Fermented mango and passion fruit juices bio-enriched with selenium by fruit-origin lactic acid bacteria.

CRESPO, L.; GAGLIO, RAIMONDO; FRANCIOSI, ELENA; MADRID, YOLANDA; DE VUYST L.; SETTANNI, LUCA; MOZZI F.; PESCUMA M.

Egmond aan Zee

Simposio; LAB13 Symposium; 2021

Fruits are important sources of bioactive compounds for human health. Selenium (Se) is an essential micronutrient with antioxidant capacity. Both, fruits and Se, are consumed below the recommended daily intake. Lactic acid bacteria (LAB) can biotransform Se salts (toxic) into organic Se (non-toxic), improve fruit storage, and increase their bioactive compound content. Growth (cfu/ml), sugar metabolism (HPLC), phenolic content (Folin-Ciocalteu), and Se accumulation (ICP-MS) by Levilactobacillus brevis CRL2051 and Fructobacillus tropaeoli CRL2034 in pasteurized mango/passion fruit juice with (0.15 mg/L) or without Se were studied. The persistence of inoculated LAB in raw juices was evaluated by RAPD-PCR and MiSeq Illumina. The strains grew 1-2 log cfu/mL but could not eliminate native microorganisms in raw juices. In pasteurized samples, both strains (single or combined) consumed fructose (44-98 %) and glucose (88-100 %) and produced lactic acid, whereby mannitol and acetic acid were detected in F. tropaeoli fermented juices. The highest Se accumulation (68-70 µg/L) and phenolic compound concentrations (24-20 mg GAE/ml) were found in fermented juices with L. brevis and the mixed starter culture. In summary, both LAB strains can be used to formulate a functional fermented fruit juice bio-enriched in Se, with low sugar content, and increased free-phenolic compound concentrations.