Nowadays, there is a growing interest for foods with a lower sugar content and rich in fiber and biologically active substances. The main purpose of this study was to prepare flakes from non-traditional pigmented cereals (Oryza sativa, Chenopodium quinoa, and Eragrostis tef) and to analyze their fibre, sugar, and in vitro digestibility values. Regarding phenolic antioxidants (soluble, soluble conjugated, and insoluble bound fractions), their content and antioxidant activity were measured using spectrophotometry and high performance liquid chromatography (HPLC) methods. Hydrothermally treated grains resulted in flakes with higher total dietary fibre contents (11.1-24.4%), quinoa and teff flakes were rich in maltose (up to 42.0 mg/g). Non-traditional flakes had lower in vitro digestibility, but conversely, they exhibited the highest phenolic contents corresponding with the highest antioxidant activity values (up to 2.33 mg Gallic acid equivalent/g of total phenolic content and 1.59 mg Trolox equivalent/g for 2,2-diphenyl-1-picrylhydrazyl (DPPH) in case of brown teff). Among free phenolics, the main contributors to an antioxidant activity were p-coumaric, o-coumaric, and gallic acids (r > 0.8186); among the soluble conjugated fractions, they were epigallocatechin, epicatechin, caffeic, and vanillic acids (r > 0.5935); while caffeic, protocatechuic, and ferulic acids (r > 0.5751) were the main contributors among the insoluble bound phenolics.

Department of Food Analysis and Chemistry Tomas Bata University in Zlín Vavrečkova 275 760 01 Zlín Czech Republic

Department of Food Engineering Bolu Abant Ízzet Baysal University Gölköy Campus 14030 Bolu Turkey

Zobrazit více v PubMed

Rossel C.M., Marco C. Rice. In: Arendt E.K., Dal Bello F., editors. Gluten-Free Cereal Products and Beverages. 1st ed. Academic Press; Cambridge, MA, USA: 2008. pp. 81–100.

De Brier N., Gomand S.V., Joye I.J., Pareyt B., Courtin C.M., Delcour J.A. The impact of pearling as a treatment prior to wheat roller milling on the texture and structure of bran-rich breakfast flakes. LWT—Food Sci. Technol. 2015;62:668–674. doi: 10.1016/j.lwt.2014.08.015. DOI

Melini V., Panfili G., Fratianny A., Acquistucci R. Bioactive compounds in rice on Italian market: pigmented varieties as a source of carotenoids, total phenolic compounds and anthocyanins, before and after cooking. Food Chem. 2019;277:119–127. doi: 10.1016/j.foodchem.2018.10.053. PubMed DOI

Luithui Y., Nisha R.B., Meera M.S. Cereal by-products as an important ingredient: Effect of processing. J. Food Sci. Technol. 2019;56:1–11. doi: 10.1007/s13197-018-3461-y. PubMed DOI PMC

Ryan L., Thondre P.S., Henry C.J.K. Oat-based breakfast cereals are a rich source of polyphenols and high in antioxidant potential. J. Food Compos. Anal. 2011;24:929–934. doi: 10.1016/j.jfca.2011.02.002. DOI

Rocchetti G., Lucini L., Lorenzo Rodriguez J.M., Barba F.J., Giuberti G. Gluten-free flours from cereals, pseudocereals and legumes: Phenolic fingerprints and in vitro antioxidant properties. Food Chem. 2019;271:157–164. doi: 10.1016/j.foodchem.2018.07.176. PubMed DOI

Losada-Barreiro S., Bravo-Díaz C. Free radicals and polyphenols: The redox chemistry of neurodegenerative diseases. Eur. J. Med. Chem. 2017;133:379–402. doi: 10.1016/j.ejmech.2017.03.061. PubMed DOI

Vici G., Belli L., Biondi M., Polzonetti V. Gluten free diet and nutrient deficiencies: A review. Clin. Nutr. 2016;35:1236–1241. doi: 10.1016/j.clnu.2016.05.002. PubMed DOI

Prückler M., Siebenhandl-Ehn S., Apprich S., Höltinger S., Haas C., Schmid E., Kneifel W. Wheat bran-based biorefinery 1. Composition of wheat bran and strategies of functionalization. LWT—Food Sci. Technol. 2014;56:211–221. doi: 10.1016/j.lwt.2013.12.004. DOI

Shen Y., Jin L., Xiao P., Lu Y., Bao J. Total phenolics, flavonoids, antioxidant capacity in rice grain and their relations to grain color, size and weight. J. Cereal Sci. 2009;49:106–111. doi: 10.1016/j.jcs.2008.07.010. DOI

Walter M., Marchesan E., Massoni P.F.S., da Silva L.P., Sartori G.M.S., Ferreira R.B. Antioxidant properties of rice grains with light brown, red and black pericarp colors and the effect of processing. Food Res. Int. 2013;50:698–703. doi: 10.1016/j.foodres.2011.09.002. DOI

Scaglioni P.T., de Souza T.D., Schmidt C.G., Badiale-Furlong E. Availability of free and bound phenolic compounds in rice after hydrothermal treatment. J. Cereal Sci. 2014;60:526–532. doi: 10.1016/j.jcs.2014.08.005. DOI

Yeo J.D., Shahidi F. Effect of hydrothermal processing on changes of insoluble-bound phenolics of lentils. J. Funct. Foods. 2017;38:716–722. doi: 10.1016/j.jff.2016.12.010. DOI

AOAC . Association of Official Analytical Chemists International. 5th ed. AOAC; Arlington, VA, USA: 2007.

