Glycoalkaloid, phenolic, and flavonoid content and antioxidative activities of conventional nonorganic and organic potato peel powders from commercial gold, red, and Russet potatoes

Authors: Friedman, Mendel; KOZUKUE, NOBUYUKI - Seowon University, Korea; KIM, HYUN-JEONG - Keimyung University; CHOI, SUK-HYUN - Seowon University, Korea; MIZUNO, MASASHI - Kobe University

Submitted to: Journal of Food Composition and Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/25/2017
Publication Date: 4/27/2017
Citation: Friedman, M., Kozukue, N., Kim, H., Choi, S., Mizuno, M. 2017. Glycoalkaloid, phenolic, and flavonoid content and antioxidative activities of conventional nonorganic and organic potato peel powders from commercial gold, red, and Russet potatoes. Journal of Food Composition and Analysis. 62:69-75. https://doi.org/10.1016/j.jfca.2017.04.019.
DOI: https://doi.org/10.1016/j.jfca.2017.04.019

Interpretive Summary: The annual world production of about 1.3 billion tons of food waste that include potato peels could be used to provide a useful and inexpensive source of high-value compounds for industrial, medical, and food uses. Potato peels available from large-scale peeling of potatoes from the production of French fries, potato chips, and other edible potato products can serve a source for of biofuel and biomanure and high-value compounds, including glycoalkaloids and phenolic compounds. Potato peel extracts have also been investigated for medical and food properties. For example, potato peel extracts retarded lipid peroxidation of irradiated meat, minced mackerel, and soybean oil, and improved the nutritional quality of cakes. The main objective of the present study was to determine the glycoalkaloid, phenolic compound, and total flavonoid content as well as antioxidative effects of potato peel powders prepared from three conventional and three organic store-bought potatoes. To our knowledge, this is the first report on peels from organic potatoes. The results show wide variation in the content of bioactive compounds. The described methods and results could be used to evaluate the composition of peels from other potato cultivars and might help in the selection of peels from potato varieties for their nutritional, medical, and industrial benefits.

Technical Abstract: The content of glycoalkaloids a-chaconine and a-solanine, individual and total phenolics compounds, and total flavonoids for three peels prepared from conventional and three from organic commercial potatoes as well antioxidant activities using three different methods were evaluated. Glycoalkaloids and individual phenolic compounds (caffeic, chlorogenic, and isochlorogenic acids) were determined using HPLC and LC-MS, and total phenolic and flavonoid content by colorimetry. In the six samples, there was a 5.6-fold, 5-fold, 3.8-fold, and 2.5-fold variation in the content of total glycoalkaloids, phenolic comounds, flavonoids, and antioxidative activities, respectively. The results may or may not reflect the composition of peels from other potato varieties derived from nonorganic and organic commercial potatoes, as well as newly developed cultivars that are grown and stored in different environments, which could be investigated further. The described methods could be used to determine the composition and antioxidative activities of peels derived from other potato cultivars as well as aid in compositional, nutritional, medical, and industrial studies on potato peel to relate composition to multiple described functions and activities.