METHOD OF MANUFACTURING PROCESSED COCONUT MILK

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 including a step for treating a coconut milk with a protein deamidase, the flavor of the coconut milk can be improved.

Claims

1. A method of manufacturing processed coconut milk, comprising a step of treating coconut 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 coconut milk.

3. A flavor improving agent for coconut milk, comprising a protein deamidase.

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

5. The flavor improving agent according to claim 3, wherein the flavor improvement is enhancement of milk feeling.

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

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

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

9. The flavor improving method according to claim 7, wherein the coconut milk with improved flavor is coconut milk with enhanced milk feeling.

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

Description

EXAMPLES

[0046] 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.

[0047] The protein deamidase used in the following test examples is a protein glutaminase derived from Chryseobacterium proteolyticum (protein glutaminase “Amano” 500; titer: 500 U/g). The activity of the protein deamidase was measured by the following method.

[0048] (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.

[0049] (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).

[0050] (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.

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

Test Example 1

(1) Preparation of Coconut Milk

[0051] Two cups of coconut long (fine cut of copra) and four cups of water were mixed and pulverized with a mixer for 2 minutes to prepare a coconut slurry. The coconut slurry was filtered with a strainer bag to prepare coconut milk. The prepared coconut milk was parceled out under stirring. The content of the soluble solids in the coconut milk is about 1 to 8 wt % (about 2 wt % in the coconut milk used in the present test example), and the content of the protein in the coconut milk calculated from the content of the protein of coconut is about 1 wt %.

(2) Enzyme Treatment

[0052] A protein glutaminase (PG) was charged in an amount shown in Table 1, and reacted at 60° C. for 1 hour or 2 hours. The enzyme deactivation 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 without charging PG and performing an enzyme treatment reaction at 60° C., but performing only treatment at 90° C. for 15 minutes. Processed chickpea milk (content of the soluble solids: about 7 wt %, content of the protein: about 3.3 wt %) or processed soy milk (Comparative Examples 2 to 5) was also prepared in the same manner as in Comparative Example 1 and Example 4, respectively, except that chickpea milk or soy milk (that is, soybean milk) was used instead of coconut milk.

(3) Evaluation

[0053] The obtained processed coconut milk, processed chickpea milk, and processed soy milk (these are also collectively referred to as “processed plant milk”) were subjected to sensory evaluation on pH (25° C.) and flavor (sweetness, milk feeling, and raw material aroma). The results are shown in Table 1.

<Sensory Evaluation on Sweetness>

[0054] Sweetness was evaluated on the basis of the following criteria, using the sweetness of the processed plant milk not subjected to the PG treatment as a standard. [0055] −: No enhancement of sweetness is observed. [0056] +: Sweetness was enhanced. [0057] ++: Sweetness was further enhanced.

<Sensory Evaluation on Milk Feeling>

[0058] Milk feeling (milky flavor) was evaluated on the basis of the following criteria, using the milk feeling of the processed plant milk not subjected to the PG treatment as a standard. [0059] −: No enhancement of milk feeling is observed. [0060] +: Milk feeling was enhanced.

<Sensory Evaluation on Raw Material Aroma>

[0061] Raw material aroma (coconut aroma in the case of the processed coconut milk, chickpea aroma in the case of the processed chickpea milk, and soybean aroma in the case of the processed soy milk) was evaluated on the basis of the following criteria, using the raw material aroma of the processed plant milk not subjected to the PG treatment as a standard. [0062] −: No enhancement of raw material aroma is observed. [0063] +: Raw material aroma is enhanced.

TABLE-US-00001 TABLE 1 PG (U) Per Per 1 g of Raw 100 ml soluble solid Per 1 g of Reaction Milk aroma Material of milk content protein condition pH Sweetness feeling material Com- Coconut 0 0 0 6.34 Standard Standard Standard parative milk Example 1 Example 1 Coconut 50 About 25   About 50   60° C.-1 hr 6.26 + + + milk Example 2 Coconut 50 About 25   About 50   60° C.-2 hr 6.25 + + + milk Example 3 Coconut 250 About 125  About 250  60° C.-1 hr 6.11 ++ + + milk Example 4 Coconut 250 About 125  About 250  60° C.-2 hr 6.1 ++ + + milk Com- Chickpea 0 0 0 6.32 Standard Standard Standard parative milk Example 2 Com- Chickpea 250 About 35.5 About 75.5 60° C.-2 hr 6.13 — — — parative milk Example 3 Com- Soy milk 0 0 0 — Standard Standard Standard parative Example 4 Com- Soy milk 250 20.8 50 60° C.-2 hr — — — — parative Example 5

[0064] As shown in Table 1, by the protein glutaminase treatment of the coconut milk (Examples 1 to 4), as compared with a case where the coconut milk was not treated with a protein glutaminase (Comparative Example 1), enhancement of sweetness, enhancement of milk feeling, and enhancement of coconut aroma were observed, and a particularly remarkable effect of improving flavor was observed. On the other hand, in the case of the chickpea milk and the soy milk (Comparative Examples 2 and 3 and Comparative Examples 4 and 5), the protein glutaminase treatment did not enhance any of sweetness, milk feeling, and raw material aroma, and no effect of improving flavor was observed.