KR20020061214A - The Manufacturing Process of Freeze-Dried Product of Grain, Vegetables, Fruits and Edible Seaweeds Treated with Heated Steam Process and Freeze-Dried Product produced by the Manufacturing Process - Google Patents

Abstract

PURPOSE: Provided are a manufacturing process of a freeze-dried product of grain, vegetables, fruits and edible seaweeds treated by heated steam process and the freeze-dried product produced thereby. Therefore, the freeze-dried product maintains characteristic properties including taste, nutrients, color, etc., and controls E. coli on the its surface effectively. CONSTITUTION: The manufacturing method comprises the steps of: washing raw ingredients selected form the group consisting of grain, vegetables, fruits, and edible seaweeds, with purified water repeatedly; spraying heated steam on the ingredients through a nozzle for 20-60 seconds while passing the ingredients through a tunnel with a conveyer, to sterilize microorganisms, such as E.coli and the like; placing them on a tray; and quick freezing then freeze-drying them.

Description

Manufacture method of freeze-dried foods of grains, vegetables, fruits, and seaweeds using surface instant sterilization of foods, and freeze-dried foods by the method of the manufacturing process {The Manufacturing Process of Freeze-Dried Product of Grain, Vegetables, Fruits and Edible Seaweeds Treated with Heated Steam Process and Freeze-Dried Product produced by the Manufacturing Process}

The present invention, in the manufacture of lyophilized foods using grains, vegetables, fruits, seaweeds, etc., saturated steam for 20 seconds to 60 seconds depending on the raw material through a high-pressure spray nozzle installed in multiple angles on the surface of the washed raw material Method of preparing a freeze-dried food and effective control of E. coli adhered to the surface of the raw material, while maintaining the characteristics of food, such as taste, nutrition, color, properties, etc. by spraying the lyophilized food produced by the method It is about food.

In recent years, due to the improvement of the economic level and the consumer's level of consciousness due to the development of material civilization, people are increasingly interested in health, nature, and the environment, and this trend is particularly affecting the food sector more closely. Rapid food developments have made foods that look more delicious and delicious fill the wider food stores, but consumers are more willing to pay more for natural, natural-oriented foods. Consumers are increasingly seeking food that can taste the taste and nutrition of fresh raw materials through minimal processing or sterilization rather than processing methods up to now. In response to this change in consumer consciousness, many food companies are trying to improve quality through so-called minimal processing.

Among the food processing methods developed so far, one of the processing methods that can best meet these needs of consumers is the fast freeze drying technology, one of the drying technologies. Freeze-drying technology is widely used as a drying method for vegetables and spices in that it can maintain the essential characteristics of the food itself, such as taste, nutrition, aroma, and color, despite the disadvantage that processing costs are much higher than general drying methods. .

In terms of preservation of essential characteristics such as taste and nutrition in food, the most important factor to consider is hygiene safety. Sterilization of harmful microorganisms such as E. coli is an essential processing process. . In this respect, the sterilization process is also a necessary process in the manufacture of lyophilized food.

Sterilization methods that have been mainly used in the manufacture of lyophilized foods include: ① Hot water immersion treatment (branching) method in which raw materials are immersed for 5 to 15 minutes in hot water of 80 ° C to 100 ° C, or ② Sterilization of chlorine system · Sterilization of microorganisms using disinfectant, ③Disinfection method using radiation.

However, the hot water immersion treatment method is a method that should be deteriorated due to high sterilization treatment at high temperature, which is likely to cause nutrient components to be destroyed, loss of flavor components, and changes in physical properties and colors. The chlorine sterilization method has various problems, such as a strong disinfection smell, which makes the working environment worse and there is a possibility that chlorine may remain after washing. Radiation sterilization method has been used for sterilization of livestock and agricultural products for a long time, and it has little effect on food quality. However, the scope of use is still limited by law. In addition to this, it is true that it is difficult to use due to the radiation resistance of the general consumer.

Therefore, in the manufacture of lyophilized food, there is an urgent need to develop a processing technology that can effectively control harmful microorganisms such as E. coli while minimizing the loss of inherent characteristics of food such as taste, nutrition, color, and physical properties. The inventors have also conducted a long research on this field.

