JPS625572B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing frozen eggs with less freeze denaturation. Egg yolks from chicken eggs are widely used as raw materials for mayonnaise, confectionery and bread making, and various methods have been developed to prevent spoilage and maintain freshness. Among these methods, the freezing method is a typical method for storing eggshells without removing them. However, frozen egg yolks, which are obtained by freezing the egg yolk liquid obtained by breaking eggs, undergo freezing denaturation during long-term storage, and even when thawed, the proteins do not return to their original state, resulting in coagulation. For this reason, egg yolk liquid has traditionally been salted or sweetened to prevent freeze denaturation, but if salt or sugar is added to an extent that sufficiently prevents freeze denaturation, frozen egg yolks will have a salty or sweet taste. This was unavoidable and had the disadvantage of limiting its use as frozen egg yolk. This drawback is found not only in egg yolk liquid, but also in frozen egg liquid containing egg yolk, such as whole egg liquid. The present inventors have overcome the shortcomings of the conventional frozen egg production method, and have developed a method of freezing eggs that causes less freeze denaturation even during long-term storage, and also reduces the difference in the degree of freeze denaturation depending on the method of freezing. He conducted extensive research to develop a method for producing eggs. As a result, it was discovered that the purpose could be achieved by adding a small amount of protease to egg yolk liquid or egg liquid containing egg yolk in advance, performing enzymatic treatment for one hour or more, and then inactivating it by heating. I've reached it. That is, the present invention provides a method for producing frozen eggs, which comprises adding protease in advance to freezing an egg yolk solution or an egg solution containing egg yolk, enzymatically treating the solution for at least one hour, and then inactivating it by heating. This is what we provide. The egg yolk liquid used in the method of the present invention is generally obtained by breaking the egg and separating it from the egg white, and the egg yolk mixed egg liquid can be whole egg liquid or egg yolk liquid and egg white liquid. Examples include mixtures of and in arbitrary proportions. In the method of the present invention, proteases are appropriately selected and used from those existing as extracorporeal enzymes and intracorporeal enzymes of animals, plants, and microorganisms. Preferred examples include those existing in plants such as papain, fuicin, and bromelain. Those derived from animal bodies, such as pancreatin, and those derived from microorganisms, such as Prozyme "Amano" P or A [trade name, Amano Pharmaceutical Co., Ltd.
Manufactured by Nagase Sangyo Co., Ltd. Denateam AP [Product name, manufactured by Nagase Sangyo Co., Ltd.]
Filamentous fungal proteases such as or neovitalase NP or AP (trade name, manufactured by Towa Koso Co., Ltd.), Prolysin 5 [trade name, manufactured by Ueda Chemical Co., Ltd.], Aloase K-2 [trade name, manufactured by Yakult Biochemical Co., Ltd.] Bacterial proteases such as those manufactured by Co., Ltd. are available.
The PH is 5.8 to 6.2, and the PH of whole egg fluid is 7.2 to 7.8, so when using egg yolk fluid or whole egg fluid as egg fluid,
It is preferable to use a protease with an optimum pH of 5.0 to 9.0. In the present invention, the amount of these proteases added varies depending on conditions such as the type of protease, the composition of the egg fluid, and the enzyme treatment temperature, but it is usually in the range of 0.0001 to 0.5%, preferably 0.001 to 0.3% based on the egg fluid.
