In a groundbreaking study recently published in Food Science and Biotechnology, researchers have unraveled the intricate relationships between glass transition temperature, water activity, and their profound impacts on the flowability and caking behavior of grain by-product powders. Grain by-products, long regarded primarily as waste or low-value materials, have increasingly become the focus of scientific inquiry due to their extensive application potential in food and feed industries. Yet, the challenge of understanding and manipulating their physical properties to optimize usability has remained elusive—until now.
The study dives deep into the phenomenon of the glass transition temperature (Tg), a critical thermal parameter that marks the conversion of amorphous materials from a brittle, glassy state to a more rubbery and flexible one. Tg is paramount in determining a powder’s physical stability, directly influencing how these increasingly important grain powders handle moisture and external mechanical stresses. The implications for industries relying on powder flow and stability are significant, particularly in terms of processing efficiency, storage lifespan, and end-product quality.
Water activity (aw), a measure of free water available in powders, is a parallel factor that profoundly modifies the physical behavior of grain by-product powders. The researchers underscored the dynamic interplay between water activity and Tg, illustrating how variations in moisture levels can alter the temperature at which these powders transition, thereby affecting their flow characteristics. This dual relationship is pivotal to preventing caking—a common issue where powders adhere and form solid masses—thus impairing handling and product quality.
Experimental investigation was performed across multiple types of grain by-product powders, meticulously measuring their glass transition temperatures under different controlled water activity environments. The data demonstrated a clear trend: as water activity increases, the glass transition temperature decreases, facilitating a shift towards a rubbery state at lower temperatures. This shift, while beneficial for powder flexibility, comes at the cost of decreased flowability and increased susceptibility to caking during storage or transport.
One of the major insights from the research relates to the formulation and processing conditions of grain powders. The study elucidates how controlling water content and temperature within industrial setups can be strategically used to maintain powders in a desired physical state, either glassy and stable for extended shelf life or rubbery for enhanced functional properties. Balancing these parameters presents a precise control mechanism for manufacturers, potentially revolutionizing powder-based production lines.
Further, the study sheds light on the molecular underpinnings responsible for these macroscopic behaviors. Water molecules, acting as plasticizers, infiltrate the powder matrix and disrupt molecular interactions, thereby lowering Tg. This understanding clarifies why certain powders, under specific humidity conditions, can range from free-flowing to fully caked. It also provides a scientific basis for designing moisture-resistant coating technologies or modified atmospheres tailored to the unique properties of these powders.
Integral to the research was an exploration of how different grain by-products exhibit variation in their glass transition and water activity profiles. Such variability suggests that each powder type demands specialized handling protocols, debunking any unified approach to flowability challenges. This insight encourages customization in product design and storage, fostering innovation in how grain by-products are repurposed across sectors.
The team’s novel approach to quantifying flowability and caking tendencies through sophisticated rheological measurements and moisture sorption isotherms allows for predictive modeling of powder behavior under varying environmental conditions. These predictive capabilities are invaluable for supply chain management, reducing losses and improving operational predictability in food manufacturing and storage.
Of particular note is the implication of this study for sustainability and food security. By enhancing the usability of grain by-products, traditionally underutilized materials can transition into valuable ingredients, reducing waste and contributing to circular economy models. The ability to store these powders longer without caking or flow issues means food infrastructure resilience can be bolstered in regions susceptible to resource scarcity or transportation challenges.
Moreover, the interdisciplinary nature of the research, merging principles from materials science, food technology, and chemistry, exemplifies the burgeoning field of food powder science as a key frontier for innovation. It reveals that the microscopic stabilities tied to temperature and moisture are not mere academic concepts but actionable parameters that directly affect how these raw materials are transformed into consumer-ready products.
The implications extend beyond the food industry, with pharmaceutical, cosmetic, and chemical industries also benefiting from improved control over powder properties. The insights related to Tg and aw are applicable in designing powders that maintain uniformity and activity over time—a critical factor for drug delivery systems and cosmetic formulations reliant on powdered ingredients.
Critically, the study also addresses the economic dimension of powder handling. Improved flowability reduces the need for frequent processing delays or machine stoppages caused by caking and bridging. This enhanced efficiency directly translates to cost savings and reduced energy expenditure, underpinning more sustainable manufacturing practices in an era where green technologies are increasingly demanded.
This pioneering investigation sets a new standard for understanding how environmental and thermal variables shape the behavior of grain by-product powders. It invites future research to expand on these foundational results, exploring the effects of additional factors such as particle size distribution, chemical composition, and storage conditions on powder performance.
The insights illuminated in this research underscore the transformative potential of mastering powder science principles. Through precise manipulation of glass transition temperatures and water activity, industries can unlock the full potential of grain by-products, turning erstwhile processing challenges into opportunities for innovation and sustainability. The quest to optimize powder flow and minimize caking is not merely a technical challenge but a crucial enabler of a more efficient and environmentally conscious future.
Ultimately, this remarkable study charts a course toward smarter, data-driven industrial processes, where the invisible molecular dance of water and thermal energy dictates the large-scale physical outcomes critical for product integrity. As granular powders become ever more integral to modern production, these findings herald a significant leap forward, promising enhanced product stability, economic savings, and ecological benefits.
With this leap in understanding, manufacturers of grain by-product powders—and powders broadly—stand on the cusp of a new era. By harnessing the science of glass transition and moisture control, they can now engineer products tailored not just for functionality but designed for resilience in a world where food resources must be conserved and valorized.
This comprehensive elucidation provided by Kim, Ye, Oh, and colleagues embodies the future of powder science, offering a roadmap that intersects material physics and practical application—a synergy critical for innovation across several pivotal industries.
Subject of Research: The influence of glass transition temperature and water activity on the flowability and caking behavior of grain by-product powders.
Article Title: Effects of glass transition temperature and water activity on the flowability and caking of grain by-product powders.
Article References:
Kim, BH., Ye, SJ., Oh, SM. et al. Effects of glass transition temperature and water activity on the flowability and caking of grain by-product powders. Food Sci Biotechnol (2026). https://doi.org/10.1007/s10068-026-02093-0
Image Credits: AI Generated
DOI: 25 January 2026
Tags: caking behavior of powdersflowability of grain by-productsfood science and biotechnologyglass transition temperature effectsgrain by-products in food industrymoisture impacts on grain powdersoptimizing powder usabilityphysical properties of grain materialsscientific research on grain materialsstability of powder productsthermal parameters in food processingwater activity in grain powders
