Effect of Cooking Methods on Bioactivity of Polyphenols in Purple Potatoes

Abstract

Purple-fleshed potato (Solanum tuberosum L.) is a good dietary source of anthocyanins, flavonols, and polyphenolic acids, mostly chlorogenic acid. The objective of this study was to examine the impacts of cooking methods including boiling, steaming, and the newly developed vacuum-sealed boiling (VSBoil) on extractability and bioactivity of polyphenolic compounds in a purple potato (PP) cultivar, Purple Pelisse. Data showed that boiling and steaming reduced the total polyphenolic content in PP. High-performance liquid chromatography analysis showed that steaming slightly reduced the extractable chlorogenic acid content, while VSBoil increased it. For DPPH free radical scavenging activities, VSBoil and steaming effectively preserved the antioxidant activity of a polyphenol-rich extract of PP, while boiling resulted in a significant reduction compared to raw potato extract. All extracts effectively suppressed bursts of intracellular reactive oxygen species in human colonic epithelial cells upon hydrogen peroxide induction, of which the extract from the VSBoil group showed the highest antioxidant potential. In addition, all extracts showed anti-inflammatory effects in Caco-2 cells induced with tumor necrosis factor-α. In conclusion, the content and bioactivity of extractable polyphenols were largely retained in PP subjected to different cooking processes. VSBoil resulted in the highest content of extractable polyphenolic compounds and bioactivity among tested cooking methods.

Cooking methods affected the phytochemicals and antioxidant activities of potato from different varieties

“…Our results were consistent with early studies ( Rytel et al, 2014 , Lemos et al, 2015 ), they reported that cooking had a detrimental effect on total phenolic, after roasting, boiling, microwaving and steaming, the total phenolic content decreased from 209 ± 35.7 mg GAE/100 g (fresh weight) to 38.1 ± 7.5, 137.6 ± 0, 74.0 ± 1.3, 130.4 ± 3.7 mg GAE/100 g (fresh weight), respectively. In another study, Sun et al (2021) also showed that boiling and steaming reduced the total polyphenolic content in potato. The decrease of total phenolic in cooked potato might attribute to the thermal-degradation or the leaching during cooking.…”

A Mixture of Pure, Isolated Polyphenols Worsens the Insulin Resistance and Induces Kidney and Liver Fibrosis Markers in Diet-Induced Obese Mice

“…In addition, it is not only the natural food matrices that are essential [ 74 , 75 ], but also the preparation process and the conditions under which it is ingested (e.g., cooking, juicing, etc.). It has been widely demonstrated that cooking affects the phytochemical content of foods as well as their chemical structures and the bioavailability of their bioactive compounds; in other words, how a food is processed before consumption may be directly related to its health effects [ 76 , 77 , 78 , 79 , 80 , 81 ].…”

Variability of Bioactive Substances in Potatoes (Solanum Tuberosum L.) Depending on Variety and Maturity

“…Hamouz et al [49] reported a more than two to three times higher content of polyphenols in purple-fleshed potatoes compared to yellow-fleshed. Sun et al [10] reported a total polyphenol content in purple-fleshed potatoes at the level of 6.50 mg GAE g −1 DW. Our purple-fleshed potatoes (Violet Queen) harvested in September showed a higher TPC (33.4 mg GAE g −1 DW).…”

“…In addition to essential macronutrients, potatoes also contain many phytonutrients such as polyphenols, anthocyanins, flavonoids, and carotenoids [1,10]. In plants, polyphe-nols play many endogenous roles, including plant growth and development, cell wall synthesis, and pigmentation, and have a protective effect, defending plants from biotic stress (insects, bacteria, viruses) and abiotic stress (UV radiation, free radicals) [2,11,12].…”