Microwave drying of Siraitia grosvenorii and its effect on the Vitamin C content

Abstract

Siraitia grosvenorii (Luo hanguo, LHG) is a unique edible and medicinal plant in China. Drying the LHG with a rapid, highly efficient method and keeping good quality are urgent problems. In this paper, the changes of Vitamin C (VC) content in LHG under microwave drying were studied. The effects of key drying parameters (microwave power, drying time and microwave intermittent ratio) on the quality of LHG have been investigated by orthogonal experiments to reduce the loss of VC in the process of microwave drying. The optimum drying parameters for drying LHG were microwave power of 80 W, drying time of 30 min and microwave intermittent ratio of 1: 1. The optimally treated LHG has 34.072 mg/100g of VC content. These results have indicated that the microwave-heating not only prolongs the storage duration of the LHG but also reduces the moisture content and VC content, while the natural yellow-green color of the LHG is not affected much.

A comprehensive review of Siraitia grosvenorii (Swingle) C. Jeffrey: chemical composition, pharmacology, toxicology, status of resources development, and applications

“…In addition, a new strategy to protect LHG, is through the use of microwave heating. The technique involves applying microwave power of 80 W, with a time parameter of 30 min and a microwave interval ratio of 1:1 ( Zhou et al, 2018b ). This method not only extends the storage life of LHG, but also minimizes the loss of water and vitamin C content.…”