Addition Of Guar Gum Research Articles

Development and characterization of “Greek Salad” edible films

“Greek salad” edible films, made from tomato puree, juices of cucumber, bell pepper and onion, oregano oil and apple pectin with and without olive oil and guar gum were successfully prepared and characterized for water vapor permeability, oxygen permeability, tensile properties, moisture sorption isotherm, heat sealing ability and color. It was found that the addition of olive oil to the basic film increased its water vapor permeability, while the incorporation of guar gum had no impact on it. The addition of olive oil and guar gum affected the tensile properties, the isotherms for moisture sorption and the color of the films. All films demonstrated good heat-sealing properties. The FTIR spectra of the films displayed several interesting characteristics, confirming the films’ composition. The sensory evaluation of the four edible films revealed that all samples scored close to or above 3 (on a scale of 0–5) in most sensory attributes, indicating general acceptability among panelists. Notably, films containing guar gum exhibited higher homogeneity and transparency, while films containing olive oil showed the highest odor, flavor, and taste intensities, but also more pronounced defects and undesirable aftertastes. The basic film appeared more balanced in most sensory attributes.It was concluded that overall the advantages of adding olive oil and guar gum to the basic film were not significant. Future experiments will concentrate on optimizing the production of the basic film and exploring the possibility of using it for packaging oily foods.

Underlying mechanisms of different polysaccharides on the texture characteristics and protein digestibility of soybean curd

This study aimed to investigate the effects of the addition of potato starch (PS) and guar gum (GG) at different concentrations (0.4 and 0.8%) on the physical properties, protein conformation, and in vitro digestibility of soybean curd. The results indicated that the PS acted as a filler in the protein structure, enhancing the firmness, springiness, and chewiness of the soybean curd. GG encapsulated the disorganized filamentous protein matrix, increasing the adhesiveness of the soybean curd. The addition of GG and PS reduced the hydrophobic interactions and disulfide bonds responsible for cross-linking soybean curd proteins, while forming more hydrogen bonds with the proteins (p < 0.05). GG formed the most hydrogen bonds with the proteins, as well as reduced β-sheet content and transformed into more random coil and β-turn (p < 0.05). Also, the addition of GG (particularly at 0.8%) significantly reduced the degree of protein hydrolysis (31.98%) in soybean curd, resulting in fewer small molecular weight peptides and lower total amino acid content (3386.79 μg/g protein) at the end of in vitro digestion (p < 0.05). In contrast, the addition of a small amount of PS (0.4%) did not affect the protein digestibility of soybean curd. This study clarified the impact of polysaccharide additions on modifying the soybean curd texture and protein digestibility.

Technical-functional and surface properties of white common bean proteins (Phaseolus vulgaris L.): Effect of pH, protein concentration, and guar gum presence

Legumes are abundant sources of proteins, and white common bean proteins play an important role in air–water interface properties. This study aims to investigate the technical-functional properties of white common bean protein isolate (BPI) as a function of pH, protein concentration, and guar gum (GG) presence. BPI physicochemical properties were analyzed in terms of solubility, zeta potential, and mean particle diameter at pH ranging from 2 to 9, in addition to water-holding capacity (WHC), oil-holding capacity (OHC), and thermogravimetric analysis. Protein dispersions were evaluated in terms of dynamic, interfacial, and foam-forming properties. BPI showed higher solubility (>80 %) at pH 2 and above 7. Zeta potential and mean diameter ranged from 15.43 to −34.08 mV and from 129.55 to 139.90 nm, respectively. BPI exhibited WHC and OHC of 1.37 and 4.97 g/g, respectively. Thermograms indicated decomposition temperature (295.81 °C) and mass loss (64.73 %). Flow curves indicated pseudoplastic behavior, with higher η100 values observed in treatments containing guar gum. The behavior was predominantly viscous (tg δ > 1) at lower frequencies, at all pH levels, shifting to predominantly elastic at higher frequencies. Equilibrium surface tension (γeq) ranged from 43.87 to 41.95 mN.m−1 and did not decrease with increasing protein concentration under all pH conditions. All treatments exhibited ϕ < 15°, indicating predominantly elastic surface films. Foaming properties were influenced by higher protein concentration and guar gum addition, and the potential formation of protein-polysaccharide complexes favored the kinetic stability of the system.

