METHOD FOR PRODUCING PLANT PROTEIN FOOD

Abstract

The present invention addresses the problem of providing a novel production method of a plant protein food. This method comprises treating a starting plant protein material with both of a lipase and a protein deamidase (for example, protein glutaminase) to thereby improve the flavor of a plant protein food.

Claims

1. A method for producing a plant protein food, comprising causing a lipase and a protein deamidase to act on a plant protein raw material containing a protein and a fat and oil.

2. The method for producing a plant protein food according to claim 1, wherein the plant protein raw material is a soybean-derived raw material, an oat-derived raw material, an almond-derived raw material, or a coconut-derived raw material.

3. The method for producing a plant protein food according to claim 1, wherein the method comprises steps below: (1) a step of preparing a plant protein raw material containing a protein and a fat and oil; and (2) a step of treating the prepared plant protein raw material with a lipase and a protein deamidase.

4. The method for producing a plant protein food according to claim 3, wherein the plant protein food is a fermented food, and the method comprises a step below after the step (2): (3) a step of fermenting with a microorganism.

5. The method for producing a plant protein food according to claim 4, wherein the fermented food is a lactic acid fermented food, and the microorganism in the step (3) is lactobacillus.

6. The method for producing a plant protein food according to claim 1, wherein the lipase is a Candida cylindracea-derived lipase.

7. The method for producing a plant protein food according to claim 1, wherein the protein deamidase is an enzyme acting on a glutamine residue in a protein.

8. The method for producing a plant protein food according to claim 7, wherein the protein deamidase is protein glutaminase.

9. A plant protein improver comprising a lipase and a protein deamidase.

10. The plant protein improver according to claim 9, wherein the lipase is a Candida cylindracea-derived lipase.

11. The plant protein improver according to claim 9, wherein the protein deamidase is an enzyme acting on a glutamine residue in a protein.

12. The plant protein improver according to claim 11, wherein the protein deamidase is protein glutaminase.

13. The plant protein improver according to claim 9, wherein the plant protein improver is used as a fermentation smell enhancer for a plant fermented food.

14. The plant protein improver according to claim 9, wherein the plant protein improver is used as a smoothness improver for a plant protein food.

Description

EXAMPLES

[0058] In test examples below, the hydrolysis activity of the lipase was measured by the following method.

[0059] <Activity Measurement Method (Kit Method)>

[0060] The lipase activity measurement (kit method) was performed using Lipase Kit S (manufactured by SB Bioscience Co., Ltd.) according to the manual attached to the kit. However, an attached buffer solution adjusted to pH 7 was used as a buffer solution, and acetone was used as a reaction stop solution. An activity value was calculated utilizing a calibration curve prepared using Lipase AY “Amano” 30SD (30000 u/g).

[0061] Meanwhile, the enzyme activity of the protein glutaminase was measured by the method described below using Z-Gln-Gly as a substrate.

[0062] <Activity Measurement Method>

[0063] To 100 μl of a 176 mmol/l phosphate buffer solution (pH 6.5) containing 10 mmol/l of Z-Gln-Gly, 10 μl of an enzyme solution was added, the mixture was incubated at 37° C. for 60 minutes, and then 100 μl of a 12% trichloroacetic acid solution was added to stop the reaction. After centrifugation (15000 rpm, 4° C., 5 minutes), the supernatant was measured using F-kit ammonia (manufactured by Boehringer Mannheim GmbH) as follows to obtain a measured value (A1). Separately, measurement was performed in the same manner using water instead of the enzyme solution to obtain a measured value (A2). To 100 μl of F-kit ammonia reagent 2, 10 μl of the supernatant and 190 μl of water were added, the mixture was left to stand at room temperature for 5 minutes, and then an absorbance (E1) at 340 nm was measured using 100 μl of the mixture. After 1.0 μl of reagent 3 (glutamate dehydrogenase) was added to the remaining 200 μl of the mixture, the mixture was further left to stand at room temperature for 20 minutes, and then an absorbance (E2) at 340 nm of the remaining 200 μl of the mixture was measured. The amount of the enzyme that releases 1 μmol of ammonia per minute under the above conditions was defined as 1 unit (1 u), and the amount thereof was determined according to the following formula.

u/ml=1.76×[A1(E1−E2)−A2(E1−E2)]

[0064] In the following test examples, flavor was evaluated based on the following criteria. In addition to the flavor, the property was evaluated based on the following criteria.

