Gelatin had been processed from bones, heads. legs and skin which got from spent hens, the sample were cleared, cut and getting rid of oil by boiling then the removal of mineral salts by hydrochloric acid 6% for 24 hours , after that soaking in diluted base ( NaOH ) 0.2N for 18 hours and washing with water, The process of extracting was made by damp heating in an electric furnace at various temperatures 65, 75 and 85 Celeries with both time periods 10 and 20 hours. After that, the process of clarification , filtration and drying the gelatin solutions were mille red, filtrated and dried, then they grinded and filling.
It had been studied the chemical contents and yield of the product and the results referred to
1-there were high significant differences due to effectiveness of the studied factors and their interaction gelatin yield.
2- It had been seen that there were significant differences due to the effectiveness of tempera- ture, gelatin sources and extracting period on the humidity percentage. There were insignif- Incant differences due to the effectiveness of interaction between the three factors on the humi- dity percentage in the processed gelatin .
3-It had found high significant differences due to effectiveness of gelatin sources, temperature and the extractor period on the percentage of oil in the processed gelatin in addition to high significant differences due to interactions between temperature and gelatin sources on the percentage of oil , whereas, there were insignificant differences due to interaction between other.
4-There were higher significant differences due to the gelatin sources, temperatures, and the interaction between the gelatin sources and temperatures on the ash percentages of the processed gelatin.
5- Its possible to process gelatin from bones , legs , heads and skins of spent hens .The best extraction temperatures were 65 c and 75 c. In temperature 85c the yield of gelatin increase low quality.
6- The results shown high percent of protein in bones and heads gelatin, but low percent in skins and legs gelatin, and shown higher percent of fat in skin gelatin than other samples.