Protein enrichment and its effects on gluten-free bread characteristics

Impacts of transglutaminase on the processing and digestion characteristics of glutinous rice flour: Insight of the interactions between enzymic crossing-linked protein and starch

Glutinous rice is extensively consumed due to its nutritious content and wonderful flavor. However, glutinous rice flour has a high glycemic index, and the storage deterioration of sweet dumplingsissevere. Transglutaminase (TG) was used to cross-link glutinous rice protein and improve the characteristics of glutinous rice products. The findings demonstrated that TG significantly catalysed protein cross-linking to form a dense protein network, reduced the viscosity of glutinous rice paste and improved the thermal stability. The protein network may physically block the access of starch granules to digestive enzymes to lower the digestion rate of starch, and attenuate the damage of ice crystal molecules to the starch structure to improve the freezing stability of starch gels. The cracking rate and water loss of sweet dumplings prepared using glutinous rice flour with TG treated for 60 min reduced significantly. In conclusion, this study broadened the application of TG in starch products.

Effects of adding proteins from different sources during heat-moisture treatment on corn starch structure, physicochemical and in vitro digestibility

Proteins impact starch digestion, but the specific mechanism under heat-moisture treatment remains unclear. This study examined how proteins from various sources-white kidney bean, soybean, casein, whey-altered corn starch's structure, physicochemical properties, and digestibility during heat-moisture treatment (HMT). HMT and protein addition could significantly reduce starch's digestibility. The kidney bean protein-starch complex under HMT had the highest resistant starch at 19.74 %. Most proteins effectively inhibit α-amylase, with kidney bean being the most significantly (IC50 = 1.712 ± 0.085 mg/mL). HMT makes starch obtain a more rigid structure, limits its swelling ability, and reduces paste viscosity and amylose leaching. At the same time, proteins also improve starch's short-range order, acting as a physical barrier to digestion. Rheological and low-field NMR analyses revealed that protein enhanced the complexes' shear stability and water-binding capacity. These findings enrich the understanding of how proteins from different sources affect starch digestion under HMT, aiding the creation of nutritious, hypoglycemic foods.

The Preparation and Characterization of Quinoa Protein Gels and Application in Eggless Bread

The properties of xanthan gum protein gels composed of quinoa protein (XG-QPG) and ultrasound-treated quinoa protein (XG-UQPG) were compared for the preparation of high-quality quinoa protein gels. The gel qualities at different pH values were compared. The gels were used to produce eggless bread. Microscopically, the secondary structure of the proteins in XG-QPG (pH 7.0) was mainly α-helix, followed by random coiling. In contrast, the content of β-sheet in XG-UQPG was higher, relative to the viscoelastic properties of the gel. Moreover, the free sulfhydryl groups and disulfide bonds of XG-QPG (pH 7.0) were 48.30 and 38.17 µmol/g, while XG-UQPG (pH 7.0) was 31.95 and 61.58 µmol/g, respectively. A high disulfide bond content was related to the formation of gel networks. From a macroscopic perspective, XG-QPG (pH 7.0) exhibited different pore sizes, XG-UQPG (pH 7.0) displayed a loose structure with uniform pores, and XG-UQPG (pH 4.5) exhibited a dense structure with small pores. These findings suggest that ultrasound can promote the formation of a gel by XG-UQPG (pH 7.0) that has a loose structure and high water-holding capacity and that XG-UQPG (pH 4.5) forms a gel with a dense structure and pronounced hardness. Furthermore, the addition of the disulfide bond-rich XG-UQPG (pH 7.0) to bread promoted the formation of gel networks, resulting in elastic, soft bread. In contrast, XG-UQPG (pH 4.5) resulted in firm bread. These findings broaden the applications of quinoa in food and provide a good egg substitute for quinoa protein gels.