[0065] <Evaluation of Effect of Improving Flavor 1 (Smell)> [0066] ----: No fermentation smell, and strong raw material odor [0067] ---: No fermentation smell, and weak raw material odor [0068] --: No fermentation smell [0069] -: Weak fermentation smell [0070] +: Slightly strong fermentation smell [0071] ++: Strong fermentation smell

[0072] <Evaluation of Effect of Improving Flavor 2 (Smell)> [0073] -: Weak sour taste [0074] +: Slightly strong sour taste [0075] ++: Strong sour taste

[0076] <Evaluation of Effect of Improving Property 1 (Smoothness)> [0077] X: Not smooth (hard and heterogeneous) [0078] Δ: Smooth (soft and homogeneous) [0079] O: Remarkably smooth (softness and homogeneity are remarkable) [0080] <Evaluation of Effect of Improving Property 2 (Smoothness)> [0081] X: Not smooth (less viscous) [0082] Δ: Slightly smooth (slightly viscous) [0083] O: Smooth (sufficiently viscous)

Test Example 1

[0084] In 400 mL of water, 200 g of soybeans was immersed and then drained, and the skin was peeled. To the skin-peeled soybeans, 500 mL or water was added and stirred with a mixer for 1 minute to be ground, and the ground product was filtered to obtain soy milk. To 150 mL of the obtained soy milk (protein concentration: 10 wt %, fat-and-oil concentration: 7.5 wt %), 75 u of protein glutaminase (Protein glutaminase “Amano” 500, manufactured by Amano Enzyme Inc.) (5 u per 1 g of raw material protein) and 3400 u (kit method) of a lipase (Lipase AY “Amano” 30SD, manufactured by Amano Enzyme Inc.) (300 u per 1 g of raw material fat and oil) were added and treated at 50° C. for 1 hour. The resulting product was thermally treated at 72° C. for 15 minutes to deactivate the enzyme, and then cooled to 40° C. To 100 mL of the obtained enzyme-treated soy milk, 3 g of sugar and 15 g of commercially available soy milk yogurt (Rivon Soygurt, manufactured by The Thai Dairy Industry Co., Ltd.) as a starter were added, fermented at 42° C. for 10 hours, and then cooled to 4° C., thereby obtaining soy milk yogurt (Example 1). For comparison, soy milk yogurt was obtained by the same method as in Example 1, except that only protein glutaminase was used in the enzyme treatment (Comparative Example 2). As a control group, soy milk yogurt was obtained by the same method as in Example 1, except that the enzyme treatment was omitted (Comparative Example 1).

[0085] The obtained soy milk yogurt was subjected to a sensory test for the flavor 1 and the property 1 described above. The results of the sensory test are shown in Table 1.

TABLE-US-00001 TABLE 1 PG addition Lipase addition amount amount Flavor 1 Property 1 (u/protein 1 g) (u/fat and oil 1 g) (smell) (smoothness) Comparative 0 0 −−−− X Example 1 Comparative 5 0 −−− Δ Example 2 Example 1 5 300 ++ ◯

[0086] As shown in Table 1, the soy milk yogurt without the enzyme treatment (Comparative Example 1) had a strong soybean odor, was hard and heterogeneous, and thus had no smoothness. Although the soybean odor was reduced by the PG treatment and a smooth texture was obtained (Comparative Example 2), the effect of improving these properties was insufficient. On the other hand, it was surprisingly found that, by addition of the lipase treatment to the PG treatment (that is, the use of PG and the lipase in combination, the fermentation smell was changed to a strong fermentation smell like normal yogurt and smoothness was also further improved (Example 1).

Test Example 2

[0087] To 400 mL of water, 200 g of soybeans was immersed. To the soybeans (with skin) after drainage, 500 mL of water was added and stirred with a mixer for 1 minute to be ground, and the ground product was filtered to obtain soy milk. To 150 mL of the soy milk (protein concentration: 10 wt %, fat-and-oil concentration: 7.5 wt %), 75 u or 225 u of protein glutaminase (Protein glutaminase “Amano” 500, manufactured by Amano Enzyme Inc.) (5 u or 15 u per 1 g of raw material protein) and 170 u (kit method) of Lipase AY (Lipase AY “Amano” 30SD, manufactured by Amano Enzyme Inc.) (15 u per 1 g of raw material fat and oil) were added and treated at 50° C. for 1 hour. The resulting product was thermally treated at 72° C. for 15 minutes to deactivate the enzyme, and then cooled to 40° C. To 100 mL of the obtained enzyme-treated soy milk, 3 g of sugar and 15 g of commercially available soy milk yogurt (Rivon Soygurt, manufactured by The Thai Dairy Industry Co., Ltd.) as a starter were added, fermented at 42° C. for 10 hours, and then cooled to 4° C., thereby obtaining soy milk yogurt (Example 2). For comparison, soy milk yogurt was obtained by the same method as in Example 2, except that only protein glutaminase was used in the enzyme treatment (Comparative Examples 3 and 4). As a control group, soy milk yogurt was obtained by the same method as in Example 2, except that the enzyme treatment was omitted (Comparative Example 5).