Permeability and Disintegration Characteristics of Loess Solidified by Guar Gum and Basalt Fiber.

Loess has the characteristics of loose, large pore ratio, and strong water sensitivity. Once it encounters water, its structure is damaged easily and its strength is degraded, causing a degree of subgrade settlement. The water sensitivity of loess can be evaluated by permeability and disintegration tests. This study analyzes the effects of guar gum content, basalt fiber content, and basalt fiber length on the permeability and disintegration characteristics of solidified loess. The microstructure of loess was studied through scanning electron microscopy (SEM) testing, revealing the synergistic solidification mechanism of guar gum and basalt fibers. A permeability model was established through regression analysis with guar gum content, confining pressure, basalt fiber content, and length. The research results indicate that the addition of guar gum reduces the permeability of solidified loess, the addition of fiber improves the overall strength, and the addition of guar gum and basalt fiber improves the disintegration resistance. When the guar gum content is 1.00%, the permeability coefficient and disintegration rate of solidified soil are reduced by 50.50% and 94.10%, respectively. When the guar gum content is 1.00%, the basalt fiber length is 12 mm, and the fiber content is 1.00%, the permeability of the solidified soil decreases by 31.9%, and the disintegration rate is 4.80%. The permeability model has a good fitting effect and is suitable for predicting the permeability of loess reinforced with guar gum and basalt fiber composite. This research is of vital theoretical worth and great scientific significance for guidelines on practicing loess solidification engineering.

Effect of guar gum and fortification by haritaki (Terminalia chebula) extract and its encapsulates on physicochemical, textural, and rheological properties of yogurt

AbstractIn the present study functional yogurt was prepared by addition of guar gum (0.5% and 1.5%) and fortification by phytochemical extract of haritaki (Terminalia chebula) extracted using supercritical CO2 and freeze dried encapsulates of the extracts. The results indicated that the addition of guar gum led to a concentration‐dependent reduction in pH, with yogurt containing 1.5% guar gum exhibiting the highest acidity. During a 24‐day storage period at 4°C, all samples displayed a decrease in pH and an increase in acidity. Notably, all variations exhibited sporadic syneresis patterns, with higher syneresis observed on the 1st day, followed by a decline on the 12th day and a subsequent rise on the 24th day of storage. The color of haritaki encapsulated yogurt appeared greener and more yellowish compared to the control samples on the 1st day, with noticeable changes in L*, a*, and b* values during storage. Texture analysis revealed that encapsulation significantly affected textural characteristics, with reduced firmness but comparable adhesiveness in some cases. The firmness of plain yogurt ranged from 0.69 to 0.72 N, while its adhesiveness was between 6.14 × 10−2 and 8.51 × 10−2 N.s. The stiffness of the samples made with encapsulates (E1–E6) ranged from 0.38 to 0.70 N, while their adhesiveness was 5.74 × 10−2 to 8.78 × 10−2 N.s. The findings demonstrate that encapsulation significantly affected the textural characteristics. However, the samples' firmness (F1–F3) was less than the control, ranging from 0.36 to 0.54 N. Encapsulated haritaki extract outperformed nonencapsulated haritaki extract in terms of phenolic and antioxidant activities, making it a preferred option for yogurt fortification. Furthermore, yogurt enriched with up to 0.5% guar gum exhibited sensory qualities similar to or even better than the control sample.