AOAC . Association of Official Analytical Chemists International. 18th ed. AOAC; Gaithersburg, MD, USA: 2005.

Hu X., Fang C., Lu L., Hu Z., Shao Y., Zhu Z. Determination of soluble sugar profile in rice. J. Chromatogr. B. 2017;1058:19–23. doi: 10.1016/j.jchromb.2017.05.001. PubMed DOI

Sumczynski D., Bubelová Z., Fišera M. Determination of chemical, insoluble dietary fibre, neutral-detergent fibre and in vitro digestibility in rice types commercialized in Czech markets. J. Food Compos. Anal. 2015;40:8–13. doi: 10.1016/j.jfca.2014.12.007. DOI

American Association of Cereal Chemists International . AACCI Approved Methods of Analysis. 11th ed. Cereals & Grains Association; St. Paul, MN, USA: 2010. Methods No. 32-05.01, 32-06.01, 32-07, 32-21.01, 32-40.01.

AOAC . Association of Official Analytical Chemists International. 17th ed. AOAC; Gaithersburg, MD, USA: 2000.

Qiu Y., Liu Q., Beta T. Antioxidant properties of commercial wild rice and analysis of soluble and insoluble phenolic acids. Food Chem. 2010;121:140–147. doi: 10.1016/j.foodchem.2009.12.021. DOI

Sumczynski D., Bubelová Z., Sneyd J., Erb-Weber S., Mlček J. Total phenolics, flavonoids, antioxidant activity, crude fibre and digestability in non-traditional wheat flakes and muesli. Food Chem. 2015;174:319–325. doi: 10.1016/j.foodchem.2014.11.065. PubMed DOI

Kotásková E., Sumczynski D., Mlček J., Valášek P. Determination of free and bound phenolics using HPLC-DAD, antioxidant activity and in vitro digestibility of Eragrostis tef. J. Food Compos. Anal. 2016;46:15–21. doi: 10.1016/j.jfca.2015.11.001. DOI

Pellegrini M., Lucas-Gonzales R., Ricci A., Fontecha J., Fernández-López J., Pérez-Álvarez J.A., Viuda-Martos M. Chemical, fatty acid, polyphenolic profile, techno-functional and antioxidant properties of flours obtained from quinoa (Chenopodium quinoa Willd) seeds. Ind. Crop. Prod. 2018;111:38–46. doi: 10.1016/j.indcrop.2017.10.006. DOI

Quiao F.-Q., Wang F., Ren L.-P., Zhou Z.-M., Meng Q.-X., Bao Y.-H. Effect of steam-flaking on chemical compositions, starch gelatinization, in vitro fermentability, and energetic values of maize, wheat and rice. J. Integr. Agric. 2015;14:949–955. doi: 10.1016/S2095-3119(14)60913-8. DOI

Zhu F. Chemical composition and food uses of teff (Eragrostis tef) Food Chem. 2018;239:402–415. doi: 10.1016/j.foodchem.2017.06.101. PubMed DOI

Koubová E., Mrázková M., Sumczynski D., Orsavová J. In vitro digestibility, free and bound phenolic profiles and antioxidant activity of thermally treated Eragrostis tef L. J. Sci. Food Agric. 2017;98:3014–3021. doi: 10.1002/jsfa.8800. PubMed DOI

Alvarez-Jubete L., Arendt E.K., Gallagher E. Nutritive value of pseudocereals and their increasing use as functional gluten-free ingredients. Trends Food Sci. Technol. 2010;21:106–113. doi: 10.1016/j.tifs.2009.10.014. DOI

Palafox-Carlos H., Gil-Chávez J., Sotelo-Mundo R.R., Namiesnik J., Gorinstein S., Gonzáles-Aguilar G.A. Antioxidant interactions between major phenolic compounds found in ’Ataulfo’ mango pulp: Chlorogenic, gallic, protocatechuhic and vanillic acids. Molecules. 2012;17:12657–12664. doi: 10.3390/molecules171112657. PubMed DOI PMC

Wang T., He F., Chen G. Improving bioaccessibility and bioavailability of phenolic compounds in cereal grains through processing technologies: A concise review. J. Funct. Foods. 2014;7:101–111. doi: 10.1016/j.jff.2014.01.033. DOI

Luthria D.L., Lu Y., John K.M.M. Bioactive phytochemicals in wheat: Extraction, analysis, processing, and functional properties. J. Funct. Foods. 2015;18:910–925. doi: 10.1016/j.jff.2015.01.001. DOI

Influence of Storage Conditions on Stability of Phenolic Compounds and Antioxidant Activity Values in Nutraceutical Mixtures with Edible Flowers as New Dietary Supplements