Comparison of the effect of hydroxyl propyl methyl cellulose, pectin, and concentrated raisin juice on gluten-free bread based on rice and foxtail millet flour

The nutritional and technological challenges of gluten-free (GF) bread have increased the need for its modification due to the growing demand for this product, especially from celiac patients. Therefore, the present study aims at evaluating the influence of hydroxyl propyl methyl cellulose (HPMC) at 1% and 2% levels, pectin at 1.5% and 2.5% levels, and concentrated raisin juice (CRJ) at 3% and 4% levels on the dough rheological properties and quality of GF bread based on rice and millet flour. The GF bread prepared with HPMC and incorporating CRJ had higher water absorption, dough development time, and dough stability. In addition, the firmness of GF bread during 24-72 h after baking in the presence of 1% HPMC with 3% and 4% CRJ followed by 2.5% pectin incorporating 3% and 4% CRJ showed a significant decrease compared to the control sample. Further, the color index of GF bread was improved with the addition of HPMC and pectin and the L* index decreased in all GF breads with CRJ. The highest volume was occupied by bread containing 1% HPMC. The results demonstrated that GF bread could be produced from a mixture of rice and millet flour and its technological quality was improved by using 1% HPMC and 3% CRJ. Therefore, it has the necessary potential for high-scale production and consumption among members of the society.

From ancient crop to modern superfood: Exploring the history, diversity, characteristics, technological applications, and culinary uses of Peruvian fava beans

The search for plant-based superfoods has shown that many regional populations already have these foods in their diet, with significant potential for production and marketing. This critical review intends to show the history, diversity, characteristics, and uses, emphasizing their significance in traditional diets and potential in the food industry of Peruvian fava beans. As a valuable plant-based protein source, fava beans offer essential micronutrients and have diverse culinary applications. Innovative food industry applications include plant-based meat alternatives, fortified gluten-free products, and a natural color, protein, and fiber source in extruded foods. Key studies have highlighted the successful incorporation of fava beans into various food products, improving their nutritional properties, though some studies also point to limitations in their sensory acceptance. Further research is needed to understand the bioactive components, health effects, and techno-functional characteristics of beans. Challenges facing cultivating and consuming fava beans in Peru include adapting to climate change, enhancing productivity and quality, and promoting consumption and added value. Addressing these challenges involves developing climate-resilient varieties, optimizing agricultural practices, and providing access to resources and financing. In conclusion, this review highlights the promising prospects of Peruvian fava beans as a sustainable, nutritionally rich, and versatile ingredient in the food industry. By harnessing their potential and overcoming challenges, Peruvian fava beans can transition from an ancient crop to a modern superfood, inspiring a global shift towards sustainable and nutritionally balanced diets, aiding the fight against malnutrition, and enriching culinary traditions worldwide.

The Nutritional Quality of Gluten-Free versus Non-Gluten-Free Pre-Packaged Foods and Beverages Sold in Hong Kong

INTRODUCTION

The consumption of gluten-free foods has continued to increase in recent years. Given their higher intake among individuals both with and without a medically diagnosed gluten allergy or sensitivity, it is important to understand how the nutritional quality of these foods compares against non-gluten-free foods. As such, we aimed to compare the nutritional quality of gluten-free and non-gluten-free pre-packaged foods sold in Hong Kong.

METHODS

Data from 18,292 pre-packaged food and beverage items in the 2019 FoodSwitch Hong Kong database were used. These products were categorized as (1) "declared gluten-free"; (2) "gluten-free by ingredient or naturally gluten-free"; and (3) "non-gluten-free" according to information presented on the package. One-way ANOVA was used to compare the differences in the Australian Health Star Rating (HSR), energy, protein, fibre, total fat, saturated fat, trans-fat, carbohydrates, sugars, and sodium content between products in different gluten categories, overall and by major food category (e.g., bread and bakery products) and region of origin (e.g., America, Europe).

RESULTS

Products declared gluten-free (mean ± SD: 2.9 ± 1.3; n = 7%) had statistically significantly higher HSR than those gluten-free by ingredient or naturally gluten-free (2.7 ± 1.4; n = 51.9%) and non-gluten-free (2.2 ± 1.4; n = 41.2%) (all pairwise comparisons p < 0.001). Overall, non-gluten-free products have higher energy, protein, saturated fat, trans-fat, free sugar and sodium, and less fibre compared with products in the other two gluten categories. Similar differences were observed across major food groups and by region of origin.

CONCLUSIONS

Non-gluten-free products sold in Hong Kong were generally less healthy than gluten-free products (regardless of the presence of gluten-free declaration). Consumers should be better educated on how to identify gluten-free foods, given that many gluten-free foods do not declare this information on the label.

