Microbial Selenization as a Strategy to Deliver Selenium and Selenium Nanoparticles in Mango-Passion Fruit Juice Fermented by Indigenous Lactic Acid Bacteria

Abstract

This study explores microbial selenization as a strategy for delivering selenium (Se) and seleno-nanoparticles (SeNPs) in a mango and passion fruit juice fermented by indigenous lactic acid bacteria (LAB). The fruit juice was fermented by a mixed culture of Se-enriched cells of Fructobacillus tropaeoli CRL2034 and Lactiplantibacillus paraplantarum CRL2051 at 30 °C for 24 h. The fermented beverages' intracellular Se and SeNPs content, antioxidant activity, microbial ability to survive gastrointestinal conditions, and sensory properties were evaluated. The mixed starter culture grew 2.04±0.17 log CFU/mL in the fruit juice after 24 h and produced lactic acid, acetic acid, and mannitol. After gastrointestinal digestion, the fermented juice exhibited high antioxidant activity (14.20±0.19 µM TE/mL) and a good survival rate (8.29±0.06 log CFU/mL). The SeNPs were detected after digestion by scanning electron microscopy. The fermented and non-fermented juices were accepted by the consumers indiscriminately and their consumption intention was similar (41.7% and 32.5%, respectively). The juices had a sensory shelf life of 30 days. An increase in the Se concentration (from 20.64 to 68.27 µg Se/L, P<0.05) in the fermented juice using selenized cells was observed. This beverage provides 40% of the recommended daily Se intake in a 200 mL serving. Combining Se and fermentation by rationally selected LAB ofers a promising strategy for enhancing fruit-based beverages' nutritional value and stability. This fermented juice could be used as a dietary supplement of Se, and as a vehicle to deliver potentially probiotic bacteria.