Study of the factors affecting growth of Celerinatantimonas sp. and gas pocket formation in Spanish-style green olives

Abstract

The defect of gas pocket formation still leads to substantial losses of yield and quality of Spanish-style green olives worldwide. This spoilage has recently been associated with the growth of Celerinatantimonas sp., and this study was aimed at investigating the influence of several factors on the growth of Celerinatantimonas , both in synthetic media as well as in the olive brines of the three olive cultivars Gordal, Manzanilla and Hojiblanca. Using synthetic media, it was found that the concentration of NaCl within current industrial levels (3.5–7.0%) did not affect the growth of Celerinatantimonas , whereas the pH was a crucial factor, the range of growth being 4.5–7.5 units. Among the acids tested, lactic acid presented the highest inhibitory action against this microorganism. The assays carried out with olive brines disclosed that the population of Celerinatantimonas and its normal fermentation products (acetic acid and ethanol) increased in all of the inoculated brines, while the reduction of gas pocket defect depended on the combined use of several factors including addition of lactic acid, control of pH and inoculation with a lactic acid bacteria starter. Hence, the maintenance of a pH below 4.5 units at the beginning of fermentation along with the addition of 0.2–0.8% lactic acid was considered necessary to inhibit growth of Celerinatantimonas and to prevent gas pocket defect. The tools proposed as conclusions of this work should be used by table olive processors in the future to reduce the incidence of this olive spoilage. • Celerinatantimonas caused gas pocket defect in processed green olives. • NaCl up to 10% did not inhibit the growth of Celerinatantimonas . • Celerinatantimonas grew in a pH range of 4.5–7.0 units. • Lactic acid at 0.2–0.8% retarded growth of Celerinatantimonas . • The combined use of pH and lactic acid may control growth of Celerinatantimonas .