Document Type

Dissertation - Open Access

Award Date

1968

Degree Name

Master of Science (MS)

Department / School

Chemistry

Abstract

For several years, plants have been screened in the search for compounds that might have a potential use in industry and which presently have no other suitable source (1). During a screening study, Mikolajczak et al. (2) found that crambe (common name for Crambe abyssinica) contained a high percentage of erucic acid. Erucic acid has many potential industrial uses and is currently being obtained from imported rapeseed (J). Because there is presently no suitable domestic source of erucic acid, crambe is a potential new crop for the United States. Field studies of crambe have shown that the seeds tend to shatter when mature and thus seed losses occur while the crop is being harvested. (4). If the crambe seed could be harvested while immature, the shattering problem would be reduced. Early harvesting would not necessarily decrease the value of the crop if the erucic acid content of the seed reached its maximum before the seed matured. Sims (5) and McKillican (6) have studied the lipid changes in maturing crambe seeds, but their experiments were not conducted in controlled environments. Sims' results show that erucic acid continually increases to maturity. Similarly McKillican states that "on a weight per seed basis, erucic acid increases steadily to maturity in crambe." However, the data she presents appear to indicate that there is a relatively constant erucic acid content from 20 DAF (days after fertilization) to maturity. Since there appears to be some variation in the above authors' results and because environmental conditions affect seed oil composition, the lipid changes in maturing crambe seed will be examined under greenhouse conditions. In the original plans of this study, all lipid classes were to be analyzed and thus a general method_ of analysis was desired. Such a method has been described by Privett et al. (7). The method involves the use of thin-layer chromatography (TLC) and densitometry. TLC has the advantages that it is fast, it has good resolving power, and it allows the detection of small quantities (8). TLC also enables the completeness of the separation of the components to be observed. Besides being suitable for the analysis of all lipid classes, the densitometric procedure permits the quantitation of compounds without removing them from the plate. Romans (9) used a whole-spot reflectance method for the quantitation of lipids on thin-layer chromatoplates. This method is similar to densitometry but does not require the expensive equipment nor does it require as much time to complete an analysis. Because of the potential usefulness of Romans method, plant lipids will be used to re-examine the precision and to determine the accuracy of the method.

Library of Congress Subject Headings

Crambe abyssinica
Lipids
Fatty acids

Format

application/pdf

Publisher

South Dakota State University

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