Conformational Changes in the Structure of Dough and Bread Enriched with Pumpkin Seed Flour

Pumpkin seed flour is a promising raw material for use in the technology of various bakery products. It has a high biological value and valuable amino acid profile. During the technological process of making bread, there are conformational changes in the protein structure. The purpose of the study was to determine the effect of pumpkin seed flour on conformational changes in the structure of protein substances of dough and bread from wheat flour by near-infrared reflection spectroscopy. The protein profile changed to complete when replacing 10% or more of wheat flour because the score for all amino acids was higher than 100%. The utilitarian coefficient indicates the same balance of amino acids in proteins of all samples. As the percentage of substitution increases, the number of amino acids used for anabolic purposes decreases, and these are more fully utilized by the body.

Gluten-free grains: Importance, processing and its effect on quality of gluten-free products

Gluten-enteropathy affects a significant number of people, making gluten a major concern in the food industry. With medical advancements, the diagnosis of allergies is becoming easier, and people who are allergic to gluten are recommended a complete gluten-free diet. Since wheat provides a major part of the energy and nutrition in the diet, its elimination affects nutrition intake of allergic population. Food scientists are working to formulate products using protein-rich gluten-free grains with quality attributes at par with gluten-containing products. Focused research has been done to provide nutrition and a variety of food to people suffering from gluten-related disorders. Efforts are being made to remove the gluten from the wheat and other gluten-containing grains, while applying different processing/treatments to enhance the properties of gluten-free grains. Hence, the present review summarizes the importance, processing, and products of different gluten-free grains. It also highlights the digestibility of gluten-free grains with clinical trials and gluten elimination strategies for gluten-containing grains.

Effect of Sourdough and Whey Protein Addition on the Technological and Nutritive Characteristics of Sponge Cake

Whey protein and sourdough ferment were used in different combinations to prepare functional sponge cakes, and their mutual influence on batter rheological behaviour as well as product physico–chemical, textural, colour and sensory properties were evaluated. All samples containing whey protein concentrate could bear the nutrition claim ‘a source of protein’. The substitution of wheat flour with whey protein significantly influenced batter viscoelastic behaviour, lowered cake-specific volume, increased product hardness, chewiness, gumminess, and browning index and modified its sensory characteristics. The incorporation of sourdough in protein-enriched sponge cakes improved product-specific volume and appearance compared to a protein-containing sample without sourdough. Although sourdough addition has less of a deteriorating effect on sponge cake rheological and textural properties, when combined with whey protein, it led to a significant reduction in batter elasticity and an increase in product hardness. It was also shown that spontaneously fermented sourdough cannot act as the only leavening agent in sponge cake production. In general, the results of this study have shown that sourdough addition can contribute to improvement in protein-enriched sponge cake quality and that further investigations are necessary in terms of different sourdough and flour type incorporation to minimize the negative effects of protein addition.

Gluten-free bakery products: Ingredients and processes

There is an increasing demand for gluten-free products around the world because certain groups of people, which have increased in the last decades, need to eliminate gluten from their diet. A growing number of people consider gluten-free products to be healthier. However, making gluten-free products such as bread is a technological challenge due to the important role of the gluten network in their development. However, other products, such as cakes and cookies usually made with wheat flour, can easily be made with gluten-free starches or flours since gluten does not play an essential role in their production. To replace wheat flour in these elaborations it is necessary to resort to gluten-free starches and/or flours and to gluten substitutes. Additionally, it can be convenient to incorporate other ingredients such as proteins, fibers, sugars or oils, as well as to modify their quantities in wheat flour formulations. Regarding gluten-free flours, it will also be necessary to know the parameters that influence their functionality in order to obtain regular products. These problems have originated a lower availability of gluten-free products which have a worse texture and are less tasty and more expensive than their homologues with gluten. These problems have been partially solved thanks to research on these types of products, their ingredients and their production methods. In recent years, studies about the nutritional improvement of these products have increased. This chapter delves into the main ingredients used in the production of gluten-free products, the processes for making gluten-free breads, cakes and cookies, and the nutritional quality of these products.

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.

