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

LAURA CRESPO; RAIMONDO GAGLIO; ELENA FRANCIOSI; YOLANDA MADRID; LUC DE VUYST; LUCA SETTANNI; FERNANDA MOZZI; MICAELA PESCUMA

Simposio; 13th LAB Symposium; 2021

Fruits are important sources of bioactivecompounds for human health. Selenium (Se) is an essential micronutrient withantioxidant capacity. Both, fruits and Se, are consumed below the recommendeddaily intake. Lactic acid bacteria (LAB) can biotransform Se salts (toxic) intoorganic Se (non-toxic), improve fruit storage, and increase their bioactive compoundcontent. Growth (cfu/ml), sugar metabolism (HPLC), phenolic content(Folin-Ciocalteu), and Se accumulation (ICP-MS) by LevilactobacillusbrevisCRL2051 and Fructobacillus tropaeoliCRL2034 in pasteurized mango/passion fruit juice with (0.15 mg/L) or without Se werestudied. The persistence of inoculated LAB in raw juices was evaluated byRAPD-PCR and MiSeq Illumina. The strains grew 1-2 log cfu/mL but could not eliminatenative 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. Thehighest 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 LABstrains can be used to formulate a functional fermentedfruit juice bio-enriched in Se, with low sugar content, and increased free-phenoliccompound concentrations.