The sorption properties, structure and shrinkage of freeze-dried multi-vegetable snack bars in the aspect of the environmental water activity

Abstract

The aim of the research was to determine the water condition in freeze-dried multi-vegetable snacks, using a method based on the determination of sorption isotherms, with particular attention to the influence of storage conditions in the variable water activity of the environment on the structure and shrinkage of the snacks tested.Models to describe the course of sorption processes were well suited to the experimental data. Due to the observed differences during sorption properties, most likely resulting from the raw material (vegetable) composition of the tested freeze-dried multi-vegetable snack bars in the form of bars, the water level was analyzed based on the description of the experimental data using BET and GAB models.Due to the observed differences in the course of sorption processes, most likely resulting from the raw material composition of the tested freeze-dried multi-vegetable snacks in the form of bars, the water level was analyzed on the basis of the description of experimental data using BET and GAB models. The samples of bars with the addition of a mixture of locust bean flour and xanthan were characterized by the most porous structure typical for freeze-dried food, regardless of the vegetable ingredients used in the recipe.