Rheological Properties Of Dough Research Articles

An Investigation of Changes in the Rheological Properties of Toast Pan Bread Dough during the Various Processing Steps of Kneading in an Industrial Bakery

The dough formation during the kneading for the industrial production of toast pan bread was examined using a series of mechanical tests to assess possible transformations in its rheological properties. For this purpose, the Young’s modulus of elasticity and squeeze flow viscometry of the doughs taken from various processing stages of the kneading process were determined. The rheological properties of the dough were assessed using dynamic and creep tests. Young’s modulus data revealed the changes in the elasticity of the dough exhibited during the different steps of kneading, whereas dynamic and creep tests indicated that throughout kneading, the dough displayed the behavior of a weak solid. Elongational viscosity measurements showed that the dough exhibited pseudoplastic behavior throughout the kneading process. The doughs from the various processing steps exhibited differences in zero shear viscosity values. It is suggested that the changes occurred during the processing stages, related to the development of secondary bonding within the gluten matrix.

Effect of polysaccharide on rheology of dough, microstructure, physicochemical properties and quality of fermented hollow dried noodles

Fermented hollow dried noodles, new products emerging in China, are delicious, easy to digest and absorb. However, due to the porous structure produced by yeast, there are still some quality problems such as easy breakage during storage, splitting during cooking and poor textural and sensory quality that need to be addressed. The influence of polysaccharides (guar gum, sodium alginate, and sodium carboxymethylcellulose) on the rheological properties of dough, the microstructure and physicochemical properties, and the quality of fermented hollow dried noodles were studied. The addition of all polysaccharides with proper concentration can improve that quality of dough, dough sheets and noodles. Among which guar gum had the best effect. 0.3% guar gum significantly increased the flexibility (6.64 mm) and expansion index (196.49%) of test sample, significantly decreased the cooking loss (5.74%) and splitting rate (10.00%), and significantly increased the elasticity (0.87) and chewiness (3680.91), respectively. At the same time, the correlation between noodle quality and dough rheological properties was established. Results indicate that polysaccharides can significantly improve the quality of fermented hollow noodles by modified the rheological properties of dough, the microstructure and physicochemical properties of dried noodles.

Effects of Artemisia dracunculus powder on dough rheology and quality properties as a novel ingredient in bread formulation.

Tarragon has a great potential to be a healthy functional food ingredient thanks to its rich antioxidant, phenolic compounds, and nutrient content. The possibility of enriching bread with tarragon was investigated. For this aim, tarragon powder was used at the rates of 0, 2, 4 and 6% instead of wheat flour. In this study, the effects of substitution on the rheological properties of bread dough and color, total phenolic content, antioxidant activity, texture, sensory, and Fourier transform infrared (FT-IR) analysis of bread samples were performed. The composition of tarragon powder showed significant protein (23.16%), crude fiber (7.4%), antioxidant (48.22 ± 0.11%), and total phenolic content (511.66 ± 1.56 mg GAE/100 g). Bread samples with increased fiber and protein content were obtained by adding tarragon powder to the bread formulation. The major differences in the FT-IR absorbance spectra for the bread samples were not observed. Additionally, tarragon powder significantly increased the antioxidative properties of breads (p < 0.05). Adding up to 4% tarragon powder to the bread formulation increased the sensory scores of the breads.

Pulsed Electric Field Treatment of Oat and Barley Flour: Influence on Enzymes, Non-starch Polysaccharides, Dough Rheological Properties, and Application in Flat Bread

AbstractThis study examined the effects of pulsed electric field (PEF) treatment on enzymes, non-starch polysaccharides, and bread-making potential of oat and barley flour. Enzyme activity, microstructure, β-glucan extractability, molecular weight (Mw) and structure of non-starch polysaccharides, dough rheology, and flat bread properties were determined. An exponential decay model explained better the residual activity of oat β-glucanase across electric field intensity than barley β-glucanase. PEF treatment of flour at 12 kV/cm for 162 ms significantly reduced β-glucanase activity (40.2–76.5%) while increasing the concentration of total β-glucans (33.5%) and water-extractable arabinoxylans (36–41%). Mw of linear β-d-glucans decreased (9%) while Mw of branched arabinoxylans increased (6–33%). Scanning electron microscopy showed changes in microstructure of barley proteins. Blending wheat flour (70%) with oat or barley flour (30% weight) after PEF treatment enhanced gluten aggregation energy (29–19%) and breakdown viscosity (18–43%) of dough, as well as increased β-glucan content (21–32%) but reduced specific volume (11–24%). The findings of this study provide a comprehensive insight into the PEF’s potential for retarding enzymatic reactions and preserving integrity of cereal non-starch polysaccharides.

