Effect of salts on pasting, thermal, and rheological properties of rice starch in the presence of non-ionic and ionic hydrocolloids

Recent progress in the industrial and biomedical applications of tragacanth gum: A review

Natural polymers have distinct advantages over synthetic polymers because of their abundance, biocompatibility, and biodegradability. Tragacanth gum, an anionic polysaccharide, is a natural polymer which is derived from renewable sources. As a biomaterial, tragacanth gum has been used in industrial settings such as food packaging and water treatment, as well as in the biomedical field as drug carriers and for wound healing purposes. The present review provides an overview on the state-of-the-art in the field of tragacanth gum applications. The structure, properties, cytotoxicity, and degradability as well as the recent advances in industrial and biomedical applications of tragacanth gum are reviewed to offer a backdrop for future research.

Effects of Acid and Salt Solutions on the Pasting, Rheology and Texture of Lotus Root Starch⁻Konjac Glucomannan Mixture

To explore the functional properties of mixed biopolymer systems affected by acid and salts. The effects of acid and salt solutions (i.e., NaCl, KCl and CaCl₂) on the pasting, rheology, texture and microstructure of lotus root starch⁻konjac glucomannan (LRS/KGM) mixtures were assessed. Acid (citric acid buffer) treatment worsened the pasting (except for breakdown viscosity), rheological (except for fluid index), and textural properties, thereby inhibiting retrogradation, weakening pseudoplasticity and thickening, and reducing mixture viscoelasticity. Furthermore, it led to destructive ruptures and large pores in the internal microstructure. Salt treatment worsened the pasting properties (except for setback viscosity), thus inhibiting retrogradation and weakening pseudoplasticity, but enhanced the rheological properties, improving thickening and fluctuating viscoelasticity of the mixture. Moreover, salt addition decreased the hardness while increasing mixture cohesiveness, and modified the elasticity, adhesiveness and internal microstructure in a salt type- and concentration-dependent manner. A salt solution concentration of 0.5 mol/L NaCl, 0.1 mol/L KCl, and 0.5 mol/L CaCl₂ led to the mixture with the best texture and gel network.

Synergistic rheological behavior and morphology of yam starch and Auricularia auricula-judae polysaccharide-composite gels under processing conditions

Polysaccharides from Auricularia auricula-judae (AP) have unique functionalities. The influence of AP-blending ratios (0.1-0.8%), temperature, pH, and ionic strength on the rheological interactions of yam starch (YS)-AP blends (YA, 6%) was investigated. YA gels showed shear-thinning behavior with flow-behavior indices of 0.28-0.37 and greater pseudoplasticity in the presence of 0.8% AP. With incremental AP addition, the viscosity and consistency indices significantly increased, whereas the activation energy decreased from 7.55 to 5.12 kJ/mol (p < 0.05). YA gels exhibited excellent thickening and heat tolerance and behaved as weak gels over an AP concentration range of 0.1-0.4% but as true gels at higher concentrations (e.g. 0.8%). The viscosity/elasticity of the combinations weakened with NaCl addition or extreme pH values. A complex 3-dimensional network structure of the YA system was confirmed by scanning electron microscopy. These results indicated that AP has great potential for functional applications in the starchy food industry.

Rheological and Pasting Properties of Naked Barley Flour as Modified by Guar, Xanthan, and Locust Bean Gums

To understand the effects of adding different gums (guar, xanthan, and locust bean gums) on naked barley flour (NBF), the rheological and pasting properties of NBF-gum mixtures were measured at different gum concentrations (0, 0.3, and 0.6% w/w). Steady shear rheological properties were determined by rheological parameters for power law and Casson models. All samples showed a clear trend of shear-thinning behavior (n=0.16~0.48) and had a non-Newtonian nature with yield stress. Consistency index, apparent viscosity, and yield stress values increased with an increase in gum concentration. Storage modulus values were more predominant than loss modulus values with all concentrations of gums. There is a more pronounced synergistic effect of elastic properties of NBF in the presence of xanthan gum. Rapid visco analyser pasting properties showed that the addition of gums resulted in a significant increase in the peak, breakdown, setback, and final viscosities, whereas the pasting temperature decreased.

The effect of salt concentration on swelling power, rheological properties and saltiness perception of waxy, normal and high amylose maize starch

The effect of salt concentration on swelling power, rheological properties and saltiness perception of waxy, normal and high amylose maize starch was investigated.

Effect of curdlan and xanthan polysaccharides on the pasting, rheological and thermal properties of rice starch

The effects of microbial polysaccharides xanthan and curdlan on the pasting, viscoelastic properties and retrogradation of rice starch were studied. The additions of xanthan and curdlan increased the peak viscosities and decreased the final viscosities. The breakdown viscosities were increased by the curdlan addition, but were decreased by the xanthan addition. The dynamic viscoelastic results showed that the addition of xanthan in rice starch significantly increased storage modulus and loss modulus. The rice starch gel with xanthan addition exhibited higher resistances to the stress and produced a stronger microstructure network. The creep recovery data were well fitted by a 4-element Burger's model. Differential scanning calorimetry showed that the addition of curdlan and xanthan decreased the melting enthalpy values and retarded the retrogradation of the rice starch gel during storage at 4 °C for 12 days. The pasting and thermal results demonstrated that the addition of xanthan could significantly inhibited the retrogradation of rice starch. It was concluded that the addition of curdlan and xanthan modified the rheology of rice starch gel in different ways and interacted under different models based on their molecular structures.

