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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Publications at this Location » Publication #421225
Research Project: New Sustainable Processes, Preservation Technologies, and Product Concepts for Specialty Crops and Their Co-Products

Location: Healthy Processed Foods Research

Title: Combined isochoric processes of freezing and supercooling

Author
item RUBINSKY, BORIS - University Of California Berkeley
item Bilbao-Sainz, Cristina

Submitted to: NPJ Science of Food
Publication Type: Review Article
Publication Acceptance Date: 8/1/2025
Publication Date: 8/24/2025
Citation: Rubinsky, B., Bilbao-Sainz, C. 2025. Combined isochoric processes of freezing snd supercooling. NPJ Science of Food. 9. Article 184. https://doi.org/10.1038/s41538-025-00542-4.
DOI: https://doi.org/10.1038/s41538-025-00542-4

Interpretive Summary: Methods for preserving biological matter at subfreezing temperatures without ice formation hold significant potential for improving preservation outcomes. Our work in this field has led to the development of three thermodynamic processes that enable ice-free preservation of food at subfreezing temperatures: isochoric (constant volume) freezing, sochoric (constant volume) supercooling, and the newly developed isochoric (constant volume) hyper-supercooling. In this review manuscript we have addressed the thermodynamics of isochoric freezing and isochoric supercooling and their applications. Additionally, we introduced the concept of isochoric hyper-supercooling and provided design guidelines for achieving the thermodynamic state of isochoric hyper-supercooling.

Technical Abstract: The preservation of food through isochoric cooling encompasses a family of processes conducted in a constant-volume system, including isochoric freezing, isochoric supercooling, isochoric hyper-supercooling, and various implementation methods. This review article traces the development of these technologies, providing a timeline along with a comprehensive listing of relevant thermodynamic processes and states. In this context, we introduce a novel food preservation technology: the isochoric hyper-supercooling process and the associated hyper-supercooling preservation state, which allows for lowering the storage temperature in a supercooled system without altering the degree of supercooling. Moreover, it enables precise control of pressure within the isochoric system. This hyper-supercooling technology operates through a multiphase isochoric system, wherein the food product—immersed in an isotonic solution—comprises one phase, and a separate pure water phase is isolated by an impermeable boundary that allows heat and pressure transfer. The process integrates isochoric freezing in the water phase with isochoric supercooling in the food phase. This study also outlines methods for designing such a system using thermodynamic data and correlations.