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ARS Home » Research » Publications at this Location » Publication #91200
Title: RAPID GUAYULE LATEX QUANTIFICATION

Author
item Nakayama, Francis
item CORNISH, KATRINA - W REG RES CTR ALBANY CA
item Vinyard, Stephen
item CHAPMAN, MARY - W REG RES CTR ALBANY CA

Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/21/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Hypoallergenic latex extracted from the guayule plant (Parthenium argentatum, Gray) for making medical products has created interest in industry and agriculture. No standard method is presently available for quantifying latex content that can be readily used in agronomic or processing research. Our objective was to develop a rapid analytical procedure to estimating latex content that can be used for screening purposes. The extraction of guayule latex first involves in the grinding of the plant in a water-based media containing an antioxidant, primarily NA2SO3, adjusted to a high pH(10) with NH4OH. The mixture, which contains the latex, ground tissue, and soil, is filtered through a coarse filter and the homogenate centrifuged. The clear fraction is separated from the solid and centrifuged again. Acetic acid is then added to coagulate the latex. The coagulant is removed from the liquid, oven-dried, and used to estimate the crude latex content. The latex does contain some resin and other plant material but these appear to be minor. In the development, several variables were studied: (a) total quantity of shrub, (b) ratio of solid to extracting solution, (c) period of grinding, (d) number of grinding and filtration, (e) length and degree of centrifugation, (f) plant parts, and (g) homogenate stability. The entire procedure involves standard equipment available in most chemical laboratories. The procedure takes about two hours, excluding sample preparation and drying. Several samples can be run concurrently, and thus, analysis per unit time can be increased.