Method for sterilizing high-quality meat- and kimchi-based processed food by means of pH adjustment and mild heating

Abstract

The present application relates to processed food, which is to be distributed at room temperature, comprising kimchi, meat and organic acid and having the pH of 3.9-4.5 and a method for preparing meat- and kimchi-based processed food by means of pH adjustment and mild heating.

Claims

1. A method for preparing a processed food distributable at room temperature, comprising the steps of (1) (a) contacting kimchi with an organic acid and then heating the kimchi contacted with the organic acid at 75° C. to 90° C., and (b) contacting meat with an organic acid and then blanching the meat contacted with the organic acid at 95° C. to 121° C.; or blanching meat in an organic acid solution at 95° C. to 121° C.; wherein the steps (a) and (b) are carried out in a separate process, and the meat is not treated with alkaline aqueous solution before contacting the meat with the organic acid or blanching the meat in the organic acid solution; (2) mixing the results of steps (a) and (b) and packaging the mixture of the results of step (a) and (b); and (3) heating the result of step (2); wherein the heating is carried out by heating at 85° C. to 95° C. for 10 minutes to 20 minutes and then heating at 105° C. to 110° C. for 5 minutes to 30 minutes.

2. The method for preparing the processed food distributable at room temperature according to claim 1, wherein the organic acid in step (a) is used in an amount of 0.1% (w/w) to 0.5% (w/w) based on the weight of the kimchi.

3. The method for preparing the processed food distributable at room temperature according to claim 1, wherein the organic acid in step (b) is used in an amount of 0.5% (w/w) to 3.0% (w/w) based on the weight of the meat.

4. The method for preparing the processed food distributable at room temperature according to claim 1, wherein the organic acid solution in step (b) has a concentration of 0.5% (w/w) to 3.0% (w/w).

5. The method for preparing the processed food distributable at room temperature according to claim 1, wherein the contact between the meat and the organic acid in step (b) is carried out at 3° C. to 10° C. for 2 to 15 hours.

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a flow chart of the method for preparing the processed food distributable at room temperature of the present application.

(2) FIG. 2 is a pH change curve of pork depending on the concentration of the lactic acid solution according to one embodiment of the present application.

(3) FIG. 3 is a pH change curve of pork depending on the concentration of the lactic acid solution during heating in the lactic acid solution according to an embodiment of the present application.

(4) FIG. 4 is a graph showing the sterilizing effect on a thermal resistance spore suspension at the time of adjusting pH with the organic acid according to one embodiment of the present application (Indication by the same alphabet character: No significant difference; Indication by different alphabetic character: Presence of significant difference; Significance test (P<0.05)).

(5) FIG. 5 is a graph showing mouthfeel of the pork in the pork kimchi stew according to one embodiment of the present application (Indication by the same alphabet character: No significant difference; Indication by different alphabetic character: Presence of significant difference; Significance test (P<0.05)).

(6) FIG. 6 is a graph showing mouthfeel of the kimchi in the pork kimchi stew according to one embodiment of the present application (Indication by the same alphabet character: No significant difference; Indication by different alphabetic character: Presence of significant difference; Significance test (P<0.05)).

BEST MODE

(7) Hereinafter, preferred examples are described in order to facilitate understanding of the present application. However, the following examples are provided only to facilitate the understanding of the present application, and the present application is not limited by the following examples.

EXAMPLES

Preparation Example 1: Preparation of Kimchi Stew Distributable at Room Temperature Containing Pork

(8) (1) Preparation of Raw Materials

(9) The raw pork was washed three times with clean water to remove contaminants on the surface, and then cut into 3.0 cm×3.0 cm×0.5 cm (width, length, thickness) to prepare pork. The cabbage kimchi was prepared by cutting to an appropriate size for a kimchi stew.

(10) (2) pH Adjustment and Heating of Kimchi (Kimchi Preprocessing)

(11) The cut kimchi was mixed with 0.3% (w/w) of lactic acid relative to the weight of the kimchi to adjust the pH of the kimchi to about 4.0. To this, nisin, a bacteriocin-based natural bactericide, was added in an amount of 0.1% (w/w) relative to the weight of the kimchi and 0.5% (w/w) of calcium lactate was added. Thereafter, the pH-adjusted kimchi was heated at 80° C. for 20 minutes.

