Voltaire Santanna
University of Rio Grande do Sul, Brazil
Title: Evaluation of pinhao (Araucaria angustifolia) seed coat as source of total polyphenols, antioxidant, antimicrobial and allelochemical agents
Biography
Biography: Voltaire Santanna
Abstract
Pinhão is a starch-rich seed produced by Araucaria angustifolia. Pinhão seed coat is as a byproduct generated in both households and farms, presenting great potential as source of natural food preservatives. The objective of this study was to evaluate total polyphenol content, antioxidant, antimicrobial and bioherbicidal properties of the residue. For this aim, pinhão seeds were cooked and peeled, and their coat were dried at 60ºC for 24h. Dried residue was crushed in industrial blender and sifted. Total polyphenol content and ABTS scavenging activity were evaluated using an aqueous extract from dried residue powder, at a concentration of 10 and 5gL-1. Pinhão seed coat extracts were also tested against pathogenic bacteria, phytopathogenic fungi and for lettuce seed germination through in vitro tests. The polyphenol analysis revealed that pinhão seed coat extract presents 53.8 mg GAE g-1 and the ABTS scavenging activity was 76.1%. The residue extract caused a decrease in seed germination and reduced the germination seed index when used in concentrations of up to 5gL-1, although it did not interfere the germinated plant root size. Additionally, the pinhão seed coat extract presented antibacterial activity against Bacillus cereus, Listeria monocytogenes, Listeria innocua and Staphylococcus aureus, but showed no anti-fungal activity. Thus, aqueous extract of pinhão seed coat can be an interesting alternative to be used as natural antibacterial and herbicide, also representing a way of solid waste management by industries and small farmers.
Figure. Pinhão seed coat extract presents antioxidant, antibacterial and herbicidal activities.