Methyl cinnamate is the methyl ester of cinnamic acid and is a white or transparent solid with a strong, aromatic odour. It is found naturally in a variety of plants, including in fruits, like strawberry, and some culinary spices, such as Sichuan pepper and some varieties of basil.
Cinnamic acid is a white crystalline compound that is slightly soluble in water and freely soluble in many organic solvents. Classified as an unsaturated carboxylic acid, it occurs naturally in many plants. It exists as cis and trans isomers, although the latter is more common.
The current lychee preservation mainly uses low-temperature refrigeration combined with drugs (fungicides, preservatives) treatment, sulphur treatment combined with acid immersion colou protection and other technologies, although the shelf life of lychee fruit can be extended to a certain extent.