Optimization of Hydrocolloid Extraction From Wild Sage Seed (Salvia macrosiphon) Using Response Surface

The effect of temperature (25–80°C), water to seed ratio (25:1–85:1) and pH (3–9) on the yield, apparent viscosity and emulsion stability index of wild sage seed hydrocolloid was investigated. The generated quadratic model showed that the optimum conditions for maximizing the responses were when temperature was 25°C, water to seed ratio was 51:1 and pH was 5.5. All hydrocolloid solutions (1% w/v) showed shear thinning behavior in different extraction conditions, consistency coefficient and flow behavior index varied from 4.455 to 9.435 (Pa.sⁿ), and 0.317 to 0.374, respectively. Besides, the chemical compositions of the seed and extracted gum were determined at optimal conditions.     

Rheological properties of selected hydrocolloids as a function of concentration and temperature

In this study, rheological properties of several food hydrocolloids (carrageenan, pectin, gelatin, starch and xanthan) were evaluated using a rotational viscometer at three concentrations (1–6%, depending on the type of hydrocolloid) and four temperatures (20, 40, 60 and 80°C). Samples were subjected to a programmed shear rate increasing linearly from 0 to 300 s⁻¹ in 3 min, followed by a steady shear at 300 s⁻¹ for 10 min and finally a linearly decreasing shear rate from 300 s⁻¹ to 0 in 3 min. Experiments were performed in duplicate. In general, the power law model fitted most of the experimental results. Xanthan gum and carrageenan (at 20^oC) were exceptions, characterized by a yield stress and hence the rheograms were fitted with the Herschel-Bulkley model. Furthermore, gelatin showed a Newtonian behavior. Three models (power, exponential and polynomial) were used to evaluate the concentration effect on apparent viscosity. Arrhenius model was used to describe the temperature effect. Among the samples, carrageenan showed the most temperature dependency and xanthan gum, the least.     

The Effects of Different Gums and Their Interactions on the Rheological Properties of a Dairy Dessert: A Mixture Design Approach

In this study, the steady and dynamic rheological properties of the dairy dessert samples (puddings) containing carrageenan, alginate, guar and xanthan gums and their combinations were investigated in a model system, and mixture design was utilized to observe the effects of the gums and their interactions. The flow behaviour of the pudding samples fitted to the Ostwald de Waele model (R ²?>?0.98). All the samples exhibited a gel structure with their higher G′ (storage modulus) values than the G″ (loss modulus) values. Carrageenan was the most effective hydrocolloid on both the steady and dynamic rheological parameters of the dairy dessert samples. On the other hand, alginate had relatively smaller effect. Furthermore, 30 pudding samples containing different gum or gum combinations were classified into two groups (A and B) by using principal component analysis (PCA). Samples containing more than 33% carrageenan in their formulations made up the group A which positively correlated to K (consistency index), η ₅₀ (apparent viscosity at shear rate 50 s^?1), G′, G″, G* (complex modulus) and η* (complex viscosity) values.     

Rheological interactions of selected hydrocolloid–sugar–milk–emulsifier systems

Rheological properties of solutions containing different ratios and concentrations of three hydrocolloids, i.e., basil seed gum (BSG), guar gum and carboxymethyl cellulose (CMC) were investigated. In addition, the effect of sucrose, skim milk powder and emulsifier, as key ice cream constituents, on the rheological properties of selected hydrocolloids was studied. Power law model was used to describe the rheological properties. Results showed that flow behaviour index of selected hydrocolloids, without any additives, was in the range of 0.501–0.789, while consistency coefficient and apparent viscosity of samples varied from 0.052 to 0.750 Pa.sⁿ, and 0.014 to 0.110 Pa.s, respectively. Addition of sucrose and emulsifier to hydrocolloids led to more viscous and more pseudoplastic solutions, whereas skim milk decreased viscosity and pseudoplasticity in some cases. BSG as a new source of hydrocolloid revealed promising results. Synergistic interactions between gums improved the viscosity of solutions, especially in the case of CMC and guar.     

