Maltodextrin Gels Research Articles

High-Protein Foods for Dysphagia: Manipulation of Mechanical and Microstructural Properties of Whey Protein Gels Using De-Structured Starch and Salts.

This study focuses on understanding the effect of ionic strength on the mechanical and microstructural properties of novel composite gels containing 13% whey protein isolate (WPI) and 4% de-structured waxy potato starch (DWPS). The DWPS is a physically modified waxy potato starch treated at 140 °C for 30 min under constant shear. Thermodynamic incompatibility between WPI and DWPS was observed upon the addition of NaCl (~75 mM) or CaCl2 (10–75 mM). The combined effects of such thermodynamic incompatibility with the changes in protein connectivity induced by varied ionic strength led to the formation of distinctive gel structures (inhomogeneous self-supporting gels with a liquid centre and weak gels with paste-like consistency) that were different from thermodynamic compatible homogeneous self-supporting gels (pure WPI and WPI + maltodextrin gels). At ≥ 250 mM NaCl, instead of a paste-like texture, a recovered soft and creamy self-supporting gel structure was observed when using DWPS. The ability to generate a range of textures in WPI gelation-based foods by using DWPS under different ionic conditions, is a feasible strategy for formulating high-protein foods for dysphagia—aimed to be either thickened fluids or soft solids. Additionally, this acquired knowledge is also relevant when formulating food gels for 3-D printing.

Structural characterization of interpenetrating network formation of high acyl gellan and maltodextrin gels

A mixed-gel of high acyl (HA) gellan gum and maltodextrin (MD) (potato DE2) demonstrated a range of physical properties with a proposed interpenetrating network. Mixed hydrocolloid gels allow for the development of novel properties that neither polymer alone could create allowing unique functionality in textures or controlled release. The aim of this work was to identify the type of network formation by examining material properties and the contribution from of each polymer. Material properties of quiescently set composite gels were characterized through bulk fracture, small deformation rheology, DSC, and microscopy. A continuous shift in fracture strain and modulus were created through mixed gels of the soft and flexible HA gellan with the firm and brittle MD. By adding MD (from 0 to 40%) at a constant 0.5% gellan, the gel true strain at fracture decreased from 0.50 to 0.18 while the Young's Modulus increased from 3 to 1780 kPa. No indication of phase separation or chemical complexation was measured. Analysis of the time-dependant MD contribution and composite material properties hypothesized a gelation mechanism in which HA gellan forms a network first and MD aggregates within the pores without phase separation. MD dominated the small deformation rheology while HA gellan appeared to dominate the fracture point. Material properties were indicative of the type of structural organization in the HA gellan MD mixed gel network.

Sport supplement use in Brazilian cyclists: Where is the information coming from?

Sport supplement use in Brazilian cyclists: Where is the information coming from?

Enhanced tracheostomy wound healing using maltodextrin and silver alginate compounds in pediatrics: a pilot study.

Tracheostomy wounds are commonly encountered in children but rarely reported. Relatively few treatments are available or have been investigated to manage this problem. Healing times for pediatric tracheostomy wounds are often unpredictable and protracted. Recent use of maltodextrin gel (MD) and a silver alginate sponge (AG) at our institution has demonstrated expedited healing and interest in this novel treatment for tracheostomy wounds. We conducted an 11-month retrospective review of children with wound complications following tracheostomy placement at a tertiary care facility. Wounds were evaluated and rated based upon the National Pressure Ulcer Advisory Panel staging system. Subjects identified with stage 2 or greater tracheostomy-related ulcers treated with MD and/or AG were included. Subject characteristics and wound healing rates were tabulated in a database that included age, wound site, initial and final wound stage, type of treatment, length of treatment, and complications. Tracheostomy wounds treated as an out-patient were excluded from the study. Eighteen subjects, which included both in-patients and out-patients, were treated with AG and/or MD during the study period for tracheostomy-related wounds. Of the 26 subjects with tracheostomies performed during the study period, 10 (38.5%) were treated for postoperative wounds. A total of 11 subjects completed their in-patient wound treatment and were thus included in the study. Average subject age was 5.3 y (range 0.25-15.6 y). Wound locations were as follows: infrastomal region (n = 8), stoma (n = 2), and lateral neck (n = 1). Six subjects had stage 2 wounds, 4 had stage 3 wounds, and 1 had a stage 4 ulcer. All wounds achieved complete epithelialization following treatment with MD and/or AG. The average length of treatment was 12.8 d (range 6-28 d). No adverse effects were identified. Postoperative tracheostomy wounds are common. The use of MD and AG provides an effective and safe treatment for tracheostomy-related ulcers.