Incorporation of intermediate wheatgrass (Thinopyrum intermedium) into bread wheat doughs: Effects on pasting and rheological properties

AbstractBackground and ObjectivesIntermediate wheatgrass (IWG), a resilient perennial grain with adaptability to difficult climates, is emerging as a compelling candidate for sustainable food solutions in bakery product applications. This study evaluated the pasting and rheological properties of doughs made from bread wheat flour and blended bread wheat–IWG flours (IWG content: 15%, 30%, 45% and 60%), with the goal of exploring the potential of IWG flour as a nutritious and sustainable ingredient in cereal‐based products.FindingsThe RVA peak, trough, and final viscosity values significantly (p &lt; .05) decreased, and the pasting temperature increased as the IWG substitution level increased. IWG‐containing flour blends had a lower retrogradation tendency compared to the control. As the IWG flour substitution level increased, both empirical (Mixograph, Kieffer dough and gluten extensibility, Glutograph) and fundamental (linear oscillatory frequency sweep and creep–recovery) rheological measurements indicated relatively weaker dough properties imparted by the addition of the IWG flour.ConclusionsThe outcomes of this research will shed light on the impacts of utilizing alternative grains, such as intermediate wheatgrass, in bakery applications. This will provide insights that could inform the development of nutritious and sustainable baked products to meet the demands of health‐conscious consumers.Significance and NoveltyThe dough weakening effect of the IWG flour was tolerated at the 15% IWG flour substitution level. At lower substitution levels, the IWG‐containing flour blends exhibited a lower retrogradation tendency compared to bread wheat flour, which could indicate lower staling of loaves of bread during bread storage without compromising the physical quality of bakery products. Finally, the present research fills a critical gap in the literature as it represents the first application of fundamental rheological methods at known and controlled strain and stresses to evaluate the physical properties of doughs prepared from IWG flour blends.

Sprouted Oats (Avena sativa L.) in Baked Goods: From the Rheological Properties of Dough to the Physical Properties of Biscuits

AbstractThis study investigated the impact of sprouted oats (SO) on dough properties and biscuit features. Unsprouted oats (USO) and SO (for 48 h and 72 h) were studied in wheat dough at 10, 20, and 30%, and gluten aggregation, mixing, and extensional properties were evaluated. USO caused a weakening in gluten aggregation capacity, an increase in water uptake, development time and dough rigidity, and a decrease in extensibility. Dough enriched in SO showed mixing profiles similar to wheat, but using SO strongly affected dough extensional properties, indicating gluten weakening. Changes in rheological properties suggested the use of SO at 20% level in biscuit production. Using oats did not affect either biscuit size or volume, but decreased both the hardness and the toughness of the product, with 72 h-SO having the greatest impact, especially on hardness. Further study will address consumer acceptability and nutritional features of the developed baked product.

Impact of frozen storage under static electric field on frozen gluten rheological properties

AbstractBackground and ObjectivesElectrostatic fields, as a new food physical processing technology, can effectively improve the quality of frozen food. The purpose of this study is to investigate the effect of electrostatic field‐assisted frozen storage (SEF) on dough rheological properties, gluten structure, and its mechanism.FindingsThe results showed that the G′ and G" of the gluten were efficiently maintained by SEF throughout frozen storage. Meanwhile, after 8 weeks of frozen storage, the relative contents of α‐helices were 25.28% and 24.76%, respectively, and the relative contents of random coils were 40.58% and 41.25%, respectively, in SEFs compared with the control group. This suggested that SEFs might affect the recrystallization of ice crystals by changing the orientation of water molecules, which, in turn, alleviated the disruption of protein secondary structural order. SEF had no effect on the gauche‐gauche‐gauche conformation. SEF reduced damage to protein senior structure by frozen storage. The glutenin macropolymer (GMP) depolymerization of the control and SEF groups was 28.55% and 28.17%, respectively, and the SEF decelerated the GMP depolymerization.ConclusionsSEF slowed the disruption of the molecular structure by reducing the depolymerization of GMP and slowing the depolymerization of the α‐helix, thus maintaining the viscoelasticity of the gluten.Significance and NoveltyExploring the mechanism of the effect of electrostatic field‐assisted frozen storage on gluten quality.