Effect of Particle Size,Temperature, and Total Soluble Solids on The Rheological Properties of Watermelon Juice: A Response Surface Approach

Central composite design was used to analyze the effect of particle size (0.075, 0.15, 0.25, 0.355, 0.425 mm), temperature (1.6, 5, 10, 15, 18.4°C) and total soluble solids (14.77, 25, 40, 50, 65.23°Brix) on the rheological properties of watermelon juice. Experimental values of consistency coefficient k, varied from 0.178–0.628 Pa sⁿ and flow behavior index n from 0.281 to 0.949. Regression equation was computed and used to predict the values of k and n. Results revealed that coefficient of determination (R²) and standard error for consistency coefficient k were 0.84 and 0.043 and for flow behavior index n were 0.42 and 0.102 respectively. Surface graphs showed that k value increased with increase in total soluble solids and particle size while decreased with temperature.     

Utilization of chestnut flour in gluten-free bread formulations

In this study, gluten-free bread formulations using chestnut and rice flours at different ratios (0/100, 10/90, 20/80, 30/70, 40/60, 50/50 and 100/0) were tested. In addition, the influence of hydrocolloid blend (xanthan-locustbean gum (LBG), xanthan-guar gum blend) and emulsifier DATEM on the rheological properties of dough formulations and quality parameters of breads were also investigated for the samples having chestnut/rice flour ratio of 10/90, 20/80, 30/70 and 40/60. Herschel-Bulkley model was found to explain the flow behavior of all dough formulations. The power-law index (n) of dough samples at 25 °C ranged from 0.52 to 0.87, the consistency index (K) of the samples ranged from 3.6 to 79 Pa sⁿ and the yield stress of the samples ranged from 4.8 to 85.9 Pa. The breads prepared with chestnut/rice flour ratio of 30/70 and containing xanthan-guar blend and emulsifier, had higher quality in terms of hardness, specific volume, color and sensory values. However, elevated levels of chestnut flour led to some deterioration in quality parameters (low volume, harder texture and darker color) regardless of gum blend and emulsifier addition.     

Rheological and Sensory Properties of Spray Dried Pekmez Mixtures with Wheat Starch-Gum

Pekmez, known also as grape molasses, was spray dried in the laboratory-type pilot drying unit to obtain pekmez powder. The flow characteristics of diluted pekmez powder (DPP), wheat starch (WS), and some hydrocolloids (locust bean gum, LBG; gum tragacanth, GT, and guar gum, GG) systems in double- or triple-mixed combinations were studied. The empirical power law model fitted the apparent viscosity-rotational speed data. DPP-gum and WS-gum mixed solutions exhibited a shear-thinning behaviour at 21°C with flow behaviour index (n) values of 0.88 ≤ n ≤ 0.94 and 0.17 ≤ n ≤ 0.32, respectively. WS-gum mixed solutions showed high shear-thinning behaviour with the highest consistency index (k = 49.93–214.24 Pa sⁿ). However, DPP-WS and DPP-WS-gum mixed solutions at the same temperature exhibited the shear-thickening behaviour with flow behaviour index (n) values of 1.02 ≤ n ≤ 1.07.     

Optimization of Gum Combination in Prebiotic Instant Hot Chocolate Beverage Model System in Terms of Rheological Aspect: Mixture Design Approach

Mixture design was used to investigate the effects of four different gums (xanthan gum, guar gum, alginate and locust bean gum) and their combinations on the rheological properties of a prebiotic model instant hot chocolate beverage (including 3.5% inulin) and to determine their interactions in the model beverage. Simplex centroid mixture design was applied to predict the physicochemical (soluble solids, pH, colour properties) and rheological parameters (consistency index (K), flow behaviour index (n) and apparent viscosity (η ₅₀)) of the samples. In the model, the optimum gum combination was found by simplex centroid mixture design as 59% xanthan gum and 41% locust bean gum, and the highest K value was 33.56 Pa s ⁿ . The increase of guar gum and alginate in the gum mixture caused a decrease in the K value of the sample.     

