Solange Teresinha Carpes

Polyphenols and palynological origin of bee pollen of Apis mellifera L. from Brazil. Characterization of polyphenols of bee pollen

The aim of this work was to study the chemical composition, botanical origin and the antioxidant activity of ethanolic extracts of bee pollen. The antioxidant activity was measured by 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH•) scavenging method and β-carotene-linoleic assay. The pollen extracts were purified using a XAD2 resin and the amount of phenolic compounds and flavonoids were identified by reverse phase-high performance liquid chromatography (RP-HPLC) and gas chromatography–mass spectrometry (GC–MS) analyses. The phenolic content of bee pollen extracts before and after the resin were 38.6 and 17.8 mg/g of gallic acid equivalent in bee pollen, respectively. Two different flavonoids (rutin and myricetin) which can be accounted by the high antioxidant activity of bee pollen extracts were identified and quantified. The total antioxidant capacity measured by the DPPH• radical method increased significantly in bee pollen extracts purified with hydrophobic resin: 24.84–94.75% (Palmeira). All samples were considered heterofloral, which were composed by pollen from Myrtaceae eucalyptus, Asteraceae and Brassicaceae families, and among others.

Shelf life and quality study of minced tilapia with Nori and Hijiki seaweeds as natural additives.

The extraction of mechanically separated meat has emerged as an attractive process. However, it increases the incorporation of oxygen and, consequently, of flavors due to rancidity. Thus, preservatives must be added. The objective of this study was to evaluate the shelf life of minced tilapia to replace synthetic preservatives with Hijiki and Nori seaweeds extracts. The application of the extracts had no effect on the chemical composition of the minced tilapia. The seaweed extracts had inhibitory effect on total volatile base nitrogen. The minced tilapia complied with the microbiological standard set by Brazilin law. The panelists detected no differences in the rancid aroma and only minor differences were detected in the color of the products. It can be concluded that the minced tilapia with added seaweed extracts were within quality standards during frozen storage.