Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, South China Agricultural University, Guangzhou 510642, China.
Guangdong Research and Development Center of Modern Agriculture (Woody Forage) Industrial Technology, South China Agricultural University, Guangzhou 510642, China.
Molecules. 2022 Dec 24;28(1):148. doi: 10.3390/molecules28010148.
(1) Background: Mulberry leaves have been widely consumed due to their richness in bioactive substances and high antioxidant activity. The choice of storage method to ensure the quality of mulberry leaves is a challenge in the supply process. (2) Methods: The differences in primary metabolites of freeze-dried mulberry leaf powder after 30 days of storage under different storage conditions (i.e., vacuum or non-vacuum, 4 °C or room temperature) were investigated. (3) Results: A low temperature and vacuum had better preservation effects on the types and activity of the primary metabolites of mulberry leaves, with vacuum preservation being the best. However, the types of primary metabolites in mulberry leaves were significantly reduced after non-vacuum storage at room temperature compared to those with other storage methods. Among the metabolites detected, including dehydroascorbic acid, various phenolic acids, amino acids, lipids, and carbohydrates showed a significant decrease in their contents of more than 40%, and there was a significant increase in the contents of various compounds of the muconic acid biosynthetic pathway compared to those in other storage methods. Moreover, the antioxidant activity of mulberry leaves stored at room temperature under non-vacuum conditions was also significantly reduced. (4) Conclusions: Vacuum storage is the most ideal storage method for preserving mulberry leaves.
（1）背景：桑叶因富含生物活性物质和高抗氧化活性而被广泛食用。选择储存方法以确保桑叶质量是供应过程中的一项挑战。（2）方法：研究了在不同储存条件（即真空或非真空、4°C 或室温）下，冻干桑叶粉储存 30 天后主要代谢物的差异。（3）结果：低温和真空对桑叶主要代谢物的种类和活性有较好的保存效果，其中真空保存效果最佳。然而，与其他储存方法相比，室温非真空储存会导致桑叶中主要代谢物的种类明显减少。在所检测的代谢物中，包括脱氢抗坏血酸、各种酚酸、氨基酸、脂类和碳水化合物在内的物质含量下降超过 40%，而各种苯乙酸生物合成途径的化合物含量与其他储存方法相比则显著增加。此外，在室温下非真空条件下储存的桑叶的抗氧化活性也显著降低。（4）结论：真空储存是保存桑叶的最理想方法。
