Cobrançosa Table Olives: Characterization of Processing Method and Lactic Acid Bacteria Profile throughout Spontaneous Fermentation

Abstract

Our major goal was the physicochemical, biochemical and microbiological characterization of Cobrançosa table olives, as support for the eventual granting of a PDO status. Seven producers were accordingly sampled throughout eleven months. Brines were analyzed for pH, salinity, acidity, and organic and phenolic compounds. Yeasts and Latic Acid Bacteria (LAB) were enumerated, and the dominant strains duly identified. Despite process variabilities, two stages appear to be shared by all manufacturers: sweetening—the renewal of water to remove bitter compounds; and salting—gradual addition of salt to brine for preservation. Yeasts dominated during sweetening, but LAB tended to be similar in viable counts (7 log CFU/mL) by the end of salting. Lactiplantibacillus (Lpb.) pentosus, Lpb. paraplantarum, Pediococcus parvulus, and Oenococcus kitaharae were the most abundant LAB found, together with an average pH of 4.1 and 6–9% for salt content. All organic acids exhibited an inverted parabolic evolution, with maxima of 3450 mg/L for lactic and 4000 mg/L for succinic by 3 months, and 2750 mg/L for acetic and 2950 mg/L for citric by 4 months. Oleuropein levels were affected by the frequency of brine renewal but decreased from 1350 to 700 mg/L, with hydroxityrosol and tyrosol increasing from 10 to 2000 mg/L and 2 to 550 mg/L, respectively, within 11 months.