A simple process to obtain onion oil by direct solvent extraction was proposed. Several solvents commonly utilized in the food industry were tested for their selectivity in the extraction of the oil of onion. Diethyl ether and methylene chloride appeared to be the most suitable solvents for the extraction operation. The direct solvent extraction method produced a yield of onion oil approximately seven times higher than the yield obtained by the steaim distillation method. A process of fermentation of the ground raw onions was used prior to the solvent extraction operation. This produced an improvement in the onion oil yield of 60% over the normal solvent extraction method. In order to determine the quality of the onion oil obtained, refractive index, specific gravity, melting point, and sulfur content were determined. Sulfur content in the onion oil obtained by the method proposed here had one-third (weight basis) of the sulfur content of commercial onion oil. Two organoleptic evaluations were conducted for commercial onion oil and for the onion oil obtained by direct solvent extraction: odor threshold determination and comparative flavor evaluation. The commercial onion oil showed a lower threshold concentration (1.6 ppb) than the onion oil obtained in the laboratory (8.4 ppb). With respect to the comparative flavor tests, the test panels did not detect a statistically significant difference between the flavor of commercial onion oil and the oil obtained by the method proposed here. / Graduation date: 1982

Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.

No description available.

No description available.

Graduation date: 1948

Thesis (Ph. D.)--University of Wisconsin--Madison, 1954. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 89-92).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1953. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 126-130).

Thesis (M.S.)--University of Wisconsin--Madison, 1953. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 41-43).

Thesis (doctoral)--Anōtatēn Geōponikēn Scholē Athn̄ōn, 1958. / Summary in English. Includes bibliographical references (p. [61]-63).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1930. / Typescript. With this is bound: Cytological studies on the parasitic relationship of Urocystis cepulae to the onion / R.I. Evans. Reprinted from American journal of botany, vol. 20, no. 4 (Apr. 1933), p. 255-268, plates 11-12. Includes bibliographical references (leaves 45-47).