Viscoelastic Behaviour During the Gelatinization of Starch Ii. Effects of Emulsifiers

Abstract

The viscoelastic behaviour during the gelatinization of starch in the presence of emulsifiers was studied in oscillatory shear. Glycerol‐monostearate and sodium stearoyl‐lactylate delayed the viscoelustic changes during gelatinization in a way which was intetpreted as related to the granules being stiffer in presence of these emulsifiers. Sodium abdecyl sulphate caused a destabilization of the granules, resulting in the rheological changes occurring at lower temperatures. Emulsifiers increased the viscous part of the rheological response. In a wary‐starch variety, where the amount of amylase is small, emulsifiers had only a small effect on gelatinization. It was concluded that the formation of an amylose‐lipid complex was of importance if an emulsifier was to exert an effect.

Modelling of Rheological Behaviour in Starch–Lipid Systems

“…Commercial glyceryl monostearate Mivaplex 600 (Eastman Kodak Co., U.S.A.) was also used, containing at least 90% monoglycerides and no more than 5% diglycerides. Glyceryl monostearate is commonly used as an emulsifier in low concentrations (8), which is the reason for using a lower concentration than the one tested with the other lipids.…”

“…Several authors studied the effects of lipids and surfactants during starch gelatinization. They found that lipids affect both granule swelling and leaching of amylose and amylopectin (7)(8)(9)(10). However, most of these studies used monoglycerides or free fatty acids as lipid phase, few studies being devoted to starchtriglyceride interactions (3)(4)(5)(6).…”

The quartz crystal microbalance as a microviscometer for improved rehabilitation therapy of dysphagic patients

“…These regions undergo water imbibition [33]. Therefore, a starch gel can be regarded as a composite material, in which the continuous phase of the amylose gel matrix has swollen gelatinized granules made up of amylopectin distributed within it [34], [35]. The rheological properties of the continuous phase and the deformability of the dispersed phase, and the interactions between these two phases are associated with the mechanical properties of starch gels [34].…”

Temperature dependence on hydration kinetic model parameters during rehydration of parboiled rice

“…The starches in parboiled rice become gelatinized, and then retrograded after cooling. Through gelatinization, alpha-amylose molecules leach out of the starch granule network and diffuse into the surrounding aqueous medium outside the granules (Hermansson and Svegmark 1996) which, when fully hydrated are at maximum viscosity (Eliasson 1986). The parboiled rice kernels should be translucent when wholly gelatinized.…”