• Journal of Biosystems Engineering
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• v.36 no.4
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• pp.252-256
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• 2011

Consumption of chicken feet has been increasing recently, thus it was necessary to produce good quality of bone less chicken feet. In the process of bone removal during chicken feet production, feeding, conveying, cutting and bone removing process takes about 90% of overall labor. Therefore, the development of a chicken feet-bone remover was necessary to reduce the cost of labor. There has been few research on the chicken feet bone removers so far in Korea as well as worldwide. So the main objective of this study was to develop a chicken feet-bone remover which is suitable for domestic circumstances. The average length of chicken feet was 113.3 mm with maximum and minimum lengths of 135.8 mm and 92.2 mm, and the average diameter of chicken leg was 12.5 mm, average width of the toe was 56.2 mm and the average weight of chicken feet was 26.4 g with maximum and minimum weight of 39.3 g and 16.9 g, respectively. Also, the average moisture content was 64.7% (w.b). The average cutting force of little toes was 15.6 N for the size ranges of less than 3.5 mm, 22.5 N, 3.5~6.0 mm and 30.3 N for larger than 6.0 mm in diameter, respectively.

• Journal of Biosystems Engineering
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• v.36 no.4
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• pp.257-266
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• 2011

Consumption of chicken feet has been increasing recently, thus it was necessary to produce good quality of bone less chicken feet. In the process of bone removal during chicken feet production, feeding, conveying, cutting and bone removing process takes about 90% of overall labor. Therefore, the development of a chicken feet-bone remover was necessary to reduce the cost of labor. The main objective of this study was to make and test of chicken feet-bone remover. The optimum vibration level of feeder wes 8, and the optimum conveyor speed was 3.6 m/min. The feeding speed of feeder were 0.18 m/s, 0.13 m/s and 0.19 m/s for the weight ranges of chicken feet of >20 g, 20~30 g and 30 g< respectively. The sensing success rates of chicken feet were 100%, 98% and 96% for the conveyor speeds of 3.0, 3.6 and 4.2 m/min respectively. The slips of chicken feet were 1.0 mm, 1.9 mm and 3.2 mm for conveyor speed of 0.8, 1.9 and 4.2 m/min respectively, with the average moisture content of 65% (w.b). The incision accuracy rates of the chicken leg were 46%, 95%, 97% for the size ranges of >15 mm, 15~18 mm, 18 mm< respectively with the velocity of cutting blade 3.9 m/s. The removal rates of the chicken feet bone were 98%, 96%, 88% for toes diameter >10 mm, 10~15 mm, 15 mm> respectively with the velocity of cutting blade 11.8 m/s.

• Food Science of Animal Resources
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• v.32 no.6
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• pp.732-739
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• 2012

The aim of this study was to investigate the effect of chicken feet gelatin and wheat fiber levels on the quality characteristics properties of semi-dried chicken jerky. The obtained chicken feet gelatin swollen with hydrochloric solution (0.1 N HCl, pH $1.31{\pm}0.02$) was dehydrated via freeze-drying. Six formulations of chicken jerky that were prepared, based on the ratio of chicken meat, chicken feet gelatin and wheat fiber, were 100:0:0, 98:0:2, 99:1:0, 97:1:2, 98:2:0 and 96:2:2, respectively. The moisture content of semi-dried chicken jerky containing 2% wheat fiber was higher than that of jerky without the added fiber (p<0.05); moreover, an increase in the content of chicken feet gelatin also increased the moisture content. The drying yield of the samples increased with an increase in chicken feet gelatin. In addition, the drying yield of samples containing 2% wheat fiber was higher (p<0.05) than those without the added wheat fiber. However, the shear force of the samples significantly decreased with the increase in chicken feet gelatin content. Further, the shear force of the samples containing 2% wheat fiber was higher (p<0.05) than those without the added wheat fiber. No significant differences, except for color, were observed in the sensory analysis among the treatments.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1638-1644
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• 2001

