MICROFLORA OF THE AEROBIC PRESERVATION OF DIRECTLY BRINED GREEN OLIVES FROM HOJIBLANCA CULTIVAR

New procedures for the preservation stage of ripe olives from Hojiblan ca cultivar were studied. An aerobic fermentative process was used wit h initial pH correction (0.3% acetic acid) and various NaCl concentrat ions: 6, 3 and 0% (w/v) in tap water. Treatments were carried out at i ndustrial level and the spontaneous changes monitored. At initial salt concentrations of 6 and 3% (w/v) NaCl, pH rose progressively, reachin g 4-3 at equilibrium maintaining during this period a constant free la ctic acidity of around 0.4% (w//v). When the initial solution was tap waste, however, the pH decreased rapidly to stabilize at about 3-7, an d lactic acidity increased continuously to reach values over 1% (w/v) at the end of the preservation process. In all treatments aeration eff ectively purged the carbon dioxide from the preservation brines, preve nting shrivelling of olives. The microbial growth was strongly influen ced by the initial NaCl concentration. At 6 and 3% only yeasts grew, t he most abundant being Pichia membranaefaciens, P. vini, P. fermentans and Hansenula polymorpha. However, when there was no NaCl, lactic aci d bacteria colonized the solution. Lactobacillus plantarum and Pedioco ccus inopinatus were the only species found. In this case there was a co-existence between yeasts and lactic acid bacteria As the treatment that supported lactic acid bacteria achieved the best final pH and aci dity for olive stability, it may help to overcome the obstacles to a l actic fermentative process during the preservation stage of ripe olive s from the Hojiblanca cultivar.