Physicochemical Properties of Casein‐Starch Interaction Obtained by Extrusion Process

Abstract

Extruded samples of starch-casein blends were processed by using a single-screw extruder. The independent variables in the process were temperature (126-1947C), moisture content (18-29%) and starch-casein blend (5-95%). These independent variables affected significantly the physicochemical and textural properties of the biopolymers. The highest values for expansion (EXP) and water absorption index (WAI) were found when a higher starch proportion was present in the blends, at 1267C barrel temperature and moisture content higher than 25%. By increasing the barrel temperature, from 1267C to 1947C, the water solubility index (WSI) and color parameter were increased. Initial viscosity (IV) and viscosity at 907C (V90) were mainly affected by the barrel temperature at 1947C. However, the viscosity at 507C (V50) was affected neither by the different extrusion variables nor by the biopolymer proportion in the blends. Compression force (CF) was strongly dependent on moisture content and casein proportion in the blend. The higher CF values were found at starch concentrations around 50% and 25% moisture content, for higher or lower values than these the obtained extruded products were softer and consequently had lower CF values.

Some functional characteristics of extruded blends of fiber from sugarcane bagasse, whey protein concentrate, and corn starch

“…In addition, high BT increased the amount of fragmented starch and the percentage of insoluble and denaturalized protein thus lowering the EI. Previous studies have shown that the maximum values of EI were found with blends of starch and casein or whey protein in concentrations of less than 10% (FERNÁNDEZ-GUTIÉRREZ et al, 2004;AMAYA-LLANO et al, 2007). The EI of starchy products was found to be related to the severity of the extrusion process, and therefore to the plastification of the material.…”

Functional properties of corn and corn–lentil extrudates

“…Generally, functional properties of extrudates are related with the molecular modifications that occur during extrusion cooking. Furthermore, the effect of protein addition on the functional properties of cereal based extrudates has been reported previously (Fernandez-Gutierrez, Martin-Martinez, Martinez-Bustos, & Cruz-Orea, 2004;Gujska & Khan, 1991a;Lin, Huff, & Hsieh, 2002;Matthey & Hanna, 1997;Onwulata, Smith, Konstance, & Holsinger, 2001). The most common protein sources used for their production are soy, caseins, whey proteins, native or isolates and to smaller extent vegetable proteins from legumes like beans and chickpeas (except soy) (Anton, Fulcher, & Arntfield, 2009;Balandran-Quintana, Barbosa-Canovas, Zazueta-Morales, Anzaldua-Morales, & Quintero-Ramos, 1998;Singh, Sekhon, & Singh, 2007;Skierkowski, Gujska, & Khan, 1990).…”

“…Although legume proteins have hydrophilic groups, the protein denaturation during extrusion cooking leads to loss of hydration capacity of proteins. The lower hydration capacity is favored by the formation of inter-and intra-molecular protein bonds with amylose and amylopectin (Fernandez-Gutierrez et al, 2004). Thus, the addition of proteins in extrudates can decrease starch molecular degradation (Matthey & Hanna, 1997).…”

Structural and textural characterization of corn–lentil extruded snacks

“…There are several studies investigating the effect of extrusion conditions on structural and textural characteristics of starch-based extrudates (Ding et al, 2006(Ding et al, , 2005Fernandez-Gutierrez et al, 2004;Onwulata et al, 2001). In these, the basic component of investigation is 0260-8774/$ -see front matter Ó 2010 Elsevier Ltd. All rights reserved.…”