Recycling preservation solutions in black ripe olive processing

The purpose of this study was to evaluate the reuse of the liquid employed to preserve black ripe olives in a new fermentation process. The fermentation of olives in these reused solutions (ozonated, acetic acid distillate and old storage solutions) produced similar results as with a fresh acetic acid solution. The pH was between 3.8 and 4.1, and the free acidity ranged from 1.4 to 2.6. Yeasts and acetic acid bacteria were the predominant microorganisms, while lactic acid bacteria grew occasionally after 6–8 months of storage. Off‐odours, fruit defects or any other spoilage were not detected in any case. Moreover, the quality of the darkened product (colour, firmness, flavour) was statistically similar for all treatments, although fruits preserved in a reused ozonated liquid showed less dark fruits (R₇₀₀ = 9.7–10.7) than the others (R₇₀₀ = 7.7–9.3). These results open the possibility of reusing the black olive solutions in a new preservation process.