Project Number: 6645-41000-005-11
Project Type: Specific Cooperative Agreement

Start Date: May 02, 2008
End Date: Oct 08, 2009

Objective:
The project aims to investigate biochemical changes in sweetpotatoes during long-term storage and the effects of these changes on the quality of fried chips. The specific objectives are: 1) determine changes in the levels of sucrose, fructose, glucose, beta-carotene, phenolic acids, and amylase activities in stored roots of selected sweetpotato varieties, 2) evaluate the effect of curing and conditioning of stored roots on sugar content, 3) assess the effects of these biochemical changes on color, texture and flavor of the fried chips.

Approach:
In the first year of the project, two commercial sweetpotato varieties and a new clone NC 99-573 developed at NC State University will be used in this study. Roots will be cured, and stored at 55 degrees F, 85-90% relative humidity for 10-12 months to provide samples which will be taken monthly for chemical analyses and frying tests at USDA-ARS and company laboratories. For the second year, the variety that performed best in chipping quality throughout the long-term storage during the first year, plus 1-2 new clones identified for chips will be stored at improved facilities to represent a variation among commercial practices of sweetpotato storage. Construction of these facilities at NCSU will be completed in time for the 2008 harvest. Root samples will be taken at 6 week intervals for 12 months to evaluate chemical changes and frying tests for quality evaluation as in year 1.