JPH0158938B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing hamburger steaks, and more specifically, the present invention relates to a method for producing hamburger steaks that can be stored without freezing, and which is sterilized at a low temperature that does not impair the quality and texture of the hamburger steaks, while maximally killing bacteria. The invention relates to a method for producing hamburger steaks. Generally, hamburgers are made from a material that is formed into a plate shape, roasted, and then frozen or frozen before being sold on the market. When this hamburger is eaten, it must be thawed from the frozen state, and during freezing, freeze denaturation occurs, resulting in a loss of taste and texture. Additionally, this hamburger steak is exposed to fairly high temperatures during roasting to sterilize the inside.
However, in order to increase the number of bacteria killed during roasting, it is necessary to roast at high temperatures, and the meat quality of the material undergoes considerable shrinkage and significant protein denaturation, resulting in oil, moisture, and
Umami components such as meat extracts are liberated, and taste, flavor, texture, etc. are likely to be lost. For this reason, recent methods have been developed, such as immersing or injecting seasonings such as sauce after roasting, or roasting or heating only the surface, freezing or freezing the inside while leaving it unheated, and packaging and selling in this state. A hamburger steak that is heated and roasted to the inside when cooked before meals has also been proposed. However, although the taste, flavor, texture, etc. of this hamburger steak can be utilized, it is necessary to keep it in a frozen or refrigerated state during the distribution process, and its handling is extremely complicated. The present invention aims to solve the above-mentioned drawbacks, and specifically proposes a method for producing hamburger steaks that can be packaged and sold after being cooled to room temperature or around 10° C. without freezing or freezing treatment. The method of the present invention will be explained in detail below. First, in a conventional manner, a hamburger material is formed into, for example, a plate shape, and then roasted and heated to such an extent that the surface is denatured by heating. Prior to this roasting, the pH of the hamburger material is adjusted to 5.0 to 6.5, preferably 5.2 to 5.8. Next, roast the hamburger steak on the surface only and roast it for 80 to 100 minutes.
℃, preferably 90 to 96℃ for 4 to 50 minutes, preferably 6 to 15 minutes using steam or the like. In this way, by adjusting the pH of the hamburger steak material in advance, roasting only the surface, and then steaming it, that is, performing a two-stage heat treatment, the heat sterilization time can be shortened, and the bacteria will be killed when the number of bacteria is 1 g. It is possible to reduce the number of particles to less than 50 per piece, and since the initial surface heating roasting has formed a hard surface layer on the surface that is hard to heat denaturation, the next steaming process heat sterilizes it to the center. However, the flavor components such as meat extract, moisture, and fats and oils do not leak out, and the internal meat hardly shrinks. In other words, if you sterilize the inside of a hamburger just by roasting it in an oven, the surface of the hamburger will be exposed to high temperatures for a considerable amount of time, and the meat will be denatured by heat, partly because the hamburger material itself has poor heat conduction. , internal moisture, meat extract, fats and oils, etc. will leak out, resulting in loss of taste, texture, etc. For this reason, the present inventors researched a method that could maximize bacterial killing and sterilization in a short time under low temperature conditions, and found that after heating only the surface by roasting in advance, steam etc. Steaming and heating at a temperature of 80 to 100°C is effective, but in this case, the factor is the pH value, and it has been found that it is most preferable to adjust the value to a range of 5.0 to 6.7. In this case, even if the processing time is about 4 to 50 minutes, it is possible to completely sterilize the inside of the hamburger without sacrificing taste or flavor, and even if the hamburger is left cooled to 10 to 25℃. ,
It has been found that when cooling and packaging are performed in a non-sterilized room, the product can be distributed on the market without freezing or freezing as in the conventional case. In other words, if only the surface of the hamburger is heated and denatured by roasting and then sterilized by heat using steam moist heat, the inside of the hamburger is evenly heated and the flavor components such as moisture, meat extracts, oils and fats inside the hamburger are heated. will not leak out. Even with moist heat, which is difficult to heat above 100°C, the processing time is about 4 to 50 minutes, and the inside of the hamburger can be sterilized extremely quickly. In addition, the PH upper limit is set to 6.7 at a processing temperature of 100℃.
For example, if the temperature is 99℃ and the processing time is about 4 minutes, the sterilization process becomes insufficient and the number of remaining bacteria cannot be reduced to less than 50.The reason why the lower limit of pH is set to 5.0 is that below this value, the quality of the hamburger meat deteriorates. This is because the acidity increases. In particular, when the pH is between 5.2 and 5.8, delicious meat quality and flavor are obtained, and bacteria are killed to the maximum. In addition, the upper limit of heating temperature is 100℃ because this temperature is the upper limit for moist heat heating under atmospheric pressure.
The lower limit is 80°C because it is difficult to increase the sterilization efficiency below this temperature. Next, after being heated in two stages as described above, the hamburger steak is transported in its heated state to a sterile room, that is, a clean room, where it is cooled with cold air to about 10 to 25 degrees Celsius, and then wrapped in clean packaging. The hamburgers are sealed and packaged before being shipped out. It is preferable that the number of airborne bacteria in a sterile room be as low as possible, and in a clean room that has passed the 10,000-bacteria standard of the Japan Aerospace Exploration Agency, the number of airborne bacteria in a sterile room should be kept at 17.6.
By keeping the number of bacteria in the hamburger steak to less than 2 bacteria/m ² , the number of bacteria in the hamburger steak can be maintained in the state immediately after sterilization, and the hamburger steak can be sold while still being cooled, and its shelf life can be extended. It is also possible to heat the hamburger steak in two stages, fill the recesses formed in the hamburger steak with melted cheese, and then cool and package it in a clean room as described above. In other words, in a hamburger steak filled with molten cheese, the specific heat of the base hamburger steak and the molten cheese differs widely, but when it is cooled in a tray packed state with cold air in a clean room, the molten cheese on the surface cools first. The melted cheese and hamburger base can be cooled almost simultaneously. Further, the illustrated apparatus is suitable for producing hamburgers as described above. That is, in the figure, numeral 1 is a product conveyor, and 2 is a product conveyor.
3 is a chute, 3 is an automatic tray filling machine, 4 is a cooling conveyor, 5 is a packaging sealing machine, 6 is a foreign object detector, 7 is a packaging machine, and the clean room shown by the dotted line is:
It consists of a tray packing room B with a temperature of about 15 to 23°C, a cooling room C with a temperature of about 10°C, and a packaging room D. First, after the formed hamburger steak is roasted only on the surface, steam heating is performed.The hamburger steak heated in two stages in this way is transferred from place A to tray filling room B by conveyor 1 in a heated state. . After that, the packed trays enter the cooling chamber C and are transferred to the cooling conveyor 4.
While being transported by
The cooled hamburger steak is then sealed by a packaging sealing machine 5 in the next packaging room D, passed through a foreign object detector 6 in a sealed packaging state, and then packed in a packaging machine 7. It will be carried out. In this case, the clean room is, for example, the tray packing room B is a class of 10,000 trays according to Spacecraft Administration standards, and the cooling room C is a class of 10,000 trays.
Packing room D is assumed to have passed the 100,000-piece level, and the amount of airborne bacteria in each room is 17.6 pieces/ ^m2.
Below, by adjusting the number of bacteria to 17.6 cells/m ² or less and 88.4 cells/m ² or less, the number of bacteria in the hamburger steak at the time of transportation will be prevented from secondary contamination and proliferation from the state immediately after sterilization until the end of sealed packaging. Can be done. Next, an example will be described. First, hamburger material was prepared using the following formulation. Hamburg steak composition example 1 Beef 25Kg Pork 25Kg Beef fat 20Kg Onion 17Kg Bread crumbs 5Kg Vegetable protein 5Kg Seasoning 3Kg Spices Some of the above ingredients, the beef and pork are shredded with a chopper, and the onion is cut into minced meat before being eaten. After adding oil and accumulating it, it was added together with other ingredients and kneaded for 7 minutes in a mixer to obtain 100 kg of hamburger dough. This hamburger dough was formed into an oval or round shape, and then heated from above with an infrared gas burner (Schubank type heater) to the extent that only the surface was slightly burnt. Next, make this hamburger at 95% under the condition of PH7.5-5.0.
Cooked with steam for 8 minutes at ~98°C. As a comparative example, it was dried and heated in an oven at 200°C. In each case, the number of bacteria per gram was determined, and the results were as shown in Table 1.

