Analytically Directed Flavor Selection in Breeding Food Crops

Abstract

<jats:p>Flavor quality is one of the most difficult traits to select in plant breeding programs due to the large number of sensory panelists required, the small number of samples that can be evaluated per day, and the subjectivity of the results. Using sweetpotato [<jats:italic>Ipomoea batatas</jats:italic> (L.) Lam.] as a model, clones exhibiting distinctly different flavors were analyzed for sugars, nonvolatile acids, and aroma chemistry to identify the critical flavor components. Differences in sugars, sucrose equivalents, nonvolatile acids, and 19 odor-active compounds were identified that accounted for differences in flavor among the clones. Using the intensity of the aroma per microliter for each of the 17 most important aroma-active compounds (maltol, 5-methyl-2-furfural, 2-acetyl furan, 3-furaldehyde, 2-furmethanol, benzaldehyde, phenylacetaldehyde, β-ionone, 1,2,4-trimethyl benzene, 2-pentyl furan, 2,4-decadienal, 2,4-nonadienal, linalool, geraniol, cyperene, α-copane and a sesquiterpene) and the relative sweetness of individual sugars × their respective concentrations, multivariate (principal component and cluster) analysis allowed accurate classification of the clones according to flavor type without sensory analysis. The level of precision was such that sweetness, starch hydrolysis potential, and the concentration of β-carotene could be accurately predicted by quantifying specific volatiles. Analytical assessment of flavor would greatly facilitate the accurate evaluation of large numbers of progeny, the simultaneous selection of multiple flavor types, and the development of superior new cultivars for a wide cross-section of food crops.</jats:p>

Potato Flavor

“…In addition, taste and aroma compounds vary in their relative impact on overall flavor. Therefore, concentrations of biochemical components may not predict their effect on flavor (Wang and Kays 2003). Despite these complications, efforts have been made to associate large scale biochemical analyses with flavor.…”

“…One strategy is to find a few major contributors to flavor by comparing phenotypically different clones and then focus on those compounds during selection (Beckmann et al 2007;Ducreux et al 2008). Another strategy is to develop flavor profiles of standard cultivars using a large biochemical data set and then characterize clones in segregating populations based on their relative positions to the standard cultivars (Wang and Kays 2003). This would identify clones that are similar to conventional cultivars, as well as clones with novel flavor profiles.…”

“…Breeders are interested in creating high antioxidant clones for their increased nutritional value, but this may have a negative effect on flavor. Increasing the terpene biosynthetic pathway that leads to increased levels of carotenoids in sweetpotatoes resulted in new flavors that consumers generally found disagreeable (Wang and Kays 2003).…”

“…In addition, the optimum flavor goal is typically not known and is likely to be variable among consumer groups. By analyzing flavor only in the advanced stages of a breeding program, breeders are unlikely to make progress toward the development of clones with superior flavor (Wang and Kays 2003). An understanding of the biochemical components of flavor may allow breeders to carry out laboratory analyses in early generations, resulting in the development of advanced selections with enhanced flavor.…”

Molecular Dissection of Sensory Traits in the Potato Tuber

“…As a result, flavor is generally only assessed in the later stages of a breeding program after selection for more easily quantifiable traits. In fact, most of the potential flavor improvements are likely to be discarded and to a large extent the market place determines whether a new cultivar is acceptable to consumers (Wang and Kays 2003).…”