Metabolism mechanisms of biogenic methane production by synergistic biodegradation of lignite and guar gum

Coalbed methane (CBM) presents a promising energy source for addressing global energy shortages. Nonetheless, challenges such as low gas production from individual wells and difficulties in breaking gels at low temperatures during extraction hinder its efficient utilization. Addressing this, we explored native microorganisms within coal seams to degrade guar gum, thereby enhancing CBM production. However, the underlying mechanisms of biogenic methane production by synergistic biodegradation of lignite and guar gum remain unclear. Research results showed that the combined effect of lignite and guar gum enhanced the production, yield rate and concentration of biomethane. When the added guar gum content was 0.8 % (w/w), methane production of lignite and guar gum reached its maximum at 561.9 mL, which was 11.8 times that of single lignite (47.3 mL). Additionally, guar gum addition provided aromatic and tryptophan proteins and promoted the effective utilization of CC/CH and OCO groups on the coal surface. Moreover, the cooperation of lignite and guar gum accelerated the transformation of volatile fatty acids into methane and mitigated volatile fatty acid inhibition. Dominant bacteria such as Sphaerochaeta, Macellibacteroides and Petrimonas improved the efficiency of hydrolysis and acidification. Electroactive microorganisms such as Sphaerochaeta and Methanobacterium have been selectively enriched, enabling the establishment of direct interspecies electron transfer pathways. This study offers valuable insights for increasing the production of biogenic CBM and advancing the engineering application of microbial degradation of guar gum fracturing fluid. Future research will focus on exploring the methanogenic capabilities of lignite and guar gum in in-situ environments, as well as elucidating the specific metabolic pathways involved in their co-degradation.

Quality improvement of microwave freeze‐dried prepared taro balls: synergistic addition of guar gum and sodium bicarbonate

Quality improvement of microwave freeze‐dried prepared taro balls: synergistic addition of guar gum and sodium bicarbonate

Effect of technological processing and recipe formulation on the physico-chemical properties of ganaches and chocolate pralines

This study investigates the impact of structural modifications of chocolate ganaches by changes in technological processing and by addition of emulsifier, milk fat, milk protein, and guar gum. Ganaches were evaluated by textural analysis, differential scanning calorimetry, frequency sweep rheology, and optical microscopy. Chocolate pralines were manufactured from studied ganaches, followed by sensory and microbial tests for consumer acceptability and shelf-life stability, respectively. Ganache subjected to a 3-min emulsification process exhibited optimal properties and was sensorially rated as the most preferred. Notably, neither the emulsifier application nor extended 6-min emulsification had significant effect on the measured properties. The addition of milk proteins and guar gum resulted in a firm and complex water-binding structure, confirmed by higher viscoelasticity and lower water activity, and resulted in a better shelf-life stability. The preparation process minimally affected melting profiles measured by DSC, however, sample with guar gum exhibited a slight shift to higher temperatures.

Effect of milk protein-galactomannans interaction on meltdown behavior in the aerated frozen model system

The microstructure of ice cream and frozen desserts is known to influence their meltdown behavior. In this study, we hypothesized that the interaction of milk protein and galactomannans, specifically the phase separation often observed between hydrocolloids and protein, along with the interaction of hydrocolloids in the serum phase, affected meltdown behavior in non-fat aerated frozen foam. Ice creams were made with protein contents from 4 to 8%, with the addition of guar gum or locust bean gum. The effect of κ-carrageenan in protein and galactomannans was also studied. Melting characteristics were compared to the rheological and structural characteristics of the ice cream as well as to the phase separation in the mix and drip-through solution. The freezing-melting process inhibited microscopic and macroscopic phase separation in most locust bean gum samples, primarily due to the cryo-gel maintaining structural integrity and altering hydrocolloid-proteins interactions. The cryo-gel structure also led to slow melting rates and stable melted foams in the 4% milk protein system even in the absence of milk fat globules and clusters. Increasing milk protein from 4% to 8% in locust bean gum samples resulted in faster melting and a transition to complete dripping, indicating the disruption of the cryo-gel structure by increased proteins. In contrast, all guar gum samples fully dripped through the mesh with a fast melting rate. A negative trend was found between phase separation and melting rate in the guar gum samples containing κ-carrageenan, indicating that the diminishing interaction between the two immiscible phases accelerated liquid drainage.

