Role of enzymes in improving the functionality of proteins in non-wheat dough systems

Rheological properties and microstructure of wheat flour dough systems with enzyme-hydrolyzed mashed potatoes

The interest in incorporating potatoes into wheat dough is increasing. However, potatoes exhibit significant viscosity during thermal processing, affecting product processing and quality. This study aims to find an effective method to reduce the viscosity of mashed potatoes. We aimed to compare the effects of different enzymes (α-amylase, β-amylase, and flavourzyme) and concentrations (0.01%, 0.05%, and 0.1%) on the micromorphology and rheological properties of mashed potatoes and potato-wheat dough. The impact of flavourzyme was the most significant (p<0.05). When enzyme concentration increased, viscosity decreased, and the degree of structural damage, indicated by increased porosity. Notably, the addition of flavourzyme can increase the content of sweet and umami free amino acids, improving the flavor of mashed potatoes. The scanning electron microscopy and confocal laser scanning microscopy images of potato-wheat dough revealed that enzyme-hydrolyzed mashed potatoes had improved homogeneity, reestablished the dough continuity, and strengthened the three-dimensional structure comprising proteins and starch. Notably, flavourzyme demonstrated the most significant effect on enhancing the protein-starch network structure. This was attributed to the exposure of functional groups resulting from protein hydrolysis, facilitating interaction with starch molecules. Our findings indicate that the addition of 0.1% flavourzyme (500 LAPU/g, pH 5.5, 55 ± 2°C, 30 min treated) was the most effective in reducing viscosity and reconstructing the gluten network. Enzymatic hydrolysis plays a vital role in the production of high-quality potato products, with particular importance in the baking industry, where flavourzyme exhibits significant potential. PRACTICAL APPLICATION: Enzymatic hydrolysis plays a vital role in the production of high-quality potato products, with particular importance in the baking industry, where flavourzyme exhibits significant potential.

Rice-Based Gluten-Free Foods and Technologies: A Review

Rice, one of the most widely consumed staples worldwide, serves as a versatile gluten-free substitute. However, review articles on technological developments in grain-free production focusing on rice are scarce. This review assesses various research results concerning the quality attributes of rice-based gluten-free foods, including bread, pasta, and beer. To optimize the key attributes in processed products, such as dough leavening in bread and the physical and cooking properties of noodles and pasta, research has focused on blending different gluten-free grains and incorporating additives that mimic the gluten function. Additionally, various processing technologies, such as starch preprocessing and extrusion puffing processes, have been employed to boost the quality of rice-based gluten-free products. Today, a variety of products, including bread, noodles, and beer, use rice as a partial replacement for barley or wheat. With rapid advancements in technology, a noticeable portion of consumers now shows a preference for products containing rice as a substitute. This trend indicates that rice-based gluten-free foods can be enhanced by leveraging the latest developments in gluten-free product technologies, particularly in countries where rice is a staple or is predominantly cultivated.

Proximate Compositions, Texture, and Sensory Profiles of Gluten-Free Bario Rice Bread Supplemented with Potato Starch

Current gluten-free food development trends tend to favour pigmented rice flour. Bario Merah Sederhana is a type of red-pigmented rice that is indigenous to Sarawak, Malaysia. This research investigates the nutritional, texture, and sensory properties of gluten-free rice bread produced from a composite of BMS rice flour and potato starch, producing samples referred to as F1 (100:0), F2 (90:10), F3 (80:20), and F4 (70:30). The gluten-free rice bread formulations demonstrated higher ash and crude fibre content and lower carbohydrate content than wheat bread. However, the crude protein content of the bread decreased significantly (p < 0.05) with a decreased amount of rice flour, owing to wheat flour containing greater protein. The crumb of rice bread appeared to be darker due to the red pigment of rice flour; in contrast, the crust was lighter than the control sample, possibly due to a lower Maillard reaction. Among rice bread formulations, F4 demonstrated the lowest hardness in dough and bread, as well as the highest stickiness and springiness in dough and bread, respectively. The wheat bread received the highest rating (p < 0.05) in the sensory test; nonetheless, among the rice breads, F4 was considered to be an acceptable formulation owing to its high score in colour (7.03), flavour (5.73), texture (6.03), and overall acceptability (6.18). BMS has potential in gluten-free rice breads; the formulation of 70% rice flour combined with 30% potato starch was indicated to be acceptable.

