Volatile aroma and physicochemical characteristics of freeze-dried coconut water using different encapsulating agents.

This research studied how different types and concentrations of encapsulating agents impacted freeze-dried coconut water products. Volatile aroma and physicochemical product characteristics were evaluated. The encapsulating agents were maltodextrin 4-8% (w/v), polydextrose 4-8% (w/v) and xanthan gum 0.1-0.3% (w/v). A plate freezer and an air blast freezer were used to pre-freeze the coconut water before drying. Freezing time had no impact on moisture content and water activity. The flavor compounds of coconut water is composed of alkanes, aldehyde, ketones, organic acids and some other flavor substances. Encapsulating agents are the main factors affecting the flavor of coconut water. Optimal conditions for producing dried coconut water were adding polydextrose at a concentration of 8%. Volatile compounds were assessed under different conditions of SPME- GC-TOFMS. The composition of flavor compounds in coconut water is complex and mainly includes esters, aldehydes, and phenols. Results showed that encapsulating agents improved the volatile aroma of dried coconut water products.

Thermal resistance of Salmonella enterica serovar Anatum on cabbage surfaces during drying: effects of drying methods and conditions.

The effects of selected drying methods, i.e., hot air drying, vacuum drying and low-pressure superheated steam drying (LPSSD), on the heat resistance of Salmonella attached on vegetable surface, which are data that have never been reported elsewhere, were investigated at drying temperatures of 50-70 °C; vacuum drying and LPSSD were carried out at an absolute pressure of 10 kPa. The selected Salmonella serovar, i.e., S. Anatum, was used as a test organism. Cabbage was used as a vegetable model to represent uneven natural surface. The results showed that drying methods had a significant effect on the drying kinetics as well as the destruction rate of Salmonella. Higher drying temperatures resulted in higher destruction rates of S. Anatum. Hot air drying was noted to be the slowest drying process, while vacuum drying and LPSSD could be used to shorten the drying time. By considering the reduction in the number of Salmonella at the end of drying, LPSSD is recommended as it has proved to yield the highest degree of S. Anatum inactivation.