The present invention is to solve and improve the problems of the prior art in the art, and to the grains such as brown rice, yulmu, barley, vegetables such as carrots, radish, fruit such as apples, pears, seaweed such as seaweed, kelp Method of manufacturing a freeze-dried food by effectively controlling E. coli adhered to the surface of the raw material while maintaining the inherent characteristics of the food such as taste, nutrition, aroma, physical properties, etc. To provide a lyophilized food prepared by the method.

1 is a schematic configuration diagram showing a surface sterilization apparatus according to an embodiment of the present invention.

2 is a cross-sectional view taken along the line A-A of FIG.

<Explanation of symbols for main parts of the drawings>

1: Chain conveyor 2: Sterilizer body

3: larynx 4: steam nozzle

5: condensate drain

The present invention for achieving the above object in the manufacture of lyophilized food using grains, vegetables, fruits, seaweeds, etc., characteristics of each raw material through a high-pressure spray nozzle installed in various ways to clean the individual raw materials in a conventional manner By spraying saturated steam on the surface of the raw material for 20 to 60 seconds to suit the requirements, the original characteristics of food such as taste, nutrition, color, and physical properties can be maintained as much as possible. It is characterized by providing a method for producing a controlled hygienically safe lyophilized food. In addition, the present invention provides a freeze-dried food prepared by sterilization.

The present invention is described in more detail as follows.

Raw materials such as grains, vegetables, fruits, and seaweeds are washed repeatedly with clean water several times, and after removing irreversible parts sufficiently, ② through high-pressure spray nozzles installed at various angles in the upper, left, and right sides of the tunnel while passing through the tunnel where the conveyor is installed. Depending on the type of raw material, it sprays about 97 ℃ to 98 ℃ of saturated steam uniformly on the surface of the raw material for an extremely short period of 20 seconds to 60 seconds, and then sterilizes microorganisms such as E. coli on the surface of the raw material. After crushing, cutting, etc. by the technology or put in a tray as it is, ④ rapid freezing in the freezer at -40 ℃, ⑤ freeze-dried by the conventional technology according to the characteristics of the raw material, excellent in quality and hygienic To prepare a safe lyophilized food.

Pre-sterilization pretreatment process in the present invention can be different depending on the characteristics of each raw material, the dried grains are preferably immersed for more than a few hours before washing so as to be able to freeze quickly, other vegetables, fruits, seaweeds can be just washed. .

The raw material which can use the present invention is not limited to the range of the embodiment, and as cereals, brown rice, brown rice glutinous rice, black flavor, glutinous rice, tea, millet, sorghum, buckwheat, barley, barley, green beans, red beans, white baek, frost tea, sesame, etc. Vegetables include carrots, cucumbers, eggplants, zucchini, bellflower, onions, lotus root, taro, bell peppers, radish, peppers, old pumpkin, mugwort, green onions, ferns, fresh vinegar, sesame leaves, sprouts, buttercups, spinach, Mali, garland chrysanthemum, mallow, cabbage, kale, stone parsley, comfrey, shiitake mushrooms, matsutake mushrooms, etc. Fruits include apples, pears, citron, kiwi, melon, watermelon, etc. , Kelp, green, seaweed, etc.

The high-pressure jet nozzle is advantageously equipped with multiple angles so that saturated steam can make uniform contact with the surface of the food, and is advantageous for the bactericidal effect. The nozzle can be installed by appropriately adjusting the installation interval according to the injection angle of the steam and the size of the tunnel, it is important to install so that the contact of the steam to the raw material can be continued without interruption during the injection time of the steam.

Saturated steam is usually 97 ℃ ~ 98 ℃ level at atmospheric pressure conditions.

It is most preferable to process the injection time of saturated steam in the range of 20 seconds to 60 seconds according to the characteristics of each raw material. Control of E. coli may be possible even in seconds or less, but 20 seconds or more is preferable in view of securing food safety through reliable control. In addition, when injecting saturated steam for 60 seconds or more, quality loss, such as loss of nutrition, may occur depending on the raw material, and therefore, saturated steam injection for 60 seconds or longer accompanied by an increase in cost is not preferable.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments and experimental examples shown in the accompanying drawings, but the present invention is not limited to the present embodiment.