Effect of Bioprocessing on Techno-Functional Properties of Climate-Resilient African Crops, Sorghum and Cowpea

Sorghum and cowpea are very compatible for intercropping in hot and dry environments, and they also have complementary nutritional compositions. Thus, the crops have the potential to improve food security in regions threatened by climate change. The aim of this study was to investigate different enzymes (carbohydrate-degrading, proteases and phytases) and lactic acid bacteria (LAB) fermentation to improve the techno-functional properties of sorghum and cowpea flours. Results show that sorghum carbohydrates were very resistant to hydrolysis induced by bioprocessing treatments. Most of the protease treatments resulted in low or moderate protein solubilization (from ca. 6.5% to 10%) in sorghum, while the pH adjustment to 8 followed by alkaline protease increased solubility to 40%. With cowpea, protease treatment combined with carbohydrate-degrading enzymes increased the solubility of proteins from 37% up to 61%. With regard to the techno-functional properties, LAB and amylase treatment decreased the sorghum peak paste viscosities (from 504 to 370 and 325 cPa, respectively), while LAB and chemical acidification increased cowpea viscosity (from 282 to 366 and 468 cPa, respectively). When the bioprocessed sorghum and cowpea were tested in breadmaking, only moderate effects were observed, suggesting that the modifications by enzymes and fermentation were not strong enough to improve breadmaking.

Ultrasound Treatment Enhanced Semidry-Milled Rice Flour Properties and Gluten-Free Rice Bread Quality

The structural and functional properties of physical modified rice flour, including ultrasound treated rice flour (US), microwave treated rice flour (MW) and hydrothermal treated rice flour (HT) were investigated with wet-milled rice flour (WF) used as a positive control. The results showed the presence of small dents and pores on the rice flour granules of US and MW while more fragments and cracks were showed in HT. XRD and FTIR revealed that moderate ultrasonic treatment promoted the orderly arrangement of starch while hydrothermal treatment destroyed the crystalline structure of rice flour. In addition, the significant decrease of gelatinization enthalpy and the narrowing gelatinization temperature were observed in US. Compared to that of SF, adding physical modified rice flour led to a batter with higher viscoelasticity and lower tan δ. However, the batter added HT exhibited highest G' and G″ values and lowest tan δ, which led to a harder texture of bread. Texture analysis demonstrated that physical modified rice flour (except HT) reduced the hardness, cohesion, and gumminess of rice bread. Especially, the specific volume of bread with US increased by 15.6% and the hardness decreased by 17.6%. This study suggested that ultrasound treatment of rice flour could improve texture properties and appearance of rice bread.

Dry Heating of Cowpea Flour below Biopolymer Melting Temperatures Improves the Physical Properties of Bread Made from Climate-Resilient Crops

Improving the technological functionality of climate-resilient crops (CRCs) to promote their use in staple foods, such as bread, is relevant to addressing food and nutrition security in Africa. Dry heating of cowpea flour (CPF) was studied as a simple technology to modulate CPF physicochemical properties in relation to bread applications. For this purpose, the melting behavior of cowpea starch and proteins in CPF was first studied and modeled using Flory–Huggins theory for polymer melting. Next, dry-heating conditions were investigated based on the predicted biopolymer melting transitions in CPF to be well below starch and protein melting. The pasting properties (i.e., peak viscosity, final viscosity, breakdown and setback) of CPF could be selectively modulated depending on temperature-time combinations without altering the thermal behavior (i.e., melting enthalpies) of CPF. Water-binding capacity and soluble solids decreased with the increased severity of the temperature-time combinations. Dry-heated CPF added to CRC-based bread significantly improved crumb texture. In particular, dry heating at 100 °C for 2 h provided bread with the highest crumb softness, cohesiveness and resilience. The positive effects on the crumb texture could be largely related to enhanced starch integrity, as indicated by a reduction in breakdown viscosity after treatment. Overall, dry heating of CPF under defined conditions is a promising technology for promoting the use of CPF as a techno-functional and protein-rich ingredient in bread-type products.

