ARS | Publication request: Patterns of fructose, glucose, and sucrose accumulation in snap and dry bean (phaseolus vulgaris) pods

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 21, 2012
Publication Date: July 1, 2012
Citation: Vanden Langenberg, K.M., Bethke, P.C., Nienhuis, J. 2012. Patterns of fructose, glucose, and sucrose accumulation in snap and dry bean (phaseolus vulgaris) pods. HortScience. 47(7):874-878.

Interpretive Summary: Consumer assessment and willingness to purchase specific vegetable varieties depends, in part, on product taste. Although taste reflects the presence, absence and balance of many flavor compounds, vegetables higher in sugars are often perceived to taste better than those lower in sugars. How sugar contents of bean pods vary as the pods grow has not been studied, and how sugars differ among varieties is not known. A two-year long research study was conducted to characterize sucrose, glucose and fructose content of growing snap and dry bean pods. The results show that different varieties accumulate different amounts of sugars, and that these differences depended more on the genetic makeup of the variety than on growth conditions. Thus, it will be possible to breed for beans that have sugar contents optimized for consumer preferences. This will provide consumers with better tasting beans, and may encourage greater consumption of snap beans as part of a vegetable-rich diet. Increased demand would benefit bean growers, canners and processors in terms of increased sales.

Technical Abstract: Sugars, including fructose, glucose, and sucrose contribute significantly to the flavor and consumer acceptance of snap beans (Phaseolus vulgaris L.). Little is known regarding differences in sugar content among dry bean and snap bean cultivars and the patterns of sugar accumulation with increasing pod size. Alcohol-soluble sugar content of five snap bean cultivars and one dry bean cultivar planted in field trials were assayed throughout pod development over two years using high-performance liquid chromatography. Significant differences in sugar accumulation patterns were observed among cultivars. In general, fructose and glucose levels decreased while sucrose levels increased with increasing pod size in the snap bean cultivars. In contrast, fructose and glucose levels increased in the dry bean cultivar while sucrose levels remained unchanged with increasing pod size. No year by genotype interactions were observed for sugar accumulation patterns. Results indicate that sieve size no. 3 (7.34 to 8.33 mm) or no. 4 (8.33 to 9.52 mm) pods are suitable for detecting difference in sugar content among genotypes.