The impact of concentration, temperature and pH on dynamic rheology of psyllium gels (original) (raw)
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Rheological Properties of the Gum Fractions from Psyllium (Plantago Psyllium L.)
Journal of Herbal Drugs: International Journal on Medicinal Herbs, 2013
Background & Aim: Psyllium (Plantago psyllium L.) is a native plant that grows widely in India and Iran. Different cases of using psyllium gum for its suitable rheological properties in a wide range of food products exist in nature. Experimental: In this study, different fractions of psyllium gum were extracted by water and alkali treatments. Rheological properties of these fractions were measured by Brookfield rheometer (RV DVIII). The obtained data was fitted by Herschel-bulkly model in three temperatures 30, 60 and 80°C. Results & Discussion: Results indicated that fractions show different behaviours during heating treatment.
Rheological Behaviour of Psyllium Gum Fractions
Journal of Microbiology, Biotechnology and Food Sciences, 2013
Psyllium (Plantago psyllium) is a native plant that grows widely in India, Iran and Pinjab. Studies showed psyllium gum has good rheological properties for using in wide range of food products. In this study, different fractions of psyllium gum extracted by water and alkali treatment. Rheological properties of these fractions determined by Brookfield rheometer (RV DVIII). Obtained data fitted in three temperatures 30, 60 and 80°C by Herschel-bulkly rheological model. Results showed that fractions have different behaviour during heating treatment. The most difference observed in AEG0.5 fraction.
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Effects of psyllium (Plantago ovata) husk powder (PHP) at various concentrations (0, 1, 2, 3 and 4%, w/w) on gelling properties of surimi from threadfin bream (Nemipterus sp.) were investigated. The addition of 1% PHP resulted in the highest increase (50%) in the breaking force (BF) of surimi gel (S), compared to that of the control gel (CON; without PHP). Lower BF was obtained for gel incorporated with PHP at the higher levels (2–4%) (p < 0.05). On the other hand, deformation (DF) was decreased with the addition of PHP at all levels compared to the CON gel. The whiteness and expressible moisture content of gels were decreased with augmenting levels of PHP (p < 0.05). Protein patterns revealed that PHP at all concentrations did not affect the polymerization of the myosin heavy chain. A loss in the elasticity of the gel was attained with the addition of PHP as indicated by decreased storage modulus (G’). A finer and more compact network was detected in gels containing 1 and 2% ...
Dynamic viscoelastic study on the gelation of basil seed gum
International Journal of Food Science & Technology, 2013
Oscillatory measurements were used to investigate the effect of temperature and concentration on the viscoelastic and gelling properties of basil seed gum (BSG). Linear viscoelastic region was determined by strain sweep and it was found in 0.5% strain. Storage modulus (G′) was greater than loss modulus (G″) in all concentrations and they increased by improving BSG concentration. Yield stress value was determined by stress sweep and it increased from 1.40 to 7.47 Pa when BSG concentration increased from 1% to 3%. Frequency sweep showed BSG solution was a typical weak gel, and complex viscosity (g*) had linear correlation with frequency. The effect of temperature on gel forming was investigated during heating (20-90°C) and cooling (90-20°C) phases. BSG was characterised as a thermo-reversible gel and did not have thermal hysteresis. Gelling temperature was raised as BSG concentration was increased. Exhibiting special rheological properties of BSG makes it as a proper synergistic gel, which can be applied in real food systems such as dairy desserts.
Small deformation viscoelastic and thermal behaviours of pomegranate seed pips CMC gels
Journal of Food Science and Technology, 2014
The current investigation presents an exploration in phase behaviour of carboxymethyl cellulose (CMC) produced from pomegranate seed pips compared to low and high viscosity CMCs (LMCMC and HMCMC) primarily at low solid concentrations. Cellulose was extracted with 10 % NaOH at 35°C for 22 h from pomegranate seed pips and converted to CMC by etherification process. Thermomechanical analysis and micro-imaging were carried out using small deformation dynamic oscillation in shear, modulated differential scanning calorimetry (MDSC) and scanning electron microscopy (SEM). The results emphasize the importance of molecular interaction and the degree of substitution in produced CMC. Thermal gravimetric analysis (TGA) thermograms showed an initial weight loss in pomegranate seed pips CMC (PSCMC) sample, which we attribute to presence of amount of moisture in sample powder. MDSC analysis of PSCMC showed five different peaks at 84, 104, 173, 307 and 361°C. Moreover, G' and G" changes were found to be dependent on both concentration and frequency. The results of frequency sweep and tan δ indicate that PSCMC solutions can be classified as weak gels.
2013
Analysis of physicochemical properties of Eucalyptus citriodora gum revealed that the gum is mildly acidic, brownish in colour, ionic and has the potentials to swell four times its original volume. GCMS analysis of the gum indicated the presence of some carboxylic acids, pyran-4-one, 1,3-dioxolane, benzofuran and 1,2-ethanediyl acetate while analysis of its FTIR spectrum revealed functional groups that are common to polysaccharides. Scanning electron micrograph of the gum also revealed the existence of particle aggregations with some internal bridges within the system. Rheological properties of the gum were found to be affected by pH, concentration, temperature and by the presence of some electrolytes (KCl, CaCl2, AlCl3 and urea). Average value of intrinsic viscosity deduced from Huggins and Kraemer plots was 3.51 dL/g while the sum of their constants was 0.36 (i,e< 0.5 and suggested the absence of molecular association). Calculated value of the Power law constant was (b = 0.812)...
Compositional and rheological properties of Alyssum homolocarpum seed gum, as a new source of thickening agent for application in food industries, were investigated in this study. The extracted gum primarily comprised carbohydrates (61.0 ± 0.6%), proteins (17.9 ± 1.0%) and uronic acids (10.9 ± 0.8%); the main carbohydrates were galactose (65.7%) and rhamnose (18.3%). The polysaccharide backbone was chiefly composed of 1,2-rhamnose, 1,3- and 1,3,6-galactose glycosidic linkages. The average molecular weight of the polymer was 122.5 × 106 g mol-1. Attenuated total reflectance-Fourier transform infrared spectroscopy and ζ-potential measurements revealed that Alyssum homolocarpum seed gum with multiple carboxylic groups was negatively charged in water in the pH range 3–11. Rheological behaviors of the extracted gum were investigated between 0.5–5.0% (w/w) concentrations and temperatures of 5–50°C. Viscosity profile showed shear thinning behavior at all concentrations and temperatures. The pseudoplasticity degree (N) of the extracted polymers increased with concentration while temperature changes did not show any specific trend on N values. The flow activation energy, quantified using an Arrhenius equation decreased from 11.00 to 5.17 (kJ/mol) as shear rate increased, which implied that the aqueous solutions flowed more easily at higher shear rates. The mechanical spectra derived from strain sweep and frequency sweep measurements indicated viscoelastic behavior in all of samples. Frequency sweep data showed that aqueous solutions of gum, displayed weak gel behavior over the range of tested concentrations and temperatures: as dynamic moduli increased with the increased frequency and storage modulus was always greater than loss modulus.