Method of manufacturing processed chickpea milk

Abstract

We provide processing technology that can improve the flavor of chickpea milk. [Solution] A method for producing processed chickpea milk, which includes a step of treating chickpea milk with a protein deamidation enzyme, can improve the flavor of chickpea milk.

Description

Technical Field

[0001] The present invention relates to a processing technology capable of improving the flavor of chickpea milk. More specifically, the present invention relates to a method for producing processed chickpea milk, a flavor improver for chickpea milk, and a method for improving the flavor of chickpea milk.

Background Art

[0002] Beverages rich in nutrients such as protein have been widely favored by people because they can easily provide nutrients. On the other hand, due to the recent increase in vegetarians, allergy problems, and religious reasons, etc., soy milk made from soybeans rich in plant protein has become widely popular as an alternative to animal milk represented by cow's milk.

[0003] Regarding soy protein, various modification treatments have been studied for the purpose of improving its existing properties and providing foods with new taste characteristics.

[0004] For example, Patent Document 1 describes that the yield of soy protein from soy flour can be improved by treating soy flour with a protein deamidating enzyme. Also, Patent Document 2 describes that polyglycerol fatty acid esters having fatty acids with 12 to 22 carbon atoms as the main constituent fatty acids are effective as a dispersion stabilizer for soy milk. Furthermore, Patent Document 3 describes that by performing a deamidation treatment on soy milk with a cation exchange resin and / or a phytic acid removal treatment with an anion exchange resin, precipitation is less likely to occur with a coagulant.

[0005] On the other hand, due to the fact that protein is not unrelated to allergy problems, the need to respond to further diversification of palatability, and the increasing awareness of avoiding the intake of genetically modified soybeans frequently used in soy milk, there is a need for more options in addition to soy milk for food and beverages containing plant protein.

[0006] Chickpeas are gaining attention as a soybean alternative. Like soybeans, they contain isoflavones and are high in protein, but they are lower in fat and richer in dietary fiber than soybeans. Chickpeas are also available commercially in the form of chickpea paste or chickpea milk. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2000-50887 [Patent Document 2] Japanese Patent Publication No. 2008-283900 [Patent Document 3] Japanese Patent Publication No. 2015-159765 [Overview of the project] [Problems that the invention aims to solve]

[0008] The history of chickpea processed foods is very short, and compared to major processed foods such as soy milk, processing techniques have not yet been sufficiently explored. Chickpea milk has a uniquely rich flavor compared to soy milk, but it is also characterized by a lingering aftertaste and a milder initial taste compared to nut milks such as almond milk and coconut milk. These characteristics are also traits that should be improved in terms of chickpea milk's flavor. Considering the potential for the future expansion of chickpea milk's popularity, technologies that can improve the flavor of chickpea milk are desired to meet the diversifying taste preferences of consumers.

[0009] Therefore, the present invention aims to provide a processing technology that can improve the flavor of chickpea milk. [Means for solving the problem]

[0010] As a result of diligent research by the inventors, it has been discovered that the flavor of chickpea milk can be improved by treating it with a protein deamidation enzyme, which was previously unknown to have a taste-improving effect on plant-based milks. That is, the present invention provides the invention in the following embodiments.

[0011] Item 1. A method for producing processed chickpea milk, comprising the step of treating chickpea milk with a protein deamidation enzyme. Item 2. The manufacturing method according to Item 1, wherein the protein deamidation enzyme is used at a concentration of 0.1 U or more per gram of soluble solids of the chickpea milk. Item 3. The manufacturing method according to item 1 or 2, wherein the chickpea milk is treated with α-amylase. Item 4. A flavor enhancer for chickpea milk containing a protein deamidation enzyme. Item 5. The flavor enhancer described in Item 4, wherein the flavor improvement is an enhancement of the crispness of the aftertaste. Item 6. The flavor enhancer according to item 4 or 5, wherein the flavor enhancement is an increase in the richness of the initial taste. Item 7. A method for improving the flavor of chickpea milk, comprising the step of treating chickpea milk with a protein deamidation enzyme to obtain chickpea milk with improved flavor. Item 8. The flavor improvement method according to Item 7, wherein the chickpea milk with improved flavor is chickpea milk with an enhanced clean aftertaste. Item 9. The flavor improvement method according to item 7 or 8, wherein the flavor-improved chickpea milk is chickpea milk with enhanced initial richness. [Effects of the Invention]

[0012] The present invention provides a processing technology that can improve the flavor of chickpea milk. [Modes for carrying out the invention]

[0013] 1. Method for producing processed chickpea milk The present invention relates to a method for producing processed chickpea milk, characterized by including a step of treating chickpea milk with a protein deamidation enzyme. The present invention relates to a method for producing processed chickpea milk, and will be described in detail below.

