Reuse of ozonated alkaline solutions as fermentation brines in Spanish green table olives

The water used to reduce the excess NaOH after the immersion of green olives in lye becomes a heavily polluted, alkaline wastewater (AW) once it has come into contact with the fruits. Its treatment with ozonated air for 72 h (TAW) destroyed all polyphenols in the solution. A comparison of the microbial, physicochemical, and organoleptic characteristics of olives processed in the traditional way (W) and those reusing AW or TAW was made. The reuse of TAW or diluted TAW (TAW + W) as fermentation brines led to a shorter lag phase, higher maximum specific growth of lactobacillus, and higher lactic acid accumulation (in TAW) than the traditional process; differences among other physicochemical characteristics were not relevant, except that reused brines (AW) always had higher polyphenol contents. The organoleptic panel test did not detect significant differences among treatments in acidic taste, firmness, pit detachment, or olive color. Overall quality was fairly similar for olives from the traditional process and those from the reused TAW. Direct (or diluted) reuse of AW was also possible but produced a more bitter tasting olive.