Food Science and Technology Department


Date of this Version



A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Food Science & Technology, Under the Supervision of Professor Harshavardhan Thippareddi. Lincoln, Nebraska: May, 2011
Copyright 2011 Valli Kannan


Application of high voltage pulsed electric fields (PEF) to plant tissues increases porosity of the plant cells, enhancing juice extraction from fruits and vegetables. Red cabbage and beetroot are rich sources of bioactive compounds anthocyanins and betalains, respectively. Pulsed electric field (red cabbage: 1 kV/cm electric field strength, 0.66 µF and 20 pulses; red beets: 1.5 kV/cm electric field strength, 0.66 µF and 20 pulses) was applied to whole red cabbage and beetroot to enhance juice extraction. Total polyphenols, anthocyanins (red cabbage), betalains (beetroot) and total antioxidant activity (ABTS and DPPH) of the extracted juice was determined. The bioactivity of the juices on colon cancer cell line HCT-116 (p53 +/+ and p53 -/-) were analyzed. The anti-proliferative activity, apoptosis and cytotoxicity were determined. Pulsed electric field treatment increased (p ≤ 0.01) juice extraction, total phenolics, anthocyanins (red cabbage), betalains (beetroots) and antioxidant activity of both red cabbage and beetroot juice compared to non-PEF extracted samples. The juices reduced colon cancer cell proliferation, increased apoptosis and did not exhibit cytotoxicity. There was no difference between the PEF extracted and non-PEF extracted juice with respect to its bioactivity on cancer cells.