Rheological properties of batter systems containing different combinations of flours and hydrocolloids

The rheological properties of batters formulated using different combinations of wheat, corn, and rice flours with two types of hydrocolloids, namely methylcellulose (0.5%, 1% and 1.5%) or xanthan gum (0.2%), were studied. Control samples were formulated with combinations of flours without the added hydrocolloids. The effects of hydrocolloids on rheological characteristics of the batter systems were measured using a controlled stress rheometer at a temperature of 15 °C. The effects of hydrocolloids on dynamic viscoelastic parameters as functions of temperatures were evaluated. All the batters showed shear thinning behaviour with flow behaviour indices in the range 0.34–0.67. Addition of xanthan gum lowered the flow index values, imparting a higher degree of pseudoplasticity to the batter samples compared to methylcellulose. The consistency index of the control batter samples varied from 0.46 to 69.2 Pa sⁿ. Addition of xanthan gum or methylcellulose significantly increased the batter consistency index value. The gums changed the onset temperature of structure development, and the storage (G′_max) and loss moduli (G″_max) of the batter systems. However, no statistically significant effects were observed on the peak temperature of batter systems in which the G′ reached a maximum value. Xanthan gum increased both G′_max and G″_max, whereas at higher concentrations methylcellulose increased G′_max but lowered G″_max. Copyright © 2007 Society of Chemical Industry     

Rheological properties of gluten-free bread formulations

In this study, the rheological properties of rice bread dough containing different gums with or without emulsifiers were determined. In addition, the quality of rice breads (volume, firmness and sensory analysis) was evaluated. Different gums (xanthan gum, guar gum, locust bean gum (LBG), hydroxyl propyl methyl cellulose (HPMC), pectin, xanthan–guar, and xanthan–LBG blend) and emulsifiers (Purawave^™ and DATEM) were used to find the best formulation for gluten-free breads. Rice dough and wheat dough containing no gum and emulsifier were used as control formulations. The rice dough containing different gums with or without emulsifiers at 25 °C showed shear-thinning behavior with a flow behavior index (n) ranging from 0.33–0.68 (except pectin containing samples) and consistency index (K) ranging from 2.75–61.7 Pa sⁿ. The highest elastic (G′) and loss (G″) module were obtained for rice dough samples containing xanthan gum, xanthan–guar and xanthan–LBG blend with DATEM. When Purawave^™ was used as an emulsifier, dough samples had relatively smaller consistency index and viscoelastic moduli values compared to DATEM. The viscoelastic parameters of rice dough were found to be related to bread firmness. Addition of DATEM improved bread quality in terms of specific volume and sensory values.     

Viscosity drives texture perception of protein beverages more than hydrocolloid type

Hydrocolloids are added to alter rheological properties of beverages but have other properties that can contribute to overall taste and texture perception. In this study, tapioca starch and λ-carrageenan were used to determine how hydrocolloid type, viscosity level (4–6 mPa·s, 25–30 mPa·s, and 50–60 mPa·s at 50 s⁻¹), and complexity of the system (aqueous, skim milk, or whole milk) influence sensory taste and texture of fluids. All fluids were shear thinning; however, skim milk and whole milk solutions that contained carrageenan had much higher low shear viscosity and lower high shear viscosity than those with starch. There was a significant effect of viscosity level on sensory perception of consistency, creamy/oily, mouthcoating, and residual mouthcoating in aqueous, skim milk, and whole milk beverages, and a weak effect of hydrocolloid type. However, normalizing creamy/oily, paste, and mouthcoating against sensory consistency removed the effect of hydrocolloid type. Flavors (cream, cooked, cardboard, and melon/cardboard) were associated with the type of hydrocolloid and milk protein ingredient. Temporal dominance of sensations showed that samples exhibit similar temporal sensory profiles, although the addition of hydrocolloids enhanced dominance of creaminess even in samples without fat. Hydrocolloid type did not significantly influence mouthcoating or the persistence of astringency. Additionally, increasing viscosity from 3 to 74 mPa·s at 50 s⁻¹ did not suppress perceived sweet or salty taste. The results suggest that in fluid systems with viscosity levels typically found in beverages, textural properties are determined by viscosity and independent of the type of hydrocolloid.     

