Different methods for textural evaluation of freeze-dried candies during storage

Area of Science:

• Food Science
• Material Science
• Sensory Science

Background:

• Freeze-drying is a common method for preserving food products like candies.
• Alternative sweeteners are increasingly used in food development, potentially affecting texture.
• Understanding textural changes during storage is crucial for product quality and consumer acceptance.

Purpose of the Study:

• To analyze the textural changes in freeze-dried candies made with different sweeteners (honey/isomalt and isomalt/stevia) during storage.
• To compare instrumental, sensory, and image analysis methods for evaluating food texture.
• To assess the correlation between different textural analysis techniques.

Main Methods:

• Two types of freeze-dried candies (honey/isomalt and isomalt/stevia) were developed and stored.
• Instrumental analysis measured texture parameters like Fmax and W.
• Sensory analysis evaluated hardness, fracturability, and crispness.
• Image analysis assessed structural homogeneity and uniformity.

Main Results:

• Fresh candies exhibited distinct textures: honey/isomalt (HI) was compact, while isomalt/stevia (IS) was porous and crunchy.
• Storage led to a significant decrease (approx. 60%) in instrumental hardness (Fmax) and work of fracture (W) for both candy types.
• Sensory analysis corroborated these findings with reduced hardness, fracturability, and crispness.
• Image analysis indicated increased homogeneity and smoothness in HI candies post-storage.
• A strong positive correlation was found between instrumental, sensory, and image analysis techniques.

Conclusions:

• Freeze-dried candies undergo significant textural degradation during storage, regardless of sweetener type.
• Instrumental, sensory, and image analysis are complementary methods for a comprehensive understanding of food texture.
• The combined application of these methods provides robust insights into complex food textural changes.