Shear scission through extrusion diminishes inter-molecular interactions of starch molecules during storage. (December 2018)

• Record Type: Journal Article
• Authors: Roman, Laura; Gomez, Manuel; Hamaker, Bruce R.; Martinez, Mario M.
• Is Part Of: Journal of food engineering. Volume 238(2018)
• Page Start: 134
• Page End: 140
• Publication Date: 2018-12
• Subjects: Extrusion -- Flour -- Starch -- Retrogradation -- Texture -- Amylopectin; Food industry and trade -- Periodicals; Food -- Analysis -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Analyse -- Périodiques; Aliments -- Recherche -- Périodiques; 664.005
• DOI: 10.1016/j.jfoodeng.2018.06.019
• Languages: English
• ISSNs: 0260-8774

Abstract

Abstract: The starch retrogradation behavior of native and extruded maize, wheat and rice flours were compared to better understand the efficacy of extrusion to decrease the propensity of different starches to form inter-molecular interactions. In all flour pastes, the increase of the storage modulus (G′) during a 7-day storage (representing inter-molecular interactions) was diminished with extrusion, albeit this effect was not detectable in rice due to the low gel consistency. Furthermore, thermo-rheological analyses revealed two distinct mechanisms depending on the cereal source. In maize and wheat flours, AM fragmentation through extrusion (detected through HPSEC) decreased the residual G′ at 85 °C of 7-day stored gels, which represents AM-AM physical junction zones that build gel structure. On the other hand, the extrusion of rice flour, which contains starch with lower AM ratio, resulted in a marked AP fragmentation that decreased the relative G′ drop, representing inter-molecular interactions involving AP. Highlights: The effect of extrusion of cereal flours on starch retrogradation was investigated. Extrusion resulted in different starch fragmentation in maize, wheat and rice flours. The tendency of starch to form inter-molecular interactions decreased after extrusion. In maize and wheat, amylose-amylose physical junction zones decreased after extrusion. In rice, extrusion reduced the inter-molecular interactions involving amylopectin.