EFFECT OF BRINE CONSTITUENTS ON THE CONTENT AND PROPERTIES OF WATER IN THE PORCINE MUSCULUS LONGISSIMUS DORSI

A b s t r a c t . The capacity to bind water exerts a cruci al influence on the quality of cured products manufactured from whole muscles and subjected to thermal treatment. The experimental material comprised the lumbar and thoracic parts of the longissimus dorsi (musculus longissimus lumborum et musculus longissimus thoracis) muscle of pigs. The aim of the performed experiments was to analyse the impact of different composition of brines which con tained a specific quantity of salts of inorganic ac ids on the value of active acidity, water activity, water holding capacity and the way of water binding. It w as found that both parts of raw longissimus dorsi muscle differed with regard to the pH value, water activity and molecular dynamics of bound water. The water holding capacity as well as the mutual relationships between the quantities of free and bound waters wer e identical. The type of the applied brine exerted some influence on the level of water holding capacity. T he relative amount of free water in relation to bou nd water analysed on the basis of relaxation measurements was the highest when the mixture of sodium chloride and sodium triphosphate was applied. The mixture of chloride and sodium diphosphate reduced the relative content of free water in relation to b ound water in comparison with the application of br ine which contained only NaCl and increased it in comparison with the application of diphosphate. The pres ence of sodium chloride increased water activity, w hile the presence of phosphates decreased this para meter. The lumbar part of the examined muscle showed higher water activity. The application of the salt mixture did not change the value of water activity in comparison with NaCl alone for the lumbar part but increased water activity for the thoracic part of t he muscle. K e y w o r d s : low field NMR, water activity, water holding capacity