44C-20 |
Total phenolics and anthocyanin accumulation in colored potato varieties at different stages of tuber development. |
L. F. REYES1, J. G. Loaiza, and L. Cisneros-Zevallos. (1) Department of Horticultural Sciences, Texas A&M University, Horticulture and Forest Science Bldg, Room 202, College Station, TX 77843-2133 In recent years novel crops such as colored potatoes have been presented as new sources of anthocyanins. Anthocyanins, a group of phenolic compounds, are natural pigments that can potentially replace some artificial colorants used in the food industry. By determining adequate growth stages of potatoes, the nutritional and industrial value of these products might be improved. Our objective was to determine the accumulation of anthocyanins in different colored potato varieties at different stages of tuber development. Anthocyanin accumulation from purple, red and yellow-flesh potatoes harvested from Texas and Colorado was quantified in our study. After potato seeds were planted, potatoes were harvested at 87, 108, 155 days and analyzed for anthocyanins, total phenolics and antioxidant activity. Total anthocyanins, total phenolics and antioxidant activity in potatoes was determined by spectrophotometric techniques in which extracts were assayed at specific wavelengths. Our results showed that Texas cultivars decreased in anthocyanin content with harvest time ranging from 27 to 58% in colored potatoes (All Blue, Penn Purple, RC2003-2, Penn Purple), and from 66 to 82% in yellow-flesh potatoes (Corn3, ATX9202-3Ru, Russet Nugget). Data obtained for total phenolics and antioxidant activity showed similar behavior as that observed for anthocyanins. Similar trends were also observed for Colorado cultivars (All Blue, Corn3, ATX9202-3Ru, Russet Nugget, NDC4069-4R/R), although concentrations in general were 30% higher. In addition, all varieties showed a 4.9 to 16.6-fold increase in potato weight with time. These results suggest that climatic conditions of a growing location are mainly responsible for the amount of anthocyanins accumulated in potatoes. Anthocyanin synthesis and distribution within the tuber simultaneously occurs with an increase of tuber size through time. The anthocyanin concentration is diluted with tuber mass increase, however harvest at late stages of product growth produce larger yields and overall higher amounts of anthocyanins.
Session 44C, Fruit & Vegetable Products: Chemistry
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