Development of scale-up isochoric freezing equipment for better preserving litchi fruit: Basic characteristics, aroma quality, and water status

Isochoric freezing is a hot research topic among recent novel food preservation methods, and litchi fruit is highly perishable, requiring reliable preservation techniques to maintain its quality and extend its shelf life for fresh consumption. In the current study, the effects of isochoric freezing and storage (IFS) at −2.5 °C on the preservation of fresh litchis for 35 days were investigated as compared with traditional frozen storage (TFS) at −18 °C and chilled storage (CS) at 4 °C on physicochemical characteristics (mass change, total soluble solid content, ascorbic acid content, and 2,2-diphenyl-1-picrylhydrazyl free radical scavenging capacity), colour quality, aroma profile, texture, and water status. Results showed that IFS was superior to TFS and CS in terms of colour, texture, and water status of litchi aril. Hierarchical cluster analysis (HCA) integrated multiple parameters to assess the overall quality of stored litchis, further demonstrating that isochoric freezing best preserves litchi quality in a manner most similar to fresh fruit.