Thermally Induced Flavor Compounds

Abstract

Submitted for publication 7 Sept. 1999. Accepted for publication 6 Jan. 2000. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact. E-mail address: kaysstan@arches.uga.edu Given the number of recent reviews on flavor chemistry (Acker et al., 1990; Berger, 1995; Mathlouthi et al., 1993; Schab and Crowder, 1995; Shallenberger, 1993; Spielman and Brand, 1995), especially relative to thermally generated volatiles such as those produced via the Maillard reaction (For, 1983; Ikan, 1996; Mottram, 1994; Parliment et al., 1994; Whitfield, 1992), we have confined our review to a critique of chemical components and reactions modulating flavor, touching upon how thermally derived flavors overlap into the sphere of horticulture. Why would horticulturists be even remotely interested from a professional standpoint in the flavor of cooked products? Isn’t this really the realm of food scientists or food chemists, i.e., changes in food products during or after cellular death? Thermally generated flavors are in fact a relevant horticultural topic. First, flavors of most horticultural food products are largely generated during cooking. Vegetable crops, for example, are usually cooked before they are eaten [e.g., 370 of 390 commercially cultivated vegetable crops from around the world are routinely to intermittently cooked (Kays and Silva Dias, 1996)], and cooking significantly alters their flavor. In addition, although fruits tend to be thought of as eaten raw, a major portion of the total production is processed (Table 1). In many cases, processing involves a thermal treatment, which alters the flavor of the final product. Therefore, a major portion of horticultural food crops are cooked and much of their final flavor is the result of cooking. Second, the eventual cooked flavor of such products varies with the chemistry of the product and how it is handled prior to cooking. There are many examples of differences in flavor among cultivars of a particular fruit or vegetable. The basic chemistry of the fruit or