(12) (3) pH Adjustment and Heating of Pork (Meat Preprocessing)

(13) It was confirmed that the pH of the final pork could be adjusted to 4.2 or less when adding lactic acid in an amount of 0.5% (w/w), 1.0% (w/w), 1.5% (w/w), 2.0% (w/w), 2.5% (w/w) and 3.0% (w/w), relative to the weight of the pork, to the washed and cut pork, allowing the lactic acid component to permeate into the pork by storing (curing) at 5° C. for 12 hours, and then heating (blanching) it in water at 100° C. for 5 minutes, or adding the pork to the lactic acid solutions of 0.5% (w/w), 1.0% (w/w), 1.5% (w/w), 2.0% (w/w), 2.5% (w/w), 3.0% (w/w) and 4.0% (w/w) relative to the weight of water respectively and heating (blanching) at 100° C. for 5 minutes, when adding 2.5% (w/w) or more of lactic acid, or when heating in the lactic acid solution of 3.0% (w/w) or more (FIGS. 2 and 3).

(14) (4) Packaging and Mild Heating Sterilizing

(15) The kimchi prepared in Preparation Example (2) and the pork prepared in Preparation Example (3) were mixed and packaged in a thermal resistance pouch, heated at 95° C. for 20 minutes, and then heated for 15 minutes after raising the temperature to 110° C. The pH of the final product was confirmed to be about 4.1.

Experimental Example 1: Measurement of Sterilizing Effect of Kimchi Preprocessing

(16) The sterilizing effect by the preprocessing performed in Preparation Example (2) and whether or not the sterilizing effect was maintained after storage for 6 months were confirmed by measuring the number of microbes. The measurement of the number of microbes was performed by the clone count method after culturing at 37° C. for 48 hours using an appropriate medium depending on each bacteria. The medium was a plate count agar (PCA) medium in the case of the total bacteria, a TSA (tryptic soy agar) medium in the case of thermal resistance bacteria (Bacillus subtilis strain) and a potato dextrose agar (PDA) medium in the case of fungi (yeast and mold).

(17) As a result, it was confirmed that the total bacteria, the thermal resistance bacteria and the fungi were all killed and thus sterilized. In addition, even after storage for 6 months under storage conditions at cold storage (15° C.), 25° C., 35° C. and 45° C., no proliferation of microbes was observed. Thus. it was confirmed that it was sterilized at a commercial level (table 1).

(18) TABLE-US-00001 TABLE 1 Detailed Total Thermal Storage treatment bacteria resistance condition Sample method (CFU/g) bacteria Fungi Refrigerated Control non-treated 10.sup.4~10.sup.5 10.sup.2  10.sup.1  storage group group (15° C., 6 Preparation Lactic acid 0 0 0 months) Example (2) pH adjustment (4.0) + 80° C. heating Room Control non-treated TNTC 10.sup.2  10.sup.1  temperature group group (>10.sup.6).sup.   storage Preparation Lactic acid 0 0 0 (25° C., 6 Example (2) pH months) adjustment (4.0) + 80° C. heating Warm Control non-treated TNTC 10.sup.3  10.sup.2  storage group group (>10.sup.6).sup.   (35° C., 6 Preparation Lactic acid 0 0 0 months) Example (2) pH adjustment (4.0) + 80° C. heating Medium Control non-treated TNTC 10.sup.4  10.sup.2  temperature group group (>10.sup.6).sup.   storage Preparation Lactic acid 0 0 0 (45° C., 6 Example (2) pH months) adjustment (4.0) + 80° C. heating Identification of the sterilizing effect by kimchi preprocessing * TNTC: Too numerous to Count, (Estimated as no less than 1 million of bacteria/g)

Experimental Example 2: Measurement of Sterilizing Effect by Meat Preprocessing

(19) In order to identify the sterilizing effect on meat by the preprocessing performed in Preparation Example (3), each of the pork, the chicken, and the beef was preprocessed as described in Preparation Example (3). The number of microbes was measured in the same manner as in Experimental Example 1 above.

