# The Influence of Storage Conditions and Gelatin Concentration on Changes in Selected Physical Properties of Freeze-Dried Coated Carrot Bars

## TL;DR

This study examines how storage conditions and gelatin concentration affect the physical properties of freeze-dried coated carrot bars over time.

## Contribution

The study provides new insights into the optimal storage conditions and gelatin concentration for maintaining the quality of freeze-dried carrot snacks.

## Key findings

- Storage temperature and duration significantly affected water activity, dry matter, hygroscopicity, mechanical properties, and color.
- Coated freeze-dried carrot bars stored for 3 months at 25 °C showed optimal physical properties.
- Gelatin concentration had the most significant effect on control samples (not stored).

## Abstract

The aim of the study was to determine the effect of storage conditions and gelatin concentration on changes in selected physical properties of freeze-dried coated carrot bars. Freeze-dried carrot snacks were prepared and coated with an addition of 8% and 12% porcine gelatin. They were stored at different temperatures (4 °C, 25 °C, and 40 °C) for 3 and 6 months. After this time, selected physical properties of coated freeze-dried products were tested. The study’s results indicated that time and temperature significantly impacted water activity, dry matter content, hygroscopicity, mechanical properties, and color. Based on most of the tested features, the coated freeze-dried product should be stored for 3 months at 25 °C. The water activity was low (0.261), with high dry matter content (96%), a porosity value at 81%, and high hardness, while the total color difference was at 18.2. However, there were no notable changes in the porosity and internal structure of the samples based on storage temperature and duration. The most substantial effect of gelatin concentration on the tested features was observed in the control samples (coated and not stored). Developing sustainable packaging for freeze-dried carrot bars is a future challenge. Edible packaging allows for the use of food industry byproducts and is ecological.