Tailoring the morphology and rheology of phase-separated biopolymer gels using microbial cells as structure modifiers

Four nonviable, edible single-celled microorganisms (Lactobacillus delbrueckii subsp. bulgaricus, Saccharomyces cerevisiae, spirulina and chlorella) were used as micron-sized particles to control the microstructure and rheology of phase-separated gelatin (6 wt %) and maltodextrin (6 wt %) gels. Mixed biopolymer solutions containing 2 wt % cells were quenched from 90 °C to a holding temperature (Th) of 40 °C for 2 different holding times (th) of 30 s or 10 min. Samples were then quenched to 25 °C for rheological measurements and microstructural analysis. Presence of cells altered the phase separation kinetics and resulting microstructure. Notably, L. bulgaricus and S. cerevisiae yielded a bijel-type bicontinuous structure. Addition of cells generally limited the loss in gel elastic modulus (G′) normally associated with thermally-induced protein-polysaccharide phase separation. Strain sweep measurements suggested that phase-separated gels became stiffer in the presence of the cells. The increase in the rate of phase separation typically seen with addition of NaCl was greatly curtailed by the presence of the microorganisms, but only if they were negatively-charged (yeast and algae). Addition of the positively-charged bacteria intensified the adverse effect of NaCl on G′. These results demonstrated that nonviable, edible single-celled microorganisms may be used as a novel form of natural structure modifiers for applications ranging from gel fillers to Pickering stabilization of water-in-water emulsions. Finally, these results present the first instance of an edible bijel-like structure.

Physical and sensory aspects of maltodextrin gel addition used as fat replacers in confectionery filling systems

Confectionery fillings are products used in confectionery and baking industry containing approximately 30–40 g fat/100 g product. Due to the high fat content, they have considerable high caloric value. Therefore, there is a trend to decrease fat content in confectionery filling formulations. The objective of this study was to investigate the feasibility of using two types of maltodextrin gels as potential fat replacers in confectionery fillings.Vegetable fat was partially replaced by potato maltodextrin and specially derived waxy-maize maltodextrin aqueous gels (15 and 20 g/100 g) in three different ratios (5, 10 and 15 g/100 g). The increase in the amount of fat reduction resulted in an increase in hardness and change in colour of the final product. According to sensory analysis performed by trained sensory panel as well as by measurements of product acceptance–preference performed by untrained panellists (consumers), confectionery filling with 5 g/100 g fat reduction had the highest scores. However, according to product acceptance–preference test, it was estimated that the final product with 15 g/100 g fat reduction was also sensory acceptable.

THE IMPACT OF MALTODEXTRIN‐BASED FAT MIMETICS ON RHEOLOGICAL AND TEXTURAL CHARACTERISTICS OF EDIBLE VEGETABLE FAT

ABSTRACTThe functionality of two types of maltodextrins as fat mimetics was studied. Vegetable fat was replaced at levels of 16.7, 33.3 and 50% by different aqueous gels of maltodextrin: Pmdx (potato maltodextrin gel) and WMmdx (waxy maize maltodextrin gel). Vegetable fat without the addition of fat mimetics was used as a control sample. Steady shear viscosity, hysteresis and dynamic moduli were measured at semi‐solid conditions (30C), whereas textural measurements were determined in the solid state (20C). Up to 50% fat replacement without much change in firmness could be achieved with WMmdx. However, blends containing Pmdx expressed significant decrease in firmness. Fat replacement caused a strong increase in dynamic moduli, especially with WMmdx. Steady shear viscosity was increased at replacement levels ≥33.3% and to a larger extent with WMmdx. In contrast to Pmdx, incorporation of WMmdx did not affect the steady shear hysteresis of the blends.PRACTICAL APPLICATIONSEdible vegetable fat serves as an ingredient in many foods. In confectionary fat fillings, the vegetable fat is included to control texture and spreadability. Typical confectionary fat filling contains 30–35% fat. Because confectionary products are high in calories, development of reduced fat product with desirable taste and texture is a very challenging task.In this paper the capability of hydrated maltodextrin gel particles to replace certain amounts of fat in different foods was investigated. Therefore, rheological and textural properties of blends consisted of vegetable fat and different type, content and concentration of aqueous maltodextrin gel were determined. Hence, a step toward food products containing water stabilized by small amount of gelling maltodextrin with rheological and textural properties of conventional food product was made.

