Abstract
Debranched starch (DBS) is widely used for the preparation of retrograded resistant starch type 3 due to its linear molecular feature. Upon application, interactions of the DBS with food ingredients can cause rheological and textural changes in cooked foods. This study aimed to investigate the individual effects of salt, sucrose and native starch at varying concentrations on gelation and rheological behaviour of debranched cassava starch (DBCS). Adding salt (NaCl; 0.5%–2.0% w/w) delayed gel formation. Frequency sweep tests of these gels indicated an apparent elastic solid-like behaviour with or without salt. However, the gel weakened with increasing salt concentration. This result was confirmed by reduced gel hardness and gumminess. Unlike salt, adding sugar (sucrose; 5%–15% w/w) and native cassava starch (0.5%–20.0% w/w) enhanced gel formation. Gels incorporating sucrose or native starch displayed elastic solid-like behaviour and had higher stiffness than the control. However, the dependence of their elastic moduli on frequency differed. The G′ and G″ of DBCS gels with native starch fluctuated with frequency. Texture analysis confirmed that the gels incorporating sucrose or native starch had higher strength than the control. In conclusion, salt delays gelation and reduces gel strength while sucrose and native starch show the opposite effects. Further research on the effects of other food ingredients especially protein and lipid as well as mixed ingredients on DBS gel properties is needed to gain a better understanding of DBS gel behaviours in real food systems.
Keyword:
Cassava starch, debranched starch, gel, rheology, salt, sucrose
