METHOD OF MANUFACTURING PROCESSED CHICKPEA MILK

Abstract

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

Claims

1. A method of manufacturing processed chickpea milk, comprising a step of treating chickpea milk with a protein deamidase.

2. The manufacturing method according to claim 1, wherein the protein deamidase is used in an amount of 0.1 U or more per 1 g of a soluble solid content of the chickpea milk.

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

4. A flavor improving agent for chickpea milk, comprising a protein deamidase.

5. The flavor improving agent according to claim 4, wherein the flavor improvement is enhancement of sharpness of aftertaste.

6. The flavor improving agent according to claim 4, wherein the flavor improvement is enhancement of richness of initial taste.

7. A flavor improving method of chickpea milk, comprising a step of treating chickpea milk with a protein deamidase to obtain chickpea milk with improved flavor.

8. The flavor improving method according to claim 7, wherein the chickpea milk with improved flavor is chickpea milk with enhanced sharpness of aftertaste.

9. The flavor improving method according to claim 7, wherein the chickpea milk with improved flavor is chickpea milk with enhanced richness of initial taste.

Description

EXAMPLES

[0047] Hereinafter, the present invention will be specifically described by means of Examples; however, the present invention is not to be construed as being limited to the following Examples.

[0048] Details of enzymes used in the following test examples are as follows.

TABLE-US-00001 TABLE 1 Enzyme species Abbreviation Trade name Origin Protein PG Protein-glutaminase Chryseobacterium glutaminase “Amano” 500 proteolyticum α-Amylase E5CC Kleistase E5CC Bacillus amyloliquefaciens

[0049] The activity of the protein deamidase (protein glutaminase) was measured by the following method. [0050] (1) To 1 ml of a 0.2 M phosphate buffer (pH 6.5) containing 30 mM Z-Gln-Gly, 0.1 ml of an aqueous solution containing a protein deamidase was added, the mixture was incubated at 37° C. for 10 minutes, and then 1 ml of a 0.4 M TCA solution was added to stop the reaction. As a blank, to 1 ml of a 0.2 M phosphate buffer (pH 6.5) containing 30 mM Z-Gln-Gly, 1 ml of a 0.4 M TCA solution was added, 0.1 ml of an aqueous solution containing a protein deamidase was further added, and the mixture was incubated at 37° C. for 10 minutes. [0051] (2) The amount of ammonia generated in the reaction solution was measured for the solution obtained in (1) using Ammonia Test Wako (FUJIFILM Wako Pure Chemical Corporation). The ammonia concentration in the reaction solution was determined from a calibration curve representing the relationship between the ammonia concentration and the absorbance (630 nm) prepared using an ammonia standard solution (ammonium chloride). [0052] (3) The activity of the protein deamidase was calculated from the following formula with the amount of enzyme that produces 1 μmol of ammonia per minute being defined as 1 unit (1 U). In the formula, the reaction solution amount is 2.1, the enzyme solution amount is 0.1, and Df is a dilution rate of the enzyme solution. 17.03 is a molecular weight of ammonia.

TABLE-US-00002 [Chemical Formula 1] Enzyme activity (U/mL) = ammonia concentration in reaction solution (mg/L) × (1/17.03) × (reaction solution amount/enzyme solution amount) × (1/10) × Df

Test Example 1

(1) Preparation of Chickpea Milk

[0053] In a large amount of water, 200 g of chickpeas were immersed and left to stand at room temperature for 24 hours. The water-absorbed chickpeas were collected and put into a mixer, and water was added to such an extent that the chickpeas were covered. The mixture was crushed with the mixer for 2 minutes, water was added thereto, and the mixture was further stirred to prepare a chickpea slurry. The total amount of water used for the water-absorbed chickpeas was 1.2 L. The chickpea slurry was put in a pot, E5CC (α-amylase) was added in an amount of 450 U with respect to 100 g of the soluble solid content of the chickpea slurry, and the mixture was boiled and then simmered over low heat for 20 to 30 minutes. Thereafter, the mixture was filtered with a strainer bag to prepare chickpea milk. The prepared chickpea milk was parceled out under stirring. The content of the soluble solids in the chickpea milk is about 7 wt %, and the content of the protein in the chickpea milk calculated from the content of the protein of chickpeas is about 3.3 wt %.

(2) Enzyme Treatment

[0054] A protein glutaminase (PG) was charged in an amount shown in Table 2, and reacted at 60° C. for 1 hour, 2 hours, or 3 hours. The enzyme deactivation 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 without charging PG and performing an enzyme treatment reaction at 60° C., but performing only treatment at 90° C. for 15 minutes. Processed soy milk (Comparative Examples 2 and 3) was also prepared in the same manner as in Comparative Example 1 and Example 6, respectively, except that soy milk (that is, soybean milk) was used instead of chickpea milk.

(3) Evaluation

[0055] The obtained processed chickpea milk and processed soy milk were subjected to sensory evaluation on pH (25° C.) and flavor (initial taste and aftertaste). The results are shown in Table 2.

<Sensory Evaluation on Initial Taste>

[0056] The taste sensation (initial taste) felt immediately after the milk was included in the mouth to 3 seconds was evaluated on the basis of the following criteria. [0057] −−: The initial taste is light. [0058] −: The initial taste has weak richness. [0059] +: The richness of initial taste is enhanced. [0060] ++: The richness of initial taste is further enhanced.

<Sensory Evaluation on Aftertaste>

[0061] The taste sensation (aftertaste) remaining on the tongue after the milk was included in the mouth for 3 seconds and then swallowed was evaluated on the basis of the following criteria. [0062] −−: The strong aftertaste remains. [0063] −: The aftertaste remains. [0064] +: The sharpness of aftertaste is enhanced and the aftertaste is clean. [0065] ++: The sharpness of aftertaste is further enhanced and the aftertaste is cleaner.

TABLE-US-00003 TABLE 2 PG (U) Per 1 g of Per 100 mL soluble solid Per 1 g of Reaction Initial Material of milk content protein condition pH taste Aftertaste Comparative Chickpea milk  0  0  0 6.32 − − − Example 1 Example 1 Chickpea milk  50 About 7 About 15 60° C.-1 hr 6.29 + + Example 2 Chickpea milk  50 About 7 About 15 60° C.-2 hr 6.28 + + Example 3 Chickpea milk  50 About 7 About 15 60° C.-3 hr 6.26 + + Example 4 Chickpea milk 250 About 35.5 About 75.5 60° C.-1 hr 6.16 + + + + Example 5 Chickpea milk 250 About 35.5 About 75.5 60° C.-2 hr 6.13 + + + + Example 6 Chickpea milk 250 About 35.5 About 75.5 60° C.-3 hr 6.09 + + + + Comparative Soy milk  0  0  0 — − − Example 2 Comparative Soy milk 250 20.8 50 60° C.-3 hr — − − Example 3

[0066] As shown in Table 2, in the chickpea milk (Comparative Example 1) not treated with a protein glutaminase, the richness of initial taste was weak and the strong aftertaste remained; however, by the protein glutaminase treatment (Examples 1 to 6), while the initial taste was enhanced in the richness, the sharpness of aftertaste was enhanced and the aftertaste was improved to clean flavor. In the soy milk (Comparative Examples 2 and 3), the effect of improving flavor by the protein glutaminase treatment was not observed.