Search results for "Locust bean gum"
showing 10 items of 10 documents
Influence of shear rate and concentration ratio on viscous synergism. Application to xanthan—Iocust bean gum— NaCMC mixtures Influencia de la velocid…
2000
A method is described that allows the development of an empirical approach to quantify synergistic interactions and their variations with shear rate. The approach is based on the definition of a viscous synergism index, Iv. The method is applied to xanthan-locust bean gum gels, and an equation is developed for relating the synergism index to shear rate, γ, and the locust bean gum/xanthan gum concentration ratio, z. The value of at which that function has a maximum, IMV, is calculated. This value of z provided an estimation of the proportion of gums at which maximum synergism occurs. A decreasing exponential dependence of these IMV on γ is shown. The influence of the addition of a fixed pro…
Viscous Synergism in Carrageenans (κ and λ) and Locust Bean Gum Mixtures: Influence of Adding Sodium Carboxymethylcellulose
2001
Se han estudiado las interacciones sinergicas entre la goma de garrofin (LBG) y dos tipos de carragenanos (kappa y lambda). Para cada mezcla se obtuvo el indice de sinergia viscosa, Iy, en funcion de la relacion de concentraciones, z =c'LBG/c'car, y de la velocidad de cizalla. Los valores de estos indices disminuyeron al aumentar la velocidad de cizalla en ambos sistemas binarios. En las mezclas de LBG + K, I, presento un maximo para una relacion de concentraciones z = 60/40, que puede considerarse como la optima proporcion de estas gomas en la mezcla. Sin embargo, en los sistemas LBG + A, I, aumento con z en todo el intervalo considerado, es decir, la mayor sinergia correspondio a las meno…
Influence of composition on mechanical properties of strawberry gels. Compression test and texture profile analysis / Influencia de la composición de…
1999
Fruit gels were prepared containing four levels (20, 40, 60 and 80%) of strawberry pulp, four levels (0.5, 0.7, 0.9 and 1.1 %) of hydrocolloids (kappa-carrageenan plus locust bean gum, 1:1) and two levels (0, 10%) of sucrose. Their mechanical properties were analyzed by compression (failure stress and failure strain) and by texture profile analysis, TPA (hardness, cohesiveness, springiness, adhesive ness, and chewiness). Addition of hydrocolloids produced expected increases in both stress and strain at failure. Sucrose increased failure stress but did not alter strain values. Increasing the pulp content from 20 to 80% resulted in a slight increase in stress and clearly lowered strain at fa…
Identification of two additives, locust bean gum (E-410) and guar gum (E-412), in food products by DNA-based methods.
2004
Locust bean gum (E-410) and guar gum (E-412) are high molecular weight galactomannans used by the food industry as versatile food additives. The compounds, although chemically closely related, do not have the same functional properties when used in foods, and the substitution or unadvertised addition of either could change the desired qualities of the product. Analytical discrimination between E-410 and E-412 is technically difficult since they only differ in their galactose: mannose ratios, being 1 : 4 and 1 : 2 for locust bean gum and guar gum, respectively. A qualitative DNA-based method is reported for the authentication of additives E-410 and E-412 in finished food products (ice cream,…
Oscillatory measurements for salad dressings stabilized with modified starch, xanthan gum, and locust bean gum
2006
The rheological properties of low-oil-content food emulsions were analyzed with oscillatory tests within the linear viscoelastic region. The formulations of these salad dressings usually include modified starch because of its low cost and the special creamy texture that it affords. The combination of starch with other natural gums may improve the quality of the product. A reference emulsion containing 4% modified starch and four other formulations in which the starch was partially replaced by xanthan gum (0.4%), locust bean gum (0.4%), and synergistic blends of these gums (0.03 + 0.03% or 0.1 + 0.1%) were formulated. Gels before emulsification were studied for comparative purposes. All syst…
Rheological Characterization of Low-calorie Milk-based Salad Dressings
1992
Oil-in-water emulsions of different quantitative composition, containing milk powder and locust bean gum. as stabilizing agents, showed similar rheological behavior: time-dependent thixotropic character and yield stress. Thixograms obtained for each sample could be modelled through the Hahn equation for the different shear rates. The analysis of the Hahn parameter variation for each sample as a function of shear rate led to a function σ= f(γ, t). Predicted shear stress values had relative errors lower than 10% in 99.9% of the samples studied. Analysis of composition influence on the rheological parameters showed an interactive role of gum, milk and acetic acid concentrations on emulsion con…
A contribution to the study of staling of white bread: effect of water and hydrocolloid
1996
Abstract Staling of white bread at ambient temperature was studied using differential scanning calorimetry and dynamic mechanical thermal analysis. During storage, sample hydration varied slightly, from 0 to 0.4% per day, depending on packaging conditions. An increase in rigidity was observed, which was attributed both to starch retrogradation and to changes in the organization of the amorphous part of crumb. The glass transition temperature of crumb was not significantly modified by these structural changes. Hydrocolloids did not affect the overall shape of the viscoelastic behavior of crumb in the temperature range from −40°C to 80°C, and had a limited influence on the kinetics of starch …
Creep and recovery experimental investigation of low oil content food emulsions
2008
Abstract Creep and recovery tests have been performed to study the viscoelastic behavior of low oil content food emulsions. Formulations of salad dressings usually include modified starch (MS) due to its low cost and the special creamy texture if affords. The combination of starch with other natural gums may improve the quality of the product. A reference emulsion containing 4% MS, and four other formulations in which the starch was partially replaced by xanthan gum (XG), locust bean gum (LBG) and two synergistic blends of these gums were formulated. Gels prior to emulsification were studied for comparative purposes. The viscoelastic behavior of all the systems was characterized by means of…
Influence of xanthan gum and locust bean gum upon flow and thixotropic behaviour of food emulsions containing modified starch
2007
Abstract Low oil content mayonnaises are food emulsions which exhibit shear thinning and thixotropic behaviour. They include generally modified starch in their formulation. In this work we study the effect of substituting part of this starch with other natural gums, such as xanthan gum or locust bean gum, upon the consistency and stability of the emulsions in relation to stirring. The gels prior to final emulsification have also been analyzed. Steady flow curves of all systems are well described by the Carreau model. The emulsions containing the greatest percentage of gums presented significantly higher viscosity than the reference emulsion and the emulsions containing the synergistic mixtu…
New Method of DNA Isolation from Two Food Additives Suitable for Authentication in Polymerase Chain Reaction Assays
2005
Locust bean gum and guar gum are galactomannans used as additives (E 410 and E 412, respectively) in the food industry as stabilizing agents. Analytical discrimination between the two additives in gums and foods is now feasible by molecular techniques. However, only complex and time-consuming DNA isolation protocols are available to date. We have developed simple improved protocols to obtain enough DNA suitable for PCR amplification from a few milligrams of commercial E 410 and E 412 additives (containing more than 75% polysaccharides). The suspension of additives in water or 10 mM Tris-HCl, pH 8.5, efficiently recovers DNA suitable for authentication in PCR assays. However, the Tris method…