76C-15 |
Wounding stress on carrots increases the antioxidant capacity and the phenolics content |
J. B. HEREDIA and L. A. Cisneros-Zevallos. Horticulture Department, Texas A&M University, MS 2133, College Station, TX 77840-2133 Phenolic compounds have widely gained the acceptance of people concerned about the prevention of important diseases such as several types of cancers. Phenolics can act as antioxidants by scavenging free radicals and can be found in fresh and processed fruits and vegetables that we include in our regular diet. The amount of phenolics can vary in different crops and also between varieties of the same produce. Other factors that may affect the phenolic content are different processing technologies such as fresh cutting (stress-induced) practices. However, by stressing plant tissues we may also induce the accumulation of undesired phytochemicals. So there is a need to control stresses and induce the appropriate phytochemicals to improve the quality of plant derived foods. Evaluate the effect of wounding through fresh cutting two different carrot varieties (purple and orange), and correlate it to the accumulation of phenolics and the antioxidant capacity. Regular orange and purple carrots were disinfected prior to processing. Fresh cut slices including peels (width 3-5 mm) were stored in dark conditions at 25°C. Sampling was done at 0, 12, 24, 48 and 120 hours. Total phenolics, isocoumarins, and antioxidant capacity (AOA) were evaluated using spectrophotometric methods. Dry matter and weight loss were done for using as correction factors. In regular carrots, the increase in phenolics (»3-fold) was related with an increase in the AOA (»10-fold) with a small change in isocoumarins content. Purple carrots showed similar responses, however AOA was 2 or 3 times higher. Isocoumarins were found to be higher in regular carrots (2-30-fold) compared to purple carrots at all sampling times. The increase in antioxidant capacity by stress-induced phenolics opens the possibility to explore this new processing technology for the creation of “functional” fresh or processed products.
Session 76C, Fruit & Vegetable Product: Fresh Fruits and Vegetables
|