selected within the range. In this case, if the amount added is less than 0.0001%, the enzymatic decomposition reaction will not progress, and if it exceeds 0.5%, the cost will increase, and the enzymatic decomposition reaction will continue even while the enzyme is deactivated, making it difficult to obtain products of constant quality. becomes difficult. Protease is added to the above egg fluid, and enzyme treatment is performed for 1 hour or more. If the enzyme treatment is not carried out for at least 1 hour, the egg fluid is likely to be denatured due to freezing, and the degree of freeze denaturation that occurs will be greatly affected by the freezing method, making it difficult to obtain products of consistent quality. This is because it becomes difficult. Further, the temperature during the enzyme treatment is usually 0 to 55°C, preferably 5 to 50°C, and the enzyme treatment time is usually up to 24 hours at the longest. The treatment time can be made shorter as the temperature increases. Note that the pH of the egg fluid during enzyme treatment is preferably in the range of 5 to 9 for the reasons described above. Note that the enzyme treatment conditions of the present invention can be determined as appropriate with the aim that the viscosity of the egg fluid obtained by thawing frozen eggs does not increase significantly. Normally, in order to use it as a food ingredient, it is convenient to use it if the viscosity is about 10 to 20 times higher than before freezing. Next, the enzyme-treated egg fluid is heated to sterilize it and deactivate the protease. By sterilizing and inactivating eggs by heating in this manner, frozen eggs of stable quality can be obtained without undergoing the enzyme reaction again depending on the method of thawing. The temperature and time conditions for this sterilization and inactivation are preferably 60 to 65°C for 2 to 10 minutes. In the present invention, the egg yolk liquid or egg yolk-containing egg liquid that has been heat-inactivated after the enzyme treatment is frozen at a temperature of usually -15°C to -40°C according to a conventional method, and the desired freezing temperature is obtained. Eggs can be produced. If egg yolk liquid or egg yolk-mixed egg liquid is enzymatically treated with protease for at least 1 hour and then heated to inactivate it before freezing, why does denaturation during cryopreservation become less likely to occur and the quality of the egg liquid remains stable? Although the mechanism and action of this phenomenon are not clear, the protein in the egg yolk, which is easily denatured by freezing, is degraded to some extent by protease and changed into a structure that is less susceptible to denaturation, and furthermore, the enzyme is deactivated by heat treatment. This is thought to be due to the fact that protein decomposition does not proceed beyond a certain level because of the According to the method of the present invention, it is possible to obtain frozen eggs that are free from unnecessary tastes such as saltiness and sweetness, have little freeze denaturation, and have stable quality even when frozen for a long period of time.
This can be widely used as a raw material for mayonnaise, confectionery, bread, etc. Next, the present invention will be explained in more detail based on examples. Example 1 Whole egg liquid (PH7.6) obtained by breaking eggs was stirred well to make a homogeneous emulsion, and then filtered10
0.5 g of papain and 0.25 g of prolysine 5 were added to Kg, and the mixture was cooled to 5°C and subjected to enzyme treatment. After 16 hours, it was heat-treated at 63°C for 4 minutes to sterilize and deactivate the enzyme. Next, after cooling this whole egg liquid to room temperature, 1 kg each was packed in polyethylene bags, and -25
It was stored frozen in a refrigerator adjusted to ℃. The frozen whole egg fluid was taken out every month of storage, thawed, and its viscosity was measured to determine the degree of freeze denaturation. The viscosity was measured using a B-type viscometer (manufactured by Tokyo Keiki Seisakusho Co., Ltd.). The results are shown in Table 1. On the other hand, for comparison, whole egg fluid prepared in exactly the same manner as above except that no enzyme was added was frozen under the same conditions and the degree of freeze denaturation was measured in the same manner.
The results are shown in Table 1 as a control example.

