Apply a new valve for flow injection techniqe to determine the total phenols and antioxidant activity in wheat (Triticum aestiruml)‎

Abstract EN

In this study, a new design valve was used to estimate the total phenols and antioxidant activity based on continuous flow injection analysis was developed for the assessment with Folin-Ciocalteu reagent (FCR) reducing capacity in several types of food products using gallic acid as the standards.

Solution for mixing of sample and reagent were tested (continuous flow of FCR, merging zones, and intercalated zones approaches); lower reagent consumption and higher determination throughput were attained for the merging zones approach.

The application of the proposed method to pure compounds and wheat extract provided results with detection limit was 0.05 mg L-1 for both standards, and the determination frequency was about 55 h-1, good repeatability was attained (RSD < 2.48%, n = 10) for gallic acid, whereas 120 h-1, (RSD 0.65, n = 10) for ascorbic acid.

Highest total phenols in wheat extract was (2.50 mg/g GAE, 2.0 mg/g GAE) for using FIA-FCR, FIA-UV detection respectively.

Development of FIA-DPPH, FIAFRAP system were applied for determination of radical scavenging activity RSA%, contents of antioxidant compounds as well as, the reducing power activity RPA% of obtained wheat extract has been investigated.

Radical scavenging activity was found to exhibit IC50 value for extract concentration of 7.6 μg/mL DPPH, 1/IC50 0.329 μg/mg TP GAE.

The reducing power RP was 99.9 mg RP / g wheat.

All investigated methanolic wheat extract possess reductive capabilities.