Effect of gamma irradiation and sodium hydroxide treatment on the debittering of olive ( Olea europaea ) fruits

The effect of gamma irradiation and sodium hydroxide (NaOH) treatment on the debittering of olive ( Olea europaea , var Surrany) fruits was investigated. Fruits were treated with 1, 2 or 3 kGy of gamma irradiation at a dose rate of 669 Gy h −1 . Irradiated and unirradiated fruits were processed with NaOH solution (11 g l −1 ) for 3 or 6 h and washed once per day for 3 days. The fruits were then immersed in brine (56 g l −1 sodium chloride) and stored for 12 months at room temperature. Dissolved organic and inorganic solids, Na + , K + and Ca 2+ contents, pH and electrical conductivity values were determined in the debittering solutions (lye, rinse and washing waters) and brines. Gamma irradiation significantly ( p  < 0.05) increased the dissolved organic and inorganic solids and the Na + and K + concentrations in the debittering solutions when the fruits were treated with NaOH for 3 h. On the other hand, gamma irradiation had no significant effect on these parameters, except for an increase in K + concentration, when using NaOH solution for 6 h. Gamma irradiation with NaOH treatment for 3 h decreased the concentration of Ca 2+ in the debittering solutions, whereas irradiation and treatment with NaOH solution for 6 h increased its concentration. © 2003 Society of Chemical Industry