Evaluation of phytochemicals and antioxidant activity of gamma irradiated quinoa (Chenopodium quinoa)

Abstract

Phytochemical and antioxidant activity of quinoa flour was evaluated after subjected to gamma irradiation processes at dose 3 and 6 kGy. Both non-irradiated and irradiated quinoa samples were subjected to successive extractions in ethanol solvent. The antioxidant activity after gamma irradiation treatment was investigated via Ferric reducing antioxidant power (FRAP) and radical-scavenging activity (RSA) using 2,2-diphenyl-1-picrylhydrazyl (DPPH).Total phenolic and flavonoid content were analyzed using Folin–Ciocalteu micro-method, aluminium chloride (AlCl3) method and High Performance Liquid Chromatography (HPLC). As well as, effect of irradiation treatment on saponin was also evaluated. Irradiation treatment showed slight differences in the saponin content after exposure to 3 and 6 kGy. Irradiation process enhanced both total phenolic content (TPC) and Total flavonoid content (TFC), TPC were 34.52 and 30.92 mg Gallic Acid Equivalent (GAE)/100g compared to 26.25 mg GAE/100g in non-irradiated quinoa. TFC were 67.44 and 62.89 mg Quercetin Equivalents (QE)/100g compared to 53.15 mg QE/100g. Irradiation dose 3 kGy significantly (p> 0.05) decreased the IC50 as DPPH-RSA and increased the FRAP.

Structural Characterization and Antioxidant Capacity of Quinoa Cultivars Using Techniques of FT-MIR and UHPLC/ESI-Orbitrap MS Spectroscopy

“…In this sense, the high diversity of quinoa makes it possible to find variations in the foliar area of the plants, which is related to the CO2 net assimilation and to obtain triose phosphate in the CO2 fixation phase, which allows the obtaining of starches for their translocation to sink organs [34,35]. Additionally, Reguera and coworkers found changes in the synthesis of secondary metabolites of three quinoa cultivars and highlighted that these compounds seem to be genotype-specific and could vary significantly under stressful conditions [9] The polyphenol values vary in all quinoa cultivars and are linked to climatic conditions, agronomical practices and genetic interaction [17]. Li, Lietz & Seal (2021) [36] reported 1.44-mg AG/g of total phenols and antioxidant activity between 8.61 and 522 µ m of Trolox/g under ABTS and DPPH.…”

“…Reference Abdelaleem & Elbassiony (2021) [17] reported Egyptian cultivars lacking caffeine but with values of caffeic acid, vanillic acid and apigenin up to 0.49 mg/kg, 30.5 mg/kg and 0.44 mg/kg, accordingly. The quercetin-3-glucosid concentrations observed were considerably low in this research, and the p-coumaric acid values reported were similar to those by Tang & Tsao (2017) [40].…”

“…The polyphenol values vary in all quinoa cultivars and are linked to climatic conditions, agronomical practices and genetic interaction [17]. Li, Lietz & Seal (2021) [36] reported 1.44-mg AG/g of total phenols and antioxidant activity between 8.61 and 522 µm of Trolox/g under ABTS and DPPH.…”

“…They handled short and mid-range infrared spectroscopy to single out carbohydrates, lipids and proteins present from quinoa belonging to five different geographic areas. There is also an interest that has become relevant over the recent years around examining bioactive compounds and the antioxidant capacity of seeds [17,18].…”

Antioxidant potential and α-glucosidase inhibitory activity of onion (Allium cepa L.) peel and bulb extracts

“…In this, antioxidants present in extract sample have the ability to reduce ferric tripyridyltriazine (Fe3+TPTZ) into ferrous tripyridyltriazine (Fe 2+ TPTZ). Higher absorbance might indicate towards greater antioxidant activity (Abdelaleem and Elbassiony, 2021). The obtained results of ferric reducing power depicted that onion peel samples have decreasing tendency of reduction based on the kind of solvent used for extraction (i.e., ethanol or water) when absorbance was measured at 700nm (see Figure 2).…”