KR20130085497A - Extraction method of collagen from chicken by-product - Google Patents

Abstract

PURPOSE: An extraction method of collagen from chicken by-products is provided to be able to produce useful collagen by using chicken skin, and to be able to provide a functional material capable of generating an added-value utilizing waste resources and producing high quality food. CONSTITUTION: An extraction method of collagen from chicken by-products comprises (1) a step of washing and slicing the chicken skin; (2) a step of swelling the sliced chicken skin in step (1) by dipping a dipping solution of 10 times (w/v) the weight of the chicken skin and pH 1-13 at a room temperature; (3) a step of neutralizing the swollen chicken skin in step (2) to pH 5-7 by washing in the flowing water; (4) a step of extracting with hot-water by immersing the neutralized chicken skin in step (3) in a thermo-bath preset to 75-100deg.C; (5) a step of collecting gelatin sol by filtering the extracted effluent in step (4); (6) a step of gelating the collected gelatin sol in step (5) by keeping in a refrigerator at 3-5deg.C for 4-8 hours; and (7) a step of freezing and drying the gelatin gel from step (6) at -60 to -80deg.C. [Reference numerals] (AA) Trimmed chicken skin (size of 3x3 cm after removing fats and connective tissues); (BB) Swelling after soaking (pH 1-13, room temperature, 24 hours); (CC) Neutralization by using running water (pH 3-7, 48 hours); (DD) Discharge hot water after packing (75-100°C, 1 hour); (EE) Filtration (Nylon filter); (FF) Gelation (4±1°C, 6h); (GG) Powderization after freeze-drying

Description

Extraction method of chicken by-product collagen {EXTRACTION METHOD OF COLLAGEN FROM CHICKEN BY-PRODUCT}

The present invention relates to a method for extracting useful collagen from a low-utility shell of chicken by-products, and more particularly, by swelling the chicken shell in acid and alkali to maximize the extraction yield and induced in a pH range that can be edible through neutralization process. Hot water is extracted again to remove swelling and other components. After the lyophilization relates to a method for producing a powdery collagen that is easy to utilize.

Recently, the recognition of consumers seeking a healthy life is causing a lot of social change. In various industries related to health, research and development and commercialization are being conducted to meet the needs of consumers. In particular, the food industry, which is closely related to the consumption trend, is more sensitive. Consumers pursuing health are also changing their consumption of meat, and in recent years, the trend is to prefer poultry and low-fat meat products with low fat content. Moreover, in developed countries, the level of health-consciousness is becoming more common, and the white meat of poultry is greatly preferred to the red meat such as cattle and pigs. Reflecting this level of consciousness, chicken consumption continues to increase. Chicken meat contains all of the high quality essential amino acids necessary for human metabolism, making it a better source of protein than other livestock foods. In addition, the fat content, which is the most problematic in the consumption of meat, contains polyunsaturated fatty acids such as linoleic acid, linolenic acid, and EPA (eicosa pentaenoic acid) and DHA (docosa hexaenoic acid), which are necessary for the human body. It can be said to be excellent. The major fatty acids in chicken are palmitic acid, plamitoeic acid, stearic acid, oleic acid and linoleic acid (Cortinas et al., 2004, Fatty acid content in chicken thigh and breast as affected by dietary polyunsaturation level, Poult. Sci., 83, 1155-1164).

As mentioned above, the consumption of poultry is steadily increasing every year, and in the form of consumption, it is changing from the type of whole chicken mainly to chicken to the consumption of specific parts such as breast, leg, wing (wing). . In order to obtain the part meat, the dismantling of the chicken after the slaughter is essential, and by-products such as shells, intestines, and feet are generated in the dismantled chicken. Most of the by-products are used as animal feed or some edible by-products, but their economic value is less than that of muscles. Therefore, in order to effectively utilize animal resources and create added value for the poultry industry, it is required to find efficient ways to use chicken by-products.

Collagen is a fibrous structural protein derived from animal materials and is abundant in animal skin, bones, cartilage, tendons, ligaments, blood vessels and other connective tissues. Collagen exists in the form of a triple helix with tropocollagen as the basic unit, and the composition of constituent amino acids is somewhat different depending on the form, but it is generally known that glycine, proline and hydroxyproline are mainly (Kim et al. , 2010, Extraction and bleaching of acid- and pepsin-soluble collagens from shark skin and muscle, Korean J. Food Preserv., 17, 91-99). Recently, as the effects of collagen's anti-skin aging, arthritis prevention, antihypertensive and anticancer activity have been proved, it is being used in various fields including medicines and cosmetics. Moreover, collagen has functional properties such as gel formation, water retention and emulsification stability, so that its value as a functional food material is recognized as important (Gomez-Guillen et al., 2011, Functional and bioactive properties of collagen and gelatin from alternative sources: A review, Food Hydrocolloids, 25, 1813-1827).

