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ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » Research » Publications at this Location » Publication #301972
Title: A multi-year survey of stem-end chip defect in chipping potatoes (Solanum tuberosum L.)

Author
item WANG, YI - University Of Wisconsin
item Bethke, Paul
item DRILLIAS, MICHAEL - University Of Wisconsin
item SCHMITT, WILLIAM - University Of Wisconsin
item BUSSAN, ALVIN - University Of Wisconsin

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2014
Publication Date: 10/11/2014
Citation: Wang, Y., Bethke, P.C., Drillias, M.J., Schmitt, W.G., Bussan, A.J. 2014. A multi-year survey of stem-end chip defect in chipping potatoes (Solanum tuberosum L.). American Journal of Potato Research. 92(1):79-90.

Interpretive Summary: The quality of potato tubers used to make potato chips has a large effect on finished product quality. Stem-end chip defect of potatoes causes dark colored blemishes on potato chips that are undesirable to chip processors and consumers. A multi-year survey of stem-end chip defect occurrence and severity was conducted in order to establish the relative sensitivity of different potato varieties to stem-end chip defect formation. The data show that Nicolet and Pike had fewer stem-end chip defects than other varieties across years and locations. These varieties should be considered for locations that are prone to stem-end defect formation. Planting varieties that are less prone to defect formation benefits potato growers by reducing financial risk. Chip processors benefit from having a more reliable supply of high quality potato tubers.

Technical Abstract: One of the most serious tuber quality concerns of US chip potato growers is stem-end chip defect, which is defined as a localized post-fry discoloration in and adjacent to the vasculature on the stem end portion of potato chips. The incidence and severity of stem-end chip defect vary with growing location and variety, but data describing this are not available. A multi-year and location study was conducted to evaluate different chipping varieties for resistance to defect formation and to quantify stem-end chip defect severity and incidence regionally and temporally. High temperature during the early growing season might have a strong impact on stem-end chip defect formation. Multiple tuber samplings from early growing season to late post-harvest storage demonstrated that some varieties, such as Nicolet and Pike, had fewer stem-end chip defects than other varieties across years and locations. The data also show that defects persisted in storage when severe defect incidence at harvest was greater than 15%, but defects did not persist for many varieties when severe defect incidence at harvest was less than 15%. Lastly, stem-end sucrose and glucose prior to harvest were not indicators of defect development at harvest and out of storage, but pre-harvest chip color can be significantly correlated with defect severity 10 weeks after preconditioning was finished.