Affiliation:
1. Pamukkale University, Faculty of Engineering, Department of Food Engineering
2. Burdur Mehmet Akif Ersoy University, Faculty of Engineering and Architecture, Department of Food Engineering
Abstract
The antioxidant activity (AA) and color degradation were monitored in tomato quarters (Rio Grande) during hot air drying in a cabinet drier at five temperatures (60, 70, 80, 90 and 100°C) at an airflow rate of 0.2 m/s and 20% relative humidity. AA values of fresh tomatoes determined by total phenolic content (TPC), FRAP and DPPH assays were 85.3 mg GAE, 26.2 µmol TE and 31.3 µmol TE/100g dm, respectively. Increasing drying temperature resulted in a reduction in Hunter Lab and a/b color values of tomatoes as well as their AA values. During hot air drying, the degradation of AA and color values of tomatoes followed a first-order reaction. Activation energy values for AA degradation determined by TPC, FRAP and DPPH assays were 24.36, 22.91 and 23.67 kJ/mol, respectively. High correlations were found among the TPC, DPPH and FRAP values and lycopene and β-carotene contents of tomatoes during hot air drying. Degradation kinetic data revealed that color values and tomatoes AA are susceptible to drying temperature.
Funder
Pamukkale University Research Fund
Reference47 articles.
1. [1] FAO, http://faostat3.fao.org/browse/Q/QC/E. Accessed 15 October 2016.
2. [2] Slimestad, R., Verheul, M. (2009). Review of flavonoids and other phenolics from fruits of different tomato (Lycopersicon esculentum mill.) cultivars. Journal of the Science of Food and Agriculture, 89, 1255-1270.
3. [3] Veillet, S., Busch, J., Savage, G. (2009). Acceptability and antioxidant properties of a semi-dried and smoked tomato product. Journal of Food, Agriculture and Environment 7(2), 70-75.
4. [4] Halliwell, B. (2000). Why and how should we measure oxidative DNA damage in nutritional studies? How far have we come? The American Journal of Clinical Nutrition 72(5), 1082-1087.
5. [5] Gould, W. A. (1983). Tomato production, processing, and quality evaluation. The AVI Publishing Company Inc., Westport, USA.