Acid-Extraction of Gelatin

ABSTRACT A study on acid-extraction of gelatin from dried shark\u27s skin has been carried out. The objective of this study was to experiment with the variation in the extraction methods, by means of obtaining simple procedure to extract gelatin from dried shark skin, and to analyze the characteristics of gelatin produced. This variation was attributed to the use of different pretreatment solvents (acetic and citric acids), soaking time (24 and 36 hours) and extraction temperatures (60°C and 80°C). Comparison of the methods were based on the products\u27 properties, i.e., yield ratio, chemical, physicochemical and sensory characteristics. The result showed that the combination of 24-hour acetic acid pretreatment and 80°C extraction temperature was the best among the observed methods. This method resulted in a yield ratio of 14.1% and produced white and slightly fishy wet gelatin, which turned into clear and clean sheets when dried. These sheets had a pH value of 5.88, salt content of 0.1%, moisture of 7.23%, ash of 1.74%, viscosity of 8 centipoise, gel strength of 455.06 gram/cm2 and setting point of 11°C. Deodorization still is necessary for these products to meet a food grade standard