JPH0358266B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Application of the Invention) The present invention relates to a food preservative, and more particularly to a food preservative that effectively releases ethanol to preserve food. (Prior Art) The present applicant filed an application and obtained Patent No. 1046326 regarding a food preservation method using an adsorbent in which ethanol is adsorbed to an adsorbent material. How to save
Conducted research on tools, etc., and published JP-A-55-141182.
He completed the inventions disclosed in JP-A-56-142267, JP-A-57-22680, and JP-A-57-125683. Most of these conventional techniques utilize ethanol vapor emitted from ethanol supported on silicon dioxide, freeze-dried alpha starch, or the like.
However, in these conventional methods, the question of "how much ethanol should be used" has not been sufficiently considered. As a result, using ordinary silica gel with small pore volume,
This results in waste, such as having the adsorbent carry more ethanol than necessary. The present inventors focused on this point and conducted extensive research, and discovered that even if the same absolute amount of ethanol coexists with the same food, the effect differs depending on the type of adsorbent used. Furthermore, the present inventors have found that the reason for such a difference in the effectiveness of adsorbents is closely related to the "supported ethanol dispersion properties" of each adsorbent. This "supported ethanol dissipation property" can be expressed as the rate at which ethanol, once supported by the adsorbent, is dissipated as vapor in an open environment. The present inventor discovered that there are various stages up to a level close to 1, and further discovered that this is controlled by the equilibrium water content of the adsorbent, leading to the present invention. (Structure and Effects of the Invention) The present invention is characterized in that the equilibrium moisture content at room temperature (however, the relative humidity of the environment corresponds to the water activity of the food to be stored) is 28% by weight or less, and the pore volume is 0.6ml/g or more. A food preservative in which ethanol or hydrous ethanol with an ethanol content of 80% or more by volume is supported on a porous adsorbent. In the above gist of the present invention, normal temperature is 15°C to 15°C.
Means 30℃. Furthermore, "water activity of food" is a numerical value indicating the relative humidity of the space in contact with the surface of the food (100% relative humidity is expressed as 1). The water activity of "Sakiika", which will be discussed later, is 0.75.
However, this indicates that the relative humidity in the middle of the surface of the ``split squid'' is 75%. Therefore, "the relative humidity corresponds to the water activity of the food to be stored" above means "the relative humidity is 75%" in the above example. Also, to explain the above-mentioned equilibrium water content, the dry weight of the porous adsorbent itself is Wg, and the increase in weight (moisture) when it adsorbs water and enters an equilibrium state under the conditions of the specified temperature and relative humidity. When wg is the equilibrium water content, the equilibrium water content is expressed by the following formula. Equilibrium water content=wg/Wg×100% In the present invention, there is no limitation on the “amount of ethanol or water-containing ethanol” supported on the porous adsorbent. However, in practical terms, the volume of "ethanol or aqueous ethanol" is equivalent to the pore volume of the porous adsorbent.
It is preferable to use it in the range of 30 to 90%. More preferably this range is 50-90%. The lower limit of this range is determined in order to avoid disadvantages caused by increasing the apparent volume of this food preservative, and the upper limit is determined by the "powder fluidity" of this food preservative. As a result, liquidity deteriorates considerably. Now, for a food (sakiika) that has a water activity of 0.75, which means that when the food is kept in a closed space, the relative humidity of this space is 75%, ethanol is
It has been found that when the food is supported on an adsorbent of 0.8 ml/g or more, preferably 1.1 ml/g or more, a small amount of ethanol is effective in preserving the food. (See Tables 1 and 2). Similarly, a food (castella) with a water activity of 0.825 has a pore volume of 1.1 ml/g, preferably 1.5 ml/g or more, and a water activity of 0.895.
For foods (Ningyo-yaki), the adsorbent with a pore volume of 1.5 ml/g or more was able to achieve a good preservation effect with a small amount of ethanol (Nos. 1, 3, and 4).
(see table). These results may seem irregular at first glance, but if you compare them with Table 5, which shows the equilibrium moisture content of adsorbents under different relative humidity environments, it becomes clear that a small amount of ethanol is effective in preserving food. It is understood that a certain range can be uniformly expressed as the equilibrium water content of the adsorbent under the usage environment being below a certain value (28% by weight, preferably 15% by weight). The reason why the range in which a small amount of ethanol is effective is controlled by such parameters is not clear and unexpected, and was discovered for the first time by the present inventors. Using these parameters, the amount of ethanol required as a food preservative can be predicted from the food's water activity value, and the preferred adsorbent and amount of ethanol can be determined to ensure food preservation without waste. It became possible. The adsorbent used in the present invention having such characteristics is extremely limited, unlike general silica gel and the like, which have small pore containers conventionally used for food preservation. Further, in the present invention, the water content of ethanol supported on the adsorbent is limited to less than 20% by volume. This is because it is effective when the water content of ethanol is less than 20% by volume.
Table 6 shows the results of a preservation test of a commercial version of tea steamed buns using the adsorbent shown in Table No. 5. The pore volume of the adsorbent used in the present invention is closely related to its equilibrium water content, and is an indicator of the ability of the adsorbent to support ethanol, which is originally liquid, while maintaining its powder form. From this point of view, the pore volume must be 0.6 ml/g or more, which is an essential requirement of the present invention. This value is more preferably 1 ml/g or more, and even more preferably 1.5 ml/g (see Tables 1 and 5 together). A material with a large value has the advantage that, in addition to having a small equilibrium water content, it has good fluidity even when ethanol is supported, is easy to fill into sachets, and has small variations in the amount filled. Although it is difficult to express the average pore diameter of an adsorbent with a wide pore size distribution, No. 1 in Table 1 is approximately 20 Å,
No. 2 is approximately 70 Å, No. 3 is approximately 150 Å, and No. 4 is 200 to 600 Å.
About Å, No. 5 is about 5000 to 10000 Å, No. 6 is 20 Å,
No. 7 has a diameter of 2000 Å, and the larger the average pore diameter, the larger the pore volume. In addition to ethanol, auxiliary substances such as organic acids, flavoring agents, and the like may optionally be added to the food preservative of the present invention. In addition, in order to improve the food preservation effect, it is also possible to use in combination with known preservatives with other action mechanisms, such as oxygen scavengers and carbon dioxide generators. The food preservative of the present invention is suitable for storing bread, Western confectionery, Japanese confectionery, delicacies, agricultural foods, livestock foods, marine foods, processed foods thereof, raw materials and semi-finished products thereof, etc. that are likely to be susceptible to mold growth, rot, insect damage, etc. It can be used for a wide variety of foods, and also has the effect of preserving the flexibility of foods (especially bread). The food preservative of the present invention is usually placed in a pouch made of any material such as film, paper, cloth, non-woven fabric, etc. that does not allow the adsorbent to leak out and that allows ethanol vapor or water vapor to easily permeate, and the food preservative is sealed together with the food. It is convenient to use it by placing it inside a box or bag, but its usage is not limited to this, and there are various ways to use it, such as spraying it inside a food storage container or bag, or using it as a molded product. may be adopted. Next, the results of a preservation test of foods incorporating the examples of the present invention will be described. Test Example 1 [Manufacture of sachets filled with porous adsorbent powder supporting ethanol] For the porous adsorbent shown in Table 1, anhydrous ethanol was added in a volume equivalent to 80% of the pore volume. was added and mixed in a closed container to make it support. A laminated paper of ethylene vinyl acetic acid copolymer (EVA) film (thickness: 30 nm) and Japanese paper (basis weight: 40 g/m ² ) was made into a 5 cm x 5 cm pouch with EVA inside, and the calculated amount was added to give the specified amount of ethanol. The ethanol-supported powder was filled into this small bag, and the opening was covered with a heat sheet.