The objective of this research was to evaluate alternative treatments for the best extraction condition for collagen from chicken feet. Various properties such as chemical composition, amino acid, pH, swelling percentage, yield and pure collagen, collagen loss, color (Hunter L, a and b) and electrophoresis of collagen from chicken feet treated by 5% acids (acetic acid, citric acid. hydrochloric acid and lactic acid) and soaking times (12, 24, 36 and 48 h) were evaluated. The crude protein, fat, ash and moisture contents of chicken feet was 17.42, 12.04, 5.98 and 62.05%, respectively. Amino acid composition of collagen from chicken feet indicated that the protein of collagen was markedly hydrolized by the hydrochloric acid treatment. The result of electrophoresis also supported this phenomenon. Both the swelling percentage of lactic acid and citric acid treatments were significantly higher than that of acetic acid and HC1 treatment. The pH of the acid treatments ranged from 2.43-3.62. According to the result of yield, pure collagen and loss of collagen, the best condition of extracting collagen from chicken feet was soaked in 5% lactic acid for 36 h. However, a brighter yellow color of collagen from all treatments was observed with a longer soaking time.

• Korean Journal of Poultry Science
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• v.42 no.4
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• pp.327-333
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• 2015

This study aimed to investigate the effect of chicken feet gelatin on physicochemical and sensory properties of restructured chicken jerky. Chicken feet swollen with hydrochloric solution (0.1 N HCl) were neutralized with flowing tap water, and gelatin was extracted with hot water at $75^{\circ}C$. The obtained chicken feet gelatin was dehydrated via freeze-drying. Restructured chicken jerky samples were prepared by adding the following amount of chicken feet gelatin 0%, 1%, 2%, 3%. The moisture and protein content of samples increased with an increased chicken feet gelatin. In addition, the drying yield of the samples increased with an increase in chicken feet gelatin. However, the shear force of samples significantly decreased with the increasing chicken feet gelatin content and the shear force of the control samples was the highest (P<0.05). No significant differences, except for color, were observed in the sensory analysis among the treatments. Therefore, usages of chicken feet gelatin can provide improved quality characteristics of restructured chicken jerky.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.425-430
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• 2002

Physicochemical properties of chicken feet gelatin produced under acidic and alkaline conditions were investigated. Amino acid content of chicken feet gelatin was different from that of commercial gelatin due to the differences in raw materials and production process. Yield and hardness of chicken feet gelatin reached maximum at 24 h under acidic condition and at 1 week under alkaline condition, respectively. As the soaking period increased, viscosity and clarity increased under acidic condition, while decreased under alkaline condition. Color of the acid-treated chicken feet gelatin gel was more desirable than that of the alkali-treated on based upon L, a, b values. From gel permeation chromatography of the chicken feet gelatin, 12 subunits were detected. The amount of high molecular weight subunits, which is related to viscosity and hardness, of the alkali-treated chicken feet gelatin was twice as much as that of the acid-treated one.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.656-661
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• 2023

The aims of this study were to optimize the preparation of low-molecular-weight collagen using a proteolytic enzyme (alcalase) derived from the feet of Korean native chickens, and to characterize the process of collagen hydrolysis. Foreign bodies from chicken feet were removed using ultrasonication at 28 kHz with 1.36 kW for more than 25 min. The hydrolytic pattern and molecular weight distribution of enzyme-treated collagen from chicken feet were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-performance liquid chromatography, respectively. Ideally, chicken feet should be treated at 100℃ for 8 h to obtain a high collagen content using hot water extraction. The collagen content of the chicken foot extract was 13.9 g/100 g, and the proportion of low-molecular-weight collagen increased with increasing proteolytic enzyme concentration and reaction time. When treated with 1% alcalase, the average molecular weight of collagen decreased rapidly to 4,929 Da within 5 h and thereafter decreased at a slower rate, reaching 4,916 Da after 7 h. Size exclusion chromatography revealed that low-molecular-weight collagen peptides of approximately 1,000-5,000 Da were obtained after hydrolysis with 1% alcalase for 1 h.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.307-310
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• 2003

