Protein and lipid enrichment of quinoa (cv.Titicaca) by dry fractionation. Techno-functional, thermal and rheological properties of milling fractions

Abstract

The quality of quinoa flour is greatly determined by its non-starch components, mainly protein and lipids. Dry fractionation has an important impact on the composition and physicochemical properties of quinoa flour and grits. Quinoa cv. Titicaca, the most extensively grown in Europe and little studied so far, was used in this work. Hydration, techno-functional, rheological and thermal properties of three quinoa fractions obtained by dry fractionation (fine, medium and coarse) were evaluated and related to their particle size and composition. The medium fraction (~500 μm) was enriched in protein (50%) and lipids (80%) and depleted in starch (30%) with respect to the original grain; while the coarse fraction (~1000 μm) was enriched in starch (7%) and reduced in protein (15%). The fine fraction showed the most similar functional, pasting and rheological properties to the whole grain quinoa flour. The coarse fraction led to the most consistent gels, with the elastic (G') and viscous (G'') moduli being ten and twenty times higher than those found in the other quinoa fractions and the whole grain flour. The degree of retrogradation as well as the formation of the amylose-lipid complex were markedly affected by the particle size and not so by the composition of each fraction. This work allows to conclude that dry fractionation of quinoa grains is a feasible procedure to tailoring the nutritional profile of the flour and its techno-functional and rheological properties.

Investigation of Quinoa Seeds Fractions and Their Application in Wheat Bread Production

“…G and G increased when QF addition level and PS increased. The highest G and G were observed at large PS which can be explained by the synergistic effect between starch amount and the large PS, the results being in line with those found by Solaesa et al [15]. Significant differences (p < 0.01) between QF dough samples and control were observed in loss tangent (tan δ) regarding QF addition level, although the samples with 5% and 10% addition levels did not show significant differences in this parameter.…”

“…Similar findings regarding carbohydrates from WF-QF composite flours were found by ElSohaimy et al [18]. Similar trends of the chemical compositions were previously reported by Coţovanu, Stoenescu and Mironeasa [39], by Ahmed, Thomas and Arfat [42], and Solaesa, Villanueva, Vela, and Ronda [15].…”

“…It was noticed that composite flours with medium particles had the highest protein content, followed by flours which contain small particles of QF, while the lower content of protein was found in flours with a large fraction of QF, probably as a result of the botanical structure of quinoa seeds, where proteins and minerals are localized mostly in the embryo and endosperm [12,40] and some part of the grain, richer in proteins, was broken in the form of small particles [41]. Additionally, these variations of protein content in flours enriched with quinoa flour fractions can be explained by the milling equipment used for grinding which differently influenced the structure of the endosperm (hard/soft) and type of endosperm cells (peripheral, prismatic, or central) [15]. Others authors that grounded quinoa seeds with coffee grinder found a higher protein content in small fraction [42].…”

“…The dynamic rheological testing methods indicate the viscoelastic behavior of the WF-QF dough given by the interactions between quinoa fractions and wheat gluten network. QF addition caused modifications of the rheological and textural parameters of wheat dough as a result of the gluten dilution [14][15][16]. The ingredients rich in fibers and starch could impact the gas retention of dough, leading to lower bread volume, porosity and elasticity, and higher firmness [17,18], the changes' magnitude depending on the addition level and particle size.…”

Maceração de grãos de Chenopodium quinoa Willd: efeito do tempo e temperatura

“…Os dados obtidos das análises de proteína a 5 o C e pH a 25 o C não foi possível ajustar nenhum modelo. Para massa do grão o coeficiente de regressão e a falta de ajuste também foram significativos, no entanto, a falta de ajuste apresentou um valor muito baixo, assim sua (Solaesa et al, 2020). Outros fatores que também afetam a solubilidade são a relação de grupos polares e apolares, bem como a estrutura primária, secundária, terciária e quaternária da proteína (Salcedo-Chávez et al, 2002;Aceituno-Medina et al, 2013;Föste et al, 2015).…”