[Table] Even in the case of PH7.0 and 7.2, when heating in two stages as in the method of the present invention, the number of bacteria can be reduced to PH=6.4 in Table 1 depending on the heating temperature of moist heat. in
The temperature was almost the same as that at 95℃ and 98℃, but
When the pH was 7.5, it reached over 70. In addition, under the condition of PH = 6.4, the heating time was varied from 4 to 50 minutes and steamed at 98℃, while as a comparative example, it was dried and heated in an oven to 180℃, and the number of bacteria per gram was determined. The results were as shown in Table 2.

[Table] In addition, when the hamburger steak that had been sterilized to 10 bacteria per gram was processed according to the process shown in the drawing and left in a sealed package at a temperature of 10℃ for 30 days, the number of bacteria per gram was 100. There were no problems at all.

[Brief explanation of drawings]

The drawing is a layout diagram of an example of an apparatus for carrying out the method of the present invention. Code 1...Product conveyor, 2...Chute, 3...Automatic tray filling machine, 4...Cooling conveyor, 5...Packaging sealing machine, 6...Foreign object detector, 7
...Boxing machine.

Claims (1)

[Claims] 1. Roast only the surface of the formed hamburger steak with the pH adjusted to 5.0 to 6.7, then lower the temperature.
Steam and heat at 80 to 100℃ for 4 to 50 minutes, then transport into a sterile room in the heated state and heat to 10 to 25℃ with cold air.
A method for producing hamburgers, which is characterized by packaging the hamburgers until they are cooled and then transporting them from a sterile room.