Physicochemical Properties, Glycaemic Index and Glycaemic Load of Chocolate Energy Bars Prepared with High Polyphenols Cocoa Powder and Guar Gum

This study aimed to determine the physicochemical properties, Glycaemic Index (GI) and Glycaemic Load (GL) of chocolate energy bars prepared with different percentages of guar gum (0.5%, 1.0%, 1.5%) and high polyphenols cocoa powder. Proximate analysis was determined following the official methods Association of Official Analytical (AOAC). Ten eligible respondents who met the inclusion and exclusion criteria participated in the GI and GL determination. Test and reference food were given to the participants after overnight fasting. Blood capillary finger pricks were drawn for 7 interval time at 0 until 120 min. The blood glucose responses were calculated based on Incremental Area Under Curve (IAUC). The result revealed that the fat and calorie content were significantly lower in formulations with highest guar gum percentage (p˂0.05). On the other hands the moisture, ash, carbohydrate contents, crude fibre, energy value, hardness, fracturability, pH value, and colour were all comparable to the control sample. The control and chocolate energy bars with 0.5% guar gum were in the category of high GI and GL. Whereas, the chocolate energy bars with 1.0% and 1.5% guar gum were in the medium category for both GI and GL. This study demonstrated that incorporating different percentages of guar gum in the high polyphenols chocolate energy bar changed some of the proximate compositions but not the physical properties. Furthermore, addition of guar gum affected the GI and GL as the values were reduced with the increased amount of guar gum.

Effects of hydrocolloids on mechanical properties, viscoelastic and microstructural properties of starch-based modeling clay

The effects of various hydrocolloids (guar gum, xanthan gum, and carboxymethyl cellulose) on the texture, rheology, and microstructural properties of modeling clay prepared with cassava starch were investigated. Notably, incorporation of 3 % guar gum and 4 % xanthan gum into starch-based modeling clay resulted in enhancements of 94.12 % and 77.47 % in cohesiveness, and 64.70 % and 66.20 % in extensibility, respectively. For starch-based modeling clay with added guar gum and xanthan gum, compared to formulations without hydrocolloids, the linear viscoelastic range exceeded 0.04 %, and the frequency dependence of both maximum creep compliance (Jmax) and storage modulus (G′) was significantly reduced. This indicates a more stable network structure and enhanced resistance to deformation. Results from Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (XRD) confirmed that the physical interactions between starch and various hydrocolloids, along with the addition of these hydrocolloids, inhibited the degradation effect of thermomechanical processing on the crystalline structure of starch. With the addition of guar gum, it is observed that a continuous and dense network structure forms within the starch-based modeling clay, and starch particles are distributed uniformly. In conclusion, hydrocolloids enhances the properties of starch-based modeling clay, introducing an innovative solution to the modeling clay sector.

An experimental study on dredged Qinhuai river sediment-based flowable fill treated by flocculation-cementation method

The traditional Portland cement solidification method has low efficiency in treating dredged sediments with high water content. In this study, flowable fill was prepared using dredged sediments by the flocculation-cementation method. By utilizing dredged sediments with high water content, the need for additional water during the flowable fill preparation process is eliminated. The influences of flocculant types and dosages on dehydration efficiency, flowability, and strength were investigated through a series of laboratory tests, including settling column tests, rapid dehydration tests, flowability tests, and unconfined compressive strength (UCS) tests. The results indicate that the use of flocculants improves the dehydration efficiency. The dehydration efficiency of guar gum is the highest, with a settlement rate reaching 78 mL/min during the settling stage. The inclusion of flocculants clearly impacts the flowability and UCS of flowable fill, and the addition of amphoteric polyacrylamide and guar gum decreases the flowability. Furthermore, the Portland cement dosage also has a significant influence on both the flowability and the UCS. As the cement dosage increases, the flowability decreases while the UCS increases. To study the effectiveness of flocculation-cementation method in treating dredged sediment, four sets of recommended schemes are provided based on the actual transportation and re-excavation methods employed in the project to cater for different requirements. This research holds significant reference value for both the resource utilization of dredged sediments with high water content and the engineering application of flowable fill.

