EFFECTS OF PH AND SALTS ON THE FIRMNESS OF CANNED RIPE OLIVES

The effect of mono and divalent cations (Na+, Ca++) on the firmness of ripe olives between pH 6.5 and pH 9 was studied. Calcium ions improve d the firmness of ripe olives within this range of pH although this ef fect decreased as the pH increased. At pH higher than 8.5, calcium cat ions may accelerate the softening rate of ripe olives. However, ripe o lives processed by industrial methods with an initial pH of the flesh higher than 8.5, did not lose their texture quality when calcium was a dded due to the rapid diminution of the pH during sterilization. The f irmness of ripe olives was improved when the concentration of NaCl inc reased and also originated some calcium displacement from the flesh of the fruits. However, the monovalent sodium ions did not show any acti on on firmness when calcium cations were added in the canning solution s. A higher concentration of calcium was always observed in the flesh than in the canning solutions.