Effects of pearling on proximate composition, dough rheology, bread-making quality and health-promoting components of elite wheat cultivars

Though the health benefits of whole wheat products have been widely recognized, their less desirable processing qualities limited consumers’ acceptance. Thus, it is imperative to develop processing techniques for balanced nutritional and processing qualities. In this study, we investigated impacts of two grain pearling (debranning) levels on proximate composition, dough rheological properties, food-making quality, arabinoxylans (AXs), alkylresorcinols (ARs) and phenolic acids composition of two elite bread wheat cultivars. Pearled flour (PF) of Zhongmai 175 retained very good dough extensibility (190.7–195.5 mm), while PF of Zhongmai 578 retained medium-to-strong gluten strength and acceptable bread-making quality. Compared to whole wheat flour, PF preserved major portion of the health-promoting components in wheat grains, i.e., 71.4–94.0 % for water-extractable AXs, 68.1–86.3 % for total AXs, 71.4–92.7 % for alkylresorcinols, 85.5–98.9 % for soluble ferulic acid and 67.3–83.3 % for insoluble-bound ferulic acid. Further investigation is needed to understand the effects of different kernel sizes and debranning rates on nutritional profiles of pearled grains. Taken together, our results suggested that grain pearling can be used to produce wheat products with balanced nutritional and processing quality for improved human health.

Effect of curdlan on improving dough rheological properties and performance of corresponding steamed bread

This study explored the effect of curdlan on dough rheological properties, and the performance of corresponding steamed bread. Curdlan addition significantly improved the rheological, dynamic rheological and fermentation properties of dough, and ultimately enhanced the textural and sensory properties of corresponding steamed bread. The microstructure confirmed that the dough with 0.5% curdlan had uniform size and dense gluten network. Addition of curdlan also increased the pasting temperature, the peak and final viscosities, but decreased the breakdown and setback parameters of starch. The steamed bread with 0.5% curdlan had minimum hardness (1266 g), maximum specific volume (2.50 mL/g) and highest sensory score (92.0). Storage experiments suggested that 0.5% curdlan decreased the crumb firming rate and alleviated the retrogradation of starch in steamed bread, indicating that curdlan was effective in retarding the steamed bread staling during storage. It was concluded that 0.5% curdlan had positive effect on rheological properties of wheat dough and quality of corresponding steamed bread.

Improving the Rheological Properties of Dough Obtained by Partial Substitution of Wheat Flour with Freeze-Dried Olive Pomace

Mediterranean countries are known for their high-quality olives and the production and consumption of olive oil. Olive pomace (OP), the major by-product of olive oil extraction, is receiving attention for its potential as a functional compound in food products, reflecting its physiology- and health-promoting attributes. This study assessed the physico-chemical characteristics of OP obtained from two Sardinian olive cultivars, Bosana and Semidana, and the effect of OP incorporation on the baking performance of wheat dough. We assessed the rheological parameters, pasting profile, and fermentation of doughs obtained through the partial substitution of wheat flour with OP at 0 (control), 1, 2, 3, and 5%. OP inclusion resulted in significant differences in the studied parameters compared with control samples. Positive effects included a decrease in development time, improved dough stability and storage, and superior loss modulus and gas retention capacity. Negative effects comprised an increase in dough resistance and a decrease in dough development height, gas production, gas retention, pasting profile, stickiness, and elasticity. These differences in the OP dough were due to the interactions between polyphenols and fibre with water and the starch–gluten matrix. This study found improvements in dough characteristics following the substitution of wheat flour with low percentages of OP, especially Semidana at 1%. Although higher percentages of OP would be associated with greater nutritional and health benefits, they resulted in a degradation of the dough’s attributes, producing a gluten-free-like matrix in the final product.

Extracts with Nutritional Potential and Their Influence on the Rheological Properties of Dough and Quality Parameters of Bread

Formulating basic food to improve its nutritional profile is one potential method for food innovation. One option in formulating basic food such as bread is to supplement flours with specified amounts of non-bakery raw materials with high nutritional benefits. In the research presented here, we studied the influence of the addition of curcumin and quercetin extracts in amounts of 2.5% and 5% to wheat flour (2.5:97.5; 5:95). The analysis of the rheological properties of dough was carried out using a Mixolab 2. A Rheofermentometer F4 was used to assess the dough’s fermentation, and a Volscan was used to evaluate the baking trials. The effect of the extracts on the rheological properties of dough was measured and found to be statistically significant, with curcumin shortening both dough development time and dough stability. Doughs made with greater quantities of extract had a greater tendency to early starch retrogradation, which negatively affects the shelf life of the end products. The addition of extracts did not significantly affect either the ability to form gas during fermentation or its retention, which is important because this gas is prerequisite to forming a final product with the required volume and porosity of crumb. Less favourable results were found on sensory evaluation, wherein the trial bread was significantly worse than the control wheat bread. The panel’s decision-making might have been influenced by the atypical colour of the bread made with additives, and in case of a trial bread made with quercetin, by a bitter taste. From the technological point of view, the results confirmed that the composite flours prepared with the addition of extracts of curcumin and quercetin in amounts of 2.5% and 5% can be processed according to standard procedures. The final product will be bread with improved nutritional profile and specific sensory properties, specifically an unconventional and attractive colour.