Currently produced collagen is mainly obtained from terrestrial skin such as cows or pigs or from scales of various fishes (Kim et al., 2010, Extraction and bleaching of acid- and pepsin-soluble collagens from shark skin and muscle, Korean J) Food Preserv., 17, 91-99; Shon and Eun, 2010, Korean J. Food Preserv., 17, 435-443). However, according to a report by Kim et al. (2010, Extraction and bleaching of acid- and pepsin-soluble collagens from shark skin and muscle, Korean J. Food Preserv., 17, 91-99), the cause of collagen extracted from cows or pigs is unknown. It is necessary to establish new collagen extraction materials and appropriate extraction methods, such as mad cow disease or foot-and-mouth disease transmission. Chicken by-products are attracting attention as a collagen extraction material for the improvement of these problems and the effective utilization of animal resources. In particular, research on the establishment and optimization of various extraction conditions based on chicken feet is actively conducted. There is a need for a study on chicken skin as another by-product of collagen for the effective utilization and added value of poultry resources. In general, chicken skin contains about 3% of collagen, and about 75% of type I collagen and 15% of type III collagen are the main forms (Bonifer and Froning, 1996, Chicken skin composition as affected by aqueous washings.J). Food Sci., 61, 895-898; Cliche et al., 2003, Extraction and characterization of collagen with or without telopeptides from chicken skin.Poult.Sci., 82, 503-509). However, research on the method of extracting collagen from poultry skin is inadequate compared to chicken feet or other animal breeds, and it is essential to establish an optimized extraction process to obtain high quality collagen from chicken skin containing more than 50% fat.

Patent for the method of extracting collagen from animal material is Korean Patent Registration No. 0487994 by the method of manufacturing fish gelatin, after the alkali treatment of the dried fish scales and neutralized by acid treatment again, the extracted gelatin solution is filtered and concentrated to dry and gelatin It is characterized in that the manufacturing, utilizing the fish scales that are waste resources. In addition, the Korean patent registration No. 0841206 method for producing collagen food using pork skin is characterized in that the gelatin is extracted from the pork skin at high temperature and high pressure, it is possible to prepare a food that is effective in diet using pork skin and collagen. In particular, the patent for the extraction of useful collagen by using chicken by-products include a dressing using gelatin and a method of manufacturing the same by using a Korean dressing and the method of manufacturing the same. It is characterized by the powdering of gelatin. In the method for preparing liquid collagen or powdered collagen from gelatin at room temperature, the collagen powder is prepared by heating the solid gelatin and treating the proteolytic enzyme to prepare liquid collagen at room temperature, and then drying the collagen powder. It is characterized by manufacturing. However, the proposed collagen production method basically does not establish an optimization process for obtaining useful collagen from chicken skin, and includes an advantage of maximizing extraction yield by utilizing the properties of collagen swelled in acid and alkali. Not. As a result, the extraction yield is low and the heat treatment is not performed.

Therefore, the present invention relates to a method for extracting useful collagen from the lowest utilization of chicken by-products and a method for producing collagen powder. More specifically, the swelling of the chicken skin in acid and alkali to maximize the extraction yield and to remove the swelling and other components by hot water extraction again the swelling product derived from the pH range that can be decorated through the neutralization process. After the lyophilization is also a method of producing a powdery collagen that is easy to utilize is also a feature of the present invention. In addition, the present invention, which can produce useful collagen using chicken shell, which is not currently available, is expected to greatly contribute to the improvement of national health in providing added value and using high quality food materials utilizing waste resources. In addition, it is more meaningful to provide a functional material that can produce a better quality food for the entire food industry utilizing this.

An object of the present invention, by providing a method for extracting the useful collagen from the shell of the lowest utilization of chicken by-products, not only can produce useful collagen using the chicken shell which is not currently available, but also create added value utilizing waste resources and It is to provide a functional material capable of producing high quality food.

In order to achieve the above object, the present invention (1) washing and then cutting the chicken skin; and (2) chicken skin sliced by the step (1) 10 times the weight of the chicken skin (w / v) immersed in an immersion solution of pH 1 to 13 corresponding to, swelling at room temperature; and (3) neutralizing the swelled chicken skin in running water with water to neutralize pH 5 to 7 by swelling at (2) Step; and (4) extracting hot water by soaking the chicken skin neutralized by the step (3) in a constant temperature water bath set to 75 to 100 ℃; and (5) filtering the eluate extracted by the step (4) Collecting the gelatin sol (6); and (6) gelling the gelatin sol collected by the step (5) in a refrigerator at 3 to 5 ° C. for 4 to 8 hours to gel the gel. step; And (7) lyophilizing the gelatine gel (gel) according to step (6) at -60 to -80 ° C.