Rheological properties of maltodextrin based fat - reduced confectionery spread systems

Vegetable fat for confectionery spreads was partially replaced with two different types of maltodextrin gels (potato and specialty waxy maize maltodextrin gel) used as fat replacers at 20% gel concentration. The fat replacement levels were 15%, 30% and 50%. Fullfat confectionery spread was used as a control sample. Steady shear (hysteresis loop, apparent viscosity and yield stress determination), oscillatory and firmness measurements were performed. Also, melting profile of a confectionery vegetable fat was determined in order to confirm the working temperatures of all tests. Reduced fat systems with fat replacement level above 15% resulted in the formation of a product with inverted phases, so called ′ganache′ no matter of the used maltodextrin gel type. Therefore, only systems with 15% replacement level were observed. The incorporation of both types of maltodextrin gel as fat replacers in reduced fat system resulted in significant increase in degree of thixotropy, yield stress value, apparent viscosity, elastic moduli and firmness value. Also, reduced fat systems prepared with potato maltodextrin gel expressed more significant increase in all tested rheological parameters in comparison to waxy maize maltodextrin gel containing systems. This study showed that incorporation of maltodextrin gels used as fat replacers can be performed up to 15%. However, negative influence on system rheology was observed. Therefore, further studies should focus on changing preparation techniques as well as the addition of different emulsifier.

Mechanical and Structural Properties of Maltodextrin/Agarose Microgels Composites

Abstract We present results from a new approach to the study of multicomponent gels, which allows independent investigation of the effect of phase volume and droplet size of the dispersed phase on the mechanical properties of the mixed gel composites. The method involves preparation of agarose microgels with different sizes, which are then embedded in maltodextrin gel matrices with different gel strengths. The effects of both phase volume and droplet size on composite properties are dependent on the phase modulus ratio. The higher the phase modulus ratio, the larger is the reinforcement effect and the effect of droplet size on mechanical properties of the maltodextrin/agarose composites. The observed behaviour was compared with literature models for the behaviour of composite materials.

Rheological characterisation of the gelation behaviour of maltodextrin aqueous solutions

As a prelude to the study of its co-gelation with other biopolymers, the gelation behaviour of maltodextrin Paselli SA2 has been investigated in detail. Our work extends that done previously and leads to a number of interesting new findings, regarding maltodextrin gel behaviour. Studies were made of the effect of maltodextrin concentration and temperature on gelation using viscosity, small amplitude oscillatory and spectrophotometry measurements. Our results show that the c ∗ concentration is close to the critical gelation concentration and in the region of 17%. A linear equation relating the three parameters, gel time, concentration and gelation temperature is obtained. Data obtained from rheology experiments also allow master curves to be constructed, which can be used to predict gel behaviour for any concentration or gelation temperature in the range studied. We find that the cascade model cannot be applied to our results for maltodextrin gelation. This is probably due to gelation being more closely related to a colloidal aggregation. Furthermore, a study on the influence of temperature of dissolution points out an optimum dissolution temperature leading to a quicker and stronger gel. The effect is not well understood but the presence of nuclei (aggregates of double helices of amylose) is a possible explanation.

Evaluation of a maltodextrin gel as a partial replacement for fat in a high‐ratio white‐layer cake

AbstractThe performance of maltodextrin gel as a replacement (25%, 50%, 75% and 100%) for shortening along with sucrose and high fructose corn syrup‐90 (HFCS‐90), adjusted for sweetness in each treatment, was evaluated in a high‐ratio white‐layer cake formulation. Two controls were used as a reference to fat‐replaced cakes: control A (100% fat and 100% sucrose) and control B (100% fat with 50% sucrose/50% HFCS‐90), which closely matched the sugar system of the fat‐replaced cakes. Volume of cakes showed that treatment F (100% fat‐substituted) was significantly (P< 0.05) different from the other treatments. Crust and crumb L‐ and b‐values indicated that control B produced a dark crust (P< 0.05) with a light crumb (P< 0.05) whereas treatment E (75% fat substituted) produced a light crust (P< 0.05) and treatment F a darker crumb (P< 0.05) with a significantly (P< 0.05) higher moisture content. Degree of staling significantly (P< 0.05) increased over time for all treatments. Sensory results indicated that treatment F produced a significantly (P< 0.05) moister, less adhesive and cohesive cake. Tenderness and sweetness scores indicated that treatments E and F were significantly (P< 0.05) tougher and less sweet, respectively, when compared with the other treatments. Results from both the physical and sensory analyses indicated that the combination of maltodextrin gel up to a 75% reduction for shortening and sucrose/HFCS‐90 resulted in satisfactory cakes.