Optimization of gum combination for instant pudding based on creep and recovery parameters by mixture design approach

In the present study, gum combinations used in the pudding formulation were optimized by mixture design approach based on creep and recovery measurements. For this aim, four different gums (carrageenan, alginate, guar and xanthan gum) and their different combinations were used in the formulation. The creep-recovery properties of the pudding samples prepared with different gums or gum combinations were investigated. Burger model was satisfactorily applied for the determination of the creep-recovery characteristics of the samples. The use of the carrageenan in the pudding formulation caused a decrease in deformation of the samples. Gel strength value of the pudding samples was also calculated using the data. In order to optimize the gum combination based on the creep-recovery measurements, mixture design was carried out, and it was seen that established models satisfactorily predicted the viscoelastic parameters of the samples. During the optimization of the gum combination used in the pudding formulation, desirability function was used to optimize the ingredients simultaneously based on the requirements. The gum combination including 59.5 % carrageenan and 40.5 % guar gum or 52.7 % carrageenan, 33.8 % guar gum and 13.5 % xanthan gum was determined to be the optimum in terms of quality of the product.     

Flow properties of fruit fillings

The flow properties of the fluid portion of fruit fillings were assessed to investigate the effects of gums. Results indicated that the shear rate–shear stress relations of the fluid portion of commercial fruit fillings and the model fillings made of waxy corn starch, fructose, citrate buffer, and a gum which could be guar gum, locust bean gum, CMC, xanthan gum or κ-carrageenan, fit well into the Herschel–Bulkley equation for pseudoplastic fluids. The fluid portion of the commercial fruit fillings was characterized with a yield stress between 39–51 Pa, a consistency index between 52–104 Pa·sⁿ, and a flow index (n) around 0.4. In addition, the shear rate–shear stress relations could be fitted into a modified Herschel–Bulkley equation with a flow index fixed at 0.4. Addition of guar gum, locust bean gum and CMC increased while xanthan gum and κ-carrageenan decreased the consistency and flow indices in the modified Herschel–Bulkley equation. The effect of gum addition on the apparent viscosity of model fillings varies with the type of gum, amount of addition, and shear rate.     

Effect of high pressure homogenization (HPH) on microstructure and rheological properties of hazelnut milk

The effect of high pressure homogenization (HPH) on microstructure and rheological properties of hazelnut milks was investigated. Hazelnut milk samples were produced from cold pressed hazelnut cake and homogenized up to 150 MPa pressure. Microstructural and rheological properties of products, except temperature sweep, were greatly affected by HPH treatments. Homogenized samples showed significant reduction in particle size, which turned from bimodal and poly-disperse to monodisperse distributions. HPH decreased the consistency of products from 91.82 to 0.51 Pa.sⁿ and increased flow behavior index from 0.15 to 0.36. All samples showed higher values G′ than G″, which indicates that samples could be classified as soft-gel network, and hazelnut milk samples did not obey the Cox-Merz rule without multiplying angular frequency with shift factor. In conclusion, HPH can be used to reduce the consistency of samples and the friction loss, thus minimizing the amount of energy required to flow during processing and distribution.Industrial relevance.Vegetable based beverages are available at any supermarket as an alternative to dairy products with an increasing consumer acceptance. Between these beverages hazelnut milk samples are the most noteworthy products due to important role in human nutrition and health, and moreover due to well accepted and widely consumed product. Due to its composition, hazelnut milks have very high consistency, and therefore, the energy consumption for processing and handling is too high. In this research, the high pressure homogenization (HPH) technology was successfully proposed to be used for improving microstructural properties, and hence reducing its consistency. The energy consumption during processing and distribution can be minimized by reducing the consistency and friction losses of product.     