The immersion solution is characterized by forming a range of pH 1 to 13 using hydrochloric acid (HCl) and sodium hydroxide (NaOH).

Swelling for 24 to 48 hours in the step (2).

In step (3), it is characterized in that the washing in water for 24 to 48 hours.

In step (4) it is characterized in that hot water extraction for 60 to 90 minutes.

According to the present invention as described above, the swelling of the chicken skin in acid and alkali to maximize the extraction yield and the hot water extraction of swelling products derived from the pH range that can be edible through the neutralization process to remove the scum and other ingredients By providing collagen extraction method, it is possible not only to produce useful collagen using chicken shell which is rarely utilized, but also to provide functional materials that can create added value and produce high quality food using waste resources. Has the effect of providing.

1 is a process for extracting collagen and collagen powder from chicken skin.
Figure 2 is a graph showing the weight increase rate of chicken skin according to the pH and swelling time of the swelling solution.
Figure 3 shows the extraction yield of swelled chicken skin at pH 2, 7, 13 depending on the extraction temperature (75 ℃, 100 ℃) ( ^AD significant difference in different strings ( p <0.05)).
Figure 4 is a comparison of the low kinetics of chicken skin collagen protein according to the extraction conditions (SM, standard protein marker; pH 2 and pH 13, swelling pH; 75 ° C and 100 ° C, hot water extraction temperature).

Hereinafter, the present invention will be described in detail.

(1) washing and then slicing the chicken skin; and (2) pH 1 to 13 corresponding to 10 times the weight of the chicken skin (w / v) of the chicken skin chopped by the step (1). Immersing in an immersion solution, and swelling at room temperature; and (3) neutralizing the swollen chicken skin by running water in flowing water to neutralize pH 5 to 7; and (4) (3) Extracting hot water by incubating the chicken skin neutralized by the step in a constant temperature water bath set at 75 to 100 ° C .; and (5) filtering the eluate extracted by step (4) to collect gelatin sol. And (6) gelling the gelatine sol collected by the step (5) by storing in a refrigerator at 3 to 5 ° C. for 4 to 8 hours; And (7) lyophilizing the gelatine gel (gel) according to step (6) at -60 to -80 ° C.

The swelling time may be different depending on the immersion solution in step (2), but it is preferable to swell for 24 to 48 hours, and it is preferable to rinse with running water for 24 to 48 hours in step (3). The neutralization process aims to reach a range between pH 5 and 7, which is essential for the utilization of collagen powder. In the case of acid swelling, if the water washing by running water is less than 24 hours, the required pH range is not reached. There is a problem that can not be, while washing with excessive time, there is a problem that economic loss due to unnecessary neutralization process. On the other hand, in the case of alkaline swelling, at least 48 hours must be performed to reach the above pH range.

In addition, it is preferable to extract hot water for 60 to 90 minutes in the step (4).

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are merely illustrative of the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

Example 1 Extraction of Chicken Skin Collagen and Preparation of Collagen Powder

Chicken skin was supplied from a commercial butcher and washed three times with distilled water to remove excess fat and connective tissue.

Trimmed chicken skins were prepared in pieces of uniform size of 3 × 3 cm to facilitate extraction after one wash with distilled water. Extracting collagen from chicken skin is as shown in Figure 1, the detailed method is as follows.

After measuring the weight of the washed and trimmed chicken skin, a dipping solution of pH 1 to 13 was prepared and immersed at 10 times (v / w) relative to the weight of the chicken skin and swelled for 24 hours at room temperature. At this time, the pH of the prepared immersion solution was formed in the pH range of 1-13 using HCl and NaOH, respectively, and in the case of acid immersion, lactic acid, acetic acid, citric acid, etc., it was confirmed that swelling of chicken skin is possible. The water was then washed with running water for about 48 hours to neutralize the swelling to pH 5-7. The time required for neutralization by washing with water required at least 24 hours for acid swelling and at least 48 hours for alkaline swelling. Neutralized chicken skin swelling was put in polyethylene wrapping paper, respectively, soaked in a constant temperature water bath set to 75 ℃ and 100 ℃, respectively, was performed for 1 hour hot water extraction. After hot water extraction, the eluate in the wrapper was collected by cheesecloth (nylon filter). The collected gelatin sol was stored in a refrigerator at 4 ± 1 ° C. for 6 hours for gelation, and then freed in a deep-freezer at −70 ± 1 ° C. after removing the fatty layer of the upper layer. The frozen samples were lyophilized to a final moisture content of less than 3% using a freeze-dryer (PVTFD20R, Ilshinlab, Yangju, Korea) under conditions of -40 ° C and 80 × 10 -3 torr.