[0014] 1-1. Chickpea Milk Chickpeas are the seeds of the genus Cicer arietinum in the legume family, and are also known as garbanzo beans, Egyptian beans, or chana beans. While the Kabri and Daisy varieties are common types of chickpeas, either variety can be used in this invention.

[0015] Chickpea milk is typically prepared by extracting juice from soaked chickpeas. Specific examples of chickpea milk preparation methods include preparing a chickpea slurry by soaking chickpeas in water and then crushing them, or by soaking chickpea flour in water and then filtering the prepared slurry after heating.

[0016] From the viewpoint of improving solubility, chickpea milk is preferably treated with α-amylase. In this case, chickpea milk can be prepared by adding α-amylase to the chickpea slurry in the example of the chickpea milk preparation method described above, and then heating it. The α-amylase used in this case is not particularly limited, but preferably it is α-amylase derived from the genus Bacillus, and more preferably it is α-amylase derived from the species Bacillus amyloricuefaciens.

[0017] Regarding the amount of α-amylase used, for example, 100 to 10,000 U, preferably 200 to 5,000 U, more preferably 300 to 1,000 U, even more preferably 350 to 700 U, and even more preferably 400 to 500 U per 100 g of soluble solids in the chickpea slurry. The activity of α-amylase is defined as the amount of enzyme that reduces the iodine-induced coloration of potato starch by 10% per minute using potato starch as a substrate, with 1 unit (1 U) being defined as the amount of enzyme that does so.

[0018] As the heating temperature of the chickpea slurry, for example, 90°C or higher, preferably 95°C or higher, and more preferably the boiling temperature (that is, the upper limit temperature of the heating temperature) can be mentioned. As the sieve used for filtering the heat-treated chickpea slurry, a normal food filtering bag used for soy milk squeezing or the like can be used.

[0019] In chickpea milk, the amount of water relative to 1 part by weight of chickpeas is, for example, 4 to 10 parts by weight, preferably 5 to 8 parts by weight, and more preferably 6 to 7 parts by weight. The soluble solid content in chickpea milk is, for example, 3 to 10% by weight, preferably 5 to 8% by weight, and the protein content in chickpeas is, for example, 1 to 8% by weight, preferably 2.5 to 5% by weight.

[0020] 1-2. Protein deamidation enzymes As the protein deamidase used in the present invention, as long as it is an enzyme that exhibits the action of decomposing the amide group-containing side chain of a protein without involving the cleavage of peptide bonds and the cross-linking of proteins, its type, origin, etc. are not particularly limited. Examples of protein deamidases include those derived from the genus Chryseobacterium, Flavobacterium, Empedobacter, Sphingobacterium, Aureobacterium, or Myroides, and protein glutaminase derived from the genus Chryseobacterium, which are disclosed in JP2000-50887A, JP2001-218590A, and WO2006 / 075772A1. As these protein deamidases, one kind may be used alone, or a plurality of kinds may be used in combination.

[0021] Among these protein deamide enzymes, from the viewpoint of further enhancing the flavor-improving effect of chickpea milk, protein deamide enzymes derived from the genus Chryseobacterium are preferred, more preferably protein glutaminases derived from the genus Chryseobacterium, and even more preferably protein glutaminases derived from the species Chryseobacterium proteoricum.

[0022] Protein deamide enzymes can be prepared from the culture medium of the microorganism from which the above-mentioned protein deamide enzymes originate. Specific preparation methods include recovering the protein deamide enzyme from the culture medium or cells of the above-mentioned microorganisms. For example, when using a protein deamide enzyme-secreting microorganism, the cells can be recovered from the culture medium by filtration, centrifugation, etc., as needed, and then the enzyme can be separated and / or purified. When using a protein deamide enzyme-non-secreting microorganism, the cells can be recovered from the culture medium by filtration, centrifugation, etc., as needed, and then the cells can be crushed by pressurization, sonication, etc., to expose the enzyme, and then the enzyme can be separated and / or purified. The enzyme separation and / or purification method can be any known protein separation and / or purification method without particular limitation, such as centrifugation, UF concentration, salting out, and various chromatography methods using ion exchange resins. The separated and / or purified enzyme can be powdered by drying methods such as freeze-drying or vacuum drying, and can also be powdered using appropriate excipients and / or drying aids in the drying method. The separated and / or purified enzymes can also be liquefied by adding appropriate additives and sterilizing by filtration.

[0023] Commercially available protein deamidation enzymes can also be used, and a preferred example of such an enzyme is "Amano" 500 protein glutaminase manufactured by Amano Enzyme Co., Ltd.

[0024] The titer of the 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.

