JP2013034413A - Preservation method of fruit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preservation method of fruits with which fruits can be easily and inexpensively preserved for a long period of time while keeping the hardness of fruits, the color of pericarp, and the eating quality.SOLUTION: The preservation method of fruits includes (1) a storage process for wrapping the fruit with a preservation bag that consists of a polypropylene film of 40 μm or more, (2) a deaeration process for deaerating air from the preservation bag, (3) a sealing process that seals up the preservation bag, and (4) a refrigeration process for refrigerating the fruit under a temperature of 1-5°C.

Description

  The present invention relates to a method for preserving fruits that can be preserved while maintaining the hardness, fruit color, and taste of fruits such as strawberries over a long period of time.

  Fruits, especially fruits such as persimmons, none, and apples, are grown outdoors, so the harvest season is limited, although there are some differences depending on the production area. On the other hand, consumers' demand for fruits remains throughout the year. For this reason, producers desire to provide fruits at relatively high prices outside the harvest period in accordance with consumer demand. Therefore, methods for preserving harvested fruits for a long period of time have been studied.

  Specifically, a method of storing harvested fruits in a refrigerator for a long period of time, a method of storing harvested fruits in a bag made of polyethylene or the like and storing them at room temperature, and a method combining these have been developed (non-patent literature). 1, see Non-Patent Document 2 and Non-Patent Document 3.)

  However, with these methods, the fruit softens during storage, so it cannot be stored while maintaining its hardness, and the color changes during storage and the taste changes. There was a point. For this reason, for example, in the case of sweet potatoes such as Fuyudon, Jiroro, and Nishimura Hayao, if they are sold as raw food between April and June (about half a year after harvest), there will be great demand. Could not be sold.

Bunmuro Masahiko et al., “Practical application of long-term storage of oysters 'plain-nuclear-free' fruits using short-term astringency, individual packaging and refrigeration technology”, Horticulture magazine 71 (2): 300-302 (2002). Bibi N, et al., "Phenolics and physico-chemical characteris-tics of persimmon during post-harvest storage.", Nahrung. 2001 Apr; 45 (2): 82-86 "Distribution and utilization laboratory result information", "Suppression of the occurrence of skin black spots by ice storage of long-term storage oyster" Fuyu "", [online], Production Environment Laboratory, Distribution Processing Department, Distribution and Utilization Laboratory, [2011 July 21, 2009], Internet <URL: http://farc.pref.fukuoka.jp/farc/seika/seika15/8seino07.htm>

  It is an object of the present invention to provide a method for preserving fruits that can be preserved easily and inexpensively over a long period of time while maintaining fruit hardness, skin color, and taste.

  The main feature of the present invention is that the fruit is stored in a storage bag made of a film of a specific material and thickness, the storage bag is deaerated and sealed, and then refrigerated for storage.

  According to the fruit preservation method of the present invention, the fruit can be preserved for a long period of time while maintaining the hardness, fruit color, and taste of fruit such as strawberries. As a result, fruits can be shipped in the off-season when the supply declines, although there is a demand for fruits, which can contribute to an increase in the income of farmers who produce fruits.

FIG. 1 is a graph showing the results of examining the effects of the material and thickness of a storage bag on the change in hardness (softening rate) of fruits over time.

  The fruit preservation method of the present invention includes (1) a storing step, (2) a deaeration step, (3) a sealing step, and (4) a refrigeration step. Therefore, details of the process will be described below.

(1) Storage process A storage process is a process of storing a fruit in a preservation | save bag manually or with a machine. Here, as a fruit, fruits, such as a persimmon, nothing, and an apple, can be used, for example. Among these, sweet potatoes such as Tomiyu rice cake, Jiroro rice cake, and Nishimura Hayao are more preferred because they produce less ethylene during storage and can be eaten raw.

  The storage bag can be used without particular limitation as long as a polypropylene film having a thickness of 40 μm or more is laminated and the three sides thereof are bonded in a bag shape by a known method such as heat. An example of such a storage bag is a storage bag made of an activated polypropylene film as described in JP-A-9-59402, specifically, the trade name “Aura Pack” (Bell Green Wise). it can. When the thickness of the polypropylene film is less than 40 μm, it is difficult to preserve the fruit for a long time due to the influence of outside air. Further, the upper limit of the thickness of the polypropylene film is not particularly limited, but the upper limit of the thickness of the commercially available product is 60 μm.

