JPH0568510A - Method for keeping quality of edible algae - Google Patents

Abstract

PURPOSE:To improve the preservability of edible algae and keep the quality of the algae while keeping the characteristics of the material in high efficiency by applying a high pressure of a specific range to edible marine algae, etc. CONSTITUTION:The quality of edible algae such as marine algae (e.g. tangle, wakame seaweed and laver) or fresh water algae (e.g. Phylloderma sacrum) can be maintained by applying a pressure of 50-500MPa to the algae.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for improving the shelf life of edible seaweeds or freshwater algae while maintaining the quality of the raw material as it is.

[0002]

2. Description of the Related Art Generally, as a method for improving the shelf life of edible seaweeds or freshwater algae, methods such as blanching, drying, and salting are used, but the shelf life is not always sufficient. The treatment method of 1 tends to impair the flavor and properties of raw algae. In addition, recently, a quality preservation method by far infrared treatment has been reported, but according to it, although the shelf life is improved, since the process of blanching is necessary, the flavor and properties of raw algae are lost, and It is considered that the treatment cost tends to increase because it is necessary to continue to apply far infrared rays during storage.

[0003]

As described above, the conventional method for maintaining the quality of edible algae does not provide a good shelf-life effect, but also the flavor and properties of raw algae are impaired, and depending on the method, the treatment cost is low. Can be higher. Therefore, an object of the present invention is to provide a method for maintaining the quality of edible algae that can maintain the shelf life at low cost while maintaining the flavor and properties of the edible algae material.

[0004]

Means for Solving the Problems As a result of various investigations by the present inventors, edible seaweeds or freshwater algae are acted on (pressurized) with a specific pressure far exceeding the normally used height range. By doing so, they have found that the above-mentioned object can be achieved. The present invention has been made based on the above findings, and provides a method for maintaining the quality of edible algae, which comprises applying a pressure of 50 to 500 MPa to edible seaweed or freshwater algae. Hereinafter, the method for maintaining the quality of the edible alga of the present invention will be described in detail. As described above, the method for maintaining the quality of edible algae of the present invention achieves the desired quality maintenance of edible algae by applying a specific pressure to edible seaweed or freshwater algae.

As the edible algae used in the present invention, among seaweeds, there are kelp, seaweed, Nori, Astragalus japonica, and the like. As freshwater algae, there are Suizenjinori. These edible algae are not limited to raw,
The present invention can be applied to a product that has been heat-treated by blanching, or a product that has been frozen, salted, or dried. Further, in the present invention, it is important that the pressure acting on the edible algae is 50 to 500 MPa in order to exert a sufficient effect. As will be described later in Examples, by exerting a pressure in the above range on the edible alga, a good quality retention effect can be obtained. The pressure to act on
When it is lower than 50 MPa, the shelf life of the edible algae is not sufficient and a good quality preserving effect is not recognized. On the contrary, applying a pressure exceeding 500 MPa is not realistic from the viewpoint of food processing because the equipment becomes complicated and large-sized.

There is no particular limitation on the time for which the pressure is applied, but it is preferable to hold the pressure for 5 to 30 minutes after reaching the desired pressure, and if it is shorter than 5 minutes, the quality retention effect is lowered. However, the time required for the treatment in the present invention may be shorter than the time required for the treatment method used in the above-mentioned conventional quality retention method. Further, the temperature at which the pressure is applied is not particularly limited, and the present invention can be applied within a temperature range of about 100 ° C from the frozen state. However, when pressure is applied at room temperature or lower, the effect of maintaining quality while maintaining the flavor and properties of the material of edible algae, which is one of the features of the present invention, becomes more apparent. In addition, it is needless to say that the commonly used additives such as seasonings can be added in order to maintain the quality of the edible alga according to the present invention. According to the present invention described above, it is possible to quickly (at low cost) improve the shelf life while maintaining the flavor and properties of the material for edible algae.

