Influence of hydrocolloids on dough handling and technological properties of gluten-free breads

Celiac disease is a gluten-sensitive entheropathy. Later studies suggest an increasing prevalence of that disease, likely due to the development of more sensitive methods of screening. Cereals containing prolamins such as wheat, rye, barley, and oat are toxic for celiac patients, whereas corn, rice, sorghum and buckwheat are considered to be safe. The reaction to gluten ingestion by patients suffering from that chronic disease is inflammation of the small intestine leading to the malabsorption of several important nutrients, vitamins and minerals, especially of calcium and iron. Osteopenia and osteoporosis are a frequent complication accompanying coeliac disease. The only effective treatment for coeliac disease is a long-life strict adherence to a gluten-free diet. Up to now, research studies related to gluten free bakery products have been focused on the design of gluten free matrixes by combining different starches and gluten free cereals. However, no special attention has been paid to the use of those products as carriers or vehicles of micronutrients, which are necessary for celiac patients. The aim of the research was to design of gluten free formula fortified with calcium destined to bake a bread. In that order the available organic or mineral calcium supplements were analysed. Optimisation of the technological parameters, analysis of chemical and minerals composition, sensory quality and texture of bread crumb were analysed. Preliminary estimation of bread colour, odour and taste allowed to select calcium caseinate and calcium citrate as supplements affecting beneficially the sensory quality of bread. When the mixture of both of them was applied, the improvement of bread porosity and structure was also observed. Based on the sensory evaluation of bread carried out with the method of sensory profiling and in hedonic tests gluten free bread fortified with a mixture of calcium caseinate and citrate was selected as the best. Texture properties of fresh gluten free bread crumbs fortified with calcium supplements measured using compression device of Instron were considerably improved. Summarising, the application of calcium supplements such as calcium caseinate and citrate in order to fortified gluten free bread with calcium influence beneficially its sensory and nutritional properties simultaneously enhancing the structure and texture of bread.

Nutritional therapy – Facing the gap between coeliac disease and gluten-free food

Effect of heat treatment of sorghum flour on the functional properties of gluten-free bread and cake

13 - Gluten-free breads

The demand for gluten-free (GF) bread is steadily increasing. However, the production of GF bread with improved baking quality and enhanced nutritional properties remains a challenge. In this study, we investigated the effects of adding psyllium fibre (PSY) in varying proportions to buckwheat flour on the dough characteristics, bread quality, and starch digestion properties of GF bread. Our results demonstrate that incorporating PSY contributes to the formation of a gluten-like network structure in the dough, leading to an increase in the gas holding capacity from 83.67% to 98.50%. The addition of PSY significantly increased the specific volume of the bread from 1.17 mL/g to 3.16 mL/g. Bread containing PSY displayed superior textural characteristics and colour. Our study also revealed that the inclusion of PSY reduced the digestibility of starch in GF bread. These findings highlight the positive impact of incorporating PSY into GF bread, suggesting its potential in guiding the production of GF bread with a lower glycaemic index. This may be particularly beneficial for individuals seeking to regulate their blood sugar levels or adopt a low-glycaemic diet.

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.

Functional and nutritional replacement of gluten in gluten-free yeast-leavened breads by using β-conglycinin concentrate extracted from soybean flour

In this study, different emulsifiers (diacetyl tartaric acid esters of mono and diglycerides [DATEM], sodium stearol-2-lactylate [SSL], mono and diglyceride [MG], lecithin [LC] and their combination [DATEM+SSL + MG + LC]) were used in gluten-free bread formulation containing 30% fermented dough of buckwheat, quinoa, and amaranth flour. The effects of emulsifiers on the quality and staling characteristics of gluten-free breads were investigated. SSL and the combination of “DATEM + SSL + MG + LC” caused an increase in volume and specific volume and a decrease in hardness values of gluten-free breads compared to the control. In general, gluten-free breads containing the SSL and emulsifier combination had lower bread hardness, slower staling rate, and higher sensory scores. In conclusion, SSL and “DATEM + SSL + MG + LC” combination became the most suitable emulsifier applications for improving both technological and sensory quality of gluten-free breads containing fermented dough of pseudocereals. Practical applications Bread has an important place among gluten-free products, and in this study, the technological, sensory, and staling properties of gluten-free breads containing 30% fermented dough of buckwheat, quinoa, and amaranth were improved with the use of SSL and “DATEM + SSL + MG + LC” emulsifier combination. In addition to nutritional properties, products with improved technological, sensory, and staling properties were offered to the gluten-free food market.

This study aimed to examine the effect of different hydrocolloid types and combinations on the properties of gluten-free bread made using household type bread machine. In this content, four different hydrocolloids, xanthan gum (XG), hydroxypropyl methylcellulose (HPMC), carboxymethyl cellulose (CMC), and methylcellulose (MC), were used at concentrations of 3% and 5% to evaluate the moisture, baking loss, specific volume, color, texture, and sensory properties of gluten-free bread. Additionally, the quality attributes of gluten-free bread made with hydrocolloids were compared with the control bread without hydrocolloids and a commercial gluten-free mixture. As a result of the evaluations, it was determined that the control bread had the highest baking loss, and the gluten-free bread containing 5% MC had the lowest specific volume. An increase in the concentration of hydrocolloids led to an increase in specific volume, except for breads containing XG, CMC, and XG+CMC. Regarding hardness values, the control bread had the highest hardness, while gluten-free bread containing 5% HPMC+MC showed the lowest hardness. According to sensory evaluation results, gluten-free breads made with all hydrocolloids at 5% concentration provided the best results in terms of overall acceptability. Considering the results obtained, it was thought that the combination usage of different hydrocolloids was effective in improving the qualities and consumability of gluten-free bread.

