Influence of Spray-Drying and Room Temperature Storage on the Anti- and Prooxidant Properties of Fermented Juçara Pulp
1Department of Food Science and Technology, State University of Londrina, Celso Garcia Cid, Road – Pr 445 Km 380, Londrina, Paraná, Brazil
2Department of Pathology, Clinical and Toxicological Analysis, State University of Londrina, Celso Garcia Cid Road – Pr 445 Km 380, Londrina, Paraná, Brazil
3Physics Department, State University of Londrina, Celso Garcia Cid Road – Pr 445 Km 380, Londrina, Paraná, Brazil
Received: 17 April 2019
Accepted: 18 February 2020
Euterpe edulis Mart., Lactobacillus reuteri, Lactobacillus plantarum, fermented food, dehydrated fruit
Many fruits and vegetables contain compounds with antioxidant properties, but the processingand storage conditions of the food industry may damage these beneficial compoundsand produce free radicals that are associated with oxidative stress. This study aims to evaluatein vitro the antioxidant capacity and prooxidant effects of juçara pulp fermented with Lactobacillusreuteri or Lactobacillus plantarum before and after spray-drying with maltodextrin, gumarabic or gelatin and storage at 25 °C for 90 days. The antioxidant capacity was assessed bymeasuring the ability to scavenge reactive oxygen species (ROS) in the neutrophil respiratoryburst and free radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH), and by determining the totalphenolic content. The prooxidant effects were analyzed as free radical formation measuredby electronic paramagnetic resonance (EPR). Fermentation by both bacteria increased theantioxidant activity, while the spray-drying process decreased the content of phenolic compounds(65-85 %) and the DPPH scavenging ability, depending on the carrier usage. All ofthe samples inhibited ROS in the neutrophil burst, and the juçara pulp fermented by L. reuteriand dried with gum arabic exhibited the best performance. Spray-drying did not influencethe intensity or type of free radicals detected by EPR. However, storage at room temperaturedecreased the antioxidant capacity and increased free radical formation.