Effective Use of Plant Proteins for the Development of "New" Foods

Diversity in our diet mirrors modern society. Affluent lifestyles and extended longevity have caused the prevalence of diabetes and sarcopenia, which has led to the increased demand of low-carb, high-protein foods. Expansion of the global population and Westernization of Asian diets have surged the number of meat eaters, which has eventually disrupted the supply–demand balance of meat. In contrast, some people do not eat meat for religious reasons or due to veganism. With these multiple circumstances, our society has begun to resort to obtaining protein from plant sources rather than animal origins. This “protein shift” urges food researchers to develop high-quality foods based on plant proteins. Meanwhile, patients with food allergies, especially gluten-related ones, are reported to be increasing. Additionally, growing popularity of the gluten-free diet demands development of foods without using ingredients of wheat origin. Besides, consumers prefer “clean-label” products in which products are expected to contain fewer artificial compounds. These diversified demands on foods have spurred the development of “new” foods in view of food-processing technologies as well as selection of the primary ingredients. In this short review, examples of foodstuffs that have achieved tremendous recent progress are introduced: effective use of plant protein realized low-carb, high protein, gluten-free bread/pasta. Basic manufacturing principles of plant-based vegan cheese have also been established. We will also discuss on the strategy of effective development of new foods in view of the better communication with consumers as well as efficient use of plant proteins.

Optimization of gluten-free bread production with low aflatoxin level based on quinoa flour containing xanthan gum and laccase enzyme

This study was aimed to develop a new cereal-based product using quinoa flour, xanthan gum, and laccase and also to evaluate their effects on the quality characteristics of gluten-free bread (GFB). Experimental design method was applied for optimization of gluten-free formulation. The effects of three variables of quinoa flour (0-50%), laccase activity (0-2 U/g flour), and xanthan gum (0-0.5%) on the contents of total aflatoxin (TAF) and aflatoxin B1 (AFB1), color indices (L*, a*, and b*), and texture properties (hardness, cohesiveness, and springiness) of GFB were evaluated. The results showed that quinoa flour and laccase enzyme significantly reduced TAF and AFB1 (p < 0.05). The lowest AFB1 level (3.67 ± 0.96 ng/g) in the GFB formulation containing quinoa flour (40%), laccase enzyme (2.0 U/g), and xanthan gum (0.46%) was very close to the predicted amount (3.66 ± 0.96 ng/g). Quinoa flour significantly reduced the L* and a* values and increased b* value and improved the texture parameters. Laccase enzyme also improved color indices and texture properties. Therefore, the use of laccase enzyme and quinoa flour is recommended based on the desired effect on the quality characteristics of GFB.

Towards Sustainable Shifts to Healthy Diets and Food Security in Sub-Saharan Africa with Climate-Resilient Crops in Bread-Type Products: A Food System Analysis

Massive urbanization and increasing disposable incomes favor a rapid transition in diets and lifestyle in sub-Saharan Africa (SSA). As a result, the SSA population is becoming increasingly vulnerable to the double burden of malnutrition and obesity. This, combined with the increasing pressure to produce sufficient food and provide employment for this growing population together with the threat of climate change-induced declining crop yields, requires urgent sustainable solutions. Can an increase in the cultivation of climate-resilient crops (CRCs) and their utilization to produce attractive, convenient and nutritious bread products contribute to climate change adaptation and healthy and sustainable diets? A food system analysis of the bread food value chain in SSA indicates that replacement of refined, mostly imported, wheat in attractive bread products could (1) improve food and nutrition security, (2) bring about a shift to more nutritionally balanced diets, (3) increase economic inclusiveness and equitable benefits, and (4) improve sustainability and resilience of the food system. The food system analysis also provided systematic insight into the challenges and hurdles that need to be overcome to increase the availability, affordability and uptake of CRCs. Proposed interventions include improving the agronomic yield of CRCs, food product technology, raising consumer awareness and directing policies. Overall, integrated programs involving all stakeholders in the food system are needed.