[0088] The obtained soy milk yogurt was subjected to a sensory test for the flavor 1 and the property 1 described above. The results of the sensory test are shown in Table 2.

TABLE-US-00002 TABLE 2 PG addition Lipase addition amount amount Flavor 1 Property 1 (u/protein 1 g) (u/fat and oil 1 g) (smell) (smoothness) Comparative 0 0 −−−− X Example 5 Comparative 5 0 −−− Δ Example 3 Comparative 15 0 −−− Δ Example 4 Example 2 15 15 ++ ◯

[0089] As shown in Table 2, even when whole soybeans (soybeans with skin) were used, a strong fermentation smell preferable as yogurt could be imparted instead of a soybean odor by using PG and the lipase in combination, and a smooth texture was obtained (Example 2). On the other hand, only by the PG treatment, the soybean odor was slightly reduced, and the texture was soft and smooth, but the improving effect thereof was insufficient (Comparative Examples 3 and 4).

Test Example 3

[0090] To 400 mL of water, 200 g of almonds was immersed. To the almonds after drainage, 500 mL of water was added and stirred with a mixer for 1 minute to be ground, and the ground product was filtered to obtain almond milk. To 150 mL of the almond milk (protein concentration: 6 wt %, fat-and-oil concentration: 14 wt %), 45 u of protein glutaminase (Protein glutaminase “Amano” 500, manufactured by Amano Enzyme Inc.) (5 u per 1 g of raw material protein) and 3400 u (kit method) of Lipase AY (Lipase AY “Amano” 30SD, manufactured by Amano Enzyme Inc.) (160 u per 1 g of raw material fat and oil) were added and treated at 50° C. for 1 hour. The resulting product was thermally treated at 72° C. for 15 minutes to deactivate the enzyme, and then cooled to 40° C. To 100 mL of the obtained enzyme-treated almond milk, 3 g of sugar and 15 g of commercially available almond yogurt (Hooray almond your-gurt, manufactured by Crossmax Retail Co., Ltd.) as a starter were added, fermented at 42° C. for 10 hours, and then cooled to 4° C., thereby obtaining almond yogurt (Example 3). For comparison, almond yogurt was obtained by the same method as in Example 3, except that only protein glutaminase was used in the enzyme treatment (Comparative Example 6). Almond yogurt was obtained by the same method as in Example 3, except that the enzyme treatment was omitted (Comparative Example 7).

[0091] The obtained almond yogurt was subjected to a sensory test for the flavor 1 and the flavor 2 described above. The results of the sensory test are shown in Table 3.

TABLE-US-00003 TABLE 3 PG addition Lipase addition amount amount Flavor 1 Flavor 2 (u/protein 1 g) (u/fat and oil 1 g) (smell) (taste) Comparative 0 0 −− − Example 7 Comparative 5 0 − − Example 6 Example 3 5 160 ++ ++

[0092] As shown in Table 3, although a slight improving effect on the smell only by the PG treatment was recognized also in the almond yogurt, the degree thereof was insufficient (Comparative Example 6), but it was found that the fermentation smell can be intensified by further concurrently using the lipase treatment (Example 3). Regarding the taste, although the effect that the sour taste can be enhanced only by the PG treatment could not be confirmed (Comparative Example 6), it was found that a strong sour taste like yogurt can be imparted by further concurrently using the lipase treatment (Example 3).

Test Example 4

[0093] To 400 mL of water, 200 g of oats was immersed. To the oats after drainage, 500 mL of water was added and stirred with a mixer for 1 minute to be ground, and the ground product was filtered to obtain oat milk. To 150 mL of the oat milk (protein concentration: 3 wt %, fat-and-oil concentration: 2.9 wt %), 23 u of protein glutaminase (Protein glutaminase “Amano” 500, manufactured by Amano Enzyme Inc.) (5 u per 1 g of raw material protein) and 1300 u (kit method) of Lipase AY (Lipase AY “Amano” 30SD, manufactured by Amano Enzyme Inc.) (300 u per 1 g of raw material fat and oil) were added and treated at 50° C. for 1 hour. The resulting product was thermally treated at 72° C. for 15 minutes to deactivate the enzyme, and then cooled to 40° C. To 100 mL of the obtained enzyme-treated oat milk, 3 g of sugar and 15 g of commercially available almond yogurt (Hooray almond your-gurt, manufactured by Crossmax Retail Co., Ltd.) as a starter were added, fermented at 42° C. for 10 hours, and then cooled to 4° C., thereby obtaining oat yogurt (Example 4). For comparison, oat yogurt was obtained by the same method as in Example 4, except that only protein glutaminase was used in the enzyme treatment (Comparative Example 8). Oat yogurt was obtained by the same method as in Example 4, except that the enzyme treatment was omitted (Comparative Example 9).

