Antioxidants in Andean food and meals
Abstract: Abstract The constant need to improve health and to prevent disease in Bolivia, especially in the Andean region with its extreme environmental conditions (high altitude and lower temperatures), motivated us to extend studies of antioxidant sources in foods and plants, since antioxidants are believed to have major health benefits. Spectrophotometric methods, such as ABTS (2, 2’- azinobis-3-ethylbenzotiazoline-6-sulfonic acid) and FRAP (ferric reduction antioxidant power), were used to evaluate antioxidant activity. Total polyphenolic content was evaluated by Folin-Ciocalteau reagent. Individual polyphenolic compounds were identified and quantified by reverse-phase HPLC. The ABTS method showed high antioxidant activity and high polyphenol content in hydrophilic and hydrophobic parts of quinoa (Chenopodium quinoa), and in canihua (Chenopidium pallidicaule), another Andean grain. In qentu (Rumex acetosella), the highest antioxidant content and polyphenolic content was found in the hydrophilic and hydrophobic parts. In chilca (Baccharis papillosa subsp. papillosa), a medicinal Andean plant, four phenolic compounds were reported: ermannine, isokamferine, drupanine and 5,7,5’,4’-tetrahydroxy-3-methoxyflavone. Highest antioxidant activity was found in 5,7,5’,4’-tetrahydroxy-3-methoxyflavone, followed by drupanine and ermannine. When Andean tubers such as white potato and freeze- and sun-dried potato called chuño (Solanum tuberosum) were compared with colored potato (Solanum stenotomum), slightly higher antioxidant content was found in colored potatoes, but polyphenolic content was similar in both cases. A partial correlation was found between botanical classification, based on morphological identification, and polyphenol composition in colored potatoes. For the ‘Ñojchjachaya’ cultivar, a strong correlation was found, with high levels of anthocyanidins. However, a correlation could be found between the ans gene clades, levels of anthocyanidins, and other polyphenols. The correlation between color and antioxidants in colored potatoes was confirmed. Antioxidant activity in processed food and meals may increase or decrease depending on the combination of individual food items, as well as in the cooking process. In some meals, antioxidant content was slightly higher than in other processed food; this was associated with higher fiber content. Antioxidant activity was evaluated in approximately 80 samples, comprising individual foods and meals. Based on the results, the conclusion was that antioxidant activity in individual foods is overestimated in comparison with processed food.
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