DPPH radical scavenging capacity and the reducing power of free and bound phenolics from wheat and porcino (Boletus edulis) flours

Abstract

In this paper the content, DPPH radical scavenging capacity and the chelating activity on Fe 2+ of free and bound phenolics extract from wheat and porcino flours were determined. The content of phenolic compounds in the extracts of free and bound phenolics from the wheat flour was 4.49 and 196.79 μg/g, and in the porcino flour these contents were 860.02 and 30.38 μg/g, respectively. The content of total phenolics in the porcino flour was considerably higher than that in the wheat flour. For DPPH test, the IC50 the value of free and bound phenolics from the wheat flour was 2.48 and 0.23 mg/ml, respectively, and these values for phenolics from the porcino flour were 0.22 and 0.06 mg/ml, respectively. For reducing power, the IC50 value of free and bound phenolics from the wheat flour was 5.12 and 0.21 mg/ml, and from the porcino flour it was 0.87 and 0.28 mg/ml, respectively. Free and bound phenolics from the porcino flour have a better DPPH scavenging capacity, and free phenolics from the porcino flour have a better reducing power than phenolics from the wheat flour. The results show that the addition of porcino to wheat flour could improve the antioxidant potential of the wheat flour and of final food products which could be obtained from the wheat-porcino flour mixture.

The antioxidant activity and the composition of free and bound phenolic acids in dough of wheat flour enriched by Boletus edulis after mixing and thermal processing

“…The wheat flour, type 500 by ‘Fidelinka’, Subotica, Serbia, bought from the local market, and the wild, fresh mushroom ( B. edulis ) from the eco‐region Piskupovo, Leskovac, Serbia, were used. The porcino flour was obtained after fresh porcino was dried, milled and sieved (Stojanović et al ., ). The flour mixture was obtained by mixing the wheat and porcino flour in ratio of 70:30 w/w (WPF).…”

“…The solids were re‐extracted and filtered. The filtrates were combined and a final volume of 200 mL was made by methanol (Stojanović et al ., ). For DPPH radical scavenging capacity (SC) and the reducing power test, 150 mL from each sample extract was taken, mixed and evaporated in vacuum at 40 °C until dry.…”

“…(): 10 g of the sample from which the free phenolics were removed, 300 mL of distilled water and 50 mL 6 m NaOH were mixed and left to stand at room temperature for 24 h. Then, the pH was adjusted to two, and the solvent mixture of dyethylether and ethylacetate (1:1, v/v) was added. The mixture was inverted every 30 min, and after 3 h, the upper layer was removed, evaporated to dry and the residue was dissolved in 20 mL of methanol (Stojanović et al ., ). For DPPH radical SC and reducing power test, the dry residue of each sample extract was dissolved in 5 mL of hot methanol and mixed.…”

“…After incubation for 30 min, the absorbance was measured at 765 nm by a UV 21000 Spectrophotometer (Cole Parmer Instruments Company, Vernon Hills, IL, USA). The phenolic content was calculated based on the calibration curve (Stojanović et al ., ) and expressed as μg of gallic acid per g of dry basis.…”