Compositional and antioxidant properties of anthocyanin-rich products prepared from purple wheat

Citation

Abdel-Aal, E.S.M., Hucl, P., Rabalski, I. (2018). Compositional and antioxidant properties of anthocyanin-rich products prepared from purple wheat. Food Chemistry, [online] 254 13-19. http://dx.doi.org/10.1016/j.foodchem.2018.01.170

Plain language summary

Demands for anthocyanin-rich ingredients are steadily growing due to their positive effects on human health and in food coloration. Anthocyanins are natural pigments present in fruits, vegetables and grains. They are important components of the human diet, given the available body of evidence that highlights their roles in human health as antioxidant, anti-inflammatory, anti-diabetic and anti-cancer agents. The current study evaluated commercially available purple wheat as a source of functional ingredients based on anthocyanin composition and antioxidant properties. Three products were prepared namely, purple wheat whole meal flour, purple wheat bran and anthocyanin-rich powder. Anthocyanins were concentrated in the bran fraction by about 2-fold and then the bran was further processed into anthocyanin-rich powder using ethanol extraction and column purification. Batch studies showed that anthocyanin concentration factor increased by about 81- to 135-fold in the powder depending on batch size. Characterization of anthocyanins with a high-tech mass spectrometry showed a complex anthocyanin profile with 5 pigments making up 93-96% of the total anthocyanin content. These pigments were cyanidin-3-glucoside, cyanidin-3-(6-malonyl glucoside), cyanidin-3-rutinoside, peonidin-3-glucoside and peonidin-3-(6-malonylglucoside) but their concentrations varied between bran and powder. The purple wheat bran and powder exhibited exceptional antioxidant capacity based on scavenging of free and oxygen radicals, thereby increasing their potential use as functional and health-enhancing ingredients.

Abstract

Demands for anthocyanin-rich ingredients are steadily growing due to their positive functions in human health and food coloration. Commercially available purple wheat was evaluated as a source of functional ingredients based on anthocyanin composition and antioxidant properties. Anthocyanins were concentrated in the bran fraction by about 2-fold and then the bran was further processed into anthocyanin-rich powder using ethanol extraction and column purification. Batch studies showed that anthocyanin concentration factor increased by about 81- to 135-fold in the powder depending on batch size. Characterization of anthocyanins with a triple quad mass spectrometry showed a complex anthocyanin profile with 5 pigments making up 93–96% of the total anthocyanin content. These pigments were cyanidin-3-glucoside, cyanidin-3-(6-malonyl glucoside), cyanidin-3-rutinoside, peonidin-3-glucoside and peonidin-3-(6-malonylglucoside) but their concentrations varied between bran and powder. The purple wheat bran and powder exhibited exceptional antioxidant capacity based on scavenging of DPPH, ABTS and peroxyl radicals holding a promise as functional ingredients.

Publication date

2018-07-15

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