Characterization of gluten-free rice bread prepared using a combination of potato tuber and ramie leaf enzymes

A combination of freeze-dried powder of disproportionating enzyme (D-enzyme)-containing potato tuber and β-amylase-containing ramie leaf was used to improve the gluten-free (GF) bread, and its physicochemical properties were characterized. The presence of D-enzyme and β amylase in the potato tuber and ramie leaf was confirmed. Sixty five percent of partially gelatinized rice flour and 20% corn starch was combined with 10% freeze-dried potato tuber and 1% ramie leaf powder, and baked. The specific volume increased by 23% compared to the control with improved internal characteristics. Texture profile analysis revealed that retrogradation of the bread was retarded when stored for 90 h at 4 °C. The bread crumb amylose content was reduced from 14 to 9% and amylopectin branch chain-length distribution was rearranged, whereby the proportions of the branch chains with Degree of polymerization (DP) < 9 and DP > 19 decreased. The results suggest that D-enzyme and β-amylase cooperatively altered amylose/amylopectin ratio and amylopectin structure.

A review on mechanistic aspects of individual versus combined uses of enzymes as clean label-friendly dough conditioners in breads

Numerous dough improvers are used alone or in combination to enhance the quality of baked goods such as breads. While modern consumers demand consistent quality, the expectations for ingredients have changed over the past few years, and reformulations have taken place to provide "clean label" options. However, the effects and mechanisms of blended dough conditioners suitable for such baked products have not been systematically summarized. In this review, dough and bread properties as affected by different improver combinations are examined, with a focus on additive or synergistic interactions between enzymes or between enzymes and ascorbic acid. The combination of enzymes that hydrolyze starch and cell wall polysaccharides has been shown to reduce textural hardness in fresh and stored bakes goods such as breads. Enzymes that hydrolyze arabinoxylans, the main nonstarch polysaccharide in wheat, have synergistic effects with enzymes that result in cross-linking of wheat flour biopolymers. In some studies, the effects of bread improvers varied for wheat flours of different strength. Overall, bread products in which wheat is used in whole grain form or in a blend with other flours especially benefit from multiple improvers that target different flour constituents in doughs.

Technological, Nutritional and Sensory Properties of an Innovative Gluten-Free Double-Layered Flat Bread Enriched with Amaranth Flour

Celiac disease is increasing all over the world. In this context, most recent research in this area is addressing and attempting to improve the nutritional value and sensory characteristics of gluten-free (GF) food products and to enhance their technological properties. Here, amaranth flour was studied as a potential healthy ingredient for the development of an innovative GF flat bread. Starting from two different basic formulations (rice flour:corn starch and rice flour:tapioca starch, 50:50), the impact of partially replacing rice flour (6%) and starch (6%) with amaranth on the nutritional characteristics, polyphenol composition, textural, and sensory properties of the resulting GF flat breads was explored. The substitution with amaranth led to detrimental effects on the doughs’ viscometric properties, especially in the case of tapioca starch, but significantly improved the doughs’ textural properties. All the amaranth-enriched flat breads showed a better color and a significant increase in all polyphenols fractions but lower antioxidant activity. During bread storage for three days, a detrimental effect on both starch retrogradation, toughness, and extensibility properties were observed, especially when tapioca starch was used. Check-all-that-apply (CATA) sensory test results showed that the incorporation of amaranth increased yeast odor and yeast flavor perception and decreased the softness in mouth-only in tapioca-based samples. A better compromise among technological, nutritional, and sensory properties was achieved when amaranth flour was added to the basic rice and corn formulation.

A Systematic Review on Gluten-Free Bread Formulations Using Specific Volume as a Quality Indicator

This study aimed to perform a systematic review on gluten-free bread formulations using specific volumes as a quality indicator. In this systematic review, we identified 259 studies that met inclusion criteria. From these studies, 43 met the requirements of having gluten-free bread with a specific volume greater than or equal to 3.5 cm³/g. Other parameters such as the texture profile, color (crumb and crust), and sensory analysis examined in these studies were presented. The formulations that best compensated the lack of the gluten-network were based on the combination of rice flour, rice flour with low amylose content, maize flour, rice starch, corn starch, potato starch, starch with proteins and added with transglutaminase (TGase), and hydrocolloids like hydroxypropylmethylcellulose (HPMC). Of the 43 studies, three did not present risk of bias, and the only parameter evaluated in common in the studies was the specific volume. However, it is necessary to jointly analyze other parameters that contribute to the quality, such as texture profile, external and internal characteristics, acceptability, and useful life of the bread, especially since it is a product obtained through raw materials and unconventional ingredients.

