Study of Some Physicochemical and Functional Properties of Quinoa (Chenopodium Quinoa Willd) Protein Isolates

Abstract

The amino acid composition and the physicochemical and functional properties of quinoa protein isolates were evaluated. Protein isolates were prepared from quinoa seed by alkaline solubilization (at pH 9, called Q9, and at pH 11, called Q11) followed by isoelectric precipitation and spray drying. Q9 and Q11 had high levels of essential amino acids, with high levels of lysine. Both isolates showed similar patterns in native/SDS-PAGE and SEM. The pH effect on fluorescence measurements showed decreasing fluorescence intensity and a shift in the maximum of emission of both isolates. Q9 showed an endotherm with a denaturation temperature of 98.1 degrees C and a denaturation enthalpy of 12.7 J/g, while Q11 showed no endotherm. The protein solubility of Q11 was lower than that of Q9 at pH above 5.0 but similar at the pH range 3.0-4.0. The water holding capacity (WHC) was similar in both isolates and was not affected by pH. The water imbibing capacity (WIC) was double for Q11 (3.5 mL of water/g isolate). Analysis of DSC, fluorescence, and solubility data suggests that there is apparently denaturation due to pH. Some differences were found that could be attributed to the extreme pH treatments in protein isolates and the nature of quinoa proteins. Q9 and Q11 can be used as a valuable source of nutrition for infants and children. Q9 may be used as an ingredient in nutritive beverages, and Q11 may be used as an ingredient in sauces, sausages, and soups.

Effectual comparison of quinoa and amaranth supplemented diets in controlling appetite; a biochemical study in rats

“…Ranhotra et al (1993) also concluded that the quality of protein in quinoa equals that of casein. Both quinoa and amaranth are consistent in their nutritive value for a fact that their protein content is very similar and comparable to the whole milk protein casein (Escudero et al 2004;Abugoch et al 2008;James and Lilian 2009). They also contain good amount of dietary fiber, which are known to affect satiety by their water retaining capacity.…”

A Hybrid Dry and Aqueous Fractionation Method to Obtain Protein-Rich Fractions from Quinoa (Chenopodium quinoa Willd)

“…To stimulate more extensive use and create added value of (sweet) quinoa in the production of foods, ingredients derived from quinoa by fractionation have been explored by several studies, in particular, the production of protein isolates (Brinegar and Goundan 1993;Brinegar et al 1996;Chauhan et al 1999;Aluko and Monu 2003;Lindeboom 2005;Abugoch et al 2008;Aora and Alvarado 2009;Valenzuela et al 2013;Föste et al 2015;Avila Ruiz et al 2016a, b). In all these studies, the conventional wet fractionation method was applied.…”

Physicochemical and Functional Properties of Vegetable and Cereal Proteins as Potential Sources of Novel Food Ingredients

“…Several authors have compared the physicochemical and functional properties of buckwheat protein, soya protein isolate and casein (5,6,8). The functional characteristics of pseudocereals as quinoa and amaranth have also been reported in literature (5,9,10). Regarding cereals and other oilseeds, some authors have made comparisons among the protein functional properties of rice cultivars, peanut fl our and peanut protein concentrate as indicators of their potential use in food industry (11,12).…”