Use of Weibull distribution for describing kinetics of antioxidant potential changes in fresh-cut watermelon Original Research Article

Changes in antioxidant capacity, vitamin C, lycopene and total phenolic compound retention of fresh-cut watermelon stored at selected temperatures (5–20 °C) for 14 days storage were accurately described by a Weibull distribution function. The temperature dependency of the Weibull kinetic rate constants was studied through an Arrhenius-type relationship. The degradation kinetic constants of Weibull model increased with temperature. Therefore, initial antioxidant potential of fresh-cut watermelon was best maintained at storage temperature of 5 °C for 14 days. The activation energies for lycopene, vitamin C, antioxidant capacity and total phenolic compounds were 56.5 kJ mol−1, 55.9 kJ mol−1, 34.5 kJ mol−1 and 26.9 kJ mol−1, respectively. Thus, a high temperature sensitivity of lycopene, vitamin C and antioxidant capacity related reactions were observed compared to that of total phenolic compounds.