Calafate (Berberis microphylla) juice fermentation by autochthonous fruit and flower lactic acid bacteria isolates.

SEDE LUCENA, B.; ORDOÑEZ, O.; DE VUYST L.; MOZZI F.; PESCUMA, M.

Simposio; LAB13 Symposium; 2021

Calafate is an endemic plant from Patagonia that is used since pre-historic times as food and medicine. Lactic acid bacteria (LAB) improve the storage and sensory quality of fruits. LAB from Calafate fruits and flowers were isolated to be used as starter cultures for juice fermentation. Fruits and flowers (Esquel, Chubut, Argentina) were macerated, diluted, and plated on MRS agar with cycloheximide (0.1 g/L). Potential LAB were subjected to RAPD-PCR and 16S rRNA gene sequencing for identification. Two Calafate juice concentrations (15 and 30 %, v/v; 4 and 8 °Brix, respectively) adjusted to pH 5.1 were used. Microbial growth, pH, and phenolic concentrations were determined after 24 h of incubation at 30 °C. Two and eight RAPD-biotypes were detected among the fruit and flower LAB isolates, which corresponded to Lacticaseibacillus sp. and Leuconostoc sp., respectively. L. paracasei WB4 and Lc. citreum TC5 grew (1.4-2.8 log cfu/ml) and decreased pH (1.03-0.70 and 0.92-0.88, respectively), with both Calafate juice concentrations. The high initial phenolic content (1.46-2.64 g GAE/L) in 15 and 30 % juices decreased (9.4-10.9 and 20.6-22.3%, respectively) after fermentation with both LAB strains. This is the first report on LAB isolates from Calafate able to grow in high phenolic-containing fruits.