Effect of hydrogen peroxide on sour cherry anthocyanins

Abstract

Degradation of sour cherry anthocyanins was studied at different H2O2 concentrations (0.233-11.63 mmol.L-1) over the temperature range of 20-55C. Degradation reaction fitted to a first order kinetic model progressed very rapidly even at low H2O2 concentrations. Thus, the t1/2 values at 20C varied between 111-20 h in the concentration range of 0.233-2.327 mmol.L-1 H2O2. The degradation of anthocyanins occurred at a faster rate with increasing temperature at 5.82 and 11.63 mmol.L-1 H2O2 concentrations. Between 25-55C, activation energies (Ea) were 9.53 and 10.60 kcal.mol-1 for 5.82 and 11.63 mmol.L-1 H2O2 concentrations, respectively. Higher Ea value at 11.63 mmol.L-1 H2O2 concentration indicated that the effect of temperature increased at higher H2O2 concentrations. A quadratic relationship (y = -0.0031x2 + 0.0218x + 0.0008, R2 = 0.996) was found between the degradation rates at 20C and H2O2 concentrations of 0.233-2.327 mmol.L-1. According to this equation, k of 1.12 × 10-3 h-1 and t1/2 of 26 days at 20C may be expected at 0.5 ppm (0.0147 mmol.L-1) H2O2 concentration, i.e., the max. allowable H2O2 level by FDA in the finished food packages.