(20) As a result, when preprocessing using lactic acid as in Preparation Example (3), it was confirmed that there is sterilizing effect on the total bacteria, the thermal resistance bacteria and the fungi in all meat (table 2).

(21) TABLE-US-00002 TABLE 2 Thermal resistance Total bacteria (CFU/g) bacteria (CFU/g) Fungi (CFU/g) Preprocessing Before After Before After Before After Meat condition preprocessing preprocessing preprocessing preprocessing preprocessing preprocessing Pork 100° C. water 10.sup.3 10.sup.2  10.sup.2 10.sup.2  10.sup.1 0 Blanching for 5 minutes 2.5% lactic 10.sup.3 0 10.sup.2 0 10.sup.1 0 acid solution Curing for 12 hours + 100° C. water Blanching for 5 minutes 3% lactic 10.sup.3 0 10.sup.2 0 10.sup.1 0 acid solution 100° C. Blanching for 5 minutes Chicken 100° C. water 10.sup.4 10.sup.3  10.sup.2 10.sup.2  10.sup.1 0 Blanching for 5 minutes 2.5% lactic 10.sup.4 0 10.sup.2 0 10.sup.1 0 acid solution Curing for 12 hours + 100° C. water Blanching for 5 minutes 3% lactic 10.sup.4 0 10.sup.2 0 10.sup.1 0 acid solution 100° C. Blanching for 5 minutes Beef 100° C. water 10.sup.3 10.sup.2  10.sup.2 10.sup.2  10.sup.1 0 Blanching for 5 minutes 2.5% lactic 10.sup.3 0 10.sup.2 0 10.sup.1 0 acid solution Curing for 12 hours + 100° C. water Blanching for 5 minutes 3% lactic 10.sup.3 0 10.sup.2 0 10.sup.1 0 acid solution 100° C. Blanching for 5 minutes

(22) Identification of the sterilizing effect by meat preprocessing

Experimental Example 3: Measurement of Sterilizing Effect on Thermal Resistance Sporophyte Depending on pH

(23) In order to identify the sterilizing effect of Bacillus subtilis sporophyte depending on pH, effects on inhibition of proliferation and reduction of bacteria at acidic pH range of pH 4.0 to 6.0 adjusted with lactic acid for suspension of Bacillus subtilis spores were identified. The suspension of the thermal resistance spores was used after conversion to endogenous spores with thermal resistance through the control of growth environment using nutrient cells of Bacillus subtilis (ATCC6633) purchased from the Korean Federation of Culture Collections.

(24) As a result, it was confirmed that at pH 6.0 or more, spores were observed to be 10.sup.4 CFU/g or more, but the number of spores at pH 5.0 was decreased by 10.sup.1 CFU/g or more compared to the number of spores at pH 6.0 and the number of spores at pH 4.0 was decreased by 10.sup.4 CFU/g compared to the number of spores at pH 6.0 and thus at pH 4.0, spores were completely killed (FIG. 4). Therefore, it can be seen that when controlled the pH to about 4.0, it was very effective in proliferation inhibition and sterilization of thermal resistance sporophytes

Experimental Example 4: Sensory Evaluation for Preprocessing Pork

(25) Sensory evaluation for the pork heated in the lactic acid solution of 0.5% (w/w) to 4.0% (w/w) in Preparation Example (3) above was performed depending on the concentration of the lactic acid solution.

(26) Specifically, taste qualities such as overall taste, sour taste, mouthfeel, and appearance (color) preferences of each pork were relatively compared by 15 panelists for sensory evaluation.

(27) As a result, as the concentration of lactic acid solution is increased, sour taste and mouthfeel were increased and thus sensory quality was decreased. However, when adding lactic acid in an amount of 3.0% (w/w) or less, a value of 3.5 points or less was obtained, which is sensually acceptable (table 3).