Non-Conventional Yeasts from Mozzarella Cheese Whey and Artisanal Sourdoughs: Leavening Capacity and Impact on Bread Sensory Profile

Non-conventional yeasts (NCYs) (i.e., non-Saccharomyces) are used as alternative starters to promote aroma complexity of fermented foods (e.g., bakery products). A total of 66 yeasts isolated from artisanal food matrices (bread and pizza sourdoughs and milk whey) from different geographical areas of the Campania region (Italy) were screened for physiological and technological characteristics such as leavening ability, resistance to NaCl and pH, exopolysaccharide and phytase activity production, and carbohydrate assimilation. Selected and isolated microorganisms were also used to study the leavening kinetics in experimental doughs as mixed inocula of two different strains. Volatile organic compounds (VOCs) of the inoculated doughs were analyzed with solid-phase microextraction/gas chromatography–mass spectrometry (SPME/GC-MS). Most of the strains belonged to non-Saccharomyces species (Pichia kudriavzevii, Kluyveromyces marxianus) and Saccharomyces (S. cerevisiae). Several strains produced exopolysaccharides (EPSs), that are important for dough rheological properties. Moreover, yeasts isolated from whey showed extracellular phytase activity. The mixed starter culture of the S. cerevisiae and NCY strains showed a synergic effect that enhanced the doughs’ aroma complexity. The use of non-conventional yeasts mixed with S. cerevisiae strains can be advantageous in the bakery industry because they improve the bread aroma profiles and nutritional properties by bioactive molecule production.

Microwave-treated rice flour halves the need of hydroxypropyl methylcellulose in the formulation of gluten-free bread

Hydrocolloids such as hydroxypropyl methylcellulose (HPMC) are commonly used in gluten-free (GF) products to mimic the viscoelastic properties of gluten. However, GF products must meet current consumer expectations by not only being tasty and nutritious, but also adhering to ‘clean label’ principles, which involve minimizing ingredients and additives and favoring natural over chemical components. Modifying GF flours via hydrothermal treatments offers an alternative approach to reduce the use of additives in GF products. This work applied response surface methodology to study the potential reduction in HPMC dose in the formulation of GF-breads by the addition of microwave-treated rice flour (MWF) (treatment conditions: 8 min, 9 W/g, 30% moisture), without impairing their appearance, volume, and texture. The optimization study also included Water level and HPMC dose, and evaluated the dough's rheological properties at constant hydration. GF breads were made by varying the amount of native flour substituted with MWF, water level, and HPMC dose. Replacing 50% or 80% of native rice flour by MWF allowed to reduce the usual HPMC dose by more than half. This resulted in higher loaf volume and a softer crumb than their counterparts made with untreated flour and baked with the usual dose of additive (2%). Doses of HPMC as low as 0.7% with 80% MWF still resulted in breads with good texture and acceptable volume. Therefore, the structuring effect of MWF and its good performance in GF baking have been concluded, allowing to reduce the dose of additives required in formulating GF bread.

Study of composite mixtures based on durum wheat semolina and white beans flour for pasta production as specialized food products

