Project Number: 6645-41000-005-10
Project Type: Trust

Start Date: Nov 08, 2007
End Date: Nov 08, 2009

Objective:
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, pectic substances and enzyme activities (amylases and pectin esterase) 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. 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 performed best in chipping quality throughout the long-term storage during the first year, and 1-2 new clones identified for chips will be stored under conditions similar to current commercial practices for sweetpotato storage. Root samples will be taken at one month intervals for 12 months to evaluate chemical changes and frying tests for quality evaluation as in year 1. Data will be analyzed to establish the relationship between chemical changes in stored roots and the color, texture and flavor of sweetpotato chips.