[0025] The amount of protein deamide enzyme used is not particularly limited, but for example, 0.1U or more per gram of chickpea protein is used, and from the viewpoint of further enhancing the flavor-improving effect of chickpea milk, preferably 1U or more, more preferably 5U or more, even more preferably 10U or more, even more preferably 30U or more, even more preferably 50U or more, and especially preferably 70U or more. The upper limit of the range of protein deamide enzyme used per gram of chickpea protein is not particularly limited, but for example, 1000U or less, 500U or less, 200U or less, or 100U or less is used. Furthermore, as for the amount of protein deamide enzyme used, for example, 0.1U or more per gram of soluble solids of chickpea milk is used, and from the viewpoint of further enhancing the flavor-improving effect of chickpea milk, preferably 1U or more, more preferably 5U or more, even more preferably 10U or more, even more preferably 20U or more, and even more preferably 30U or more. There is no particular upper limit to the amount of protein deamide enzyme used per gram of soluble solids in chickpea milk, but examples include 2000U or less, 1000U or less, 500U or less, or 200U or less. Furthermore, as for the amount of protein deamide enzyme used, for example, 1U or more per 100mL of chickpea milk, from the viewpoint of further enhancing the flavor improvement effect of chickpea milk, preferably 5U or more, more preferably 10U or more, even more preferably 20U or more, even more preferably 100U or more, even more preferably 150U or more, and particularly preferably 200U or more. There is no particular upper limit to the amount of protein deamide enzyme used per 100mL of chickpea milk, but examples include 5000U or less, preferably 2000U or less, more preferably 1000U or less, and even more preferably 500U or less.

[0026] Regarding the activity of protein deamidase enzymes, one unit (1U) is defined as the amount of enzyme that releases 1 μmol of ammonia per minute using benzyloxycarbonyl-L-glutaminylglycine (Z-Gln-Gly) as a substrate.

[0027] 1-3. Reaction conditions, etc. In the process of treating chickpea milk with a protein deamidation enzyme, a chickpea milk composition containing chickpea milk and the protein deamidation enzyme is prepared by adding the protein deamidation enzyme to the chickpea milk, and the enzymatic treatment reaction (i.e., the reaction that improves the flavor of chickpea milk) can be carried out by maintaining the chickpea milk composition in a heated state.

[0028] The heating temperature (enzyme treatment reaction temperature) of the chickpea milk composition is not particularly limited and can be appropriately determined by those skilled in the art depending on the optimal temperature of the enzyme used, but for example, 40 to 70°C is preferred, preferably 50 to 70°C, more preferably 55 to 65°C, and even more preferably 58 to 62°C.

[0029] The enzyme treatment reaction time for the chickpea milk composition is not particularly limited and can be appropriately determined according to the preparation scale of the composition, but for example, 0.5 hours or more, preferably 1 hour or more. The upper limit of the enzyme treatment reaction time range is not particularly limited, but for example, 24 hours or less, 12 hours or less, 8 hours or less, 6 hours or less, or 4 hours or less can be cited.

[0030] The enzyme treatment reaction can be terminated by enzyme inactivation treatment using high heat. Examples of enzyme inactivation treatment temperatures include 85°C or higher, preferably 90°C or higher, and examples of enzyme inactivation treatment times include 5 to 25 minutes, preferably 10 to 20 minutes.

[0031] The chickpea milk composition after enzyme treatment is subjected to post-treatment such as filtration as needed to obtain processed chickpea milk (i.e., chickpea milk with improved flavor).

[0032] 2. Flavor enhancer for chickpea milk and method for improving the flavor of chickpea milk As described above, protein deamidation enzymes can improve the flavor of chickpea milk. Therefore, the present invention also provides a flavor enhancer for chickpea milk and a method for improving the flavor of chickpea milk.

[0033] The chickpea milk flavor enhancer of the present invention is characterized by containing a protein deamidation enzyme. In the present invention, "flavor enhancement" includes "enhancing the crispness of the aftertaste" and / or "enhancing the richness of the initial taste."

[0034] The present invention relates to a method for improving the flavor of chickpea milk, characterized by comprising the step of treating chickpea milk with a protein deamidation enzyme to obtain chickpea milk with improved flavor. As described above, "improved flavor" includes "enhanced aftertaste" and / or "enhanced richness of initial taste."

[0035] Furthermore, "aftertaste" refers to the taste that lingers on the tongue after swallowing a beverage, while "initial taste" refers to the taste perceived immediately after taking a beverage into the mouth, especially within 3 seconds. An enhanced "crispness" in the aftertaste means that the aftertaste doesn't linger for as long, resulting in a cleaner, more refreshing aftertaste. An enhanced "richness" in the initial taste means that the initial taste feels more intensely flavorful.

[0036] The types of ingredients used, the amounts used, etc., in the above-mentioned chickpea milk flavor enhancer and chickpea milk flavor enhancer are as shown in section 1, "Method for Manufacturing Processed Chickpea Milk." [Examples]

[0037] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples.

