test examples was protein glutaminase derived from Chryseobacterium proteolyticum (Protein Glutaminase "Amano" 500; titer 500 U / g). Protein deamidase activity was measured by the following method.

[0034] (1) 0.1 ml of an aqueous solution containing protein deamidase was added to 1 ml of 0.2 M phosphate buffer (pH 6.5) containing 30 mM Z-Gln-Gly, and the mixture was incubated at 37°C for 10 minutes. The reaction was then stopped by adding 1 ml of 0.4 M TCA solution. As a blank, 1 ml of 0.4 M TCA solution was added to 1 ml of 0.2 M phosphate buffer (pH 6.5) containing 30 mM Z-Gln-Gly, and 0.1 ml of an aqueous solution containing protein deamidase was then added. The mixture was then incubated at 37°C for 10 minutes. (2) The amount of ammonia generated in the reaction solution obtained in (1) was measured using an Ammonia Test Wako (Fujifilm Wako Pure Chemical Industries, Ltd.). The ammonia concentration in the reaction solution was calculated from a calibration curve showing the relationship between ammonia concentration and absorbance (630 nm) prepared using an ammonia standard solution (ammonium chloride). (3) The activity of protein deamidase was calculated using the following formula, where 1 unit (1U) is the amount of enzyme required to produce 1 μmol of ammonia per minute. In the formula, the volume of the reaction solution is 2.1, the volume of the enzyme solution is 0.1, Df is the dilution factor of the enzyme solution, and 17.03 is the molecular weight of ammonia.

[0035] [ka]

[0036] Test Example 1 (1) Preparation of coconut milk Two cups of coconut long (shredded copra) were mixed with four cups of water and ground in a blender for two minutes to prepare a coconut slurry. The coconut slurry was strained through a strainer to prepare coconut milk. The prepared coconut milk was divided into small portions while stirring. The soluble solids content of the coconut milk was approximately 1-8% by weight (approximately 2% by weight for the coconut milk used in this test example), and the protein content in the coconut milk calculated from the protein content of the coconut was approximately 1% by weight.

[0037] (2) Enzyme treatment PG (protein glutaminase) was added in the amounts shown in Table 1, and the mixture was reacted at 60°C for 1 or 2 hours. Enzyme inactivation treatment was performed at 90°C for 15 minutes to obtain processed coconut milk (Examples 1 to 4). Processed coconut milk (Comparative Example 1) was also prepared by treating the mixture only at 90°C for 15 minutes, without adding PG or performing the enzyme treatment reaction at 60°C. Furthermore, processed chickpea milk (soluble solids content: approximately 7% by weight, protein content: approximately 3.3% by weight) or processed soy milk (Comparative Examples 2 to 5) were also prepared in the same manner as Comparative Example 1 and Example 4, respectively, except that chickpea milk or soy milk (i.e., soy milk) was used instead of coconut milk.

[0038] (3) Evaluation The resulting processed coconut milk, processed chickpea milk, and processed soy milk (collectively referred to as "processed vegetable milk") were subjected to sensory evaluation for pH (25°C) and flavor (sweetness, milkiness, and raw material aroma). The results are shown in Table 1.

[0039] <Sensory evaluation of sweetness> The sweetness was evaluated based on the following criteria, using the sweetness of processed plant-based milk that had not been treated with PG as the standard. -: No enhancement of sweetness observed +: Sweetness increased ++: Sweeter taste

[0040] <Sensory evaluation of milky taste> The milky feel (milk-like flavor) was evaluated based on the following criteria, using the milky feel of processed plant-based milk that had not been treated with PG as the standard. -: No enhancement of milkiness observed +: Enhanced milkiness

[0041] <Sensory evaluation of raw material aroma> The aroma of the raw materials (coconut aroma for processed coconut milk, chickpea aroma for processed chickpea milk, and soybean aroma for processed soy milk) was evaluated based on the following criteria, using the aroma of the raw materials of processed plant-based milk that had not been treated with PG as the standard. -: No enhancement of raw material aroma is observed +: The aroma of raw materials has been enhanced

[0042] [Table 1]

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

Claims

1. The method comprises treating coconut milk with a protein deamidating enzyme, The method for producing processed coconut milk, wherein the protein deamidating enzyme is used in an amount of 20 U or more per 1 g of soluble solids in the coconut milk.

2. A flavor improver for coconut milk containing protein deamidase.

3. The flavor improving agent according to claim 2 , wherein the flavor improvement is an enhancement of sweetness.

4. The flavor improving agent according to claim 2 or 3, wherein the flavor improvement is an enhancement of milkiness.

5. The flavor improving agent according to any one of claims 2 to 4, wherein the flavor improvement is an enhancement of coconut aroma.

6. The method for improving the flavor of coconut milk includes a step of treating coconut milk with protein deamidating enzyme to obtain coconut milk having an improved flavor.

7. 7. The method for improving flavor according to claim 6, wherein the coconut milk having improved flavor is coconut milk having enhanced sweetness.

8. The flavor improving method according to claim 6 or 7, wherein the coconut milk having an improved flavor is coconut milk having an enhanced milkiness.

9. The flavor improving method according to any one of claims 6 to 8, wherein the coconut milk with improved flavor is coconut milk with enhanced coconut aroma.

Images