[0094] The obtained oat yogurt was subjected to a sensory test for the flavor 1 described above. The results of the sensory test are shown in Table 4.

TABLE-US-00004 TABLE 4 PG addition Lipase addition amount amount Flavor 1 (u/protein 1 g) (u/fat and oil 1 g) (smell) Comparative 0 0 −−−− Example 9 Comparative 5 0 − Example 8 Example 4 5 300 ++

[0095] As shown in Table 4, although the effect of improving flavor only by the PG treatment was recognized also in the oat yogurt, the degree thereof was insufficient (Comparative Example 8), but it was found that a strong fermentation smell preferable as yogurt can be imparted by further concurrently using the lipase treatment (Example 4).

Test Example 5

[0096] To 100 mL of water, 50 g of coconut milk was added to obtain diluted coconut milk (liquid). To 150 mL of the obtained diluted coconut milk (protein concentration: 1 wt %, fat-and-oil concentration: 6 wt %), 22 u of protein glutaminase (Protein glutaminase “Amano” 500, manufactured by Amano Enzyme Inc.) (15 u per 1 g of raw material protein) and 27 u (kit method) of Lipase AY (Lipase AY “Amano” 30SD, manufactured by Amano Enzyme Inc.) (3 u per 1 g of raw material fat and oil) were added and treated at 50° C. for 1 hour, 3 g of processed starch and 4.5 g of sugar were added, and the resulting product was thermally treated at 85° C. for 30 minutes to deactivate the enzyme, and then cooled to 40° C. To 100 mL of the obtained enzyme-treated coconut milk, 15 g of commercially available coconut yogurt (Agrilife Cocogurt, manufactured by Earth Born Co., Ltd.) was added, fermented at 42° C. for 10 hours, and then cooled to 4° C., thereby obtaining coconut yogurt (Example 5). For comparison, coconut yogurt was obtained by the same method as in Example 5, except that only protein glutaminase was used in the enzyme treatment (Comparative Example 10), and coconut yogurt was obtained by the same method as in Example 5, except that the enzyme treatment was omitted (Comparative Example 11).

[0097] The obtained coconut yogurt was subjected to a sensory test for the flavor 1 and the property 2 described above. The results of the sensory test are shown in Table 5.

TABLE-US-00005 TABLE 5 PG addition Lipase addition amount amount Flavor 1 Property 2 (u/protein 1 g) (u/fat and oil 1 g) (smell) (smoothness) Comparative 0 0 −−−− X Example 11 Comparative 15 0 −−−− ◯ Example 10 Example 5 15 3 ++ ◯

[0098] As shown in Table 5, also in the coconut yogurt, it was found that, by using PG and the lipase in combination, the smell of the coconut yogurt could be modified into a strong fermentation smell preferable as yogurt, and additionally, viscosity was imparted to the coconut yogurt, so that a smooth texture was obtained (Example 5). On the other hand, a smooth texture was obtained only by the PG treatment, but the coconut smell was not changed, and the fermentation smell could not be imparted at all (Comparative Example 10).

INDUSTRIAL APPLICABILITY

[0099] According to the production method of the present invention, a plant protein food having excellent flavor can be obtained. Examples of the plant protein food produced by the present invention include plant fermented foods (for example, a lactic acid fermented plant food, more specifically, an alternative milk fermented food, further specifically, alternative yogurt (plant yogurt), an alternative dairy product lactobacillus beverage, an alternative lactobacillus beverage, an alternative cheese (plant cheese), and also include a plant protein beverage (for example, alternative milk (plant milk)), bean curd, a meat alternative prepared from a plant raw material, and alternative dairy products prepared from plant raw materials (for example, plant milk processed products such as an alternative milk fermented food).

[0100] This invention is not limited at all by the description of the above-described embodiments for carrying out the invention and Examples. Various modifications are also encompassed in this invention within the scope that does not deviate from the descriptions in the claims and can be easily conceived by persons skilled in the art. The whole contents of the articles, patent publications, patents, and the like which are clearly indicated in the present specification are incorporated herein by reference.