Experimental Example 1. Measurement of weight increase rate when swollen chicken skin

In order to determine the degree of swelling, the weight increase rate of chicken feet and chicken skin according to the pH of the immersion solution was measured after neutralization for 48 hours after swelling for 6, 12 and 24 hours. The weight increase rate was calculated by calculating the weight after swelling as a percentage of the weight before swelling. As a result of measuring the degree of swelling using the weight increase rate, a region (pH 2, 7 and 13) showing significant differences among the three sections was set.

As a result, as shown in Figure 2, the weight increase rate of the swelling of the chicken skin showed the highest weight increase rate in the range of pH 1-2 and pH 12-13, and showed a high weight increase rate through the swelling time and washing process . The highest weight gain was observed in water swelling solution at pH 2 and rinsing for 48 hours after 24 hours swelling.

Experimental Example 2. Measurement of gel extraction yield of chicken skin swelling

Each sample was weighed for hot water extraction and vacuum packed in polyethylene packaging. Then, hot water extraction was performed for 1 hour in a constant temperature water bath set at 75 and 100 ° C. The extracted eluate was filtered using a nylon filter and then stored for 6 hours in a 4 ℃ refrigerator for gelation. After removing the fat layer in the upper layer of the gelled sample was weighed and the gel extraction yield was calculated by calculating the weight of the gelled sample as a percentage of the weight of the sample before hot water extraction.

As a result, as shown in Figure 3, the gel extraction yield of chicken skin swelling showed the highest value in 100 ℃ hot water extraction after swelling at pH 2 and 100 ℃ hot water extraction after swelling at pH 13.

Experimental Example 3. Evaluation of Physicochemical Properties

After the sample used for measuring the gel extraction yield in Experimental Example 2 was frozen in an ultra-low temperature refrigerator of -70 ± 1 ° C., collagen powder was prepared using the above-described manufacturing process of collagen powder. Since the final yield was calculated by calculating the weight of the collagen powder to the weight of the raw material before swelling as a percentage. After dissolving the extracted collagen in a 7% aqueous solution, an experiment for comparing the physicochemical properties of the collagen gel was performed as follows.

(1) Determination of Crude Protein Content

Crude protein content was determined by the Micro kjeldahl method according to the AOAC method (1995, Official methods of analysis of AOAC. 16th ed. Association of analytical chemists, Washington, DC).

As a result, as shown in Table 1, the final yield and the protein concentration of the powdered collagen was evaluated as the best economically showing the highest value of the hot water extraction conditions at 100 ℃ after swelling at pH 13.

(2) pH and chromaticity measurement

5 g of the sample was collected, mixed with 20 mL of distilled water, homogenized at 8,000 rpm using a homogenizer (Nissei, Model AM-7, Japan), and measured using a glass electrode pH meter (340, Mettler toledo, Switzerland). For chromaticity measurement, L * -value representing lightness, a * -value representing redness and yellowness (color value) using colorimeter (Chromameter, CR-210, Minolta, Japan) b * -values indicating yellowness) were measured three times each. The standard color used was a calibration plate with L * -value of 97.83, a * -value of -0.43, and b * -value of +1.98.

As a result, as shown in Table 2, the pH of the 7% collagen gel showed a high pH in the treatment treatment extracted under alkaline conditions (pH 13), the whiteness and yellowness of the acid swelling, the redness of the alkali swelling significantly significantly High numbers were shown.

(3) Melting point and gel strength measurement

In order to measure the melting point, the temperature was increased by using a melting point apparatus (Melting point apparatus analyzer, ATM-01, AS ONE, Japan), and the temperature at which about half of the sample was dissolved was measured as the melting point. In order to measure the gel strength, the samples were analyzed for gel strength using a Texture Analyzer (TA-XT2i, Stable Micro System, England). At this time, the maximum value was used as the gel strength of each sample at a penetration rate of 2.0 mm / s using a 2 cm probe.

