Natural rubber is an essential material, especially for plane and truck tyres but also for medical gloves. Asia ranks first in the production of natural rubber, of which the Hevea tree is currently the sole source. However, it is anticipated that this source alone will not be able to fulfill the growing demand. Guayule, a shrub native to northern Mexico and southern United States, may also contribute. This plant not only contains polyisoprene, but also resin, a mixture of lipids and terpenoids. This review summarizes various aspects of this plant, from the usage history, botanical description, geographical distribution and cultivation practices, down to polyisoprene and resin biosynthesis including their distribution within the plant and molecular composition. Finally, the main processes yielding dry rubber or latex are depicted, as well as the properties of the various extracts along with economic considerations. The aim is to provide a wide picture of current knowledge available about this promising crop, a good feedstock candidate for a multiple-product biorefinery.

A microwave (MW) drying system was built for drying skipjack tuna. It was composed of waveguide and cavity, and a modification to the high-voltage power supply using a power electronic device to control the phase of AC input voltage to a high-voltage transformer. The calibration of the MW power enables tuning the power to be used for drying skipjack tuna. The experimental set-up was studied drying kinetics: time profiles of temperature and moisture content (%MC). The temperature was measured using a thermopile thermometer, which was connected to the microcontroller and the PC via an RS232 port. The %MC was monitored gravimetrically. The experimental results and the simulation results from finite element method computations were compared by assessing the coefficient of determination (R²) and the root-mean-square-error (RMSE). Finally, empirical and semi-theoretical models were fit to the experimental results of moisture ratio and evaluated for best fit using R² and RMSE.