JPS5835674B2 - A method of brewing sake, etc., in which lipase is added during soaking of rice. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves adding lipase to the soaking water of rice as a raw material for alcoholic beverages such as sake, and soaking the rice. This invention relates to a method for preparing steamed rice with reduced unsaturated fatty acids that inhibit ester production and using it to produce alcoholic beverages such as sake with good flavor.

Currently, highly polished rice with a refined rice ratio of about 70 is used to produce alcoholic beverages made from rice, such as sake and synthetic sake.
The reason for this is to reduce fat, ash, and protein, which are found in large amounts in the outer layer of brown rice and are considered harmful to sake brewing, and to obtain high-quality alcoholic beverages.

In general, brown rice contains lipids of factor 2 or higher, most of which are present in the outer layer, including the sprouts, and less in the interior.

Its constituent fatty acids are mainly unsaturated fatty acids such as linoleic acid and oleic acid, but as the inner layer approaches, unsaturated acids decrease and saturated fatty acids such as palmitic acid increase [Journal of the Japanese Society of Agricultural Chemistry, Vol. 47, 713 ( 1973)].

Ester such as isoamyl acetate, which is an important aroma component of sake, is produced by yeast, but its production is promoted by saturated fatty acids and strongly suppressed by unsaturated fatty acids.

Therefore, in sake brewing, where most of the fatty acids in mash are derived from raw rice, it is necessary to use highly polished rice with a large amount of unsaturated fatty acids removed in order to brew sake with a good aroma [Journal of the Japanese Society of Agricultural Chemistry, 50, 115 (1976), l.

However, in order to brew fragrant sake, if all the brewed rice is polished to a high degree, for example, if 50% of the rice is milled, the rice will be half (
As a result, the brewing of sake began to require a large amount of rice, which in turn caused the price of sake to become extremely high.

The present inventors conducted research to brew sake with a good flavor using general sake brewing, and were able to solve the problem by adding lipase to the raw rice during soaking.

In the present invention, the raw rice may be soaked by adding lipase to the water in which the raw rice is soaked.

There is no particular difference in the amount of lipase added from a very small amount to a large amount of 1, but a titer of 1 to 5 x 103 units per 1 kq (t) of polished rice is preferred.

However, especially when processing coarse white rice, glutinous rice, broken rice, rice bran, rice flour, etc. used in beer brewing, etc., it is necessary to change the amount used appropriately, and the soaking time is extremely short (sometimes too short). Even when the soaking temperature is extremely low, such as 5° C. or lower, the amount of lipase must be increased appropriately.

The raw rice is soaked for 3 to 4 hours, sometimes for 10 to 20 hours, but most of the water absorption is completed within 3 to 4 hours.
During that time (kori pase penetrates through the surface of the rice grain, acts on the lipids, and generates free fatty acids.

Because the closer to the surface of the rice grain there are more unsaturated fatty acids,
In the present invention, unsaturated fatty acids can be efficiently liberated.

After soaking is completed, the soaked rice that has been treated with lipase is steamed, and the steaming process decomposes or volatilizes the fatty acids, especially unsaturated fatty acids, that are liberated in the rice grains. The amount of unsaturated fatty acids can be significantly reduced.

The added lipase is completely inactivated by this steaming and does not migrate into the mash.

In the method of the present invention, lipase is added to the soaking water to treat the raw rice with lipase, and the unsaturated fatty acid content of the raw rice is successfully reduced significantly, thereby making it possible to brew sake with good flavor. It is something that

The method of the present invention can obtain very good results when used with ordinary white rice for sake brewing with a milling ratio of about 70φ, but it can be used to improve the polishing ratio by treating coarse white rice with a polishing ratio of 75φ or more that has a high lipid content. Good results can be obtained by producing sake with a flavor similar to that of refined sake using highly polished rice of 70% or less, and costs can be increased by increasing the utilization rate of rice, which accounts for 60% or more of the sake production cost. Compared to the control, rice is digested better, yeast ferments better, and the number of days required for mashing is often shortened.

Test Example Prepare raw rice (Brand: Nipponbare) with a rice polishing ratio of 75 φ in 1 and 2 Ohms, and put 1 ton of water into 3 soaking tanks, and make the preparations 16.1, A 2, and A 3, respectively.
Only 50 μ of lipase (3×10′ units/g) was added.

As a control for the preparation Al, raw rice was soaked for 6 hours, post-steamed, and sake was brewed in a conventional manner.

For preparation 2, raw rice was soaked in lipase-added water for 6 hours, then steamed, and sake was brewed in a conventional manner.

For preparation A3, raw rice was soaked for 6 hours, and then steamed and brewed using the conventional method. During this period, 50 μm of lipase (3 x 10' units/g) was added to the mash on the 3rd day after distillation. .

The above preparation Al, A, 2, A3 & stuck,
The content of each fatty acid in the mash was measured on the 18th day after distillation, and the quality of the sake separated from this by a conventional method was analyzed.

The results are shown in the following tables.

The following is an example of the present invention.

Example 1 After washing 100f' of Koshiji Wase from Niigata Prefecture (polishing ratio 75%), it was soaked in water containing 100 units of lipase and 2,000 units of lipase for 20 hours at 15°C, and then steamed for 30 minutes. The results of comparing the crude fat content and fatty acid composition of the steamed rice prepared with the control are shown in the table below. **The decrease in nolic acid is large.

Example 2゜One bottle of Koshiji Wase with a 70% polishing ratio and two bottles of 80 tai were used to prepare sake with a total of 400 kq of rice. '
Unit/1) was added and immersion treatment was performed.

The results are shown in the table below.
For 20 rice fields with 0 and 1 rice polishing ratio, 80% rice polishing 2 is 1
It is as short as 5 days, and for lipase treatment preparation 3 it takes 14 days and an additional 1 day.
day was shortened.

According to the results of sake production, 1 is the best, followed by 3 and 2. In particular, 3 has a high aroma, a high content of ionamyl acetate, and the lipase treatment shortens the time required for mashing, and at the same time improves the quality of coarse white rice. We were able to bring the quality of the brewed sake closer to that of highly polished white rice.

Example 3 Two bottles of Nihonbare 2.8 with a different rice polishing ratio of 70% koji rice and 75% aged rice and soaked aged rice Example 2 (2 bottles prepared using lipase in the same way as described here) A comparison was made between the brewing process and the production of sake.

The results are shown in the table below: All lipase-treated sake had higher isoamyl acetate content and better flavor than the control.

Claims (1)

[Claims] 1 Add lipase to the soaking water of raw rice and soak the rice,
A method of brewing sake, etc. with a good flavor, which is characterized by brewing using steamed soybean flour and the steamed rice obtained.