Physicochemical Properties of Quinoa Extrudates

Abstract

Response surface methodology (RSM) was used to analyse the effect of temperature, screw speed, and feed moisture content on physicochemical properties of quinoa extrudates. A three-level, three-variable, Box-Behnken design of experiments was used. The experiments were run at 16-24% feed moisture content, 130-170°C temperature, and 250-500 rpm screw speed with a fixed feed rate of 300 g/min. Second order polynomials were used to model the extruder response and extrudate properties as a function of process variables. Responses were most affected by changes in feed moisture content and temperature, and to a lesser extent by screw speed. Calculated specific mechanical energy (SME) values ranged between 170-402 kJ/kg which were lower than those observed for other cereals, most likely due to high (7.2%) fat content of quinoa. High levels of feed moisture alone, and in combination with high temperature, resulted in poor expansion. The best product, characterised by maximum expansion, minimum density, high degree of gelatinization and low water solubility index, was obtained at 16% feed moisture content, 130°C die temperature, and 375 rpm screw speed, which corresponds to high SME input. It was demonstrated that the pseudo-cereal quinoa can be used to make novel, healthy, extruded, snack-type food products.

Changes in physical properties of extruded sour cassava starch and quinoa flour blend snacks

“…The increase in water solubility index with increasing temperature and decreasing moisture was consistent with results reported for quinoa flour extrudes (DOGAN;KARWE, 2003). Taverna; Leonel; Mischan An increase in the value of WAI may probably be caused by uncovering of hydrophilic groups in extruded starch-protein material, by unfolding and loosening of biopolymer chains, greater availability, and easier penetration of structures by water molecules (MARZEC;LEWICKI, 2006).…”

“…The water absorption index found for quinoa flour was higher than that reported for unprocessed quinoa flour (1.69 g gel.g -1 ) (DOGAN; KARWE, 2003). Table 2 summarizes the estimated regression coefficients for the models fitted to the experimental results and their significance as well as their corresponding coefficients of determination.…”

“…However, molecular interactions between degraded starch, protein, and lipid components may reduce solubility (DOGAN; KARWE, 2003).…”

Twin screw extrusion of kodo millet-chickpea blend: process parameter optimization, physico-chemical and functional properties

“…Bulk density is a better measure of volumetric expansion as there is an inverse relationship between sectional and longitudinal expansion (Dogan and Karwe 2003;Ilo et al 1996). Increase in barrel temperature results in extrudates with low values for hardness, where reduced BD was observed in the present study similar to that observed by Altan et al (2008) and Bhattacharya (1997).…”

Use of cereal bars with quinoa (Chenopodium quinoa W.) to reduce risk factors related to cardiovascular diseases

“…There are several developments with quinoa flour at a smaller scale such as bread, muffins, pasta, snacks, drinks, flakes, baby foods, beer, and extrudates (ABUGOCH JAMES, 2009;DOGAN;KARWE, 2003).…”