Antioxidant Activity of Free and Bound Compounds in Quinoa (Chenopodium quinoa Willd.) Seeds in Comparison with Durum Wheat and Emmer

Authors

  • Maura N. Laus,

    1. Authors Laus, Gagliardi, Soccio, Flagella, and Pastore are with Dip. di Scienze Agrarie, degli Alimenti e dell’Ambiente, Univ. degli Studi di Foggia, Via Napoli 25–71122 Foggia, Italy. Authors Laus, Soccio, Flagella, and Pastore are with Centro di Ricerca Interdipartimentale BIOAGROMED, Univ. degli Studi di Foggia, Via Napoli 52–71122 Foggia, Italy. Direct inquiries to author Pastore (E-mail: d.pastore@unifg.it).
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  • Anna Gagliardi,

    1. Authors Laus, Gagliardi, Soccio, Flagella, and Pastore are with Dip. di Scienze Agrarie, degli Alimenti e dell’Ambiente, Univ. degli Studi di Foggia, Via Napoli 25–71122 Foggia, Italy. Authors Laus, Soccio, Flagella, and Pastore are with Centro di Ricerca Interdipartimentale BIOAGROMED, Univ. degli Studi di Foggia, Via Napoli 52–71122 Foggia, Italy. Direct inquiries to author Pastore (E-mail: d.pastore@unifg.it).
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  • Mario Soccio,

    1. Authors Laus, Gagliardi, Soccio, Flagella, and Pastore are with Dip. di Scienze Agrarie, degli Alimenti e dell’Ambiente, Univ. degli Studi di Foggia, Via Napoli 25–71122 Foggia, Italy. Authors Laus, Soccio, Flagella, and Pastore are with Centro di Ricerca Interdipartimentale BIOAGROMED, Univ. degli Studi di Foggia, Via Napoli 52–71122 Foggia, Italy. Direct inquiries to author Pastore (E-mail: d.pastore@unifg.it).
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  • Zina Flagella,

    1. Authors Laus, Gagliardi, Soccio, Flagella, and Pastore are with Dip. di Scienze Agrarie, degli Alimenti e dell’Ambiente, Univ. degli Studi di Foggia, Via Napoli 25–71122 Foggia, Italy. Authors Laus, Soccio, Flagella, and Pastore are with Centro di Ricerca Interdipartimentale BIOAGROMED, Univ. degli Studi di Foggia, Via Napoli 52–71122 Foggia, Italy. Direct inquiries to author Pastore (E-mail: d.pastore@unifg.it).
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  • Donato Pastore

    1. Authors Laus, Gagliardi, Soccio, Flagella, and Pastore are with Dip. di Scienze Agrarie, degli Alimenti e dell’Ambiente, Univ. degli Studi di Foggia, Via Napoli 25–71122 Foggia, Italy. Authors Laus, Soccio, Flagella, and Pastore are with Centro di Ricerca Interdipartimentale BIOAGROMED, Univ. degli Studi di Foggia, Via Napoli 52–71122 Foggia, Italy. Direct inquiries to author Pastore (E-mail: d.pastore@unifg.it).
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Abstract

Abstract:  Antioxidant activity (AA) of quinoa (Chenopodium quinoa Willd.) seeds, as well as of durum wheat (Triticum turgidum L. ssp. durum Desf.) and of emmer (T. turgidum L. ssp. dicoccum Schübler) grains, was evaluated by studying hydrophilic (H), lipophilic (L), free-soluble (FSP) and insoluble-bound (IBP) phenolic extracts using the new lipoxygenase/4-nitroso-N,N-dimethylaniline (LOX/RNO) method, able to simultaneously detect different antioxidant mechanisms, as well as using the Oxygen Radical Absorbance Capacity (ORAC) and the Trolox Equivalent Antioxidant Capacity (TEAC) assays, which measure the scavenging activity against peroxyl and ABTS [2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonate)] radicals, respectively. The species under study were compared with respect to the sum of AA values of H, L and FSP extracts (AAH+L+FSP), containing freely solvent-soluble antioxidants, and AA values of IBP extracts (AAIBP), representing the phenolic fraction ester-linked to insoluble cell wall polymers. The LOX/RNO and ORAC methods measured in quinoa flour a remarkable AAH+L+FSP higher than durum wheat, although lower than emmer; according to the same assays, the IBP component of quinoa resulted less active than the durum wheat and emmer ones. The TEAC protocol also revealed a high AAH+L+FSP for quinoa. Interestingly, the ratio AAH+L+FSP/AAH+L+FSP+IBP, as evaluated by the LOX/RNO and ORAC assays, resulted in quinoa higher than that of both durum wheat and emmer, and much higher than durum wheat, according to the TEAC protocol. This may suggest that antioxidants from quinoa seeds may be more readily accessible with respect to that of both the examined wheat species.

Practical Applications:  Quinoa seeds may represent an excellent source of natural antioxidant compounds and, in particular, of the free-soluble antioxidant fraction. These compounds may improve nutritive and health-beneficial properties of quinoa-based gluten-free products, thus expanding interest for quinoa utilization from celiac patients to the general population.

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