The quality of gluten-free bread made of brown rice flour prepared by low temperature impact mill

Our previous work reported that the brown rice flour prepared by low temperature impact mill possessed excellent physicochemical properties. The performance of brown rice flour in making gluten-free bread was further investigated. It was found that the starch crystal structure was destroyed and the damaged starch content increased as the particle size of brown rice flour decreased. The interaction between the starch and water in the model dough and the matrix structures among the endosperm masses were enhanced as the particle size decreased, making the gluten-free dough more viscoelastic. However, dough made with finer flour was too sticky, which limited the expansion of dough. Gluten-free bread prepared with medium-sized brown rice flour had favorable quality characterized by large specific volume, low hardness, numerous and homogeneous gas cells.

A Systematic Review of Gluten-Free Dough and Bread: Dough Rheology, Bread Characteristics, and Improvement Strategies

High-quality, gluten-free doughs and bakery products are clearly more difficult to produce than wheat flour-based products. The poor quality of the breads that are currently available demonstrates that manufacturing remains a significant technological problem. This is mainly due to the absence of gluten, which has a huge negative impact on dough rheology and bread characteristics. Gluten replacement is still the major challenge in the development of doughs and baked goods. The literature documents various improvement strategies. The most active approach seeks to identify alternative ingredients that can mimic the viscoelastic properties of the gluten network, notably hydrocolloids, enzymes, emulsifiers, and alternative sources of protein. However, other innovative strategies, such as high pressure, using heat to dry flour, and sourdough fermentation, have been investigated. In this context, the first aim of this review is to summarize current knowledge regarding gluten-free doughs, breads, and bakery products. Secondly, as it is clear that the manufacture of gluten-free products remains a key challenge, it suggests some improvement strategies that can boost their nutritional, technological, and sensorial characteristics.

The effect of Quinoa flour and enzymes on the quality of gluten-free bread

Gluten-free products usually are produced by refined flours such as rice and corn flour, which the bran is separated during processing. These flours are not nutritionally as rich as gluten containing products. Moreover, gluten-free bread has several technical problems such as unfavorable texture, low volume, quick staling, and weaker color and taste compared with the wheat flour products. In this research, gluten-free bread with various substitution of quinoa (0%, 15%, and 25%) was produced and the effects of lipase and protease enzymes on the quality of bread were investigated. The gluten-free bread properties like physicochemical properties, rheological properties, and bread microstructure were evaluated. Moreover, the sensorial properties were assessed. The results have demonstrated that gluten-free bread with quinoa flour has favorable properties. Also, lipase and protease enzymes could improve the quality of the bread containing quinoa. Protease and lipase enzymes increased the bread volume, specifically in sample containing 15% quinoa substitution. Moreover, the staling was delayed in sample 25% quinoa substitution. The bread was accepted by consumers, and the highest score belonged to 25% substitution of quinoa flour.

Development of gluten-free non-yeasted dough structure as factor of bread quality formation

The article is devoted to the study of the influence of hydrocolloids and animal protein concentrates on the formation of the foam-like structure of gluten-free non-yeast dough as the main factor for bread quality formation. The use of CMC in a concentration of 0.5% is found to be appropriate. The bread volume increases to 236 cm3.100g-1 in comparison with the control sample in water – 202 cm3.100g-1. It is proved that the suggested additives in the amounts of 0.5 ‒ 1.0% Helios-11 and 0.5% CMC solution cause 100% resistance of egg white foam. In this case, the foaming ability increases with the addition of Helios-11 only in amounts up to 1.0%, then decreases for higher amounts of Helios-11 or in the presence of CMC. This can be explained by the increase in density of the whipping mass and the ability of both additives to thicken solutions. In the presence of the additives, the foamy texture of the dough changes. The number of large pores (0.7 – 1.5 mm) decreases almost fourfold, and the number of small and very small pores (0.1 ‒ 0.5 mm) increases significantly. The index of form resistance of the control sample is 32, and in the presence of 0.5% CMC with 0.5 ‒ 1.0% APC is 20 ‒ 21, which indicates a decrease in the surface tension of the aqueous solutions with additives, to a large extent, in the case of joint use.

