Date of Award:


Document Type:


Degree Name:

Doctor of Philosophy (PhD)


Nutrition, Dietetics, and Food Sciences

Department name when degree awarded

Food Science and Technology

Committee Chair(s)

D. K. Salunkhe


D. K. Salunkhe


Harris O. Van Orden


Ethelwyn B. Wilcox


Paul B. Larsen


The common tomato of our garden belongs to the natural order Solanaceae and the genus Lycopersicum. The name from lykos, a wolf, and persica a peach, is given to it because of the supposed aphrodisiacal qualities, and the beauty of the fruit. By culture and use it is a vegetable, botanically it is a fruit and among the fruits, it is a berry being indehiscent, pulpy, with one or more seeds that are not stones.

Though the tomato was not recognized as a valuable food until about a century ago, its merit is now universally accepted. Often it is referred to as "the poor man's orange" for it is rich in vitamins and in malic and citric acids, possessing besides, a fine appetizing flavor. The popularity of the tomato in man's diet is due to the fact that it is a most rewarding crop for the home garden. It grows well practically everywhere, affording high nutritional values.

The demand for and acceptance of fresh tomato fruit is based largely on its nutritional value, flavor, aroma, taste, and other characteristics, such as color and texture. These quality criteria are dependent primarily on the structure and chemical composition of the fruit. The importance of quality in tomatoes beyond that which can be expressed in calories per gram, or even in vitamin content, is generally accepted in the United States. In order to meet this increasing demand throughout the year tomatoes often have to be grown in the greenhouses. Therefore, in commercial greenhouses, the tomato has replaced lettuce as the principal crop and it is likely to remain as an important underglass crop.

Flavor is a composite of taste and odor. Odor is produced by many aromatic substances which are present in fruit. Flavor itself is a very complex sensation. The physiological basis of flavor perception is extremely complex and not clearly understood. Flavor chemistry is a comparatively new field of research. Tomato fruit quality is determined mainly by the sugar acid ratio, pectins, color, and flavor. Among these color and flavor are probably the most useful criteria for estimating maturity of tomato fruit. Higher quality is associated with redness of color and prominence of flavor. The flavor of a fruit becomes pronounced when the sugar content is at its maximum and the color of the skin acquires the richest shade.

Isolation of volatile components from natural products is often difficult. Typical flavor and aroma of tomato fruit is primarily due to its volatile components. Neither complete analysis for nor synthesis of tomato flavor has been accomplished due to the marathon of problems associated with the extraction, separation, and identification techniques. The primary aim of this investigation was to separate and identify some of the major flavor and aroma components in the developing tomato fruit and also to assess the influence of certain physiological and biochemical changes on the biosynthesis of these components during fruit growth.