JPH0119873B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention utilizes a freezing point depressant to maintain foods in a specific low temperature region below 0°C for a long period of time in an unfrozen state. This article relates to a method for reducing harmful microorganisms, etc. [Prior Art] Conventionally, as a method for sterilizing or sterilizing various harmful microorganisms present in foods, foods are subjected to high-temperature heat treatment and held at a high temperature of about 70 to 100 degrees Celsius for a predetermined period of time. A method of sterilization or sterilization is generally widespread. However, although this high-temperature heat treatment method can be expected to have sufficient sterilization and sterilization effects, the quality of foods changes significantly due to high-temperature heating, and in particular, the original flavor and quality of foods are significantly damaged, and the structure of foods changes. This causes physical and chemical changes that completely eliminate the original texture of foods, and it is extremely difficult to retain the so-called freshly picked flavor, especially in the case of fresh foods. Therefore, methods such as applying radiation treatment and adding disinfectants and preservatives have been implemented in order to maintain the freshness to some extent, but in reality, there are problems with integrity, quality deterioration, etc. However, these methods have not yet been widely used as methods for sterilizing and sterilizing general fresh foods. [Problems to be solved by the invention] As described above, although conventional food sterilization and sterilization methods are useful for specific foods, they are particularly difficult to sterilize fresh foods such as concentrated livestock and marine products. , as a sterilization method, it is insufficient, and in the current era of high distribution of fresh foods, it is necessary to establish a new sterilization and sterilization technology that does not damage the original flavor and quality of foods. However, there was a situation in which there was a strong need to resolve this issue as an issue in this field. In view of these circumstances, the present inventor has conducted various research studies with the aim of developing and establishing effective sterilization and sterilization techniques that do not impair the flavor and quality of foods. , food at 0℃
Harmful microorganisms, especially pathogenic bacteria, contained in foods are rapidly reduced and killed within the following minus temperature range, and within the unfrozen temperature range of foods up to the freezing point of the food. They discovered that there is a so-called clear zone where harmful microorganisms can become harmful. The present inventors have discovered that the effect of reducing the number of particles, etc., is remarkable, and have come to relate this invention. That is, the present invention is directed to various harmful microorganisms existing in foods, particularly agricultural, livestock and marine products, specifically vegetables, fruits, grains, fish and shellfish, livestock meat, etc., and secondary processed products thereof. The purpose of the present invention is to provide a method for reducing the amount of food without causing damage to the flavor and quality of these foods, and furthermore, by using the reduction method, among the foods,
For agricultural, livestock and fishery products, we will develop useful storage techniques to maintain their freshness for long periods of time, and for secondary processed products, we will develop useful storage techniques to maintain their freshness and prevent the harmful effects and quality deterioration of harmful microorganisms present in foods. It also includes the purpose of providing food processing and manufacturing technology in a completely clean environment. [Means for Solving the Problems] The structure of the present invention taken to achieve such an object is to treat foods with a freezing point depressant to lower the freezing point to -6°C or lower. This is a method for reducing various harmful microorganisms present in foods, which is characterized by keeping point-adjusted foods in a low temperature range from -3°C to the freezing point for a long period of time. Foods include, for example, agricultural and aquatic products such as vegetables, fruits, grains, fish and shellfish, and livestock meat, as well as various secondary processed products using these as raw materials, such as various pickles and fermented products. Refers to various foods such as foods, paste products, processed meat products, noodles, breads, processed fruit products, processed fish and shellfish products, etc.
As the freezing point depressant, one or more freezing point depressing substances selected from various ordinary organic acids or their salts, sugars, alcohols, salts, etc. and compressed natural agricultural, livestock, and marine products may be used. Refers to an antifreeze mixture prepared by mixing a natural antifreeze extract obtained by extraction through filtration or its concentrated extract, and further, if necessary, an appropriate combination of an enzymatic decomposition product of water-soluble gelatin, etc. do. The freezing point depressing agent used in the present invention is obtained by grinding the meat raw material and pressing the juice, which is then treated with enzymes such as protease, if necessary, and filtered under reduced pressure. The main substance is the obtained filtrate (antifreeze) or an antifreeze concentrate prepared by vacuum freezing and concentrating the liquid, and for example, salt,
It is preferable to use an antifreeze mixture obtained by appropriately combining and mixing ethyl alcohol, an enzymatic decomposition product of water-soluble gelatin, and the like. For fish and shellfish, we mainly use antifreeze extracts or concentrates thereof, which are prepared by grinding fish and shellfish raw materials, squeezing the juice, subjecting it to enzyme treatment such as protease if necessary, and filtering it under reduced pressure. To this, sodium acetate,
It is preferable to use an antifreeze mixture prepared by mixing common salt, an enzymatic decomposition product of water-soluble gelatin, etc. in an appropriate combination. Furthermore, for vegetables and fruits, raw materials such as vegetables and fruits are ground, vitamin C is added if necessary, and after vacuum filtration treatment,
It is preferable to use an antifreeze concentrate prepared by vacuum freeze concentration as the main ingredient, and to use various organic acid salts, common salt, etc., and an oxygen decomposition product of water-soluble gelatin. and in each case sodium acetate,
It is preferable to limit the use of additives such as salt as much as possible and to make maximum use of various raw materials, that is, antifreeze extracts or concentrates thereof that exist in natural agricultural, livestock, and marine products. Table 1 shows the freezing point of concentrated extracts of naturally occurring antifreeze prepared from various raw materials. Alternatively, by mixing two or more types of gelatin and, if necessary, an enzymatic decomposition product of water-soluble gelatin, the freezing point can be adjusted to -2 to -2.
It becomes possible to lower the freezing point to -20°C, and by using these components in combination, it is possible to obtain a freezing point lowering effect that cannot be achieved by using each component alone.

