Recent Progress of Gas Hydrate Technology for Non‐Thermal Concentration of Liquid Foods

Gas hydrate technology has emerged as a promising non‐thermal approach for concentrating liquid foods, offering an alternative to conventional thermal and freeze‐concentration methods. The process is driven by the crystallization of hydrate cages, which trap the guest gases, primarily food grade CO 2 , under moderate pressures (3.0–8.0 MPa) and low temperatures (1°C–10°C). Hydrate‐based concentration maintains thermal stability of heat‐sensitive compounds and decreases the level of thermal damage and energy requirement, compared with conventional methods. Recent studies have demonstrated effective concentration performance in a variety of food matrices. Apple juice has been concentrated up to 45 °Brix, while coffee extracts reached 40 wt.% total solids. In CO 2 hydrate‐assisted concentration, orange juice achieved a dehydration ratio (DR) of 57.2% at 4.1 MPa, whereas tomato juice reached a maximum DR of 65.2% at 3.0 MPa. Hydrate formation kinetics also improved with increasing pressure, with rate constants rising from 0.94 × 10 −8 to 1.65 × 10 −8 J −1 mol 2 s −1 as feed pressure increased from 1.81 to 3.1 MPa. The selective exclusion of solutes from the hydrate lattice enables superior retention of thermolabile bioactive compounds. Experimental findings showed a 1.7‐fold increase in vitamin C content and more than a 2‐fold increase in total phenolics, with minimal thermal degradation. However, industrial implementation remains constrained by slow hydrate formation kinetics and prolonged induction times, particularly in sugar‐ and pectin‐rich systems. This critical review discusses hydrate formation principles, concentration methods using various gases, recent technological advancements, applications in liquid food concentration, and key research challenges required for commercial‐scale feasibility.