[0038] Details of the enzymes used in the following test examples are as follows:

[0039] [Table 1]

[0040] The activity of protein deamidase (protein glutaminase) was measured using the following method. (1) 1 ml of 0.2 M phosphate buffer (pH 6.5) containing 30 mM Z-Gln-Gly was mixed with 0.1 ml of aqueous solution containing protein deamidase, incubated at 37°C for 10 minutes, and then 1 ml of 0.4 M TCA solution was added to stop the reaction. As a blank, 1 ml of 0.4 M TCA solution was mixed with 1 ml of 0.2 M phosphate buffer (pH 6.5) containing 30 mM Z-Gln-Gly, followed by 0.1 ml of aqueous solution containing protein deamidase, and incubated at 37°C for 10 minutes. (2) The amount of ammonia produced in the reaction solution was measured using the Ammonia Test Wako (Fujifilm Wako Pure Chemical Corporation) for the solution obtained in (1). The ammonia concentration in the reaction solution was determined from a calibration curve showing the relationship between ammonia concentration and absorbance (630 nm) prepared using ammonia standard solution (ammonium chloride). (3) The activity of the protein deamide enzyme was calculated using the following formula, with the amount of enzyme that produces 1 μmol of ammonia per minute defined as 1 unit (1 U). In the formula, the volume of the reaction solution is 2.1, the volume of the enzyme solution is 0.1, and Df is the dilution ratio of the enzyme solution. Also, 17.03 is the molecular weight of ammonia.

[0041] [ka]

[0042] Test Example 1 (1) Preparation of chickpea milk 200g of chickpeas were soaked in a large amount of water and left at room temperature for 24 hours. The soaked chickpeas were collected and placed in a blender, and water was added until the chickpeas were covered. The blender was used to crush the chickpeas for 2 minutes, and then water was added and the mixture was blended further to prepare a chickpea slurry. The total amount of water used for soaking the chickpeas was 1.2L. The chickpea slurry was placed in a pot, and E5CC (α-amylase) was added in an amount equivalent to 450U per 100g of soluble solids in the chickpea slurry. After bringing it to a boil, it was simmered over low heat for 20-30 minutes. After that, it was strained through a sieve to prepare chickpea milk. The prepared chickpea milk was divided into smaller portions while being stirred. The soluble solids content in the chickpea milk was approximately 7% by weight, and the protein content in the chickpea milk, calculated from the protein content of chickpeas, was approximately 3.3% by weight.

[0043] (2) Enzyme treatment Protein glutaminase (PG) was added in the amounts shown in Table 2 and reacted at 60°C for 1, 2, or 3 hours. Enzyme inactivation treatment was performed at 90°C for 15 minutes to obtain processed chickpea milk (Examples 1 to 6). Processed chickpea milk (Comparative Example 1) was also prepared by performing only the 15-minute treatment at 90°C without adding PG or performing the enzyme treatment reaction at 60°C. Furthermore, processed soy milk (Comparative Examples 2 and 3) was prepared in the same manner as Comparative Examples 1 and 6, except that soy milk (i.e., soybean milk) was used instead of chickpea milk.

[0044] (3) Evaluation Sensory evaluations were conducted on the pH (25°C) and flavor (initial and aftertaste) of the obtained processed chickpea milk and processed soy milk. The results are shown in Table 2.

[0045] <Sensory evaluation regarding initial taste> The taste perceived immediately after placing the food in the mouth and within 3 seconds (initial taste) was evaluated based on the following criteria. --: The initial taste is mild. -: Has a subtle richness at the beginning. +: Enhanced richness of the initial flavor ++: The initial richness of the flavor is further enhanced.

[0046] <Sensory evaluation regarding aftertaste> The taste (aftertaste) remaining on the tongue after holding the product in the mouth for 3 seconds and swallowing was evaluated based on the following criteria. --: Leaves a strong aftertaste. -: Leaves a lingering aftertaste +: The aftertaste is sharper and more refreshing. ++: The aftertaste is sharper and more refreshing.

[0047] [Table 2]

[0048] As shown in Table 2, chickpea milk that was not treated with protein glutaminase (Comparative Example 1) had a weak initial richness and a strong aftertaste. However, protein glutaminase treatment (Examples 1-6) enhanced the initial richness while improving the aftertaste, resulting in a cleaner flavor. No improvement in flavor was observed in soy milk (Comparative Examples 2-3) due to protein glutaminase treatment.

Claims

1. A method for producing processed chickpea milk, comprising the step of treating chickpea milk with a protein deamidation enzyme.

2. The manufacturing method according to claim 1, wherein the protein deamidation enzyme is used at a rate of 5 U or more per gram of soluble solids of the chickpea milk.

3. The manufacturing method according to claim 1 or 2, wherein the chickpea milk is treated with α-amylase.

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