Effect of Tempering Conditions on White Sorghum Milling, Flour, and Bread Properties

The effects of room temperature water, hot water, and steam tempering methods were investigated on sorghum kernel physical properties, milling, flour, and bread-making properties. Overall tempering condition and tempering moisture content were found to have a significant effect on the physical properties. Milling properties were evaluated using a laboratory-scale roller milling flowsheet consisting of four break rolls and eight reduction rolls. Room temperature tempering (18% moisture for 24 h) led to better separation of bran and endosperm without negatively impacting flour quality characteristics i.e., particle size distribution, flour yield, protein, ash, damaged starch, and moisture content. Bread produced from the flour obtained from milling sorghum kernels tempered with room temperature water (18% m.c for 24 h) and hot water (16% m.c at 60 °C for 18 h) displayed better bread-making properties i.e., high firmness, resilience, volume index, higher number of cells, and thinner cell walls when compared to other tempering conditions. Room temperature water tempering treatment (18% m.c for 24 h) could be a better pretreatment process for milling white sorghum kernels without negatively impacting the flour and bread-making quality characteristics.

Sourdough Biotechnology Applied to Gluten-Free Baked Goods: Rescuing the Tradition

Recent studies suggest that the beneficial properties provided by sourdough fermentation may be translated to the development of new GF products that could improve their technological and nutritional properties. The main objective of this manuscript is to review the current evidence regarding the elaboration of GF baked goods, and to present the latest knowledge about the so-called sourdough biotechnology. A bibliographic search of articles published in the last 12 years has been carried out. It is common to use additives, such as hydrocolloids, proteins, enzymes, and emulsifiers, to technologically improve GF products. Sourdough is a mixture of flour and water fermented by an ecosystem of lactic acid bacteria (LAB) and yeasts that provide technological and nutritional improvements to the bakery products. LAB-synthesized biopolymers can mimic gluten molecules. Sourdough biotechnology is an ecological and cost-effective technology with great potential in the field of GF products. Further research is necessary to optimize the process and select species of microorganisms robust enough to be competitive in any circumstance.

Characteristics of gluten-free potato dough and bread with different potato starch-protein ratios

The poor retention of fermentation gases and air is a critical issue for gluten-free (GF) products. To better understand the effect of potato flour on the characteristics of GF bread, the mechanistic relations between potato starch and potato protein in different ratios at 9:1, 8:2, 7:3, 6:4 and 5:5 for GF dough were investigated for viscoelasticity, thermal properties, moisture, microstructures, and bread quality. The results reveal that potato starch had a relatively important role in both dough and bread. The viscous character of dough was highest at a proportion of 6:4, with a more compact microstructure and better bread color, volume, hardness, chewiness, resilience and springiness. With decreasing starch content, the gelatinization and retrogradation enthalpy decreased, and the relaxation time of immobilized water and free water increased significantly. These results are believed to be helpful for processors to develop and optimize GF breads with potato starch and potato protein.

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.

Optimization xanthan gum, Roselle seed and egg white powders levels based on textural and sensory properties of gluten-free rice bread

A response surface methodology based on Box-Behnken design was deployed to optimize gluten-free bread formulation based on rice flour. Roselle seed powder (15, 25 and 35%), egg white powder (10, 20 and 30%) and xanthan gum (0.5, 0.75 and 1%) were selected as independent variables. The purpose of the optimization was to achieve maximum porosity and sensory properties as well as minimum hardness of bread samples. The results showed that the Roselle seed and egg white powders had a significant effect (p ≤ 0.05) on hardness, porosity and sensory characteristics of bread. However, xanthan gum did not show a significant effect (p > 0.05) on sensory properties. The design revealed the optimum formulation for gluten-free rice bread with low crumb firmness and improved porosity and sensory values by using 0.73, 30 and 25% of xanthan gum, Roselle seed and egg white powders, respectively. In addition, the optimized gluten-free bread showed higher nutritional properties in terms of total protein, ash, oil and fiber contents as well as lower staling rate compared to the control.

