Filler functionality in edible solid foams

Area of Science:

• Food Science
• Materials Science
• Polymer Science

Background:

• Particulate ingredients like fibers, proteins, starch granules, and whole grains are used in edible brittle foams (e.g., expanded starchy snacks).
• The full functionality of these ingredients in food applications is not completely understood.
• Insights from synthetic polymeric foams with (nano)fillers can inform their use in food.

Purpose of the Study:

• To review the functionality of particulate ingredients in edible brittle foams.
• To highlight the importance of bubble nucleation and cell opening for snack texture.
• To address the impact of hygroscopic properties and nutritional value on snack expansion.

Main Methods:

• Literature review comparing particulate ingredients in edible foams with fillers in synthetic foams.
• Analysis of the role of hygroscopic properties of fillers on water competition with starch.
• Discussion of processing methods like extrusion and compartmentalization for optimizing filler functionality.

Main Results:

• Filler ingredients primarily enhance bubble nucleation and cell opening, crucial for snack texture, over mechanical strength.
• The hygroscopic nature of fillers affects water availability, influencing glass transition and boiling points critical for expansion.
• Nutritional enhancement of fillers can adversely affect snack expansion, but processing strategies can mitigate this.

Conclusions:

• Particulate ingredients are not inert fillers; their hygroscopic properties significantly influence edible brittle foam expansion.
• Optimizing filler functionality requires decoupling processing steps and potentially using compartmentalization techniques.
• Understanding filler-water interactions is key to controlling snack texture and expansion.