R&D RADIO: How Water Activity Keeps Shelf-Stable Food Safe, Crunchy, and Fresh

What this episode covers

Zachary Cartwright, Principal Food Scientist at AQUALAB by Addium, explains water activity (a_w) as the capacity of water to drive biological, chemical, and physical changes in food products. He details how a_w above 0.6 enables microbial growth, while specific thresholds cause textural issues like caking in powders or sogginess in snacks. The conversation covers the difference between moisture content and water activity, the use of moisture sorption isotherms to predict shelf life, and how sustainable packaging with different water vapor transmission rates impacts stability. Cartwright advises brands to access testing via universities or labs, but emphasizes that in-house meters with direct sensors and temperature control are ideal for quality control.