Increasing the number of chronic non-communicable diseases around the world is a critical social problem in many countries. In this regard, the creation of specialized foods that correct dysfunctions of the human body is a priority direction in science and food industry. Legumes are characterized by a high content of protein, minerals and trace elements, which determines their possible use as the main raw materials for creating specialized foods. The aim of this research was to present a medical, biological and technological justification for the possibility of producing pasta based on composite mixtures of durum wheat semolina and white bean flour as specialized foods with increased protein content and optimal mineral ratio. Material and methods. The objects of the study were grains of durum wheat (grade Krasnokutka-13), whole meal flour from white beans, composite mixtures in various percentages, and pasta from them. The nutritional and biological value of durum wheat semolina and bean flour was determined experimentally, the nutrient profile of the developed composite mixtures - by calculation. The rheological properties of dough from composite mixtures and the cooking properties of pasta made from them were assessed. Results. It has been established that increase in the proportion of white bean flour in composite mixes elevated calcium and protein content, optimized an amino acid profile, the ratio of calcium to phosphorus, significantly reduced the glycemic load. Bean flour introduction into composite mixtures positively affected the rheological properties of the dough and products from it, in particular, on the speed and energy intensity of dough kneading and aging processes of starched polysaccharides, however, lead to a decrease in dry pasta strength. The pasta made from composite mixtures meets the technological requirements for pasta in terms of a number of basic indicators, namely: the volume of dry pasta, the volume of pasta after cooking and the boilability coefficient. Conclusion. The rheological and technological properties of composite mixtures and their nutrient profile make it possible to recommend them for the production of pasta, as specialized foods.

Vegetable raw materials as a way to improve the quality of bakery products

The development of the food industry is aimed at developing products with new consumer properties: low in sugar and fat, with an increase in the amount of dietary fiber, vitamins and minerals. As one of such an approach, the use of non-traditional vegetable raw ingredients (whole grain flour from sprouted grain (WG) and pectin) can be proposed, which will allow the formation of high-quality food products of a functional orientation. The conducted studies have shown that the above components have an effect on the dough rheological properties: the extensibility of the dough decreases with the introduction of pectin by more than 2 times, the values of the farinograph quality index increase, and the best result is characteristic with the introduction of 2% pectin. The use of WG slightly increases the time of dough formation, while the dough resistance to kneading and the farinograph quality index increase by an average of 54 – 240% from the amount of replacement. Control and experimental bread samples have fairly high total values of organoleptic evaluation. The specific volume of bread increased by 12% when adding WG, and by 8% when adding pectin.

Determination of Rheological and Chemical Properties of Hemp, Rosehip Seed and Safflower Flours

The use of alternative flour in the production of cereal products such as bread can improve the functional and nutritional properties of bread. However, the addition of substitute flour to wheat flour may have some technological, sensory, and rheological disadvantages. To eliminate these problems, the alternative flours should be used in different proportions. The aim of this study is to evaluate the remaining proportions of hemp, safflower and rosehip seeds, which are raw materials of edible and cosmetic oil industry, after oil extraction and to determine their chemical properties (protein, fat, ash) and to investigate the effect on rheological dough properties with Mixolab when used as a substitute for wheat flour. Accordingly, safflower, hemp and rosehip seed flour were added to wheat flour in five different amounts (5, 7.5, 10, 15 and 20%), focusing on displacement. The addition of flour increased protein, fat, ash, phenolic content, and antioxidant capacity. It was found that the addition of 10% safflower and hemp seed flour and 7.5% rosehip seed flour had a positive effect on rheological properties. For all three flour additions, dough development time, stability, and percent protein softening values increased, while water holding capacity decreased. Flours added at 15% or more began to negatively affect rheological properties. This study shows that 3 different flours, which can be added up to 10%, improve the rheological properties, chemically enrich them and improve their functional properties.

Effects of Frozen Storage Time, Thawing Treatments, and Their Interaction on the Rheological Properties of Non-Fermented Wheat Dough.

In this study, the effects of frozen storage time, thawing treatments, and their interaction on the rheological properties of non-fermented dough were evaluated. Texture profile analysis (TPA), rheological measurements, including strain/frequency sweep, and creep-recovery measurement were applied to the dough. Compared with unfrozen fresh dough, the frozen storage time (S) and thawing treatment (T) influenced almost all indicators significantly, and their mutual effects (S × T) mainly affected the hardness and springiness. Frozen time was the main factor resulting in the destruction of non-fermented dough during the thawing treatments. Moreover, refrigerator thawing (4 °C) produced a dough with minimal changes in the rheological properties, regardless of the frozen storage time. Meanwhile, microwave thawing resulted in lower G' and lower zero shear viscosity (η0) values, as well as higher maximum creep compliance (Jmax) and hardness values. Moreover, the difference between the three thawing treatments was exacerbated after 30 days of frozen storage. SEM images also showed that long-term frozen storage combined with microwave thawing seriously destroyed the rheological properties, structural stability, and inner microstructure of the dough.