Example 1 Preparation of Lyophilized Food by Surface Instant Sterilization of Grains

After immersing the brown rice for 3 hours at room temperature, washing with water several times and passing saturated conveyor through the conveyor tunnel in the thickness of 1cm ~ 2cm, the saturated steam was installed in the top, left, right and right sides of the tunnel at 20cm intervals for 10 seconds, 15 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds, 60 seconds, 65 seconds, 120 seconds continuously sprayed on the surface of the raw material, put in a tray to freeze quickly, and dried in a freeze dryer to 7% or less moisture The freeze-dried brown rice was prepared, and the product was prepared in the same manner as Yulmu, barley. Freeze-dried brown rice, yulmu, barley E. coli (E-coli) was measured, the results are shown in Table 1.

TABLE 1

Control Effects of Escherichia Coli in Lyophilized Food Prepared by Surface Instant Sterilization of Grains

(+: Positive,-: negative)

As shown in Table 1, brown rice, yulmu, barley was obtained satisfactory results of E. coli negative by saturation steam injection over 20 seconds, E. coli was not completely sterilized in 20 seconds or less.

<Example 2> Preparation of lyophilized food by surface instant sterilization of vegetables

Wash the carrots several times with clean water, remove enough irreversible parts, and saturate steam for 10 seconds, 15 seconds, 20 through the high-pressure jet nozzles installed at 20cm intervals in the upper and left sides of the tunnel. After spraying continuously on the surface of the raw material for seconds, 30 seconds, 40 seconds, 50 seconds, 60 seconds, 65 seconds, 120 seconds, and then crushed, cut, etc. by conventional techniques, put in a tray and freeze rapidly. Freeze-dried carrots were prepared by drying the water to 7% or less in a freeze dryer, and radish and courgette were also prepared in the same manner. Freeze-dried carrot, radish, courgette (E-coli) was measured, the results are shown in Table 2.

TABLE 2

Control Effects of Escherichia Coli in Lyophilized Foods Prepared by Surface Instant Sterilization of Vegetables

(+: Positive,-: negative)

As shown in Table 2, the carrot, radish, and zucchini were satisfactory results of all of the E. coli negative by saturated steam injection for 20 seconds.

Example 3 Preparation of Lyophilized Food by Surface Instant Sterilization of Fruits

The apples were washed several times with clean water, and after removing the irreversible parts sufficiently, the saturated steam was squeezed through the high-pressure jet nozzles installed at intervals of 20 cm on the left and right sides of the tunnel. After spraying continuously on the surface of the raw material for seconds, 30 seconds, 40 seconds, 50 seconds, 60 seconds, 65 seconds, 120 seconds, and then crushed, cut, etc. by conventional techniques, put in a tray and freeze rapidly. A freeze-dried apple was prepared by drying it to 7% or less in a freeze dryer, and a product was prepared in the same manner as the pear. Freeze-dried apple, pear E. coli (E-coli) was measured, the results are shown in Table 3.

TABLE 3

Control Effects of E. Coli on Lyophilized Foods Prepared by Surface Instant Sterilization of Fruits

(+: Positive,-: negative)

As shown in Table 3, a satisfactory result of negative for E. coli of apples and pears was obtained by spraying saturated steam for 20 seconds, and pears were able to coliform negative even with saturated steam spraying of 15 seconds.

Example 4 Preparation of Lyophilized Food by Surface Instant Sterilization of Seaweeds

Wash the seaweed several times with clean water repeatedly, remove enough irreversible parts, and saturate steam for 10 seconds, 15 seconds, 20 through high-pressure jet nozzles installed at 20cm intervals in the top, left and right sides of the tunnel. After spraying continuously on the surface of the raw material for seconds, 30 seconds, 40 seconds, 50 seconds, 60 seconds, 65 seconds, 120 seconds, put into a tray through a process such as cutting by a conventional technique, and then freeze-dried Freeze-dried apples were prepared by drying the water at 7% or less, and the product was prepared in the same manner. Freeze-dried seaweed, E. coli of kelp was measured, and the results are shown in Table 4.

