An innovative and effective method of separating chicken meat and bone from chicken skeleton was developed in this study. Different heating approaches to chicken skeleton were compared to optimize cooking conditions including cooking temperature and cooking time. The separation efficiency of chicken meat and bone in different conditions, including flow direction, impeller speed and the liquid level rising velocity were also studied. Experimental results demonstrated high temperature cooking and assisted mechanical stirring could improve separating rate of chicken skeleton. Liquid flow entering at tangent entrance direction of the kettle could maintain the stability of the liquid level and smoothness of the separation process. The outflow rate of chicken meat increased as the liquid level rising velocity raised, and approached to the maximum value at 0.80 cm/s. The practical application test showed that the best conditions for separation of chicken skeleton were: 45 min cooking time at 114°C; tangent flow direction; stir speed of 200 r/min; the liquid level rising velocity of water is 0.8 cm/s. Using this approach, the value of chicken bone was increased, product specialization was enhanced, and the results could be used in future high value chicken product development.
According to the national economic and social development statistics released by the National Bureau of Statistics in 2013, the annual output of Chinese poultry is 17,890,000 tons [
The current poultry processing technology and equipment in China are unable to separate chicken meat from chicken skeleton completely [
By using ultrafine grinding processing method, United States, Japan and other countries convert chicken skeleton into mud, mud meaty, bone meal, and then processed into bone paste, made of cancellous bone, bone MSG, white meat sauce and other products, but these products do not meet the Chinese diet and did not solve the high amount of the domestic chicken skeleton utilization problems completely [
Using different high pressure cooking on chicken skeleton [
Chicken skeleton was obtained from Jinan market and stored at −18˚C. It was unfreezed before use.
The processing flow is shown in
It can be seen the schematic diagram of the equipment in
The chicken bone and meat filtered out from the chicken soup were poured into the separation tank(a) after cooking; filled half tank of water to water-storage tank and then pump was started and the water was pumped into the separation tank(a). When filled
the separating tank(a) with half tank of water, the electric generator started to work and mixing propeller begin to stir which accelerates the separation of chicken meat and bone. According to buoyancy force of water, chicken meat was forced through filter in the separation tank(b) by pipeline. The chicken meat stayed on the filter, while the water flowed back into water-storage tank again, and enter the next cycle. The chicken skeleton cycle would last for 5 minutes, and the bone was discharged through discharge hole. In the end, chicken meat and chicken bone were completely separated from chicken skeleton. Pure chicken, chicken bone and soup were successfully obtained.
Chicken skeleton was cooked with pressure cooker and common stainless steel kettle separately. The time was started to calculate once boiling was achieved for stainless steel kettle. While, for pressure cooker, the time started when air valve was uplifted, the working pressure was 0.18 Mpa (combined with standard atmospheric pressure) and temperature reached 114˚C. Heating process was stopped when the scheduled time of 30 min and 45 min was reached.
The separation products of chicken meat and bone were weighted after staying for 10 min on the stainless steel filter screen of 60 mesh.
Drawing with Origin 7.5, data were analyzed using a one-way analysis of variance (ANOVA). Mean separation was done by the Duncan’s multiple range test using SPSS version 17.0. Differences were considered statistically significance at P < 0.05.
One kilogram fresh frozen chicken skeleton were prepared, and water was added at the rate of 1:1 (w:w). Cooked chicken skeleton was obtained by different cooking process at 100˚C for 45 min, and 114˚C for 30 min and 45 min respectively. In this process, transformer to control electrical power was used, and kept the contents in simmer state. Then, the cooked chicken was filtered out from the chicken soup. It was cooled to room temperature and poured into the separation vessel 1. The separating vessel 1 was filled with half tank of water, then the power of the electric machinery 2 was turned on, and paddle 3 began to stir at 200 r/min to mix the compounds. This process would last for 2 min. After that, the chicken bone and chicken meat was obtained from chicken skeleton. Residual meat from the bone was collected and weighted after staying for 10 min on the stainless steel filter screen of 60 mesh. The results are shown in
One kilogram of prepared chicken meat was weight and put into separate container.
Group | Heating temperature (˚C) | Heating time (min) | Outflow of chicken meat (%) |
---|---|---|---|
A | 100 | 45 | 46.33 ± 3.76a |
B | 114 | 30 | 81.33 ± 3.48*b |
C | 114 | 45 | 93.01 ± 0.29*c |
Values are expressed as Mean ± SE; *P < 0.05, within a column, means followed by different letters were significantly different at level of 0.05; LSD multiple comparison tests were used.
The liquid level rising velocity and impeller speed was controlled at 0.80 cm/s and 200 r/min respectively. The outflow volume of meat was recorded in five minutes under the tangential and radial direction respectively. The graph of outflow rate of chicken meat against separating time at different liquid injection direction is shown in
Three hundred gram of prepared chicken bone was weighed and put into the separate container. The liquid level rising velocity was controlled at 0.80 cm/s and the impeller speed at 200 r/min. The outflow volume of bone in five minutes under the tangential and radial direction was recorded. The outflow of bone was calculated. The result is shown in
One kilogram of prepared chicken meat was weighed and put into the separate container. The liquid level rising velocity was controlled at 0.80 cm/s and the liquid injection was set in tangential direction. The outflow volume of meat in five minutes under the impeller speed of 0 r/min and 200 r/min was recorded respectively. The plot of outflow rate of chicken meat against the separating time at different impeller speed is shown in
Group | Injection direction | Outflow rate of bone (%) |
---|---|---|
A | tangential | 0 ± 0.41 |
B | radial | 5.92 ± 1.2* |
Values are expressed as Mean ± SE; *P < 0.05.
