Evaluation of the possible contribution of phenylpropanoids to potato discoloration

Authors: LIN, SEN - Washington State University; HNINSI, MOE - Washington State University; Feldman, Max; Navarre, Duroy - Roy

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/10/2021
Publication Date: 2/26/2021
Citation: Lin, S., Hninsi, M., Feldman, M.J., Navarre, D.A. 2021. Evaluation of the possible contribution of phenylpropanoids to potato discoloration. American Journal of Potato Research. 98:130-138. https://doi.org/10.1007/s12230-021-09824-5.
DOI: https://doi.org/10.1007/s12230-021-09824-5

Interpretive Summary: Potato is important for food security because it is high yielding and nutrient dense, including with compounds called phenylpropanoids that are nutritionally desirable because of their wide array of health-promoting effects. However, a concern for developing new varieties with higher amounts of phenylpropanoids is whether this would potentially increase the amount of discoloration in wounded or bruised potatoes, which would increase waste and limit commercial acceptance. ARS scientists at Prosser, WA and Washington State University showed that phenylpropanoids do not appear to be the key factor in determining how susceptible a potato variety is to bruising or browning. They show potatoes can have high amounts of phenylpropanoids without having high amounts of tyrosine. These findings suggest that potatoes with higher amounts of dietarily desirable phenylpropanoids can be developed, without increasing the risk of discoloration. Such potatoes would increase food security by reducing waste and increasing nutrition, while appealing to consumers who are increasingly prioritizing the nutritional value of foods

Technical Abstract: Potato is staple food that promotes global food security. One major source of waste are culls due to discoloration of the tubers, some types of which may be associated with nutritionally desirable phenylpropanoids. We examined blackspot bruising, and enzymatic browning of tuber slices and potato juice in 12 different cultivars. Discoloration was measured, along with polyphenol oxidase activity and total phenolics. A strong correlation was not observed between any of these factors. Furthermore, no correlation was observed between tyrosine and chlorogenic acid amounts in 56 varieties. These results showed phenylpropanoids were not the major determinant of discoloration in these potatoes and suggested that potatoes can be developed with higher amounts of phenylpropanoids without inadvertently increasing the amounts of tyrosine. Collectively, this work supports the hypothesis that potatoes can be developed with higher amounts of health-promoting phenylpropanoids without increasing waste due to discoloration