Effects of Modified Atmosphere On Biochemical and Physiological Characteristics of Zanthoxylum L. Bud During Postharvest Storage

In order to examine the influence of modified atmosphere on biochemical and physiological characteristics of Zanthoxylum L. bud during postharvest storage, seven treatments using different combinations of CO₂ and O₂ levels were evaluated in this experiment, i.e., 2% CO₂/6% O₂, 6% CO₂/6% O₂, 10% CO₂/6% O₂, 14% CO₂/6% O₂, 6% CO₂/2% O₂, 6% CO₂/10% O₂, 6% CO₂/14% O₂. Air was used as the control treatment. Respiration and ethylene release rate, fresh and dry weight, ethanol and acetaldehyde content, and levels of chlorophyll, soluble sugar, and vitamin C of the fruit samples were measured at 1, 4, 7, 11, 15, and 18 days after storage. Results showed that the appropriate CO₂ and O₂ combinations could decrease the respiration and ethylene release rate, postpone the peak of ethylene release, reduce the loss of fresh and dry weight of Zanthoxylum L. bud, and avoid the accumulation of ethanol and acetaldehyde. As a result, contents of chlorophyll, soluble sugar, and vitamin C were well maintained. For example, at 18 days after storage, the chlorophyll, soluble sugar, and vitamin C contents of the bud in the 10% CO₂/6% O₂ treatment were 1.61mg/g, 2.76%, and 41.2mg/100g , respectively, which were higher than that of the control by 18.1%, 21.3% , and 217.8%, respectively. In this experiment, the best modified atmosphere treatment was 10% CO₂/6% O₂, followed by the treatment of 6% CO₂/6% O₂. The two treatments could result in a shelf life of Zanthoxylum L bud above 15 days. In contrast, the 14% CO₂/6% O₂ and 6% CO₂/2% O₂ combinations led to ethanol and acetaldehyde accumulations and reduced the contents of chlorophyll, soluble sugar, and vitamin C, causing a significant decline in the postharvest quality of Zanthoxylum L. bud.