Guar Gum, Gellan Gum Biopolymer Soil Stabilization

In civil engineering and construction, soil stabilization is an important aspect. There are diverse conventional techniques to improve soilproperties and for soil stabilization. This study explores the viability of twotypes of biopolymers, Guar gum and Gellan gum, as sustainable and ecofriendly additives for clayey soil stabilization. Compaction, unconfined compression test, permeability, consistency limit, consolidation tests were performed in the study. The sample for the test has been prepared that biopolymer has been mixed with soil in different proportions. These biopolymers forms hydrogels when they get activated, and it enhances the bonding between soil particles thereby increasing the strength. Treating soilwith biopolymer increases dry unit weight and decreases optimum moisturecontent (OMC).Addition of gum solution reduces friction between soil particles, leading to marginal increase in dry unit weight. Higher the biopolymer content lower is the OMC content and soil become more stiff. The compressive strength and load bearing capacity isfound increasing soilbiopolymerspecimen upon different days of curing. For every tested percentage of treatment the percentage reduction factor rises withbiopolymer concentration due to drop in void ratio that results in a drop in the soil's permeability. Guar Gum and Gellan Gum are used as stabilizers in soil treatment, increasing liquid and plastic limits, shrinkage limit, and viscosity. They activate hydrogels, strengthen bonding activity, and increaseshrinkage limit. The addition of Guar Gum and Gellan Gum improves soil biopolymer mix viscosity and adhesion. The findings of this study positivelyimply that adding this material to weak soil would improve the soil’s characteristics.

Development and characterization of a biodegradable film based on guar gum-gelatin@sodium alginate for a sustainable environment.

A significant amount of plastic trash has been dumped into the environment across the world, contributing to the present white pollution crisis. Therefore, plastic manufacturing and disposal must be examined. Biodegradable plastics (BPs) have recently become the subject of study due to their beneficial biodegradability and harmlessness, and they have been the most efficient method for addressing the issue of plastic pollution. This study aims to enhance the synthesis of biodegradable polymers from sodium alginate (Na-Alg) with the addition of guar gum, corn starch, and gelatin using the solution-casting method, followed by mixing in suitable proportions and drying at a certain temperature, resulting in thin film formation. To enhance qualities of the already produced polymer, additional substances such as glycerol, PVA, and latex were added as plasticizers. Characterization techniques such as scanning electron microscopy (SEM), tensile strength, thermogravimetric analysis (TGA), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), differential scanning calorimetry (DSC), UV-vis spectroscopy, and Fourier transform infrared (FTIR) spectroscopy were used to study structural characteristics, surface morphology, polymeric linkages, water absorption capabilities, chemical conductivity, and light transmittance of the newly formed films. These characterization results depict a remarkable achievement in the sense of the high degradability and impressive tensile strength of the newly formed films. In addition, SEM images indicated a porous structure with interconnected pores. FT-IR confirms the occurrence of molecular interactions between separate components. Consequently, different films showed different behavior of degradability, and it is suggested from interpreting the results that the polymeric films may be a viable biodegradable option.