Effect of ficin‐hydrolyzed wheat gluten on bread quality and in vitro antioxidant activity before and after simulated gastrointestinal digestion

AbstractThis study aimed to investigate the effect of adding ficin‐hydrolyzed wheat gluten at different levels (0%, 1%, 2%, 4%) on bread quality, and in vitro antioxidant activity before and after simulated gastrointestinal digestion. Our findings revealed that the incorporation of the generated wheat gluten hydrolysates (WGH) up to 4 g per 100 g flour positively affected the technological and physical–chemical characterizations of breads, including dough rheological properties, color, specific volume, and moisture. The texture profile analysis indicated reductions in hardness, springiness, and chewiness of the breads, and confirmed anti‐staling properties during storage. The enriched breads received satisfactory scores from the sensory panel and were perceived as less stale after a 4‐day period of storage. The aroma score of the 4% WGH bread was significantly higher than other treatments. Regarding taste, the 4% WGH bread scored the lowest, but the obtained value was not statistically significant. The enriched breads exhibited DPPH, ABTS radical scavenging, and Fe2+ chelation abilities that increased in response to higher levels of hydrolysate incorporation, and these antioxidant activities were enhanced after simulated gastrointestinal digestion. Our findings confirm that it is possible to apply ficin‐generated WGH to enhance physicochemical, nutritional, and biological quality of bread.

Influence of Hazelnut and Walnut Oil Cakes Powder on Thermal and Rheological Properties of Wheat Flour.

The aim of the study was to assess the influence of the addition of powdery hazelnut oil cakes (HOC) or walnut oil cakes (WOC) to wheat flour (WF) on its selected thermal and rheological properties. In the research material, part of the wheat flour (5%, 10%, 15%) was substituted with powdery oil cakes based on hazelnuts and walnuts. The control sample was wheat flour (100% WF). In the tested systems with the addition of hazelnut oil cakes (WFHOC) and walnuts (WFWOC), the characteristics of the gelatinization and retrogradation processes were determined using the DSC method, the gelatinization characteristics of 10% pastes using the RVA method, flow curves and viscosity curves, as well as mechanical spectra. Based on the results obtained, it was found that the type of oil cakes and the level of their addition significantly influenced the thermal and rheological properties of the tested systems. Partial replacement of wheat flour with HOC or WOC significantly influenced most DSC parameters. The highest values of gelatinization enthalpy ∆HG and retrogradation ∆HR were characteristic of the WFWOC5% sample (5.9 J/g) and the control sample (1.3 J/g), respectively. All tested systems showed the properties of shear-thinning non-Newtonian fluids, and the partial replacement of wheat flour with HOC or WOC resulted in a significant reduction in the maximum viscosity of pastes, increasing with the increase in the proportion of oil cakes. WFHOC-based pastes were characterized by higher values of the G' and G″ modulus, while their values and the values of the K' and K″ parameters decreased as the share of oil cakes increased. Gels based on all tested systems showed the nature of weak gels (tan δ = G″/G' > 0.1). Replacing part of the wheat flour with nut oil cakes modified the thermal and rheological properties of pastes and gels, and the observed changes were influenced by both the origin and the level of addition of powdered oil cakes. It was found that WFHOC/WFWOC15% systems had reduced viscosity and weakened viscoelastic properties compared to systems with a lower OC content, which is not a favorable feature from the technological point of view. However, these systems were the most stable, which is an advantageous feature. However, for baking purposes, research should be carried out on the rheological properties of dough made from these mixtures.

Processing, physicochemical and nutritional properties of steamed bread fortified with Chinese Huai-shan Yam

Chinese Huai-shan Yams (HSY) is a source of diverse nutrients, such as allantoin, resistant starch, and non-starch polysaccharides, which is the homology of medicine and food in China. Chinese Steamed Bread (CSB) has gained popularity recently. HSY powder was added to wheat flour to make nutritionally fortified CSB. Three flour improvers were used to enhance the dough thermo-mechanical properties, dough rheology, and physical properties of CSB fortified with HSY powder (up to 30 %). The results showed that the combination of 6 % gluten, 0.3 % xanthan gum, and 100 U/kg TGase can greatly improve the quality of CSB fortified with HSY powder (30 %). The specific volume was increased from 2.00 to 2.97 cm3∙g−1 which was 16.7 % higher than the standard CSB with pure wheat flour, while the hardness, adhesiveness, gumminess, and chewiness were decreased to some extent. During storage, the hardness of the improved CSB was significantly suppressed and the enthalpy was significantly decreased. More importantly, the estimated glycemic index of CSB containing HSY and the improved group decreased from 75.4 to 68.1 and 64.8 respectively. The findings indicated the feasibility of formulating HSY-fortified foods with enhanced nutritional quality.