EFFECT OF AIR INCORPORATION ON THE FERMENTATION OF NATURALLY BLACK OLIVES AT INDUSTRIAL SCALE

DOLORES M. E. ÁLVAREZ, ABEL LÓPEZ, DIANA LABUCKAS, MARCELA L. MARTÍNEZ , ALICIA L. LAMARQUE

Brasil

Conferencia; CIGR - International Conference of Agricultural Engineering XXXVII Congresso Brasileiro de Engenharia Agrícola; 2008

The use of aireation and the addition of calcium cloride to improve de naturally black olives quality, at industrial scale, was studied with Arauco cultivar. Fermentation was undertaken under aerobic and anaerobic condition, with and without the addition of calcium cloride. The initial condition were: 8 % NaCl, pH 4.2, and a relation of 4800 kg olives/1700 l brine for each fermenter. Process was monitored using physical, chemical and microbiological analysis of brine. Olive samples were analysed at the begining and end of the fermentative period for chemical composition and fruit quality based on color and fruit firmness. The incorporation of air in the fermentation causes an increase in acidity, lower pH values, further development of microbial flora and consequently lower concentration of reducing sugars at the end of the process. No significant differences were found in chemical composition of products except for protein content. Texture of olives were higher under aerobic conditions and with the addition of CaCl2. Surface color were not significant different between treatments. To improve these feature the relation kg olives/litres of brine must be reduced.