二氧化氯释放膜在鲜切火龙果保鲜中的应用

Application of Chlorine Dioxide-releasing Film for the Preservation of Fresh-cut Pitaya

摘要:

以亚氯酸钠和柠檬酸为主要原料，制备了气态二氧化氯（ClO2）释放膜，并探讨了在4 ℃下该释放膜对鲜切火龙果抑菌效果、氯残留及营养感官品质的影响。结果表明，在含有ClO2 释放膜的包装体系中，ClO2 的释放时间为24~28 h，最大释放量达0.44 mg/L。释放膜中亚氯酸钠和柠檬酸含量越高，ClO2释放速率越大、释放时间越短。ClO2 释放膜可有效抑制细菌和酵母菌的生长。在经ClO2释放膜处理的鲜切火龙果中检测到氯离子和氯酸盐两种氯残留化合物，其中氯离子含量在贮藏期显著上升，但氯酸盐残留量与对照组的无显著差异，该处理未造成基于氯残留的安全隐患。ClO2释放膜可显著抑制火龙果可溶性固形物含量的下降，在贮藏期8 d时使得可滴定酸含量增加10%左右。ClO2 释放膜处理会造成火龙果中维生素C和总酚的损失，其中在贮藏期8 d时维生素C含量下降17%~32%，总酚的损失率可通过减少释放膜中亚氯酸钠和柠檬酸含量显著降低到27%以下。此外，ClO2 释放膜可显著抑制火龙果的褐变并降低POD活性。因此，ClO2 释放膜能够明显延长鲜切火龙果的贮藏期，使其维持较好品质。

Abstract:

Gaseous chlorine dioxide-releasing film was prepared using sodium chlorite and citric acid as the main raw materials. The antimicrobial properties, chlorine residues, and effects of the film on the nutritional and sensory quality of fresh-cut pitayas during storage at 4 ℃ were investigated. The results show that, in a packaging system containing the gaseous chlorine dioxide-releasing film, the gaseous chlorine dioxide release time was 24~28 h and the maximum chlorine dioxide release was 0.44 mg/L. Moreover, higher sodium chlorite and citric acid content in the film resulted in faster chlorine dioxide release rates and shorter release times. Chlorine dioxide-releasing film effectively inhibited the growth of bacteria and yeast. Chloride and chlorate were the two chlorine residues detected in the fresh-cut pitaya treated with the chlorine dioxide- releasing film. The chloride content increased significantly over the storage period. In contrast, no significant differences in chlorate content were observed between the treated and untreated groups, indicating that this treatment does not cause chlorine residue-related safety concerns. The results also suggest that the film significantly inhibited decreases in the soluble solid content of the pitaya. On the 8th day of storage, the titratable acid content increased by approximately 10%. The chlorine dioxide-releasing film caused losses of vitamin C and total phenols in the pitaya; the vitamin C content decreased by 17%~32% by the 8th day of storage. The total phenol loss rate could be significantly reduced to less than 27% by reducing the sodium chlorite and citric acid content in the film. In addition, the chlorine dioxide-releasing film effectively alleviated pitaya browning while remarkably reducing peroxidase activity in the pitaya. Therefore, chlorine dioxide-releasing film can prolong the storage life and maintain the quality of fresh-cut pitaya.