This study investigated the nutritional components of jokpyun. Jokpyuns made with cow feet and two kinds of jokpyun were added 30% of chicken and dry codfish to 70% of cow feet, respectively. There was no difference in moisture contents among three jokpyuns. Crude protein content was higher in jokpyun made with cow feet than in those added chicken and dry codfish. Contents of lipid and ash in jokpyuns added chicken and dry codfish were higher than those of jokpyun made with cow feet. The ratio of unsaturated fatty acid in jokpyun added dry codfish was the highest, but, that of linoleic acid was the highest in jokpyun added chicken than the others. Amino acid contents were higher in the order of glycine, proline, alanine, glutamic acid and composition of essential amino acid was similar to soupstock made with beef shank and leg bone. The contents of glycine and alanine in jokpyun added codfish and that of glutamic acid in jokpyun made with cow feet were the highest. Especially, among essential amino acids lysine was the highest in all jokpyuns. Methionine and valine were higher jokpyun added chicken and jokpyun made with cow feet than the others. Calcium and phosphorous were higher in jokpyun added chicken than in others. From these results, jokpyun, especially added chicken, was seemed to be more nutritious than other jokpyuns.

• Korean Journal of Poultry Science
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• v.46 no.3
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• pp.137-154
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• 2019

This study was conducted to develop and compare Samgyetang broth from extract of pre-treated chicken feet. Chicken feet were subjected to non-heating (control), heating at $70^{\circ}C$ for 12 h in a hot air dryer, and heating at $180^{\circ}C$ for 1 h in an oven. The heat-treated chicken feet were extracted at $121^{\circ}C$ for 1 h and 2 h, respectively. The extract was placed in a pouch with whole chicken carcass ($470{\pm}10g$). The sealed Samgyetang retort was made according to the industrial method. The pH of the extract from preheated chicken feet was lower than that extracted from fresh chicken feet. The Thiobarbituric Acid Reactive Substances (TBARS) value of the preheated chicken feet extract was significantly lower (P<0.05) than that of fresh chicken feet extract, but there were no significant differences among the broths. As the extraction time increased, the pH and TBARS value decreased in the extract (P<0.05) but increased in the broth (P<0.05). According to the sensory evaluation test, the extract from 1 h hot air heating and drying was significantly better in appearance, aroma, and overall preference than the other treatments (P<0.05). The GC-MS results showed that benzaldehyde and benzothiazole, which are widely known to give meat and nuts flavor, were detected in those treatments (P<0.05). The Samgyetang broths prepared from 1 h hot air heating and drying extract were significantly higher in the overall acceptability according to the sensory test (P<0.05). In summary, the quality of retort Samgyetang broth can be improved by adding chicken feet extract which is subjected to heating and drying for 1 h.

• Food Science of Animal Resources
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• v.35 no.1
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• pp.101-107
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• 2015

The aim of this study was to investigate the effects of various marination processes on the quality characteristics of chicken breast prepared with chicken feet gelatin and wheat fiber. The chicken feet gelatin was swollen with hydrochloric solution (0.1 N HCl, pH $1.31{\pm}0.02$) and dehydrated by freeze-drying. The composition (w/w) of the marinade was water (10%), soy sauce (12%), phosphate (0.3%), wheat fiber (1.5%), and chicken feet gelatin (1.5%). Three samples of chicken breast were manufactured with Tumbler (only tumbler), Tenderizer (tenderizer and tumbler), and Injector (injector and tumbler). The water content of the Injector sample was significantly higher than those of the Tumbler and Tenderizer samples (p<0.05). During heating, the lightness of all chicken breasts increased and the redness decreased. The tumbling and cooking yield of the Injector sample were significantly higher than those of the Tumbler and Tenderizer samples (p<0.05). The shear force of the Tenderizer sample was significantly lower than that of the Tumbler and Injector samples (p<0.05). No significant differences, except for color, were observed in the sensory analysis of the samples. Thus, the proper selection of mechanical processing is important to improve the quality characteristics of marinated chicken breast, considering the types of final products.