Sulphur dioxide and other preservatives are frequently used in fool to extend its shelf life. Sulphur dioxide fumigation is increasingly used in herbal industry for its pesticides and anti-bacterial properties in a cheap and convenient manner. Such a process can alter the quality of herbs by damaging the bioactive compounds, changing chemical profile, and generating detrimental exogenous materials. To maintain quality, premium herbs are processed with low levels of Sulphur dioxide.
Through careful selection and processing, Eu Yan Sang Superior Gingko Nut is able to retain its herbal goodness without any use of Sulphur dioxide fumigation.