Factors Influencing Zein-Whole Sorghum Flour Dough Formation and Bread Quality

Zein is known to able to form viscoelastic dough with wheat-like properties under certain conditions. Several studies have been conducted to explain the mechanism behind this ability and to improve the functionality and end-use quality of zein-based dough systems. However, most of this research has been conducted using zein in combination with isolated starches or high-starch flours. To investigate the production of additional zein-whole sorghum flour breads, experiments were conducted to determine factors impacting zein-whole sorghum flour dough and bread quality. Optimizing water levels, using defatted zein and/or sorghum flour, and increasing zein content in dough formulas were investigated as initial formulation steps. Of these factors, increasing zein content from 20% to 30% (flour weight basis) had the greatest impact, resulting in stronger zein-based dough and improved bread quality. Additives and zein treatments shown to impact zein functionality were then investigated for their effect of zein-whole sorghum flour breads. Mixing zein and whole sorghum flour with 0.5% hydrogen peroxide, 5% ethanol, or 3% hydroxypropyl methylcellulose resulted in improved dough strength and bread quality. Breads made from whole white sorghum flour had improved quality compared to zein-based breads made with black or high-tannin whole sorghum flour. PRACTICAL APPLICATION: Zein is known to be able to form wheat-like dough when mixed under the right conditions. Most of the research on zein-based dough and food products has used high-starch flours. This project investigated optimizing the production of zein-whole sorghum flour dough and bread as an alternative. Increasing the zein content in the formula and using additives including ethanol and HPMC produced breads from zein-whole sorghum flour that were like those made with zein and pure starch.

Impact of broad beans addition on rheological and thermal properties of wheat flour based sourdoughs

Broad bean flour is a valuable source of proteins and micronutrients and can efficiently balance the nutritional value of wheat flour. The aim of the study was to assess the impact of wheat flour substitution by native and germinated broad beans on the water related, thermal and rheological properties of the composite flours and sourdoughs. Regardless of the investigated flour, temperature increase resulted in significant decrease of water soluble index. Addition of broad bean to wheat flour affected the swelling power. Differential scanning calorimetry measurements on flours indicated two peaks at ∼70 °C assigned to starch gelatinization, and ∼100 °C attributed to amylose-lipids complexes disruption. The same thermal dependent events were highlighted through the rheometric temperature ramp test. Sourdoughs were further obtained out of the composite flours and dynamic rheometric analysis showed that fermentation improved flow resistance. Wheat substitution by broad bean flour increased sourdoughs consistency due to the higher protein content.

Recent practical researches in the development of gluten-free breads

Wheat bread is consumed globally and has played a critical role in the story of civilization since the development of agriculture. While the aroma and flavor of this staple food continue to delight and satisfy most people, some individuals have a specific allergy to wheat or a genetic disposition to celiac disease. To improve the quality of life of these patients from a dietary standpoint, food-processing researchers have been seeking to develop high-quality gluten-free bread. As the quality of wheat breads depends largely on the viscoelastic properties of gluten, various ingredients have been employed to simulate its effects, such as hydrocolloids, transglutaminase, and proteases. Recent attempts have included the use of redox regulation as well as particle-stabilized foam. In this short review, we introduce the ongoing advancements in the development of gluten-free bread, by our laboratory as well as others, focusing mainly on rice-based breads. The social and scientific contexts of these efforts are also mentioned.

Gluten-Free Products for Celiac Susceptible People

The gluten protein of wheat triggers an immunological reaction in some gluten-sensitive people with HLA-DQ2/8 genotypes, which leads to Celiac disease (CD) with symptomatic damage in the small intestinal villi. Glutenin and gliadin are two major components of gluten that are essentially required for developing a strong protein network for providing desired viscoelasticity of dough. Many non-gluten cereals and starches (rice, corn, sorghum, millets, and potato/pea starch) and various gluten replacers (xanthan and guar gum) have been used for retaining the physical-sensorial properties of gluten-free, cereal-based products. This paper reviews the recent advances in the formulation of cereal-based, gluten-free products by utilizing alternate flours, starches, gums, hydrocolloids, enzymes, novel ingredients, and processing techniques. The pseudo cereals amaranth, quinoa, and buckwheat, are promising in gluten-free diet formulation. Genetically-modified wheat is another promising area of research, where successful attempts have been made to silence the gliadin gene of wheat using RNAi techniques. The requirement of quantity and quality for gluten-free packaged foods is increasing consistently at a faster rate than lactose-free and diabetic-friendly foods. More research needs to be focused on cereal-based, gluten-free beverages to provide additional options for CD sufferers.