(28) TABLE-US-00003 TABLE 3 Concentration Sour Appearance of lactic Heating Overall taste taste Mouthfeel (color) acid solution condition (5 point scale) preference preference preference Note .sup. 0% 100° C., 3.8.sup.a 3.8.sup.a 3.9.sup.a 3.8.sup.a Control blanching for group 5 minutes 0.5% 100° C., 3.8.sup.a 3.7.sup.a 3.8.sup.a 3.8.sup.a Treated blanching for group 5 minutes 1.0% 100° C., 3.7.sup.a 3.7.sup.a 3.7.sup.a 3.8.sup.a Treatment blanching for group 5 minutes 1.5% 100° C., 3.7.sup.a 3.7.sup.a 3.7.sup.a 3.7.sup.a Treatment blanching for group 5 minutes 2.0% 100° C., 3.6.sup.a 3.6.sup.a 3.6.sup.b 3.6.sup.a Treatment blanching for group 5 minutes 3.0% 100° C., 3.5.sup.b 3.5.sup.b 3.5.sup.b 3.5.sup.b blanching for 5 minutes 4.0% 100° C., 3.0.sup.c 3.0.sup.c 3.0.sup.c 3.3.sup.b Treatment blanching for group 5 minutes Results of sensory evaluation for preprocessed pork * Significance test (P < 0.05); Same alphabet character: No significant difference.

Experimental Example 5: Measurement of Sterilizing and Sterilizing Maintenance Effect by Mild Heating after Preprocessing

(29) The pork kimchi stew prepared in Preparation Example (4) was measured for sterilization and its maintenance effect. The number of microbes was measured in the same manner as in Experimental Example 1 above.

(30) As a result, for the pork kimchi stew prepared in Preparation Example (4), no proliferation of microbes was observed even after storage for 6 months under storage conditions at cold storage (15° C.), 25° C., 35° C. and 45° C. Thus, it was confirmed that the pork kimchi stew was sterilized at a commercial level and can be distributed at room temperature.

(31) TABLE-US-00004 TABLE 4 Detailed Total Thermal Storage Sample treatment bacteria resistance condition group method (CFU/g) bacteria Fungi Refrigerated Control Mild heating 10.sup.4  10.sup.2  10.sup.1  storage group non-treated (15° C., 6 months) Refrigerated Preparation Lactic acid 0 0 0 storage example (4) pH (15° C., 6 adjustment + months) mild heating Room Control Mild TNTC 10.sup.2  10.sup.1  temperature group sterilizing (>10.sup.6).sup.   storage non-treated (25° C., 6 months) Room Preparation Lactic acid 0 0 0 temperature example (4) pH storage adjustment + (25° C., 6 mild heating months) Warm Control Mild TNTC 10.sup.4  10.sup.2  storage group sterilizing (>10.sup.6).sup.   non-treated Warm Preparation Lactic acid 0 0 0 storage example (4) pH adjustment + mild heating Medium Control Mild TNTC 10.sup.4  10.sup.2  temperature group sterilizing (>10.sup.6).sup.   storage non-treated Medium Preparation Lactic acid 0 0 0 temperature example (4) pH storage adjustment + mild heating

(32) Measurement results of sterilizing and sterilizing maintenance effect by mild heating after preprocessing.

Experimental Example 6: Identification of Mouthfeel of Pork at the Time of Mild Heating after Preprocessing

(33) When the meat is treated with organic acid, the moisture holding ability of meat is reduced, and the texture of meat became tough. Accordingly, the mouthfeel of the fork in the pork kimchi stew prepared in Preparation Example (4) and the mouthfeel when using additional food additives were evaluated. The mouthfeel was confirmed by the firmness value measured with a texture analyzer (TA-XTPLUS, Stable micro system Co. Ltd., Surrey, England).

(34) Specifically, the firmness measurements in the texture analyzer were performed at a pretest speed of 2.0 mm/sec, at a test speed of 1.0 mm/sec, at a posttest speed of 2.0 ram/sec, and at a strain of 20% using a plunger with a diameter of 5 mm. Each of the measurements was repeated 20 times using the same region, and the accuracy of the experimental data was increased by using the average value as the measured value, which is calculated after excluding the outliers by the Chauvenet's outlier rejection method (p<0.05).

