Effects of alkali neutralization with CO2 on fermentation, chemical parameters and sensory characteristics in Spanish-style green olives (Olea europaea L.)

This paper aimed to study CO2 use as alkali neutralizing agent instead of the traditional washings with water, in Spanish-style green olives. Titratable acidity, pH, sugars and microbial populations were monitored during processing. CO2 treatment was effective in reducing water-soluble carbohydrate loss from the olives during washing step and affected combined acidity and lactic acid fermentation. The final pH of the fermented brine was higher than in control, mainly due to high buffering capacity of the solution. CO2 treatment allowed the reduction of more than 80% of the wastewaters. Sensory evaluations of the end product were carried out. Olives treated with CO2 were perceived to be more intense in acidic taste than control, while for texture attributes no differences were detected.