Integrated biological and radiofrequency thawing for frozen shiitake mushrooms: Quality assessment

An integrated thawing strategy combining a composite biological solution (mussel foot protein, inulin, trehalose, calcium chloride) with radiofrequency (RF) heating (TS + RF) was developed for frozen shiitake mushrooms. TS + RF achieved rapid and uniform thawing (166 ± 15 s), which was 19.4% faster than the second-fastest TS + MV group (206 ± 24 s) and only 2.1% of the natural air thawing (CK) time (8000 ± 92 s). TS + RF maintained excellent microbial safety (0.62 Log CFU/g), 22.5% lower than the second-best TS + UT group (0.80 Log CFU/g) and 76.3% lower than CK (2.62 Log CFU/g). Compared with natural air, microwave-assisted, and ultrasound-assisted thawing in the same solution, TS + RF best preserved flavor compounds and texture (hardness 622 g, elasticity 1.22, vs. fresh sample hardness 680 g and elasticity 1.35). LF-NMR analysis confirmed minimized water migration, with bound water increased by 21.2% relative to CK and free water mobility reduced by 64% relative to CK. Critically, TS + RF significantly reduced membrane lipid peroxidation (MDA 1014.69 μmol/kg, 3.9% lower than the second-best TS + UT group) and electrolyte leakage (relative conductivity 45.19%, 7.6% lower than TS + UT), demonstrating superior cell membrane integrity. Electronic sensors revealed enhanced umami and reduced off-flavors in TS + RF samples. Chemometric analyses (PCA/HCA) of multiple quality indicators clearly distinguished TS + RF from other treatments, with TS + RF showing the closest overall quality profile to fresh mushrooms. The synergistic mechanism involves RF's volumetric uniform heating that minimizes thermal damage, combined with the cryoprotective and membrane-stabilizing effects of the biological solution. This integrated strategy offers a promising solution for high-quality industrial thawing of frozen shiitake mushrooms and other delicate plant-based foods.