Chemical Profiles of Herbal Compress and Their Persistence Affected by Steaming and Storage Time

Abstract

The steamed herbal compress is one of the well-known traditional medicines used to relieve pain and stress and to promote emotional and physical well-being. Although it has several therapeutic benefits due to its chemical compounds, there are insufficient reports on the effect of steaming of the herbal compress to promote the release of active compounds and its shelf life. Hence, this study aims at analysing the effect of various steaming processes and storage conditions on the chemical composition of most commonly used herbs such as kaffir lime, lemongrass, plai, soap pod, tamarind, and turmeric. The herbs were extracted with solid-liquid and Soxhlet-mediated extraction using 95% ethanol, hexane, and water as solvents. The analysis of chemical profiles of herbs indicated that Soxhlet extraction is the best extraction procedure based on the extraction yield and abundance of eluted compounds. The herbs were then steam-processed according to the traditional practice of using herbal compress with water alone, and water in combination with 5% ethanol or 5% coconut oil to analyse the effect of steaming. The results indicated that a steaming process can promote the release of bioactive compounds from herbs. The effect of storage was also investigated by storing herbs for 1 day and 7 days at 4°C. The finding suggested that storage has resulted in changes in the bioactive composition of herbs pointing to the necessity of modifying storage conditions to eliminate the loss of beneficial compounds. Thus, this study can be helpful for product development to improve the quality of products by modifying their steaming or storage conditions.