[0007]

EXAMPLES The method for maintaining the quality of edible algae of the present invention will be described in more detail below with reference to examples. Example 1 About 100 g of raw wakame seaweed was packaged in a polyethylene bag, and a pressure in the range of 10 to 500 MPa was applied to the wakame seaweed at 0 ° C. to maintain the state for 10 minutes. on the other hand,
For comparison, a fresh seaweed was simply packaged in a polyethylene bag. Immediately after treatment, these treated raw wakame seaweed are stored in a refrigerator (temperature: 10 ° C), and a part of them is taken out over time to measure the viable cell count and sensory test (mainly for the degree of softening of tissue and rancid odor). Or not). The results are shown in Table 1,
2 shows.

Table 1 Time-dependent changes in the viable cell count of treated raw wakame seaweed. ────────────────────── Storage days Viable bacteria count (colony / lg tissue) (day) ─────────────── ──Processing pressure (MPa) (0 ℃, 10 minutes) ──────────────── 0 * 10 50 100 ──────────────── ─────── Immediately after treatment 510 520 510 370 2 500 610 420 250 4 600 590 540 250 7 1200 1300 900 300 9 5400 4800 3000 870 12 9600 15000 5500 1600 ──────────── ────────── *: Comparison

────────────────────── Storage days Viable bacteria count (colony / lg tissue) (day) ──────────── ───── Processing pressure (MPa) (0 ℃, 10 minutes) ──────────────── 200 300 400 500 ────────────── ───────── Immediately after treatment 30 30 50 10 2 50 40 10 20 4 100 10 10 10 7 100 90 30 170 9 1100 150 20 10 12 900 560 140 80 ─────────── ─────────────

Table 2 Changes with time in the properties of the treated raw wakame seaweed. ──────────────────────────────── Storage days Properties (softening of tissues, rancidity) (days) ──── ────────────────────── Processing pressure (MPa) (0 ℃, 10 minutes) ───────────────── ────────── 0 * 10 50 100 200 300 400 500 ──────────────────────────────── ─ Immediately after processing − − − − − − − − 2 − − − − − − − − 4 ± − − − − − − − 7 + + ± ± ± ± − − 9 + + ± ± ± ± − − 12 + + + + ± ± − − ───────────────────────────────── *: Softening of comparative control tissues and generation of rancidity Are almost parallel phenomena.
The symbols in the table have the following meanings. -: No change from raw seaweed before treatment. ±: Slightly softened tissue and rancid odor are observed. +: Softening of tissue and obvious rancid odor.

No matter which pressure in the range of Tables 1 and 2 is applied to the raw seaweed, the properties of the raw seaweed (tissue hardness,
No change was observed in sensory properties such as flavor, color tone, and flavor). When the viable cell count immediately after the treatment in Table 1 was observed, a bactericidal effect on raw wakame seaweed was clarified by applying a pressure of 100 MPa or more, and accordingly, an increase in the viable cell count during storage was suppressed. This indicates that the time to corruption has been extended. However, at a pressure of 50 MPa or less, the bactericidal effect was extremely small, and the degree of increase in the viable cell count during storage was no different from that of the control.

Looking at the viable cell count of the control in Table 1, this viable cell number is higher than that under the pressure, but compared with the viable cell number when general food is spoiled. Not quite. Nevertheless, Table 2 shows that the properties of the control have clearly changed. That is, the tissue softened and a bad smell started to appear from the 4th day of storage. When a pressure of 100 MPa or more is applied, the change in properties is obviously suppressed, especially 30
At 0 MPa or higher, almost no change in properties was observed after storage for 12 days. However, at pressures below 50 MPa, softening of tissues and generation of rancid odor occurred as in the control, and changes in properties could not be suppressed. This change in the properties of the raw wakame seaweed occurs when the viable cell count is low as shown in this Example, and is therefore not due to the influence of the microorganisms in the raw seaweed but rather due to the activity of an autolyzing enzyme. Thought to be a thing. Therefore, it is considered that the pressure deactivates this autolytic enzyme-like activity. As described above, applying a pressure of 50 MPa or more to the raw seaweed, preferably a pressure of 100 MPa or more suppresses the growth of microorganisms and the action of the enzyme in the raw seaweed, and is effective in maintaining the quality of the raw seaweed. I knew that.

