JPH0795849A - Production of roasted sweet potato distributable at normal temperature and preservable for long period of time - Google Patents

Abstract

PURPOSE:To provide a production method of roasted sweet potato preservable at normal temperature for a long period of time and not changing its color during storage. CONSTITUTION:A sweet potato is roated at 200 deg.C for one hour, cooled to a state of the potato to be held by a hand and heated and sterilized by using a packaging material having low oxygen permeability such as laminated aluminate film, replacing air in a package with nitrogen by a gas packing type packaging machine so as to maintain the central temperature of the potato sealed in an atmospheric pressure state at 105 deg.C for 10 minutes. The prepared product has no wetting of skin and no change in the color of roasted sweet potato even after long-term preservation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for producing a baked product which enables distribution and storage of the baked product at room temperature for a long period of time. More specifically, the baked product has a unique flavor, taste and color for 3 months. The present invention relates to a baked product manufacturing method which can be stored without loss over a long period of time and has a simple manufacturing process.

[0002]

2. Description of the Related Art Conventionally, there has been freezing storage as a long-term storage method for baked goods, but it requires thawing and reheating, and it is mainly used for business due to the troublesome operation, and it is hardly consumed for general use. The quality of the baked products at room temperature, which are characterized by their simplicity, is about one week for current commercial products, and one month at the longest, which is far from the three months required by users. limited.

Up to now, several proposals have been made regarding manufacturing methods of baked goods. That is, JP-A-52-108047 (method for producing frozen baked goods), JP-A-54-135254 (method for manufacturing packaged baked potatoes), JP-A-61-104762 (manufacturing method for baked goods), and 61-135562 (manufactured method for baked goods) ) No. 62-236464 (method for producing baked goods with a pattern) No. 63-305684 (method for producing baked potatoes that can be stored at room temperature for a long time) is known. The above mentioned is also a freezing roasting method of heating and thawing,
Also, there is a trouble in distribution, the same is a shaped baking separated from the original shape of the sweet potato, and the same is also a stone or ash baking, which is sterilized by sealing it in a packaging film using a pot, but for a short period of time. It can only be stored for a short period of time, it has been peeled and hermetically sealed with a packaging film, and sterilized, but it can only be stored for a short period of time, and it is baked in a far-infrared ray generator. Is a method for producing baked goods that can be stored at room temperature for a long time, but it is only stored for one month.

[0004]

When the above-mentioned known techniques are individually examined, no method has been proposed which can easily preserve the roasted potato for a long time (3 months). Since the thermostable bacteria still exist in the roasting broth after firing, it rots in a short period of about 5 days in normal sterilization with hot water or steam (100 ° C or lower).
Further, even if it is soaked in a sterilizing agent before firing and then fired and sterilized with boiling water or steam (100 ° C or less), it is only stored for about one month.

[0005] Further, if the roasted potatoes are vacuum-packed with a packaging material having a high oxygen permeability and stored, there is a problem that the meat is discolored at the same time as rotting and the product is in a water-wetted state, and the appearance is low.

A dehydration method by centrifuging has been proposed to wet the product with water, but since the water content in the baking process is originally dehydrated, the baking process is different from the original water, and the product is in a dry state, which naturally has a different texture. My throat gets worse.

[0007]

[Means for Solving the Problems] In order to keep the baked product for a storage period of 3 months, 10
A heat sterilization method at 0 ° C or higher was examined. As a condition for complete sterilization of heat-resistant bacteria in baking, the temperature of the baking center is 105 ° C.
It was found that this temperature should be maintained for 10 minutes or more. That is, in the case of vacuum packaging, if the diameter is about 5 cm, it is necessary to sterilize at 105 ° C. for 40 minutes. If the diameter of the sprouts is small, the sterilization time may be shortened. Also, if the diameter of the sponge is large, it is necessary to raise the sterilization temperature or lengthen the sterilization time. However, as a consumer's preference, potatoes whose diameter is far from 5 cm are considered unsuitable as raw materials for baking. As a result, it is possible to safely manufacture a baked product that can be stored for a long period of time without using a dangerous germicide.

[0008] When the roasted potatoes are vacuum-packed with a packaging material having a high oxygen permeability and stored, the meat color changes, so the prevention of this color change was examined. It was found that this discoloration was related to the oxygen permeability of the packaging material. In other words, the packaging material for preventing roasted flesh from discoloring meat and storing it for a long time at room temperature has an oxygen permeability of 20 ml / m ² · atm · 24 hrs.
It became clear that it must be below (20 ° C). In order to completely prevent it, it is desirable to use an aluminum laminate film having almost no oxygen permeability.

