Source Year: 2000

Commercial development of hypoallergenic latex from Parthenium argentatum for the manufacture of latex medical and household goods is hampered by the lack of information on latex stability in the harvested shrub prior to processing. In this paper, we investigate the effect of post-harvest storage on extractable latex content of guayule branches. We found that harvested guayule branches can be stored at 4 oC for at least two weeks without compromising latex yield, provided that dehydration does not occue. When stored hydrated at 4 oC, latex levels declined between 2 and 5 weeks in all branch sizes with the most latex lost from the smallest branches and the least from the medium ones. The latex levels declined due to a combination of conversion of latex into solid rubber in situ and rubber degradation, depending upon the branch size. Overall rubber degradation from the latex and solid rubber pools in the branches was substantial in the smallest branches, but was not seen in the largest. Latex levels declined more quickly at warmer temperatures, even when the branches were hydrated, and were adversely affected by even slight dehydration.