The effect of selected hydrocolloids on the rheological properties of processed cheese analogues made with vegetable fats during the cooling phase

The aim of this work was to observe the influence of different hydrocolloids on changes in the rheological properties of processed cheese and their analogues within the process of cooling depending on the type of the fat used (butter, coconut fat and palm oil). κ‐carrageenan, ι‐carrageenan, λ‐carrageenan, arabic gum and locust bean gum were used at a concentration of 1.0% w/w. With the decreasing temperature during the cooling period, an increase in the complex modulus (G*) was observed in all samples tested. Within the cooling period, the sample with the addition of κ‐carrageenan showed both the most significant increase in G* in comparison with the control and the highest values of hardness after a 7‐day storage period regardless of the type of the fat used. The samples with coconut fat were assessed as the hardest. On the other hand, the samples with palm oil showed the lowest hardness (with the same hydrocolloid used). In the gelling hydrocolloids (κ‐ and ι‐carrageenan), only small changes in temperature of coil‐to‐helix transition were observed (in range of 2–7 °C) as a result of the addition of different types of fat.     

Pasting Properties of Non‐waxy Rice Starch‐Hydrocolloid Mixtures

The swelling and pasting properties of non‐waxy rice starch‐hydrocolloid mixtures were investigated using commercial and laboratory‐generated hydrocolloids. The swelling power of the rice starch‐hydrocolloid mixtures was generally depressed at low concentration of hydrocolloids (0–0.05%), but increased directly with increasing hydrocolloid concentrations (0.05–0.1%). In gellan gum dispersion, the swelling power at 100°C was higher than that of control. The rice starch‐hydrocolloids mixtures showed shear‐thinning flow behavior (n = 0.26–0.49). Hydrocolloids except the exopolysaccharide from S. chungbukensis (EPS‐CB) increased apparent viscosity and consistency index (K) of rice starch dispersions, but decreased the n value. Hydrocolloids enhanced the trough and final viscosity of rice starch dispersions but EPS‐CB reduced the viscosity of rice starch pastes. Hydrocolloids lowered peak viscosity but addition of guar gum resulted in high peak viscosity, apparent viscosity, and consistency index of rice starch dispersions. Total setback viscosity appeared to be not affected by hydrocolloids at low concentration (0.05%). The hot and cold paste of the starch‐gellan gum mixture exhibited the highest viscosity values in the Brookfield viscometer.     

A Comparison of the Stability of Beverage Cloud Emulsions Formulated with Different Gum Acacia- and Starch-Based Emulsifiers

Abstract: The performance of several hydrocolloids (3 gum acacias, 1 modified gum acacia, and 3 modified starches) in stabilizing beverage emulsions and corresponding model beverages was investigated employing different core materials, emulsifier usage levels, and storage temperatures. Concentrated emulsions were prepared using orange terpenes or Miglyol^® 812 (comprising medium-chain triglycerides, MCT) weighted 1:1 with ester gum, stored at 25 or 35 °C, and analyzed on days 0, 1, and 3. On day 3, model beverages were made from each emulsion, stored at both temperatures, and analyzed weekly for 4 wk. Stability of concentrated emulsions was assessed by measuring mean particle size and by visual observations of ringing; beverage stability was judged similarly and also by loss of turbidity. Particle size measurements showed concentrated emulsions containing gum acacia or modified gum acacia with either core material were stable over 3 d storage at both temperatures whereas those made with modified starches were not, destabilization being faster at 35 °C. Beverages based on orange terpenes, in contrast to Miglyol, yielded smaller mean particle sizes, both on manufacture and during storage, regardless of hydrocolloid used. Visual observations of ringing generally supported this finding. Modified gum acacia was evaluated at both recommended and higher usage levels, stability increasing in the latter case. In general, all gum acacia and modified gum acacia emulsifiers were superior in stability to those based on modified starches, at either temperature, for orange terpene-based beverages. In Miglyol-based beverages, similar results were seen, except 1 modified starch performed as well as the gum acacia products.     

