THERMAL GELATION PROPERTIES OF 2 DIFFERENT COMPOSITION SARDINE (SARDINA-PILCHARDUS) MUSCLES WITH ADDITION OF NONMUSCLE PROTEINS AND HYDROCOLLOIDS

A Thermal Scanning Rigidity Monitor was used to study heat gelation in two sardine minces (S1 and S2) differing in compositional properties (fat content (S1=4.3%, S2=9.6%) and water content (S1=76.5%, S2=72.0%) ), protein functionality (soluble protein (S1=62.6%, S2=49.8%) and vis cosity (S1=3140 cP, S2=2323 cP)), as well as the contribution to gelat ion of a number of nonmuscle proteins (egg white, soy protein, sodium caseinate, wheat gluten) and hydrocolloids (iota-carrageenan and starc h). The batter of the mince, characterised by higher protein solubilit y and viscosity and lower fat content (S1), exhibited greater structur al stability at temperatures above 50 degrees C. The addition of gelli ng ingredients always produced an increase in maximum rigidity values, except in the case of sodium caseinate or starch-containing batters o f mince with low protein solubility and viscosity (S2), where the rigi dity is considerably inferior throughout the experimental temperature range. Of the non-muscle proteins assayed, batters contanining egg whi te presented the highest rigidity at maximum gelation peak, mainly in the low quality mince (S2). Iota-carrageenan also increased rigidity c onsiderably with respect to the controls. Addition of starch gave less rigidity than iota-carrageenan, although it helped stabilise the form ed gel at high temperatures (80 degrees C). Copyright (C) 1996 Elsevie r Science Ltd.