[Table] The results of this table show that in the case of no enzyme treatment (experiment number 2), the viscosity rapidly increased by 293.5 times after one month of frozen storage compared to before the start of frozen storage, and freezing denaturation was significant. On the other hand, it can be seen that in the case of the present invention (experiment number 1), the viscosity increase was only 13 times that before the start of frozen storage, which was much smaller. In addition, in experiment number 1, the enzyme was added to the egg fluid and immediately, without taking time for enzyme treatment,
When we measured the viscosity of egg fluid that had been frozen and stored at -10°C and -25°C for one month and then thawed, the viscosity of the egg fluid stored at -10°C was 1500 cp, and that stored at -25°C was 3100 cp. Indicated. On the other hand, in Experiment No. 1 (stored at -25℃) shown in Table 1, the viscosity of the sample stored for one month was 260cp, and the viscosity of the sample stored at -10℃ for another month was 250cp. It was hot. From this, the method of the present invention, in which the enzyme is treated and then inactivated by heating, can be subject to the enzyme reaction again depending on the way of freezing, such as the difference in freezing temperature, and the way of freezing and thawing. It can be seen that frozen eggs with little influence and constant quality can be obtained. Example 2 After filtering 10 kg of egg yolk liquid obtained by breaking eggs and separating them from egg whites, the temperature was raised to 50°C, and Prozyme "Amano" P
Alternatively, 2 g each of A and Denazyme AP were added, and enzyme treatment was performed at 50° C. for 5 hours with stirring. Next, it was heat-treated at 65°C for 10 minutes to sterilize and deactivate the enzyme. Next, this egg yolk liquid was cooled to room temperature, packed in polyethylene bags in 1 kg portions, stored frozen in a -25°C refrigerator in the same manner as in Example 1, and tested for the degree of freeze denaturation in the same manner as in Example 1. The results are shown in Table 2. Exactly the same test was also conducted on an egg yolk solution prepared in exactly the same manner as above except that no enzyme was added. The results are also shown in Table 2.

[Table] From this result, when enzyme treatment is not performed (experiment number 2), freezing denaturation is significant after 1 month of storage, and even after thawing, the viscosity is approximately 2000 times higher than before starting frozen storage, and the viscosity is more than 2000 times that of normal egg yolk liquid. On the other hand, in the case of the present invention, it had a CP of 3500 even after 8 months of storage, and could be used as an ingredient for confectionery, bread, and mayonnaise. Example 3 To 2000 kg of emulsion of sterilized whole egg liquid with pH 7.6, 200 g of Tacinase N-11-100 and Aroase K-2100 were added.
Add g and mix well, maintain the temperature at 35℃ and cook for 2 hours.
A time enzyme treatment was performed. Next, this whole egg liquid was heated to 63
After inactivating the enzyme by heat treatment at ℃ for 3 minutes,
The mixture was cooled to room temperature, packed in 5-gallon cans (approximately 19 volumes) in 16 kg portions, and placed in a freezer adjusted to -40°C to freeze. Even if the frozen egg yolk obtained in this way is taken out and thawed after being stored for 8 months, the degree of denaturation is small.
Since no denatured curd was produced, it could be used as a raw material for custard pudding, egg tofu, and chawanmushi without homogenization. Example 4 1000 kg of egg yolk liquid with pH 6.2 was heated to 50°C, 50 g of pancreatin and 50 g of bromelain were added thereto, stirred well, and enzyme treatment was performed for 5 hours while maintaining the above temperature. The enzyme was then heat-treated at 65°C for 10 minutes to inactivate the enzyme, and then cooled to room temperature, packed in 16kg portions into 5-gallon cans, and stored frozen in a freezer adjusted to -20°C. The obtained frozen egg yolk had little freezing denaturation and could be used as a raw material for mayonnaise even after 8 months of storage. Example 5 1000 kg of egg yolk liquid with pH 6.2 was cooled to 5°C, and 200 g of Denazyme AP and 100 g of Prozyme "Amano" A were added.
After adding and mixing well, the mixture was immediately packed into 5-gallon cans at 16 kg, and the mixture was stored in a refrigerator adjusted to below 10°C for 16 hours, and at the same time enzyme treatment was performed. Next, rapid freezing was performed at -40°C without deactivating the enzyme by heating, to obtain frozen egg yolks with little freeze denaturation. Even after 8 months of storage, this product gave egg yolk liquid that could be used as a raw material for milk pudding when thawed.

Claims (1)

[Scope of Claims] 1. A frozen egg characterized in that when freezing egg yolk liquid or egg yolk mixed egg liquid, protease is added in advance, enzyme treatment is performed for one hour or more, and then heat inactivation is performed. manufacturing method. 2 The amount of protease added to egg yolk liquid or egg yolk mixed egg liquid is 0.0001 to 0.5% of the weight of egg liquid.
A method for producing frozen eggs according to claim 1.