36E-75 |
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J. B. HEREDIA and L. Cisneros-Zevallos. Dept. of Horticultural Sciences, Texas A&M Univ., 202 Horticulture and Forestry Science Bldg., 2133 TAMU, College Station, TX 77843-2133 The wide distribution of phenolics in plants has stimulated interest in their potential use as health promoting antioxidants compounds. According to our previous studies, ethylene and methyl jasmonate can regulate the phenolic metabolism of diverse fresh-cut produce, affecting the total phenolic content, and the antioxidant capacity. Adequate manipulation of abiotic stresses like wounding (fresh-cutting) and plant hormones, can elicit the accumulation of more bioactive phenolic fractions, and can also restrict the accumulation of isocoumarins that could negatively impact the flavor of carrot products. Our objective was to determine how wounding and exogenous applications of ethylene, methyl jasmonate and 1-MCP would affect phenolic profiles in fresh-cut carrots. Carrots were obtained from a local supermarket and sanitized previous to manipulation. Ethylene (1000 ppm) and methyl jasmonate (250 ppm) were applied to whole and fresh-cut tissues, before and after 1-MCP applications. Samples were stored for 4 d at 23° C. Total phenolics and antioxidant capacity (AOX) were evaluated spectrophotometrically. The phenolics profile was obtained by HPLC-DAD. Results showed that wounding, wounding combined with methyl jasmonate and ethylene increased phenolic content by ~50, ~200 and ~150%, respectively. Chlorogenic acid was the main phenolic compound synthesized in all treatments. On the other hand, isocoumarins was mainly synthesized in ethylene treated compared to methyl jasmonate treated samples. The presence of 1-MCP inhibited the synthesis of phenolics due to ethylene and only partially in methyl jasmonate treated samples. The synthesis of phenolic compounds in fresh produce may be tailored by selecting and combining appropriate stresses such as wounding, ethylene, methyl jasmonate and 1-MCP.
Session 36E, Fruit & Vegetable Products: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |