Biotechnological preparation of chicken skin gelatine using factorial design of experiments

Abstract

Poultry meat production steadily increases and its by-products including legs or skins may be further utilized to prepare gelatine, generally by using alkali or acid substances. Since they are toxic, different methods are desirable, e.g. applying proteolytic enzymes. Using enzymes is beneficial as they shorten processing time and reduce the required water amount. Processing conditions (the enzyme amount during the pre-treatment, first and second extraction temperature and time) of the process may influence gelatine quality and its yield. In this study, gelatines were prepared from chicken skin at different conditions in the series of combined factorial design of experiments. The significance of the influence of the conditions on the quality (gel strength, viscosity, melting and gelling point) and yield of chicken skin gelatine (CSG) was observed. The highest yield (31.5%) was obtained at the conditions of the enzyme amount of 0.8%, first extraction temperature 80 degrees C and time 30 min, second extraction temperature 90 degrees C and time 60 min. Furthermore, the highest CSG quality of gel strength (190 Bloom), viscosity (4.06 mPas), melting point (38.3 degrees C) and gelling point (20.5 degrees C) was obtained at the conditions of 0.2%/ 50 degrees C/30 min in the first extraction.