(35) As a result, the mechanical strength value of the pork (test group 1) in the pork kimchi stew prepared in Preparation Example (4) was 1.45 kgf, and test group 2, in which 1.0% (w/w) trehalose and 3.0% (w/w) edible oil (soybean oil, CJ Cheil Jedang) were mixed together, showed a firmness value of 1.12 kgf. Therefore, in test group 2, the strength of tissue was reduced by about 25% compared to test group 1. In addition, it can be seen that in the case of test group 3 containing 0.1% (w/w) of pineapple juice, the firmness value was 0.93 kgf, which was about 35% lower than test group 1, and thus in both cases, the tough mouthfeels are reduced by a decrease in firmness, and thus the mouthfeel preference of the pork can be improved (FIG. 5).

Experimental Example 7: Comparison of Mouthfeel of Kimchi at the Time of Mild Heating after Preprocessing

(36) In the case of retort kimchi processed food prepared by heat-sterilizing the kimchi at 121° C., the firmness of the kimchi was very lowered and the mouthfeel was degraded, and the firmness of the kimchi in the pork kimchi stew prepared in Preparation Example (4) was confirmed in the same manner as Experimental Example 6 above.

(37) As a result, the firmness of the kimchi treated by the retort sterilizing in the canned form food sold on the market was measured to be 0.4 kgf, the firmness of the kimchi in the pork kimchi stew prepared in the same way as in Preparation Example (4) without adding calcium lactate at the time of performing the preprocessing as in Preparation Example (2) above was measured to be 0.7 kgf, and the firmness of the kimchi in the kimchi stew prepared in Preparation Example (4) was measured to be 0.8 kgf. Therefore, it was confirmed that the firmness was increased by 75% to 100% [statistical significance (p<0.05)] (FIG. 6). Thus, it can be seen that the kimchi in the kimchi stew prepared in Preparation Example (4) can have improved mouthfeel preference compared to the commercial kimchi which was retort-processed.

Experimental Example 8: Sensory Evaluation for Mild Heat-Treated Kimchi Stew after Preprocessing

(38) The sensory evaluation for the pork kimchi stew prepared in Preparation Example (4) was performed.

(39) Specifically, taste qualities such as overall taste of the pork kimchi stew prepared in Preparation Example (4), mouthfeel of the kimchi in the pork kimchi stew, sour taste intensity of the pork, and appearance (color) were relatively compared by 15 panelists for sensory evaluation (table 5).

(40) As a result, the kimchi in the kimchi stew prepared in Preparation Example (4) had no significant difference in overall taste, flavor, color and mouthfeel in comparison to the retort sterilized kimchi and showed statistical significance (p<0.05) better than the conventional retort sterilized kimchi in terms of sensory quality.

(41) In addition, the sensory quality of the pork kimchi stew itself prepared in Preparation Example (4) was evaluated as 3.7-4.0 points which is considered to have superior statistical significance (p<0.05) compared to 3.2˜3.5 points of the retort products distributable at room temperature, which is sold on the market.

(42) In addition, although the pork in the pork kimchi stew prepared in Preparation Example (4) was pH adjusted by organic acid, the sour taste intensity of the pork was assessed to be the level which has no statistical significance compared to the control group and thus it has been found that the pH adjustment method of the meat of the present application using the organic acid is also acceptable in terms of taste qualities.

(43) TABLE-US-00005 TABLE 5 Detailed Mouthfeel Sour taste Sample treatment Overall taste of the intensity Appearance Storage Sample group method (5 point scale) kimchi of the Pork (color) property Raw Control Retort 3.3.sup.b 3.0.sup.b — 3.2.sup.b Room material group kimchi temperature of (121° C., distribution the 10 minutes) kimchi Preparation Lactic 3.9.sup.a 3.8.sup.a — 3.7.sup.b Room Example (4) acid pH temperature adjustment distribution (4.0) + 80° C. heating Pork Control Retort 3.4.sup.b 3.2.sup.b 3.0.sup.b 3.4.sup.b Room kimchi group kimchi temperature stew stew(121° C., distribution 20 minutes) Preparation Lactic 4.0.sup.a 3.8.sup.a 3.2.sup.b 3.8.sup.a Room Example (4) acid pH temperature adjustment distribution (4.2) + mild heating Results of sensory evaluation for the mild heat-treated kimchi stew after preprocessing * Significance test (P < 0.05); Same alphabet character: No significant difference.