| Institution: | 1. Food Science and Technology Programme, c/o Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore;2. National University of Singapore (Suzhou) Research Institute, 377 Linquan Street, Suzhou Industrial Park, Jiangsu 215123, People’s Republic of China;1. School of Tea & Food Science and Technology, Anhui Agricultural University, Hefei, 230036, China;2. Department of Applied Chemistry, School of Science, Anhui Agricultural University, Hefei, 230036, China;3. Biotechnology Center of Anhui Agricultural University, Anhui Agricultural University, Hefei, 230036, China;1. Department of Food and Nutrition, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul, 133-791, Republic of Korea;2. Department of Food & Fermentation, Far East University, Gamgok, Eumseong, Chungbuk, 369-700, Republic of Korea;3. Department of Functional Crop, National Institute of Crop Science (NICS), Rural Development Administration (RDA), Jeompiljaero, Miryang, Gyeongnam, 627-803, Republic of Korea;4. Department of Food Bioscience & Technology, College of Life Science & Biotechnology, Korea University, Seoul, 133-791, Republic of Korea;1. China National Rice Research Institute, Hangzhou 310006, China;2. University of Manitoba, Department of Food and Human Nutritional Sciences, Winnipeg R3T 2N2, Canada |
| Abstract: | The effect of thermal processing on the degradation of the phytochemicals in black rice flour by means of fluorescence spectroscopy and degradation kinetics was investigated. In order to investigate the influence of food matrices, a comparative analysis between integral rice flour and different fractions was performed. The preliminary compositional results suggested a higher content in phytochemicals in fraction four of the seven fractions of black rice flour, which was sifting through a sieve with a diameter of 180 μm. The compositional complexity was highlighted by fluorescence spectroscopy. The heat-treatment caused structural changes that led to red- or blue-shifts in maximum emission. The first-order kinetic model was used to describe the mechanism of degradation. The activation energies were 10.07 ± 1.04 kJ/mol for total polyphenolic, 7.26 ± 0.58 kJ/mol for total monomeric anthocyanins and 6.71 ± 1.12 kJ/mol for antioxidant activity in case of integral flour extract. For fraction four extract obtained by, the Ea values were: 3.51 ± 0.53 kJ/mol, 11.49 ± 1.47 kJ/mol, 15.80 ± 1.50 kJ/mol and 19.91 ± 3.27 kJ/mol, respectively. The calculated values of the activation energy revealed higher temperature dependence of total polyphenols in integral flour and of antioxidant activity in fraction four, respectively. |
