January 06, 2025 | Foods |
Researchers from Hainan Academy of Agricultural Sciences, South China Agricultural University, the Ministry of Agriculture and Rural Affairs, and Hainan Academy of Inspection and Testing in China developed a chlorine dioxide (ClO₂) slow-releasing card to improve postharvest litchi preservation. Chlorine dioxide is widely recognized for its safety and effectiveness in maintaining fruit quality during storage.
In this study, a color-variable ClO₂ slow-releasing card was developed using a two-layer design. Card A was soaked in sodium chlorite (NaClO₂) and calcium chloride (CaCl₂), while Card B contained oxalic acid, CaCl₂, and natural pigments. The two cards were dried and adhered using gelatin, creating a system capable of continuously releasing ClO₂ for over 120 hours at temperatures between 5–25 °C. The card also changed color from dark yellow to white, providing a visual indicator of its activity.
Litchi samples treated with different numbers of ClO₂ cards were evaluated for their quality over seven days. The results showed that litchi treated with half a card (T1) had better pericarp color, lower respiration rates, and reduced browning compared to untreated fruit. The findings suggest that slow-releasing ClO₂ technology can effectively delay pericarp browning and improve litchi quality, offering an efficient and economical postharvest preservation method.