Effect of sucrose fatty acid esters with different hydrophilic-lipophilic balance values on pasting and rheological properties of waxy rice flour

Effects of sucrose fatty acid esters (SEs) with hydrophilic-lipophilic balance (HLB) values of 5 (S-570), 9 (S-970), and 15 (S-1570) on the pasting and rheological properties of waxy rice flour (WRF) were investigated. Rapid Visco Analyzer (RVA) showed that addition of SEs affected the pasting properties of WRF. Rheological experiment includes the steady shear flow characteristics, and dynamic viscoelastic properties were also determined using a controlled-stress rheometer. The steady shear tests demonstrated that the viscosity data fitted well with the power law model (R ²≥0.976) and all WRF pastes exhibited typical pseudoplastic and shear-thinning properties. Dynamic rheological measurements revealed that the addition of S-970 and S-1570 significantly increased the values of G' and G″ of samples, whereas the addition of S-570 decreased these values. The addition of S-1570 reduced the value of tanδ, whereas S-570 and S-970 increased it.

Effect of Acacia Gum, NaCl, and Sucrose on Physical Properties of Lotus Stem Starch

Consumer preferences in east Asian part of the world pave the way for consumption of lotus stem starch (LSS) in preparations such as breakfast meals, fast foods, and traditional confectioneries. The present study envisaged the investigation and optimization of additives, that is, acacia gum, sodium chloride (NaCl), and sucrose, on water absorption (WA), water absorption index (WAI), and water solubility index (WSI) of LSS employing response surface methodology (RSM). Acacia gum resulted in increased water uptake and swelling of starch; however, NaCl reduced the swelling power of starch by making water unavailable to starch and also due to starch-ion electrostatic interaction. Sucrose restricted the water absorption by binding free water and decreased amylose leaching by building bridges with starch chains and thus forming rigid structure.

Effect of Sucrose Addition on Rheological and Thermal Properties of Rice Starch–Gum Mixtures

The effect of sucrose at different concentrations (0, 10, 20, and 30% w/w) on rheological and thermal properties of 5% (w/w) rice starch (RS) pastes mixed with guar gum (GG) and xanthan gum (XG) was examined. The flow behavior index (n) values of RS–gum mixtures in the presence of sucrose were higher than those of the control (0% sucrose), whereas their K and σoc values were lower. The RS–XG–sucrose mixtures showed much higher dynamic moduli values than the control, while the RS–GG–sucrose mixtures, except for the 30% sucrose concentration, showed lower values, indicating that the viscoelastic properties of RS–XG mixtures were greatly affected by the addition of sucrose. In general, differential scanning calorimetry studies showed that the presence of sucrose resulted in an increase in the gelatinization temperatures and a decrease in gelatinization enthalpy. These results could facilitate the development of RS-based products with improved thermal and rheological properties.

Gluten-free dough-making of specialty breads: Significance of blended starches, flours and additives on dough behaviour

The capability of different gluten-free (GF) basic formulations made of flour (rice, amaranth and chickpea) and starch (corn and cassava) blends, to make machinable and viscoelastic GF-doughs in absence/presence of single hydrocolloids (guar gum, locust bean and psyllium fibre), proteins (milk and egg white) and surfactants (neutral, anionic and vegetable oil) have been investigated. Macroscopic (high deformation) and macromolecular (small deformation) mechanical, viscometric (gelatinization, pasting, gelling) and thermal (gelatinization, melting, retrogradation) approaches were performed on the different matrices in order to (a) identify similarities and differences in GF-doughs in terms of a small number of rheological and thermal analytical parameters according to the formulations and (b) to assess single and interactive effects of basic ingredients and additives on GF-dough performance to achieve GF-flat breads. Larger values for the static and dynamic mechanical characteristics and higher viscometric profiles during both cooking and cooling corresponded to doughs formulated with guar gum and Psyllium fibre added to rice flour/starch and rice flour/corn starch/chickpea flour, while surfactant- and protein-formulated GF-doughs added to rice flour/starch/amaranth flour based GF-doughs exhibited intermediate and lower values for the mechanical parameters and poorer viscometric profiles. In addition, additive-free formulations exhibited higher values for the temperature of both gelatinization and retrogradation and lower enthalpies for the thermal transitions. Single addition of 10% of either chickpea flour or amaranth flour to rice flour/starch blends provided a large GF-dough hardening effect in presence of corn starch and an intermediate effect in presence of cassava starch (chickpea), and an intermediate reinforcement of GF-dough regardless the source of starch (amaranth). At macromolecular level, both chickpea and amaranth flours, singly added, determined higher values of the storage modulus, being strengthening effects more pronounced in presence of corn starch and cassava starch, respectively.