Solid-like components in carbohydrate gels probed by NMR spectroscopy

Solid-like components in maltodextrin and inulin model gels were probed with NMR spectroscopy. 1H NMR cross-relaxation experiments yielded quantitative information about the ageing process during which the immobile fraction of the polymer increased. The increase of immobile protons was correlated with crystallization in the gels. From the growth rate of the amount of solid-like component in inulin and maltodextrin gels different kinetics of ageing were deduced. In the case of inulin, the fraction of immobilized polymer was reduced at lower polymer concentration which was correlated with the observed decrease in the gel strength. Firming of the inulin gel took longer when starting from totally dissolved polysaccharide material, as was the case with solutions prepared at temperatures exceeding 82°C. However, neither the kinetics of solidification, nor the fraction of immobilized polymer at equilibrium appeared to be influenced by the temperature at which the starting solution had been prepared. Additionally, molecular mobility of maltodextrin chains and interaction with water in the gel was investigated by 13C 1D and 2D solid-state NMR. The molecular mobility of the polymer chains was studied as a function of storage time and storage temperature and turned out to be higher in gels stored at higher temperatures. Water binding was probed with the WISE experiment. Lower molecular mobility of polysaccharide chains as well as stronger interaction with water in gels stored at lower temperature was attributed to the formation of a 3D polymer network accompanied by partial crystallization.

Hochdruckeinfluß auf gelbildende Maltodextrine Teil 1: Makrostruktur, thermodynamische und fluiddynamische Wirkungen

The influence of static high pressure (600MPa) on physical and chemical properties of maltodextrin powders, which have had low degrees of hydrolysis (DE 2-8%) and water contents of 5-24% w/w, and maltodextrin gels (15 % w/w) have been investigated. No cleavage of covalent bonds has been proved. High pressure treatment results in structural changes depending on water content, ageing and specification of the material. Structural changes concern the physical micro- and macro-structure. In comparison with the untreated material, a more compact maltodextrin powder with an increased solid-density density has been produced. The physical-chemical properties have changed after high pressure treatment. We found a series of weak glass transitions with pressure-treated as well as non-treated maltodextrin powders, which appear as series of local extreme values in the first derivative of DSC thermograms. Maltodextrin powders, which have aged after high pressure treatment, show increased peak temperatures and extrapolated onset temperatures of the 50-70°C endothermic event and increased glass transition temperatures in DSC above a water content of 12% (w/w). Glass transition temperatures between 22°C and 155°C have been determined within the investigated moisture range of 24-5% (w/w). Maltodextrin gels are more homogeneous after high pressure treatment and keep a stable consistency, also after ageing (48 h), whereas the untreated sample separates out. It has been shown, that pressure-treated maltodextrin gels have a higher mechanical and thermal stability. Presumably, the use of pressure results in a deformation of the network of the concentrated solution and primary gel respectively, but chances for restructuring arise from this deformation.

GLYCEMIC RESPONSE TO LIQUID, SOLID AND GEL FORMS OF CARBOHYDRATE718

This study determined the blood glucose and insulin response to 3 meals containing equal amounts of carbohydrate in liquid (L), solid (S), and gel (G) form. On 3 separate occasions, 20 ♂ subjects fasted overnight, then consumed in random order a meal containing 40 g of carbohydrate in the form of rice, a maltodextrin beverage, or a maltodextrin gel. Blood samples were drawn from an indwelling venous catheter before the meal, and at 15 min intervals for 90 min. Blood glucose was determined by spectrophotometric analysis, and insulin was determined by radioimmunoassay. A two-way ANOVA with repeated measures revealed that the mean glucose and insulin responses to L and G were virtually identical, with the exception of a slightly faster rise in insulin with L in the first 15 min. The glycemic response to S was significantly lower in the first 30 min; however, glucose and insulin remained significantly higher than for L and G at 60, 75, and 90 min. Although the response pattern differed for insulin, the areas under the curve (AUC) for L, S, and G were not different (3293.3 ± 361.3, 3351.6 ± 473, 3116.9 ± 240.6μU·ml-1·min-1, respectively; P=0.684). The AUC for glucose also were not different (617.4 ± 24.9, 627.1 ± 23.7, 609.0 ± 22.8 mM·min-1, respectively; P=0.746). In conclusion, the total glycemic response to equivalent amounts of carbohydrate was similar whether it was in L, S, or G form, although the time course of the glucose and insulin responses varied.