【table】

【table】

[Table] Regarding this point, for example, the freezing point of 1/5 radish antifreeze concentrate is -4.5℃, but it is
The freezing point of a mixed antifreeze solution containing 1% sodium lactate and 3% sorbitol was -7.2°C. Using such freezing point depressants to adjust the freezing point of foods to -6°C or lower is because in the region from -6°C to 0°C, if it is -3°C or lower, so-called mesophilic bacteria Even if it is possible to stop the activity of microorganisms and further reduce or kill them (see Figure 4), it is difficult to reduce or kill psychrotrophic bacteria (see Figure 5), and it is difficult to reduce or kill all microorganisms. At least -6 to become mortal
The reason for this is that it requires a freezing point below ℃. By keeping the temperature below -6°C, it becomes possible to reduce and sterilize mesophilic bacteria and psychrophilic bacteria, which indicates that -6°C is the critical temperature for reducing microorganisms. found. This is the technical basis for specifying the freezing point at -6°C or lower. In this case, if the food is kept at -3℃ or below, it is possible to stop the activity of mesophilic bacteria and psychrotrophic bacteria, so -
3°C can also be considered a critical temperature in the sense that it is the line at which microorganisms cease their activity, and by keeping food at -3°C or lower, the activity of harmful microorganisms present in the food is stopped. In addition, mesophilic bacteria can be reduced and killed, so the holding temperature of foods is specified in the low temperature range from -3℃ to the freezing point of the food concerned. be. The period of time during which the food is maintained in this low temperature range varies depending on the type of food, etc., and can be appropriately selected from a variety of ranges from 2 to 3 days to 60 days. By adopting the above configuration, harmful microorganisms, etc. contained in various foods such as agricultural, livestock and marine products can be reduced and killed without damaging the flavor and quality of the foods. The industrial applicability of this invention is remarkable in that it has become possible to do so. Next, by disclosing examples of the present invention below, notable points of the effects of the present invention will be explained in detail, but of course the present invention is not limited to these examples. Example 1 Chicken meat, a type of livestock meat, was ground and pressed, the juice obtained was treated with protease at 30°C for 5 hours, and the extract prepared by vacuum filtration was 1/4
A 1/4 concentrated extract of chicken antifreeze was prepared. Using this as the main ingredient, an antifreeze mixture was prepared by further adding and mixing 3% each of common salt and ethyl alcohol, and 11% of a protease decomposition product of water-soluble gelatin.
Using the antifreeze mixture as a freezing point depressant, immersing chicken meat in it to adjust its freezing point, and then keeping it at a low temperature of -3°C for 14 days to see how the amount of E. coli bacteria contained therein has decreased. Tested. The -3°C storage temperature area was defined as the freezing temperature area, and as a control,
The refrigerated area (+5°C) and the frozen area (-20°C) were similarly tested for the reduction of E. coli. As is clear from Figure 1, compared to -20°C in the freezing area, the ice temperature decreased from the beginning of storage, and the rate of decrease was faster, reducing and killing E. coli bacteria more than in the freezing area. It turns out that there are specific effects that can be achieved. Example 2 Chicken meat, a type of meat, is soaked in 3% saline solution,
In the same manner as in Example 1, the sample was stored under low temperature conditions of -3°C and tested to see if the amount of Staphylococcus contained therein was reduced. The -3°C storage temperature area was designated as the freezing temperature area, and as a control, the refrigerated area (+5°C) and frozen area (-20°C) were similarly tested for the reduction of staphylococci. As is clear from Figure 2, the freezing temperature -3℃ section is compared to the freezing section -20℃.
It was found that it has a specific effect of high reduction rate of Staphylococcus. Example 3 Regarding the reduction of fungi in overnight-dried curry, a kind of fish and shellfish, a freezing point depressant was obtained in the same manner as in Example 1, and dried overnight after being sprayed with it in a freezing temperature zone (-3℃). ), and a control group was tested in a refrigerated area (+5°C) and a frozen area. As shown in Figure 1, the freezing temperature area is almost the same as the frozen area, showing no tendency for fungal growth at all, whereas the refrigerated area shows a sudden tendency for fungal growth immediately after storage, and within two weeks.
It reached 10 ^-8 . It has been found that fungi can be maintained in a reduced state in freezing temperatures. Example 4 Regarding pickled Tsuda turnip, a type of vegetable,
Tests were conducted to determine the reduction of mesophilic bacteria, psychrophilic bacteria, and yeast contained in the samples by holding them at low temperatures of -3°C and -6°C for 30 days, and then increasing the temperature to +5°C. As a freezing point depressant, a mixture prepared by mixing 3% common salt, 1% sodium lactate, and 3% Solcubit was used, mainly consisting of 1/5 concentrate of turnip antifreeze. The -3℃ and -6℃ storage temperature zones were used as freezing temperature zones, and as a control, the refrigerated zone (+
5°C) was similarly tested for reduction of mesophilic bacteria, psychrophilic bacteria, and yeast. As is clear from Figure 4, mesophilic bacteria tended to decrease in the freezing temperatures of -3°C and -6°C, and no bacterial growth was observed even after the temperature was raised to +5°C after 30 days. , was found to be dead. As is clear from Figure 5, psychrotrophic bacteria also show a decreasing trend in the freezing temperature zones of -3℃ and -6℃, but when the temperature is raised to +5℃ after 30 days, the decrease is -3℃. The freezing temperature zone at ℃ shows a tendency to proliferate from 10 days after heating, whereas the freezing temperature zone at -6℃ shows no growth tendency at all even when the temperature is raised to +5℃, and it further decreases. It was found that there is a peculiar tendency to It was found that even psychrotrophic bacteria were completely killed in the freezing temperature zone of -6°C. Subsequently, yeast showed almost the same tendency as psychrotrophic bacteria, and in the freezing temperature zone of -3℃, +5℃
However, in the -6℃ freezing area, there was a tendency to decrease even after the temperature was raised to +5℃, and -6℃.
It was found that yeast bacteria were completely killed in the freezing temperature zone of ℃. According to the present invention, foods whose freezing point has been adjusted to -6°C or lower by adding a freezing point depressant to -3°C or less by dipping or spraying are treated.
Since it is kept in a low temperature range from ℃ to the freezing point adjusted above for a long time, at -3℃ or below,
The activity of mesophilic bacteria and psychrotrophic bacteria can be stopped, and even if the temperature is raised to the positive side (for example, +5°C) at -6°C or lower, the activity of psychrotrophic bacteria can be stopped. In addition, in the case of yeast,
When the temperature is raised (+5°C) after being maintained at -3°C, almost the same behavior (proliferation tendency) as that of psychrotrophic bacteria is observed. It was also observed that the activity started when the temperature was raised. Therefore, the present invention not only makes it possible to reduce harmful microorganisms, but also does not impair the flavor of foods due to the use of freezing point depressants in combination with the above-mentioned various freezing point depressants. .

