Influence of composition on mechanical properties of strawberry gels. Compression test and texture profile analysis

Fruit gels were prepared containing four levels (20, 40, 60 and 80%) of str awberry pulp, four levels (0.5, 0.7, 0.9 and 1.1%) of hydrocolloids (kappa- carrageenan plus locust bean gum, 1:1) and two levels (0, 10%) of sucrose. Their mechanical properties were analyzed by compression (failure stress an d failure strain) and by texture profile analysis, TPA (hardness, cohesiven ess, springiness, adhesiveness, and chewiness). Addition of hydrocolloids p roduced expected increases in both stress and strain at failure. Sucrose in creased failure stress but did not alter strain values. Increasing the pulp content from 20 to 80% resulted in a slight increase in stress and clearly lowered strain at failure. Fruit pulp addition produced increasing hardnes s, chewiness and adhesiveness values, and lowered cohesiveness and springin ess. MANOVA analysis of TPA data showed that while gel hardness was mainly governed by hydrocolloid concentration, both cohesiveness and adhesiveness were clearly dependent on the proportion of fruit pulp.