Effect of 'Californian' process on the texture of Hojiblanca olive (Olea europaea L) harvested at different ripening stages

The tensile properties of the skin and the flesh of the table olive, ‘Hojiblanca’ produced in Spain, which underwent the ‘Californian style’ process (step 1: brine; step 2: lye; step 3: heat and brine), were determined. The stiffness and strength of the skin were significantly higher than those of the flesh at all processing stages. The results showed that step 2 resulted in a decrease in strength of the skin. The strength of the flesh increased after step 2 but decreased after step 3 due to heat treatment at 121 °C for 30 min. These changes in strength varied with the degree of maturity for the flesh. An increase in strain at failure was observed in the skin after step 2, whereas no significant changes were detected in the flesh. A decrease in strain at failure was observed in the skin and the flesh further to step 3. After step 2, the stiffness of the skin decreased significantly, whereas that of the flesh increased, the latter decreasing with increasing degree of maturity. The largest effects were in the strength and stiffness of the skin after sodium hydroxide treatment affecting their wax content. Maturity has a larger effect on flesh than on skin mechanical properties.