Improvement of Printability Properties of High-Protein Food from Mealworm (Tenebrio molitor) Using Guar Gum for Sustainable Future Food Manufacturing

Increasing the availability of alternative protein from insects is important for solving food shortages. Not only are insects a rich source of protein, but using insect as ingredients could reduce food waste. Insects are thus a potentially valuable ingredient for food industries and even sustainable food. The three-dimensional production of food for future food has gained attention owing to its potential to reduce autonomous food production and produce sustainable food. This study investigated the printability and rheological properties of a high-protein food system derived from mealworms and guar gum used to improve printability. The stability and rheological properties were analyzed for various printing parameters. The results indicate that the yield stress of the mealworm paste dramatically increased (39 to 1096 Pa) with even a small guar gum concentration resulting in an increase (0 to 1.75%). Increasing the guar gum concentration thus resulted in a mealworm paste that had a more significant value of hardness and cohesiveness but reduced adhesiveness (p &lt; 0.05). In conclusion, the addition of guar gum increased viscosity, and caused the paste to exhibit a shear thinning behavior and ability to support itself and was thus more stable. In summary, introducing guar gum resulted in a mealworm paste with rheological properties more suitable for printing in terms of printability and stability.

Lubrication behavior of mixed colloidal systems: Effect of interactions between polysaccharides and oil droplets/ protein particles

The lubrication behavior of food systems is critical for sensory perception and consumer acceptance. This behavior depends on the components present in food and their interactions. In the present study, binary systems were designed to systematically investigate the effect of the interactions (i.e. repulsive and attractive interactions) between components on lubrication properties. Whey protein-stabilized emulsion droplets or whey protein aggregates functioned as dispersed particles, while polysaccharides were present in the continuous phase. Polysaccharides with different molecular characteristics, i.e. xanthan (charged, stiff), pectin (charged, semi-flexible) and guar gum (non-charged, flexible), were selected. We observed that bridging due to attractive interactions between polysaccharides and particles (oil droplets or proteins aggregates) induced extensive particle aggregation, leading to increased friction coefficients. Such bridging was reduced as the concentration of polysaccharides increased, decreasing both cluster size and friction coefficient. In the case of systems with the same charge, weaker depletion interactions led to the formation of particle aggregates, resulting in increased friction coefficients. This was mostly observed for pectin. Conversely, addition of xanthan and guar gum did not cause extensive aggregation and a more homogeneous microstructure was observed. As a result, lower friction coefficients were obtained. The friction coefficients were reduced further when more xanthan or guar gum were added, the highly charged xanthan being more effective. Overall, for both types of interactions, systems with a more homogeneous microstructure (i.e. smaller clusters) resulted in lower friction, indicating that the microstructure of the systems was the primary determinant of lubrication behavior.

Modulation of the retrogradation kinetics of sweet potato starch by the addition of pectin, guar gum, and gallic acid

The effects of the addition of pectin (P), guar gum (GG), and gallic acid (GA) on the pasting properties and retrogradation kinetics of sweet potato starch (SPS) during storage at 4 °C were evaluated by whiteness, as a measure of turbidity, molecular mobility, and differential scanning calorimetry analysis. The incorporation of GG increased the peak, hot paste, breakdown, and final viscosities of the systems, while the opposite resulted with the addition of P and GA. Gallic acid was particularly effective in delaying the progress of SPS retrogradation, since lower whiteness and retrogradation degree and kinetic parameters were obtained throughout the storage assay. Proton population and relaxation times analysis confirmed higher water molecules retention in the presence of GA, which limited hydration and swelling of SPS, thus reducing its posterior retrogradation. Besides, its low molecular weight and high polarity could have hindered starch molecules' reassociation through non-covalent interactions. A concentration-related effect was observed for P, since 1% addition delayed retrogradation, but it was accelerated when 2% were added due to changes in inter and intramolecular interactions between pectin and SPS. Finally, GG promoted SPS retrogradation, which could be explained by the breakage of the structure of swollen starch granules that facilitated ulterior reorganization. Results confirmed that SPS retrogradation can be successfully modulated by the incorporation of pectin, guar gum, or gallic acid for different gluten-free industrial applications.