Effect of hydrocolloids on gluten‐free batter properties and bread quality

The objectives of this study were to assess the effect of the addition of different hydrocolloids on gluten‐free batter properties and bread quality and to obtain information about the relationship between dough consistency and bread quality. Breads were made of rice, corn and soy flours and 158% water. Following hydrocolloids were added: carrageenan (C), alginate (Al), xanthan gum (XG), carboxymethylcellulose (CMC) and gelatine (Gel). Batter consistency, bread specific volume (SV), crumb analysis, crust colour, crumb hardness and staling rate were determined. Hydrocolloids increased batter consistencies: the highest value was obtained with XG, which doubled that of control batter, followed by CMC. Breads with hydrocolloid presented higher SV than control, especially with XG whose SV was 18.3% higher than that of control bread. A positive correlation was found between SV and batter consistency (r = 0.94; P < 0.05). Crumbs with Gel, XG and CMC presented higher cell average size. XG and CMC crumbs looked spongier. Breads containing hydrocolloid evidenced lighter crusts. Crumb firmness was decreased by XG and CMC addition, and staling rate was slower. Overall, XG was the hydrocolloid that most improved gluten‐free bread quality. These results show that, in formulations with high water content, batter consistency is strongly associated with bread volume.     

Improving Adhesion of Seasonings to Crackers with Hydrocolloid Solutions

Food powders were applied on crackers that had been coated using water, oil, emulsion, sucrose, or hydrocolloid solutions. The hydrocolloids that were used include gellan gum, kappa‐carrageenan, methylcellulose, gum karaya, gum tragacanth, gum arabic, guar gum, modified starch, and maltodextrin. Solutions of similar hydrophobicity to the powder gave the greatest adhesion. NaCl, barbecue (BBQ), ranch, and sour cream & onion (SC&O) seasoning showed greatest adhesion with water, cheese powder with an emulsion of 12.5% to 25% oil, and cocoa powder with oil. For NaCl, BBQ, ranch, and SC&O seasoning, hydrocolloids improved the adhesion over using water alone, with gellan gum providing the greatest adhesion. Hydrocolloid structural differences, including the presence or absence of branching, substitution of sugar units, and molecular weight affect water binding and thickening of the hydrocolloid spray that seemed to be significant factors affecting adhesion of powders to the target surface. For cheese powder, hydrocolloids were capable of replacing the oil within an emulsion while improving or maintaining the same level of adhesion, with gum arabic providing the greatest adhesion. For cocoa powder, hydrocolloid solutions were ineffective adhesives due to differences in hydrophilicity that result in insolubility. The effect of hydrocolloid concentration on adhesion was dependent both on the hydrocolloid type and the concentration that is sprayable, with 0.5% being the optimum concentration for most gums. Adhesion using sucrose solutions was determined by particle size and relative hydrophobicity. Increasing sucrose concentration decreased adhesion of smaller particles, but increased adhesion of larger particles. Adhesion of NaCl significantly increased with decreasing NaCl size using oil, water, and sucrose solutions.     

Linear Rate of Water Crystallization as Influenced by Temperature of Hydrocolloid Suspensions

The object of this study was to assess the abilities of various hydrocolloids to inhibit water crystallization at temperatures ranging from −3 to −5°C. In all instances, decreases in the initial super-cooling temperature or the hydrocolloid concentration caused increases in the linear rate of crystallization. The linear rate of crystallization vs. temperature plots indicated that suspensions of guar gum alone or with microcrystalline cellulose, locust bean gum, and carrageenan exhibited the greatest temperature dependence, whereas suspensions of guar gum-sucrose, carboxymethylcellulose-sucrose, and sodium alginate alone or with microcrystalline cellulose exhibited the least temperature dependence. At a 1% (wt/vol) level of use, guar gum and locust bean gum exhibited the smallest linear rate of crystallization at −5°C and carrageenan and sodium alginate (1.5% wt/vol) exhibited the largest. The results obtained from this study indicate that hydrocolloids retard the rate of water crystallization and that some are more effective than others. However, all hydrocolloids tested are far less effective than sucrose in retarding rate of water crystallization.