Enzymatic assisted extraction of gelatin from Beloga (Huso huso) fish skin in response surface method (RSM)

Document Type : Research Paper

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Abstract

Fish gelatin, by benefiting the lower melting point, quicker mouth melting and presenting elastic characteristics is considered as the most proper substitute for mammalians gelatin and as a Halal food item. The aim of this study was to evaluate the effects of temperature at three levels of 30, 40 and 50 ºC, enzyme at 0.055%, 0.01% and 0.1% (w/w) levels and pH at 2, 3 and 4 levels on the quality of extracted gelatin from Huso huso fish skin. Accordingly, the gel strength in form of breaking force and distance, yield and color (L*a*b*) and whiteness of resultant gelatin were determined.  According to the results, the highest gelatin yields as 21.65% was related to the enzymatic assisted method at 50 ºC, 0.01% enzyme at pH=2, whereas it was obtained as 10% at the chemical extraction method. Based on the results, despite from temperature, by increasing of pH and enzyme percentage, the firmness of gelatin was increased (p<0.05). The highest firmness was recorded at 30 ºC, 0.1% enzyme at pH=4. The color data revealed that lightness (L*), redness (a*) and whiteness of enzymatic extracted gelatin powder was higher that the chemical extracted one (p<0.05). The highest lightness was observed at 40 ºC, 0.055% enzyme at pH=3. In conclusion, by application of 30 ºC and 0.1% enzyme at pH=4 the highest gelatin with the highest firmness is achievable, while using 50 ºC and 0.01% enzyme at pH=2 could results the gelatin yield.

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