Tetraselmis chuii as a Sustainable and Healthy Ingredient to Produce Gluten-Free Bread: Impact on Structure, Colour and Bioactivity

The objective of this work is to increase the nutritional quality of gluten-free (GF) bread by addition of Tetraselmis chuii microalgal biomass, a sustainable source of protein and bioactive compounds. The impact of different levels of T. chuii (0%-Control, 1%, 2% and 4% w/w) on the GF doughs and breads' structure was studied. Microdough-Lab mixing tests and oscillatory rheology were conducted to evaluate the dough´s structure. Physical properties of the loaves, total phenolic content (Folin-Ciocalteu) and antioxidant capacity (DPPH and FRAP) of the bread extracts were assessed. For the low additions of T. chuii (1% and 2%), a destabilising effect is noticed, expressed by lower dough viscoelastic functions (G' and G'') and poor baking results. At the higher level (4%) of microalgal addition, there was a structure recovery with bread volume increase and a decrease in crumb firmness. Moreover, 4% T. chuii bread presented higher total phenolic content and antioxidant capacity when compared to control. Bread with 4% T. chuii seems particularly interesting since a significant increase in the bioactivity and an innovative green appearance was achieved, with a low impact on technological performance, but with lower sensory scores.

Ferreira LM, A. Peres J, R. N. A. Barros AI, Raymundo A. Impact of Acorn Flour on Gluten-Free Dough Rheology Properties

Gluten is a fundamental ingredient in breadmaking, since is responsible for the viscoelastic behaviour of the dough. The lack of gluten has a critical effect on gluten-free dough, leading to less cohesive and less elastic doughs, and its replacement represents a challenge for bakery industry. However, dough rheology can be improved combining different ingredients with structural capacity and taking advantage from their interactions. Although acorn flour was used to bake bread even before Romans, nowadays is an underexploited resource. It presents good nutritional characteristics, particularly high fibre content and is naturally gluten free. The aim of this study was to use acorn flour as a gluten-free ingredient to improve dough rheology, following also market trends of sustainability and fibre-rich ingredients. Doughs were prepared with buckwheat and rice flours, potato starch and hydroxypropylmethylcellulose. Two levels of acorn flour (23% and 35% w/w) were tested and compared with control formulation. Micro-doughLAB was used to study mixing and pasting properties. Doughs were characterised using small amplitude oscillatory measurements (SAOS), with a controlled stress rheometer, and regarding Texture Profile Analysis (TPA) by a texturometer. Dietary fibre content and its soluble and insoluble fractions were also evaluated on the developed breads. Acorn flour showed promising technological properties as food ingredient for gluten-free baking (improved firmness, cohesiveness and viscoelasticity of the fermented dough), being an important fibre source.

Yogurt as an Alternative Ingredient to Improve the Functional and Nutritional Properties of Gluten-Free Breads

Absence of gluten in bakery goods is a technological challenge, generating gluten-free breads with low functional and nutritional properties. However, these issues can be minimized using new protein sources, by the addition of nutritional added-value products. Fresh yogurt represents an interesting approach since it is a source of protein, polysaccharides, and minerals, with potential to mimic the gluten network, while improving the nutritional value of gluten-free products. In the present work, different levels of yogurt addition (5% up to 20% weight/weight) were incorporated into gluten-free bread formulations, and the impact on dough rheology properties and bread quality parameters were assessed. Linear correlations (R² > 0.9041) between steady shear (viscosity) and oscillatory (elastic modulus, at 1 Hz) values of the dough rheology with bread quality parameters (volume and firmness) were obtained. Results confirmed that the yogurt addition led to a significant improvement on bread quality properties, increasing the volume and crumb softness and lowering the staling rate, with a good nutritional contribution in terms of proteins and minerals, to improve the daily diet of celiac people.

Production of prebiotic gluten-free bread with red rice flour and different microbial transglutaminase concentrations: modeling, sensory and multivariate data analysis

The aim of this study was to develop gluten-free bread formulated with red rice flour and microbial transglutaminase and prebiotic (inulin). First, the physicochemical analysis of minerals present in red rice flour was performed. Response surface methodology was used to analyze the effects of microbial transglutaminase (MTgase) [0.5; 1.0 and 1.5%] in combination with fermentation time (FT) [60; 80 and 100 min] on the quality parameters of gluten-free bread. Acceptance test was used to evaluate the sensory characteristics of breads together with multivariate analysis of data. The addition of MTgase increased bread volume, hardness and chewiness. However, the cohesiveness and springiness of all breads remained unaffected. The formulation (1.0% MTgase and 80 min FT) presented the best sensory attributes through PCA (principal component analysis) and greater acceptance. Overall, red rice flour, prebiotic and MTgase are promisingly useful ingredients for the production of gluten-free quality bread.