As a result, as shown in Table 3, the melting point of the acid swelling treatment showed a lower melting point than the alkali swelling, and showed a low value as the extraction temperature increases regardless of the swelling pH. Gel strength also showed a similar trend, showing the best gel strength under 75 ℃ hot water extraction conditions after alkali swelling. Lim et al. (2002, Optimizing extraction conditions for chicken feet gelatin.Korean J. Food Sci.Technol . 34, 824-829) reported similar results with the decrease of hardness with increasing extraction temperature and time. This phenomenon is because the gel formation ability of gelatin decreases with increasing extraction temperature and time.

(4) Confirmation of molecular weight of extracted collagen

The molecular weight of collagen extracted under each condition was determined using the method of Laemmli (1970, Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature, 227, 680-685). Molecular weight markers include myosin (200 kDa), β-galatosidase (116.25 kDa), phosphorylase b (97.4 kDa), serum albumin (66.2 kDa) and ovalbumin (45 kDa) from BIO-RAD (Bio-Rad Laboratories, CA, USA) ), carbonic anhydrase (31 kDa), typsin inhibitor (21.5 kDa), lysozyme (14.4 kDa), and aprotinin (6.5 kDa) were used as standard reagents. Collagen samples were homogenized using 10 times (v / w) extraction buffer (40 mM Tris, 10 mM EDTA, 10 mM 2-mercaptoethanol, 0.2% Triton X-100, pH 7.5, 4 ° C) to increase purity. It was. The homogenate was centrifuged at 10,000 g for 10 min at 4 ° C, then the supernatant and sample buffer (3.8 mL of secondary distilled water, 1.0 mL of 0.5 M Tris-HCl, pH 6.8), 8.0 mL of glycerol, 10% (w / v) SDS 1.6 mL, 2-mercaptoethanol 0.4 mL, 1% (w / w) bromophenol blue 0.4 mL) were mixed 1: 1, and reacted for 5 minutes in a constant temperature water bath at 100 ° C. 10 μL of the mixed solution was injected into the well of 10% SDS-polyacrylamide gel, followed by electrophoresis with electrophoretic buffer solution (0.025 M Tris-HCl, 0.192 M glycine, 0.1% SDS, pH 8.3), followed by gel staining solution (0.25% Coomassie). brilliant blue). Thereafter, decolorization with ethanol: acetic acid: water = 25: 8: 65 confirmed the molecular weight pattern of the collagen protein.

As a result, as shown in Figure 4, the main collagen constituting the chicken skin as a result of the electrophoresis is 200 kDa molecular weight in the form of α1 and α2 chain and dimer derived from tpye-I collagen present between the molecular weight 120 kDa and 130 kDa It is determined by the degree of β chain. Collagen extracted from alkaline swelling showed a distinct low molecular protein pattern compared to collagen extracted under acid swelling conditions. This is considered to be related to the result of high extraction yield and protein concentration when extracted under alkaline conditions.

In the meantime, the results of this experiment were statistically processed through GLM (General Linear Model) procedure of SAS program (1999, SAS / STAT Software.Release 8.1, SAS Institute Inc., Cary, NC, USA). The mean comparison was done by Duncan's multiple test ( p <0.05).

Having described specific portions of the present invention in detail, it will be apparent to those skilled in the art that this specific description is only a preferred embodiment and that the scope of the present invention is not limited thereby. It will be obvious. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (5)

(1) washing and then rinsing the chicken skin;
(2) immersing the chicken skin chopped by the step (1) in a dipping solution of pH 1 to 13 corresponding to 10 times (w / v) of the weight of the chicken shell, swelling at room temperature;
(3) washing the swollen chicken skin by step (2) in water and neutralizing it to pH 5-7;
(4) extracting hot water by soaking the chicken skin neutralized by the step (3) in a constant temperature water bath set at 75 to 100 ° C;
(5) collecting the gelatin sol by filtering the eluate extracted in step (4);
(6) gelling the gelatine sol collected by step (5) for 4 to 8 hours in a refrigerator at 3 to 5 ° C .; And
(7) lyophilizing the gelatine gel (gel) according to the step (6) at -60 to -80 ℃; extraction method of chicken by-product collagen comprising a.
The method of claim 1,
The immersion solution is an extraction method of chicken by-product collagen, characterized in that to form a pH range of 1 to 13 using hydrochloric acid (HCl) and sodium hydroxide (NaOH).
The method of claim 1,
Chicken by-product collagen extraction method characterized in that the swelling for 24 to 48 hours in the step (2).
The method of claim 1,
Chicken by-product collagen extraction method characterized in that the washing in water (24) for 24 to 48 hours in the step (3).
The method of claim 1,
Chicken by-product collagen extraction method characterized in that the hot water extraction for 60 to 90 minutes in the step (4).

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