Combined effect of xanthan gum and water content on physicochemical and textural properties of gluten-free batter and bread

The objective of this study was to evaluate the combined effect of xanthan gum (XG) on physicochemical, rheological and textural properties of gluten-free batter and bread. To prepare gluten-free batter, different levels of XG (1.5, 2.5 and 3.5%) and water (90, 100 and 110%) were added to a base formula of rice (50%), maize (30%) and quinoa flours (20%); and the batters were evaluated in a factorial design. Several properties on both batter (stickiness and back extrusion) and its corresponding bread (loaf specific volume, baking loss, water activity and pH, texture profile, mean cell area, mean cell density, cell size uniformity, void fraction, mean cell compactness and mean cell aspect ratio) were then evaluated. Higher XG doses (p < .001) tended to produce batters of lower stickiness, adhesion and cohesive-strength, yet, of higher firmness, consistency, cohesiveness and viscosity index. After baking, these loaves presented lower specific volume; lower crumb a_w, pH, hardness, springiness, mean cell area and void fraction; and higher (p < .001) chewiness, resilience, mean cell density, cell size uniformity and mean cell compactness. The sticker and less consistent batters produced with higher WC rendered larger bread loaves of softer and more springy/resilient crumbs with greater mean cell size and void fraction. Gluten-free loaves of good appearance in terms of higher specific volume, lower crumb hardness, higher crumb springiness, and open grain visual texture were obtained in formulations with 110% WC and XG doses between 1.5 and 2.5%.

Dynamic viscoelasticity of protease-treated rice batters for gluten-free rice bread making

Papain (cysteine protease), subtilisin (Protin SD-AY10, serine protease), and bacillolysin (Protin SD-NY10, metallo protease) increased the specific volume of gluten-free rice breads by 19-63% compared to untreated bread. In contrast, Newlase F (aspartyl protease) did not expand the volume of the rice bread. In a rheological analysis, the viscoelastic properties of the gluten-free rice batters also depended on the protease categories. Principal component analysis (PCA) analysis suggested that the storage and loss moduli (G' and G″, respectively) at 35 °C, and the maximum values of G' and G″, were important factors in the volume expansion. Judging from the PCA of the viscoelastic parameters of the rice batters, papain and Protin SD-AY10 improved the viscoelasticity for gluten-free rice bread making, and Protin SD-NY effectively expanded the gluten-free rice bread. The rheological properties differed between Protin SD-NY and the other protease treatments.

Proteins of Amaranth (Amaranthus spp.), Buckwheat (Fagopyrum spp.), and Quinoa (Chenopodium spp.): A Food Science and Technology Perspective

There is currently much interest in the use of pseudocereals for developing nutritious food products. Amaranth, buckwheat, and quinoa are the 3 major pseudocereals in terms of world production. They contain high levels of starch, proteins, dietary fiber, minerals, vitamins, and other bioactives. Their proteins have well-balanced amino acid compositions, are more sustainable than those from animal sources, and can be consumed by patients suffering from celiac disease. While pseudocereal proteins mainly consist of albumins and globulins, the predominant cereal proteins are prolamins and glutelins. We here discuss the structural properties, denaturation and aggregation behaviors, and solubility, as well as the foaming, emulsifying, and gelling properties of amaranth, buckwheat, and quinoa proteins. In addition, the technological impact of incorporating amaranth, buckwheat, and quinoa in bread, pasta, noodles, and cookies and strategies to affect the functionality of pseudocereal flour proteins are discussed. Literature concerning pseudocereal proteins is often inconsistent and contradictory, particularly in the methods used to obtain globulins and glutelins. Also, most studies on protein denaturation and techno-functional properties have focused on isolates obtained by alkaline extraction and subsequent isoelectric precipitation at acidic pH, even if the outcome of such studies is not necessarily relevant for understanding the role of the native proteins in food processing. Finally, even though establishing in-depth structure-function relationships seems challenging, it would undoubtedly be of major help in the design of tailor-made pseudocereal foods.