A Comparative Study of Partial Replacement of Wheat Flour with Whey and Soy Protein on Rheological Properties of Dough and Cookie Quality

The development of wheat-based foods that are enriched with proteins is increasingly popular. The purpose of this study was to compare the effects of partial replacement of wheat flour with whey and soy proteins (0–30%) on the rheological properties of dough and cookie-making quality. The incorporation of whey protein (WP) diluted the concentration of gluten, leading to an increase in dough development time (MDT) and breakdown torque and a decrease in stability time (MST) and minimum torque (MMT). The gelation of WP during the heat treatment increased dough peak torque (MPT), G′, and G′′. As a contrast, the addition of soy protein (SP) increased dough MST, MDT, and MMT. The aggregation of SP helped increase G′ and decrease tan δ of the dough in oscillatory shear tests. The weak gelling effects and higher water absorption of SP decreased MPT, G′, and G′′ of the dough during heat treatment. With SP, the spread ratio of cookies first decreased from 6.39 to 5.66 and then increased to 6.86, and the overall acceptability scores ranged from 6.62 to 7.02, indicating that the formed soy protein network helped maintain the dough structure for obtaining an improvement in the quality of bakery products.

Influence of Protein and Water Addition on Gluten-Free Dough Properties and Bread Quality

The diversity and nutritional value of the gluten-free products is challenging because of the increasing segment of population with celiac disease. In order to address this issue, the effects of different proteins (powdered eggs, soy, lupin, sodium caseinate and whey) to the gluten-free formulation based on rice and maize flours were assessed. The dough hydration was varied from 55 to 105 %, and dough rheological properties and bread characteristics were tested. The nature of the proteins and water level added to the gluten-free bread recipes has a decisive role on product quality. The best results in terms of rheological behavior were recorded for samples with powdered eggs, soy and lupin protein addition, at water absorption of 95–105 %. Concerning the bread quality, our results showed that protein addition to the rice and maize flours gluten-free formulations allows the improvement of crumb texture.

Non-gluten proteins as structure forming agents in gluten free bread

The study aimed to evaluate the effects of selected protein isolates and concentrates on quality and staling of gluten-free bread, in the absence of other structure-forming agents such as guar gum and pectin. The applied preparations included albumin, collagen, pea, lupine and soy. Their addition had various effects on rheological properties of the dough and volume of the bread. Volumes of the loaves baked with soy and pea protein were smaller, while those with albumin significantly larger than control. Presence of non-gluten protein caused changes in crumb structure (higher porosity, decrease in cell density, higher number of pores with a diameter above 5 mm) and its color, which was usually darker than of unsupplemented starch-based bread. The least consumer's acceptance was found for bread baked with soy protein. The presence of pea and lupine preparations improved sensory parameters of the final product, providing more acceptable color and smell in comparison to control, while soy caused a decrease of all analyzed consumer's scores. The addition of protein caused an increase in bread hardness and in enthalpy of retrograded amylopectin, during bread storage.

Understanding gluten-free dough for reaching breads with physical quality and nutritional balance

In the last decade the development of gluten-free foodstuffs has attracted great attention as a result of better diagnoses of coeliac disease and a greater knowledge of the relationship between gluten-free products and health. The increasing interest has prompted extensive research into the development of gluten-free foodstuffs that resemble gluten-containing foods. This review aims to provide some insights on dough functionality and process conditions regarding bread quality and to point out recent research dealing with the nutritional composition of those products. Gluten-free dough results from the combination of different ingredients, additives, and the processing aids required for building up network structures responsible for bread quality. Some relationships between dough rheology and bread characteristics were established to identify possible predictor parameters. Regarding bread-making processes, the impact of mixing, dough treatment and baking is stated. Nutritional quality is an important asset when developing gluten-free breads, and different strategies for improving it are reviewed. Gluten-free bread quality is dependent on ingredients and additives combination, but also processing can provide a way to improve bread quality. Nutritive value of the gluten-free breads must be always in mind when setting up recipes, for obtaining nutritionally balanced bread with adequate glycaemic index.