Further, in order to prevent the condition of the wetness of the skin, which has a low appearance rating in the vacuum packaged product, without changing the moisture content of the baked product, it is necessary to solve the problem by making the inside of the package atmospheric pressure. I understood. In other words, by packing without vacuum packaging, the skin of the baked goods will get wet with water immediately after sterilization, but after 2 days the skin will dry and the original water content will be maintained inside the baked goods, and the texture of the interior will be apparent. Was also good. However, when atmospheric pressure is applied to the inside of the package, a gas phase exists. This gas phase needs to be replaced with a gas other than oxygen, such as nitrogen, because oxygen is involved in the discoloration of the meat color of the grill.

The manufacturing process of the baked product which can be finally distributed at room temperature and stored for a long time is shown in FIG.

[0012]

[Example 1] Sweet potatoes (about 5 cm in diameter) at 200 ° C
After baking for 1 hour, cooling, vacuum packaging, and treating with a retort sterilizer at a treatment temperature of 105 to 120 ° C. for a treatment time of 10 to 40 minutes, put it in a thermostatic chamber at 20 ° C. The flesh color immediately after sterilization was measured with a color difference meter, and Hunter-L, a,
The b value is shown in Table 1.

[0013]

[Table 1]

No spoilage was observed at a treatment temperature of 105 ° C. or higher and a treatment time of 40 minutes or longer. At this time, the center of the baked product was kept at 105 ° C. or higher for 10 minutes. However, when the heat treatment is excessively performed, the flesh color has low L and b values of the color tone, and the discoloration of the flesh color becomes remarkable, which is not suitable as the flesh color of baked products. Therefore, the sterilization condition was set to 105 ° C. for 40 minutes, which is the lowest level without spoilage. With the sterilization under these conditions, the meat color of baked products was inferior to that of the untreated product, but the meat color was sufficiently commercial. Corruption rate is Equation 1
I asked for.

[0015]

[Formula 1]

[0016]

[Example 2] Sweet potatoes (about 5 cm in diameter) at 200 ° C
Bake for 1 hour, cool to a handable state, package with an aluminum laminate film, replace the air in the package with a gas filling packaging machine with nitrogen, and seal at atmospheric pressure. Due to the atmospheric pressure inside the package, heat conduction is slower than in vacuum packaging, so if you increase the sterilization temperature by 5 ° C and sterilize at 110 ° C for 40 minutes, the skin will not get wet,
Even if it is stored for a long time (3 months), the meat color does not change even when baked. Compared to the vacuum packaging of Example 1, the skin of the product was less wet and the appearance was rated higher.

[0017]

[Comparative Example] Sweet potatoes (about 5 cm in diameter) were baked at 200 ° C for 1 hour, cooled to a state where they could be hand-held, vacuum-packed with an oxygen-impermeable aluminum laminate film and an oxygen-permeable polyvinyl film, and kept at 105 ° C. It heat-sterilized for 40 minutes. After storing this in a thermostatic chamber at 20 ° C for 3 months, the meat color of the baked product was measured with a color difference meter, and Hunter-L, a, b
The values are shown in Table 2.

[0018]

[Table 2]

The flesh-colored hunter L and b values were almost unchanged in the film having no oxygen permeability, and the color tone immediately after sterilization was maintained and the product had sufficient commercial properties. Due to the decrease in b value, discoloration of meat color was remarkable and there was no commercial property. In addition, the surface of the product after vacuum packaging was in a wet state, and the appearance was extremely low.

[0020]

According to the present invention, the following effects are brought about. For a long time (3 months), you can store the roasted potatoes at room temperature in good quality, and you can quickly relish the roasted potatoes by easily reheating them in a microwave oven. Moreover, the product can be easily manufactured in a short time and can be stored for a long time (3 months) as compared with the conventional manufacturing method.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing process of a baked product that can be distributed at room temperature and stored for a long time.

Claims (1)

[Claims] 1. Sweet potatoes are baked, and nitrogen-filled packaging is performed with a packaging material having low oxygen permeability, that is, the gas phase in the packaging is replaced with nitrogen and then sealed, and the temperature of the central portion is maintained at 110 ° C. or higher for 10 minutes or more. A method for producing baked goods that can be distributed at room temperature and stored for a long period of time, characterized by performing heat sterilization as described above.