Microsoft Word - Acta_TA_9_4_2010

Background. Marination is a good method to enhance attractiveness of chicken wings, which are considered by consumers as least attractive. Sensory value of marinated wings is dependent largely on the flavour of skin, because they contain proportionally more skin than other carcass elements. Moreover, skin constitutes a natural barrier, which may facilitate or hinder the penetration of marinade components, depending on the conformation state of proteins it is composed of primarily collagen. The aim of the study was to investigate the effect of specific marinades on thermal stability of collagen – the main component of skin proteins using differential scanning calorimetry (DSC). Material and methods. Chicken wings were marinated using model marinades, marinades prepared according to original recipes and ready-to-use marinades used in industrial practice. Marinated skin samples were weighted (approx. 10 mg) and analyzed by DSC. Heating rate was 5°C/min, within the range from 20 to 100°C. Results. In analyses using model marinades denaturation temperature (Tmax) of collagen was reduced by approx. 3°C and enthalpy (ΔH) was lowered by approx. 40%. An even bigger reduction of collagen denaturation temperature (by approx. 7°C) and enthalpy ΔH (by approx. 48%) was found after the application of marinades prepared following original recipes (W1, W2, W3). In turn, the application of model marinades containing NaCl and organic acids (acetic or citric) resulted in stabilization of collagen, which was manifested by an increase of enthalpy (ΔH) by approx. 50% (for marinade containing 2% citric acid). Conclusions. Temperature and enthalpy of collagen denaturation was dependent on type of marinade. The extent of collagen denaturation affects nutritional and sensory value. Considering that time and temperature of intensive heat treatment are important factors in the formation process of carcinogenic compounds i.e. heterocyclic aromatic amines, it bis important to choose these marinades, which reduce the denaturation temperature and enthalpy of proteins.