Effect of different hydrocolloids on the physicochemical, printing, and digestion properties of 3D printed purple sweet potato

This study investigated the influence of different hydrocolloids, namely hydroxypropyl methylcellulose, xanthan gum, guar gum, flaxseed gum, and κ-carrageenan gum on the physicochemical, printing, and digestion properties of 3D printed purple sweet potato (PSP). Aside from κ-carrageenan gum, addition of these hydrocolloids could improve the 3D printing performance of PSP. Addition of hydrocolloids significantly altered the water mobility and rheological characteristics of PSP. The tanδ (G”/G’) values of PSP-hydrocolloid mixtures were strongly related to their 3D printability. The hydrogen bonds in PSP-hydrocolloid samples were weakened compared to PSP-H2O. In comparison to other hydrocolloids, the addition of guar gum significantly decreased the level of starch digestion in PSP during in vitro digestion. The release of phenolics and anthocyanins was highly correlated with the extent of starch digestion. The variations in interactions between hydrocolloids and phenolics affected the release of individual phenolics from PSP during gastrointestinal digestion and colonic fermentation. PSP-guar gum exhibited a significantly higher content of phenolics released after colonic fermentation than the other PSP-hydrocolloid samples. Overall, this study provided theoretical guidance for addition of hydrocolloids into plant-based food materials to enhance their 3D printing performance and modulate their release of intrinsic bioactives as well as digestion of starch during gastrointestinal digestion and colonic fermentation.

Edible gum addition improves the quality of freeze-dried restructured strawberry blocks.

Freeze-dried restructured strawberry blocks (FRSB) have become an increasingly popular product. In this study, the effects of six edible gums (guar gum, gelatin, xanthan gum, pectin, konjac gum, and carrageenan) on the FRSB quality were investigated. For FRSBs, compared with those in untreated samples, the 0.6 % guar gum addition increased texture profile analysis (TPA) hardness, chewiness, and puncture hardness by 29.59%, 174.86%, and 25.34%, respectively; after the 0.6% gelatin addition, the sensory evaluation sourness was reduced by 8.58%, whereas yield, TPA chewiness, and puncture hardness were increased by 3.40%, 28.62%, and 92.12%, respectively; with the 0.9% gelatin addition, the sensory evaluation sourness was reduced by 8.58%; with the 0.9% pectin addition, the yield, TPA hardness, chewiness, and puncture hardness were increased by 4.55%, 5.94%, 77.49%, and 103.62%, respectively. In summary, 0.6-0.9% pectin, gelatin, and guar gum addition are recommended to improve the main qualities of FRSBs.

Enhancing zein-starch dough and bread properties by addition of hydrocolloids

Similar to gluten, zein can form a viscoelastic network upon hydration and shear. This makes zein a promising protein to develop gluten-free bakery products. In this study, the effect of addition of different hydrocolloids (hydroxypropyl methylcellulose (HPMC), guar and xanthan gum), and the inclusion of pregelatinized starch (PG starch) and lactic acid (LA) on zein-corn starch dough and bread properties was examined. The addition of HPMC, and to a lesser extent guar gum, significantly changed the viscoelastic zein dough properties and resulted in bread samples with improved loaf volume and sensory properties. Scanning electron microscopy revealed the formation of a continuous fine foam-like structure in the zein-starch dough when HPMC and guar gum were added. This finer structure translated in a lower dough stiffness and resistance to deformation, and a higher degree of deformation characterized by lower complex moduli and increased creep compliance values. Xanthan gum addition, conversely, had an adverse effect on zein bread loaf volume which was attributed to potential weak repulsion between xanthan and zein molecules. In addition, the amount of α-helix and β-sheet secondary structures in bread samples was altered upon hydrocolloid and PG starch addition and played a role in bread crumb hardness. Overall, the zein bread with HPMC showed textural properties most similar to gluten bread. This research sheds light on different structure levels of zein-based gluten-free recipes as affected by inclusion of hydrocolloids, PG starch and LA, and provides a sound basis for the rational development of zein-based gluten-free breads.