(2) Deaeration process In this process, air is deaerated from the storage bag containing the fruits using a known means such as a suction pump. Degassing is sufficient if the storage bag and the fruit are in close contact with each other, and the storage bag need not be completely evacuated.

(3) Sealing step This is a step of sealing the storage bag containing the fruits and deaerated with a known means such as policyler or adhesive. In addition, if a commercially available vacuum deaeration sealer is utilized, (2) deaeration process and (3) sealing process can be performed with the same apparatus.

(4) Refrigeration process It is the process which refrigerates and preserves the storage bag which sealed the fruit under the temperature of 1-5 degreeC. If the fruit is stored at less than 1 ° C, it must be frozen and thawed (this greatly reduces the taste and texture). If the fruit is stored at a temperature above 5 ° C, the fruit's hardness, peel color, and taste will be reduced. Can not be stored for a long time while maintaining. In addition, what is necessary is just to perform refrigeration preservation | save by a normal method using the commercially available refrigerator used for preservation | save of a fruit, a refrigerator compartment, and a refrigerator warehouse.

  Hereinafter, the present invention will be described in more detail based on examples, but the claims of the present invention are not limited by the following examples in any way.

  Using the Fuyu persimmons collected at the end of November, the effect of the fruit preservation method according to the present invention was examined. The details are shown below for each process.

(1) Storage process Three bags were stored in a storage bag (30cm x 30cm) made of a resin film having a thickness different from that of the raw material. Here, the material and thickness of the resin film constituting the storage bag are:
(A) Polypropylene 40μm (Product name: Aura Pack, Bell Green Wise)
(B) Polypropylene 25 μm (Product name: Aura Pack, Bell Green Wise)
(C) Polypropylene 20μm (Product name: Aura Pack, Bell Green Wise)
(D) Polyethylene 50μm, 60μm (Sato Polyethylene Corporation)
(E) Nylon polyethylene 70μm, 80μm (trade name: composite film, manufactured by Suzuki Paper Industries)
It is. In addition, (a)-(e) produced 2 sets each.

(2) Degassing step and (3) Sealing step The storage bag containing the bag was degassed and sealed with a degassing sealer (manufactured by NPC). The heater temperature of the deaeration sealer at the time of sealing was set to an appropriate value according to the material of each film.

(4) Refrigeration step The sealed storage bag was refrigerated in a refrigerator (manufactured by Sanyo Electric Co., Ltd.) adjusted to 1 ° C and 5 ° C. Also, from the start of refrigeration, measure the hardness of the bags stored in the storage bag on the 90th, 120th, 150th, and 180th days by visual and tactile sensation, and the relative value (softening rate) with the start of refrigeration as 100% ).

(5) Experimental results Fig. 1 shows changes in the softening rate. 1A shows the result when refrigerated at 1 ° C., and FIG. 1B shows the result when refrigerated at 5 ° C.

  From Fig. 1, it was confirmed that when (a) 40 μm of polypropylene was used, the fruit was hardly softened after 180 days at any refrigeration temperature, and the same hardness as at the start of refrigeration was confirmed. did it. It was also confirmed that the skin color and taste were the same as those immediately after harvesting.

  When (b) to (d) are used, the fruit softens about 50% after 120 days (5 ° C.) or after 150 days (1 ° C.), and any refrigeration temperature after 180 days. It was also confirmed that the fruit softened almost 100%.

  Furthermore, when (e) is used, if the refrigeration temperature is 1 ° C, the softening degree of the fruit is suppressed to about 50% until 120 days, but after 150 days, at any refrigeration temperature Was almost completely softened, and it was confirmed that it was completely softened in 180 days.

  From the above results, it was confirmed that there was a large difference in the change in softening rate depending on the material and thickness of the storage bag. It was also found that the preservation method of the present invention can be preserved for a long period of time while maintaining the hardness, fruit color and taste of the fruit.

Claims (3)

(1) a storage process for wrapping fruits in a storage bag made of polypropylene film having a thickness of 40 μm or more;
(2) a degassing step of degassing air from the storage bag;
(3) a sealing step for sealing the storage bag;
(4) a refrigeration step of refrigeration at a temperature of 1 to 5 ° C;
A method for preserving fruits.   The method for preserving fruits according to claim 1, wherein the fruits are strawberries.   The method for preserving fruits according to claim 2, wherein the koji is sweet potato.

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