Influence of heating temperature, pH and ions on recrystallization inhibition activity of kappa-carrageenan in sucrose solution

摘要

The objective of this study was to investigate the influence of heating temperature and pH on ice recrystallization inhibition (IRI) activity of kappa-carrageenan. Results showed that temperature treatment up to 30 min at 80 degrees C has no influence on IRI activity. Recrystallization experiments at different pH adjusted by hydrochloric acid and sodium hydroxide demonstrated that the presence of sodium cations and not pH is responsible for a decreasing IRI activity with increasing sodium concentration. In addition, it was shown that the IRI activity of kappa-carrageenan depends on the type of ion. We assume that these effects are related to gelation of kappa-carrageenan which reduce the IRI activity. Furthermore, IRI activity in pH 1 solution was strongly improved. Our previous assumption that IRI activity originates from an interaction with the ice crystal surface is supported by our findings that ice crystals are more angular in solutions where kappa-carrageenan exhibits IRI activity. (C) 2016 Elsevier Ltd. All rights reserved.