Three hundred gram of prepared chicken bone was weighed and put into the separate container. The liquid level rising velocity was controlled at 0.80 cm/s and the impeller speed at 200 r/min. The outflow volume of bone in five minutes under the tangential and radial direction was recorded. The outflow of bone was calculated. The result is shown in
One kilogram of prepared chicken meat was weight and put into the separate container. The impeller speed was controlled at 200 r/min and the liquid was injected in tangential direction. The outflow volume of meat in five minutes under different flow velocity was recorded. The graph of outflow rate of chicken meat against flow velocity with increasing separating time is shown in
Three hundred gram of prepared chicken bone was weighted and put into separate container. The liquid was injected in tangential direction and the impeller speed was adjusted to 200 r/min. The chicken bone outflow rate was calculated under the liquid
Group | Speed (r/min) | Outflow rate of bone(%) |
---|---|---|
A | 0 | 2.77 ± 0.64* |
B | 200 | 0.633 ± 0.38 |
Values are expressed as Mean ± SE; *P < 0.05.
level rising velocity of 0.60 cm/s, 0.80 cm/s, 1.0 cm/s and 1.2 cm/s in both impeller speed. Result is shown in
From the results shown in 3.2, 3.3 and 3.4 the optimum conditions whereby the liquid was injected at tangential direction, impeller speed was set at 200 r/min and liquid level rising velocity was controlled at 0.8 cm/s not only can make most of the meat flow out of the separation vessel, but can also ensure the chicken bone remain in the separation vessel. Effective separation of chicken meat and bones can be achieved.
Two kilogram of fresh frozen chicken skeleton was weighed and put into the pressure cooker. Water was added according to the weight ratio of 1:1. After 10 minutes cooking, the cooked chicken skeleton was cooled to room temperature; the cooked chicken skeleton was poured through 40 mesh stainless steel sieve for 10 minutes to achieve a well-dispersed mixture of chicken meat and bone. The total weight of was about 1050 g. The mixture of meat and bone was put into a separate container. The liquid level rising velocity was controlled at 0.80 cm/s, the impeller speed was set at 200 r/min and the liquid was injected at tangential direction. The outflow volume of meat and bone in 5
Group | Liquid level rising velocity (cm/s) | Outflow rate of bone (%) |
---|---|---|
A | 0.60 | 0.00 ± 0.00a |
B | 0.80 | 0.633 ± 0.38a |
C | 1.0 | 3.33 ± 0.33**b |
Values are expressed as Mean ± SE; *P < 0.05, within a column, means followed by different letters were significantly different at level of 0.05; LSD multiple comparison tests were used.
minutes was recorded. The weight of the outflow of crude chicken meat and bone were also recorded. The residual bones in crude chicken meat and residual meat in crude chicken bone were selected out manually, and their weight was measured and recorded. The separation rate of chicken meat and bone is shown in
The results of cooking process in the separation are showed in
From
The effect of flow direction on the outflow rate of bone is shown in
Parameters | Total crude meat(g) | Total crude bone(g) | Total net meat (g) | Total net bone(g) | Separation rate of meat (%) | Separation rate of bone (%) |
---|---|---|---|---|---|---|
Tangential direction Impeller speed: 200 r/min Flow velocity: 0.80 cm/s | 661.43 | 315.74 | 595.25 | 299.12 | 90.35 | 95.76 |
the tangential direction, the bone is kept down at the bottom of the separating vessel with slow spinning rise fluid. There are a few bones that flow out with the fluid in the practical separation process. It was observed that the outflow of the bones is mainly cartilage. So it can be determined that the tangential flow can effectively prevent the outflow of the bone.
According to
The effect of impeller speed on the outflow rate of bone is shown in
It can be determined that an effective separating process chicken meat and bone from chicken skeleton was developed by the impeller speed at 200 r/min.
From
The result of effect of liquid level rising velocity on the outflow rate of bone is shown in
Therefore, the flow velocity must not too fast or too low, which would depress the separation effect. In conclusion, 0.8 cm/s is the optimum liquid level rising velocity.
From
Pressure cooking enhanced the separation process of chicken meat from chicken bone. Tangential flow kept the liquid flow stable and enabled chicken meat flow out of the separation kettle smoothly. Auxiliary mixing was conducive to the separation of chicken bone. The separation rate of meat and bone reached maximum value at the flow velocity of 0.80 cm/s. Based on the results above, the optimal conditions for the separation of the chicken skeleton were heating the chicken skeleton at 114˚C for 45 min, pumping the liquid injection in tangential direction, the impeller speed at 200 r/min and the liquid level rise rate at 0.8 cm/s. To sum up, through the optimization of the separation parameters and the methods, the equipment we designed can maximize its advantages, which is worthy for further research and application.
Gratitude is expressed to Administration of Ocean and Fisheries of Guangdong Province (A201600C05) and China Ministry of Agriculture (2014GB2E00037) for funding this research program. Appreciate is expressed to Shanwei Liqun Agriculture Development Co., Ltd for their technical assistance and support.
Jin, E.Q., Peng, C., Liao, S. and Wu, J.Z. (2016) Feasibility Study of Flotation Process in Separating Chicken from Chicken Skeleton. Food and Nutrition Sciences, 7, 1375-1385. http://dx.doi.org/10.4236/fns.2016.714125