JPH02154634A - Omission of stationary cooling period for dried fishes by microwave heating - Google Patents

Abstract

PURPOSE:To improve the quality and preparation yield of a dried fish meat by finishing the diffusion of water contained in the center portion of the fish meat in a short time by a microwave heating operation instead of the conventional stationary cooling operation. CONSTITUTION:A dried fish meat such as dried bonito or dried mackerel dried until the fourth fire process giving a water content of 25-55% or later during a roast-drying process is irradiated with microwaves in an irradiation energy of 30-100 kilo joule per kg of the dried fish meat approximately three times to finish into a roughly dried fish meat.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has been developed in such a way that the diffusion of the moisture in the center of the joints to the surface can be completed in a short time using microwaves, instead of the conventional annealing operation using static cooling.

If dried bonito flakes with a large amount of protein and thick flesh are dried continuously, the outside of the dried bonito becomes too dry, making it difficult for the moisture in the center of the dried bonito to permeate to the outside and evaporate. For this reason, conventionally the moisture in the center of the knot was diffused outward by leaving it for a long time, but by applying microwave heating with this method, the moisture in the center of the knot can be diffused to the outer periphery in a short time. We aimed to

In microwave heating, microwaves are absorbed by water or other low-molecular substances in the irradiated object, causing dipole rotation or ion vibration in the water or other low-molecular substances, converting radio wave energy into thermal energy.

This means that since the radio wave energy is directly converted into heat inside the irradiated object, moisture can easily diffuse from the inside and uniform heating can be achieved in a short time. At present, there are many examples in which this feature of microwave heating is used for drying processes, etc., but there are no examples of its application to diffusion of moisture in the center of knots, and therein lies the feature of the present invention.

Experimental example Regarding the diffusion of moisture inside dried bonito flakes by microwave irradiation.

(1) Samples Samples were dried bonito flakes that had been heated in the fourth heat, and dried bonito flakes that had been heated in the fifth heat.

(2) Experimental method? Microwave output 2.6 kW, irradiation frequency n 2450M
Two bonito flakes were simultaneously irradiated with microwaves at Hz and irradiation time for 15 seconds. After irradiation Kerato Kagaku Co., Ltd. 6Tf Kyushoso 5OIL HOISTURE HETER) IODEL
The electrical resistance was measured using J-3 to determine the moisture content.

(3) Experimental Results and Discussion Figure 1 shows the moisture content of the sample before and after irradiation, at a distance of 3 mm from the surface of the dried bonito flakes immediately after the fifth fire. The moisture content in the surface layer of each sample after microwave irradiation was greater than before microwave irradiation.

This indicates that the moisture content increased because the moisture in the center diffused to the surface due to microwave irradiation.

Next, the microwave irradiated sample and the non-irradiated sample of the bonito flakes immediately after the fourth heating were cut into rings, and the moisture content of the outer periphery and center was measured. The results are shown in FIG. In the sample that was irradiated with microwaves, there was no significant difference in the moisture content between the center and the outer periphery, but in Trial 5 Sample 1, which was not irradiated, there was a large difference between the center and the outer periphery. This indicates that the microwave irradiation caused the moisture in the center to diffuse to the outer periphery, making the moisture inside the node uniform.

The above results indicate that short-term microwave heating causes moisture diffusion in the center of the knot, making the moisture inside the knot uniform.

The present invention is characterized in that it is possible to homogenize the moisture inside the surface in a short time by microwave heating, so that fungi can be continuously dried.

By the way, when bonito flakes are irradiated with microwaves, the change in the flesh quality of bonito flakes is as shown in Table 1, with an energy level of 30 to 100.
Good results were obtained with kilojoule irradiation, but the meat quality was not satisfactory with more kilojoules of irradiation.

*(Energy concavity for node 1k()) Example An example of a process using a microwave heater during the roasting process is as follows.

Conventional method Raw materials Dokiri → Boiling → Peeling the bones → First fire → Second fire → Third fire → Fourth fire → Anmushi → Fifth fire → Anmushi → Sixth fire → Must steam → Seventh fire → Anmushi → Ha Banbi → Anmushi → Ninth Fire → Anmushi → Tenth Fire → New method for rough surface finish Raw materials Dokiri → Boiled → Handling bones → First Fire → Second Fire → Third Fire → Fourth Number fire → Microwave treatment → Fifth fire → Sixth fire → Microwave treatment → Seventh fire → Ha number fire - Microwave treatment → Nine fire → Tenth fire → Rough surface finish The new method is the conventional method fourth fire After that, the annealing process is performed six times, and the microwave treatment is performed three times to finish it as rough bush. As a result, the production time that used to take about 20 days was now completed in about 10 days. Labor and energy savings were achieved by reducing the number of manufacturing days, and the work environment was improved by eliminating the need for the factory space needed to perform the steaming process. In terms of quality, producing products with uniform moisture content in the grain direction not only improved quality but also led to improved yields.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the moisture content of the surface layer before and after irradiating the interface with microwaves at the end of the fifth hole. FIG. 2 is a diagram showing the moisture content in the center and periphery of the microwave-irradiated sample and the non-irradiated sample at the interface at the end of the fourth hole. Shocking

Claims (1)

[Claims] Joints such as bonito flakes and mackerel which have a moisture content of 25 to 55% during roasting are heated with microwaves at an irradiation energy of 30 to 100 kilojoules per 1 kg of knots to diffuse the moisture inside the knots. A method for producing joints that does not require steaming.