There are no reports of addition of carob fibre to gluten-free bread, as only carob germ flour was used. The research task was to determine what level of carob fibre can be used and how it influences the physical and sensorial properties of gluten-free bread. Especially, the knowledge of the antioxidant properties of such bread is very valuable. The gluten-free bread from rice, corn, and buckwheat flour (35:35:30%) was prepared after mixing (5 min), proofing (40 min, 30°C), and baking (45-50 min, 230°C) of dough. Carob fibre was added in the amounts of 1, 2, 3, 4, and 5% of the total flour content. The results showed that increased content of carob fibre induced significant and favourable changes in the volume, colour, and texture (hardness and springiness) of the bread crumb. Carob fibre enriched the breads with lipophilic compounds able to chelate metal ions. The activity of hydrophilic compounds was significantly higher in the case of control bread and bread with the lowest percentage of the additive. In conclusion, the highest increase in antioxidant activity was found for breads with 1 and 2% of carob fibre. The most acceptable gluten-free bread can be obtained by adding up to 2% of carob.

The influence of β-glucans on the properties of gluten-free dough and bread is still not fully explained, with the literature suggesting both positive and negative effects. The aim of this study was to investigate the effect of the molar mass of oat β-glucans on the properties of gluten-free bread. Gluten-free breads were baked under standardized conditions from a model gluten-free mix without and with a 1% or 2% share of oat β-glucans of a low molar mass of 24,540 g/mol, a medium molar mass of 85,940 g/mol and a high molar mass of 1,714,770 g/mol. The share of β-glucans affected the increase in water addition to the baking mix and dough yield proportionally to the molar mass and amount of β-glucans. The β-glucans of the highest molar mass, particularly at a 2% share, were most effective in increasing bread volume, reducing hardness and increasing the moisture content of the bread crumb on the day of baking, as well as reducing the increase in hardness and maintaining a high moisture content of the bread crumb after 1 day of storage, compared to bread without added β-glucans.

Gluten-free products from rice are gaining popularity because of its hypoallergenic characteristic. The absence of gluten results in inferior bread qualities such as hard texture, reduced volume, and shorter shelf-life. Hydrolytic enzymes are activated during germination to stimulate plant growth, and germinated brown rice (GBR) has been shown to improve gluten-free bread properties. However, the changes in hydrolytic enzyme activities under different germination conditions and their relationship with the properties of germinated rice flour and bread have not been reported. Therefore, the objectives of this work were to investigate the activities of amylases and protease in GBR under aerobic and anaerobic germination for 2 and 4 days and their impacts on starch hydrolysis, flour properties, and bread qualities. Greater enzyme activities were observed in GBR germinated under aerobic condition and a longer time, and correlated with increased sugar content and foaming capacity. Breads were prepared from GBR along with brown rice (control). GBR breads showed a greater specific volume (4% to 10%), a reduced hardness (34% to 90%), and a lower starch retrogradation (66% to 90%) compared with the control. Bread prepared from 4-day aerobic GBR had the largest reduction in starch molecular size and displayed the lowest hardness and starch retrogradation. After stored for 5 days, GBR breads exhibited no change in specific volume and less hardness and retrogradation than the control bread. In conclusion, greater activities of protease and amylases in GBR significantly increased foaming capacity and reduced starch molecule size, respectively, which were responsible for the improved GBR bread qualities. PRACTICAL APPLICATION: Rice flour is widely used as the main ingredient in gluten-free breads, which however tend to have poor texture and reduced shelf-life due to the absence of gluten. The qualities of gluten-free breads are usually improved by the addition of many ingredients such as tapioca and potato starches. Germination process naturally produces bioactive compounds and activates enzymes. Germination conditions that produce greater activities of amylases and protease can be used to produce gluten-free breads with better qualities and longer shelf-life without the addition of starch.

Innovative approaches towards improved gluten-free bread properties

The aim of the study was to investigate the effect of using various by-products (orange and apple pomace, tomato peel, pepper peel, prickly pear peel, and prickly pear seed peel) on the dough rheology and properties of gluten-free bread. The by-products were incorporated into a gluten-free bread formulation based on corn and chickpea flours (2/1 w/w). Different levels of each by-product (0, 2.5, 5, and 7.5% in the basic replacement) were tested. Wheat bread and gluten-free bread without the addition of by-products were used as controls. The results indicated that the by-products increased the maximum dough height, the total CO2 production, and CO2 retention coefficient compared to unenriched gluten-free dough. The highest K-value consistency coefficient was observed for the dough enriched with the prickly pear peel. The addition of by-products significantly improved (p < 0.0001) the specific volume of gluten-free bread, with values increasing from 1.48 to 2.50 cm3/g. The hierarchical cluster analysis and the constellation plot showed four groups: the wheat bread group, the second group containing the gluten-free control bread, the group with bread enriched by pomace, and the group with bread enriched with peels, exhibit the same effect on gluten-free bread and the peels exhibit the same effect on gluten-free bread.

The addition of fat to gluten-free (GF) bread can influence several quality attributes, such as texture and starch retrogradation. Therefore, the aim of this study was to investigate the influence of different fats on GF bread properties using two different baking methods (conventional and ohmic heating), in order to understand how these affect the physical bread quality, the formation of amylose-lipid complexes and its effect on crumb firming behavior. Fats (coconut, rapeseed, butter, and palm) with different physico-chemical properties, and physical state (solid, liquid) were tested in standard GF bread formulations. Results showed that fat significantly improved crumb pore uniformity. Crumb texture and pasting properties were mostly influenced by the type of fat, storage time and baking method. Staling was delayed in all breads added with fat due to the formation of amylose-lipid complexes, which were highest with palm fat and were usually higher when baked by ohmic heating.