96-11 |
Effect of ethylene, methyl jasmonate and temperature on the synthesis of anthocyanins in colored-flesh potatoes. |
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 The trend of food industry in recent years has been to replace synthetic food additives with natural compounds. Anthocyanins, a group of phenolic compounds, are natural pigments with high potential to achieve this goal. Novel crops such as purple or red potatoes offer the market a good source of anthocyanins. High accumulation of anthocyanins would increase the nutritional and commercial value for this product. The objective of our study was to determine if abiotic stresses could increase the accumulation of anthocyanins and phenolic compounds in colored potatoes. For this study, 4 varieties of purple and red potatoes were stored in 4-liter jars for a 3-week period and subject to ethylene (1000 ppm), methyl jasmonate (head air pressure) and air (used as control) at two temperatures (2º C and 20ºC). Total anthocyanins and phenolics were determined by spectrophotometric techniques. The results showed that the amount of anthocyanins in Texas varieties such as RC2003-2, Penn Purple and NDC4069-4 remained the same or decreased with the presence of methyl jasmonate or ethylene. However, Texas All Blue variety showed 34 to 53% increases when treated with ethylene and 85 to 96% increases in the presence of methyl jasmonate. In addition, All Blue cultivar from Colorado, when treated with ethylene did not show a significant response on the accumulation of anthocyanins or total phenolics. These stress experiments suggest that All Blue varieties have a mechanism for synthesis of anthocyanins. The lack of increase in the Colorado variety suggests a saturating concentration of anthocyanins in the tissue. Since Texas samples had low initial amounts of anthocyanins compared to those from Colorado, some accumulation could be induced.
Session 96, Fruit & Vegetable Products
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