Main content area

Influence of ionic strength on the thermostability and flavor (allyl methyl disulfide) release profiles of calcium alginate microgels

Wang, Minqi, Doi, Takahiko, Hu, Xiaoyan, McClements, David Julian
Food hydrocolloids 2019 v.93 pp. 24-33
ambient temperature, boiling, calcium alginate, cooking, dimethyl disulfide, droplets, electrostatic interactions, encapsulation, flavor, food industry, foods, hydrocolloids, hydrophobicity, ionic strength, light scattering, lipids, microgels, microscopy, models, pharmaceutical industry, sodium chloride, storage time, thermal stability, turbidity
Calcium alginate microgels are commonly used for encapsulation of biologically active agents intended for oral ingestion in the food and pharmaceutical industries. In the current study, the impact of ionic strength on the physical stability and flavor retention profile of a model hydrophobic flavor (allyl methyl disulfide, AMDS) loaded into calcium alginate microgels was investigated during simulated cooking and long-term storage. The influence of ionic strength was examined because many foods contain relatively high levels of salt, which may weaken the electrostatic interactions holding the calcium alginate microgels together. Our results showed that addition of NaCl (0–500 mM) promoted disintegration of the alginate microgels during simulated cooking from room temperature to boiling for 30 min, as well as during storage under wet conditions at ambient temperature for 7 days. Lipid droplets leaked from the microgels after heating or storage as indicated by turbidity, light scattering, and microscopy measurements with the effects becoming more pronounced at higher NaCl levels. Interestingly, the physical instability of the microgels had little impact on flavor retention during cooking. The insights gained from this study may be useful for designing and selecting appropriate microgels for different commercial applications.