Example 2 Similar to Example 1, about 100 g of raw wakame seaweed was packaged in a polyethylene bag, and a pressure of 400 MPa was applied to the seaweed at room temperature to maintain that state for 1 to 60 minutes. Processed. On the other hand, for comparison, a fresh seaweed was simply packaged in a polyethylene bag. Immediately after the treatment, these treated raw wakame seaweed were stored in a refrigerator (temperature: 10 ° C.) for 12 days, and subjected to measurement of viable cell count and sensory test. The results are shown in Table 3.

Table 3 The number of live bacteria and the properties of the treated raw seaweed after storage. ────────────────────── Pressure action time Viable count Properties (400MPa, room temperature) (colony / lg) (min) ──────── ────────────── Comparison (0min) 9600 +1 2000 ± 2 210 ± 5 80 − 10 140 − 20 40 − 30 10 − 45 10 − 60 20 − ────── ───────────────── The meanings of the symbols in the table are the same as in Table 2.

When pressure is applied to the raw wakame seaweed at any time within the range shown in Table 3, before and after that, there is no change in the properties of the raw wakame seaweed (sensual properties such as tissue hardness, flavor, color tone and flavor). I was not able to admit. According to Table 3, suppression of increase in the viable cell count of raw seaweed and suppression of change in properties were clarified when the pressure was applied for 5 minutes or longer. Further, these effects do not change even by the action of pressure for a longer time, and it is considered that the action of pressure for 60 minutes or longer is unnecessary considering the effect. Therefore, a working time of 5 to 30 minutes is sufficient to exert a pressure on the raw seaweed and maintain its quality, which is a short time as compared with the conventional processing time. According to the invention,
It was shown that the quality of raw seaweed can be maintained more quickly and economically.

Example 3 Similar to Example 1, raw seaweed, kelp, Asakusanori,
Hijiki (raw sample) and seaweed, kelp, Asakusanori, and Hijiki (preheated) that have been heated in water at 100 ° C for 10 minutes each
100 g was packed in a polyethylene bag, and a pressure of 400 MPa was applied to the sample at room temperature, and the state was maintained for 5 minutes. On the other hand, as a comparative control, a product which was simply packaged in a polyethylene bag and was not subjected to pressure was also prepared. Immediately after the treatment, these samples were stored in a refrigerator (10 ° C.), and the storage time (maintenance) until the properties of the samples changed (mainly softening of tissue and generation of rancid odor) was examined. The results are shown in Table 4.

Table 4 Storage time required for changing the properties of edible algae. ───────────────────────────── Algae Storage time (shelf life) (days) ───────────── ───────── Comparative pressure treatment * ────────── ────────── Raw sample pre-heating Raw sample pre-heating ─────── ────────────────────── Seaweed 4 20 18 16 Kelp 4 15 20 20 Asakusanori 2 7 10 10 Hijiki 2 9 15 14 ──────── ───────────────────── *: 400MPa, room temperature, 5 minutes.

According to Table 4, although any edible algae preheated had an improved shelf life, changes in properties (texture and color tone) due to heating were observed. On the other hand, in the case of applying the pressure, although the shelf life was improved to the same level as that of the case of applying the preheating or more, the change in the properties due to the pressure was hardly recognized and it was the same as that of the raw material. The combination of pre-heating and pressurization showed no improvement in shelf life over pressurization alone, and changes in properties due to heating were observed. As described above, it was found that when the pressure is applied to the edible algae, the quality retention effect more than that of the conventional (heat) treatment method can be expected regardless of the type. Further, the conventional treatment methods tended to impair the properties of raw edible algae materials, but the present invention has a feature that is hardly recognized.

[0019]

According to the present invention, it is possible to quickly maintain the quality of edible algae while keeping the characteristics of the raw materials.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Mikio Iwamoto 1-9-16 Sumiyoshidaihigashi, Izumi-ku, Sendai-shi, Miyagi

Claims (1)

[Claims] 1. A edible seaweed or a freshwater algae containing 50 to 50
A method for maintaining the quality of edible algae, which comprises applying a pressure of 500 MPa.