Evaluation of antioxidant and iron chelating activities of peptides from flaxseed (Linum usitatissimum L.)

• Grant number: 12/20492-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2012
• End date: October 31, 2013
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Principal Investigator: Flavia Maria Netto
• Grantee: Eloisa Cristina Carmignola
• Host Institution: Faculdade de Engenharia de Alimentos (FEA). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

The bioactive potential of proteins is due to certain amino acid sequences which are inactive in the precursor protein but once released by enzymatic hydrolysis, may have different biological activities. In vitro studies showed that flaxseed protein hydrolysates have different biological activities such as antioxidant, anticolesterolemic and antihypertensive. As antioxidants, amino acids, and peptides may act through different mechanisms, including reduction of reactive oxygen species or chelation with transition metals, such as iron. This project aims at evaluating the antioxidant potential and iron-binding ability of protein products of defatted brown flaxseed, with and without lignin, a phenolic compound. After flaxseed meal defatting with hexane, the protein concentrate will be obtained by alkaline extraction, precipitation at the isoelectric point, followed by neutralization. The protein hydrolysate will be produced by protein concentrate hydrolysis with Alcalase at pH 8.5 and enzyme-substrate ratio 1:90. These conditions, obtained in a previous study, produced hydrolysates with high antioxidant activity. For obtaining protein products without lignan, extraction with ethanol will be added after flaxseed meal defatting with hexane. The samples will be characterized by chromatography (RP-HPLC). The antioxidant activity of protein concentrates and their hydrolysates, with and without lignan, will be measured by the iron-binding ability and the reducing power.(AU)