[Brief explanation of drawings]

Figure 1 shows the relationship between storage temperature and the reduction status of E. coli, Figure 2 shows the relationship between storage temperature and the reduction status of Staphylococcus, and Figure 3 shows the relationship between storage temperature and the reduction status of fungi. The relationships between the two are shown. FIG. 4 shows the relationship between storage temperature and the state of decrease in mesophilic bacteria, and FIG. 5 shows the relationship between storage temperature and the state of decrease in psychrotrophic bacteria.

Claims (1)

[Scope of Claims] 1. Foods with a freezing point adjusted to lower the freezing point to -6°C or lower by treating the food with a freezing point depressant, -3
A method for reducing harmful microorganisms present in foods, which comprises keeping foods in a low temperature range from ℃ to the freezing point for a long time. 2 Freezing point depressants compress natural agricultural, livestock and fishery products,
A naturally occurring antifreeze extract obtained by extraction treatment such as filtration or its concentrated extract, and one or two freezing point lowering substances selected from various organic acids or their salts, sugars, alcohols, salts, etc. Above and above,
Claim 1: The mixture is a mixture of water-soluble gelatin enzymatically decomposed products, etc. as appropriate.
Method for reducing harmful microorganisms present in foods described in Section 1. 3. The method for reducing harmful microorganisms present in foods according to claim 1 or 2, which comprises keeping the food in a low temperature region for 30 to 60 days. 4 Foods include vegetables, fruits, grains, fish and shellfish,
Claim 1, which is livestock meat or a processed product thereof;
A method for reducing harmful microorganisms, etc. present in foods as described in paragraph 2 or 3.