【table】

[Food preservation test]

Approximately 100g of various commercially available foods (solid jelly, split squid, castella, and ningyo-yaki) each into a 20cm
Place each of the aforementioned sachets containing a predetermined amount of ethanol-carrying adsorbent into a 20cm vinyl chloride-coated nylon-polyethylene (18nm/30nm) laminate film bag (ethanol high barrier) and heat seal the opening. It was sealed tightly. Each bag was kept at 25°C and visually observed for mold growth. The results are shown in Table 2 (water activity 0.75),
Table 3 shows castella (water activity 0.825), and Table 4 shows Ningyoyaki (water activity 0.895). Also, although I have omitted to summarize it in a table, the results for solid jelly (water activity 0.59) have almost the same tendency as in Table 2, and No.
When adsorbents No. 1 and No. 6 were used, the shelf life was shorter than when other adsorbents were used.
In Tables 2 to 4, the numbers in the tables indicate the number of days until mold appears. Also, the number of days is "90" because the observation was discontinued after 90 days, so it means more than 90 days.

【table】

【table】

【table】

[Table] Note: The product without preservative was 4 days old.
Table 5 shows the equilibrium water content of the various adsorbents shown in Table 1. Comparing this Table 5 with each of Tables 2 to 4, it is found that when the equilibrium water content of the adsorbent under the usage environment is 28% by weight or less, more preferably 15% by weight or less, even with the same amount of ethanol, It is clear that the water content is better than those above, and that less ethanol is wasted.

[Table] Note: Good range is within the bold frame. Examples of the present invention used in Test Example 1 above are, for example, Adsorbent No. 2, No. .3, No. 4, No. 5, and No. 7 adsorbed 1.00 g of ethanol, and the equilibrium moisture content of the adsorbents is within the bold frame in Table 5, and all of them have a large food preservation effect. Test Example 2 Water-containing ethanol with various water contents equivalent to 80% of the pore volume was added to silicon dioxide No. 5 in Table 1 and mixed in a closed container to form a supported powder. . Perforated polyethylene film (thickness 30n)
A pouch of 5 cm x 5 cm was made using laminated paper (basis weight 40 g/m ² ) and Japanese paper (basis weight 40 g/m 2 ) with a perforated polyethylene layer inside, and the calculated amount of supported powder was filled so that the ethanol content was the specified amount. I then heat-sealed the mouth. Each of these sachets was placed in the same ethanol high-barrier film bag (20 cm x 20 cm) used in Test Example 1, along with 100 g of commercially available Chamanji Yu (water activity 0.885), heat-sealed and sealed. It was stored at ℃ and visually observed for mold growth. The results are shown in Table 6.

[Table] Note: Values indicate the number of days until mold appears.
〓30〓 indicates more than 30 days because observation was stopped after 30 days.
The silicon dioxide (No. 5 in Table 1) supporting aqueous ethanol with an ethanol concentration of 80% by volume or more used in Test Example 2 is an example of the food preservative of the present invention.

Claims (1)

[Claims] 1 Equilibrium moisture content at room temperature (however, the relative humidity of the environment corresponds to the water activity of the food to be stored) is 28
% by weight or less and a porous adsorbent with a pore volume of 0.6 ml/g or more containing ethanol or ethanol content.
A food preservative containing 80% by volume or more of hydrated ethanol.