TABLE 4

Control Effects of Escherichia Coli in Lyophilized Foods Prepared by Surface Instant Sterilization of Seaweeds

(+: Positive,-: negative)

As shown in Table 4, a satisfactory result of negative for E. coli was obtained by spraying seaweed and seaweed for 20 seconds with saturated steam.

In addition, the following experiment was carried out to determine whether the quality change according to the sterilization method of the present invention.

Experimental Example 1 Sensory Changes of Grains, Vegetables, Fruits and Seaweeds by Surface Instant Sterilization Time

Lyophilized brown rice, carrot, apple, and seaweed prepared by surface sterilization for 20 seconds or more confirmed the control effect of E. coli in Example 1, 2, 3, 4 lyophilized brown rice prepared in the same manner except for the surface sterilization process, Sensory evaluation was conducted on four items of color, aroma, texture, and overall taste using carrots, apples, and seaweed as standard samples. The sensory evaluation was evaluated by five-point evaluation method by applying the re-test comparison method among the characteristic difference identification test among 30 experienced sensory evaluation personnel. The results of the quality change recognition through statistical analysis are shown in Table 5.

TABLE 5

Sensory Changes of Freeze-Dried Brown Rice, Carrot, Apple, and Seaweed with Surface Instant Sterilization Time

(+: Difference identification,-: difference identification)

As shown in Table 5, brown rice and brown seaweed were not able to distinguish the difference from the standard sample in color, flavor, texture, and overall taste in surface instant sterilization up to 65 seconds. Sterilization was found to identify differences from standard samples in color and texture. Therefore, in order to minimize the quality changes, such as the taste, color, aroma, texture of grains, vegetables, fruits, seaweeds, it is preferable to process within a short time within 60 seconds.

Experimental Example 2 Nutritional Changes of Grains, Vegetables, Fruits, and Seaweeds by Surface Instant Sterilization Time

Lyophilized brown rice, carrot, apple, and seaweed prepared by surface sterilization for 20 seconds or more confirmed the control effect of E. coli in Example 1, 2, 3, 4 lyophilized brown rice prepared in the same manner except for the surface sterilization process, Carrots, apples, and seaweed were used as standard samples. The most important nutrients were analyzed by HPLC (High performance liquid chromatography) or GC (Gas chromatography). The results are shown in Table 6.

TABLE 6

Nutritional Changes of Freeze-Dried Brown Rice, Carrot, Apple, and Seaweed by Surface Instant Sterilization Time

(Vitamin B1, C, calcium: mg / 100g, beta-carotene: μg / 100g)

As shown in Table 6, brown rice, carrots, and apples observed changes in vitamins had almost no nutritional changes until 60 seconds, and more than 10% of nutrient loss began to appear when sterilized for more than 65 seconds. Seaweed, which observed changes in minerals, did not show any nutritional changes even after surface sterilization for more than 120 seconds. Therefore, it is most desirable to sterilize within 60 seconds to minimize the change in nutritional composition.

As described above, the method according to the present invention, by spraying saturated steam on the surface of cereals, vegetables, fruits, seaweeds for a short time while minimizing changes in the original taste, color, nutrition, and physical properties of the food, food surface Freeze-dried food that can effectively control E. coli attached to can be prepared. In addition, unlike the conventional heat sterilization, the present invention does not significantly affect the original quality characteristics of food, and thus can be recognized as a field of non-heat sterilization in that damage due to heating can be minimized. .

Claims (2)

One or more raw materials selected from the group consisting of cereals, vegetables, fruits, and seaweeds are repeatedly washed with clean water several times, and enough to remove irreversible parts, and through the tunnel where the conveyor is installed. Through the high pressure spray nozzle installed, the process of sterilizing microorganisms such as E. coli on the surface of raw material by spraying saturated steam uniformly on the surface of raw material for 20 seconds to 60 seconds, or through shredding and cutting processes A method for producing a freeze-dried food comprising a step of enclosing, and a step of freezing and then freezing in a freezer at -40 ℃. Lyophilized food prepared by the method of claim 1.