Formation of thermally reversible maltodextrin gels as revealed by low resolution H-NMR

Pulsed low resolution proton NMR (20 MHz) was applied to follow the gelation process in different thermally reversible gelling maltodextrin-water systems. Results are expressed in terms of the solidus ratio, which is the ratio of proton systems with high and low relaxation time after the application of a radio frequency pulse. The sol-gel transition process may be followed from the onset until equilibrium is reached after several days. A marked change in the signal occurs on the formation of reversible gels, which depends on the temperature, concentration, time and structural peculiarities. This behaviour is paralleled with the development of the shear modulus as well as ΔH° for melting. A linear relation between the solid-liquid ratio from NMR and X-ray crystallinity suggests that the physical basis of the NMR results is the formation of highly ordered domains as essential constituents of the gel network. Non-gelling solutions of amylopectin as well as of acetylated maltodextrins do not give ‘solid’ signals. Amylose is necessary for initiation and acceleration of the sol-gel transition. However, crystalline amylose in the precipitated, retrograded state gives solid signals too. It is to be concluded that the method applied is suitable for following sol-gel transitions if they are based on a highly ordered (crystalline) structure.

Thermodynamic parameters of the junction zones in thermoreversible maltodextrin gels

The standard breakdown entropy ΔS 0 and Gibbs free energy ΔG 0 of the junction zones in thermally reversible maltodextrin gels are calculated from thermal data as a function of the alignment coefficient P. Based on a value for P ⋍ 170 , ΔS 0 and ΔG 0 are 24 J mol −1 K and 18 kJ mol −1 respectively. The definition range of the equation for calculating ΔS 0 and ΔG 0 ends at P ⋍ 210 . This comes quite near the value P ⋍ 170 for the magnitude of the coherent scattering units in maltodextrin gels as estimated by wide angle X-ray scattering. Maltodextrin gelation is a weakly cooperative process. Because of the low entropic effect, small changes in enthalpy result in the formation of thermodynamically stable gel structures.

An NMR study of structure formation in maltodextrin systems

Water mobility in the solutions of maltodextrin during the structure formation was studied by the Proton Pulse NMR technique. The comparison of the two-component spin-spin relaxation of the maltodextrin non-exchanging CH-protons with the relaxation properties of water protons in maltodextrin-water systems in sol-gel transition mode leads to the assumption that maltodextrin gel networking involves the formation of stable clusters whose lifetime is comparable with the relaxation time of water molecules.

Real structure of a partially crystalline maltodextrin gel as revealed by wide‐angle x‐ray scattering

AbstractIn maltodextrin gels the junction zones of the network are microcrystalline domains consisting of polysaccharide chains. Such microcrystalline aggregates already exist in a 10% maltodextrin solution. If the degree of crystallinity rises above 10%, a gel is formed. In the 25% gel, 16% of the polysaccharide chains are involved in these junction zones. As calculated from the integral breadth of the peaks, the crystallite size of 17 nm is considerable smaller than the maximum dimension of 280 nm of the domains found by small‐angle X‐ray scattering. This discrepancy is caused by lattice distortions in the crystalline domains. Consequently, each domain is composed of microcrystallites.

Molecular gelation mechanism of maltodextrins investigated by wide-angle X-ray scattering

Thermally reversible maltodextrin gels are two-phase systems, composed of disc-like crystalline domains with a diameter of about 300 nm and regions containing amorphous polymer chains and water. The structure of the polysaccharide chains within the lamellae is that of the crystalline B-form of amylose, the polymer chains are arranged in double-stranded helices, which are packed in a hexagonal unit cell (a=b=1.85 nm, c (fiber repeat)=1.04 nm,γ=120‡). As revealed by measurements of the excess wide-angle X-ray scattering of the polysaccharide, gelation of the solutions is due to a partial crystallization of the polymer. In non-gelling maltodextrin solutions a crystallinity cannot be detected.

Structure of maltodextrin gels ? a small angle X-ray scattering study

The structure of maltodextrin gels was investigated by small angle X-ray scattering. The inhomogeneities in the maltodextrin gels are molecular aggregates with maximum dimensions of almost 300 nm. Their shape can be approximated by oblate ellipsoids of revolution with an axial ratio of 0.1. The radius of gyration of the aggregates amounts to about 90 nm. For this reason in the nomenclature of Papkov the gels are polymer gels of the 2nd type. The melting of these aggregates is measured by SAXS with a position sensitive detector in the range near 56 °C.