Advances in gluten-free bread technology

The properties of potato gluten-free doughs: comparative and combined effects of propylene glycol alginate and hydroxypropyl methyl cellulose or flaxseed gum

Different methods are often used to make gluten-free (GF) bread to get better bread characteristics. To explore the effects of emulsifiers and hydrocolloids on the characteristics of GF dough, different esterification levels of propylene glycol alginate (PGA), hydroxypropyl methyl cellulose (HPMC), flaxseed gum with (FG) different molecular weight, and the binary blends of HPMC/PGA and FG/PGA were added to GF dough, made with potato starch and potato protein in a ratio of 6:4. The results showed that the potato GF dough with FG and FG/PGA obtained a higher viscoelasticity than the other doughs. HPMC and FG promoted to the formation of network structure, but the network structure formed by PGA and their combination was more developed. It was found that all PGA, HPMC, FG and their combination could improve the softness of GF breads. The results provided a basis for optimizing the quality of potato GF bread.

Sorghum Flour Application in Bread: Technological Challenges and Opportunities

Sorghum has a long history of use in the production of different types of bread. This review paper discusses different types of bread and factors that affect the physicochemical, technological, rheological, sensorial, and nutritional properties of different types of sorghum bread. The main types of bread are unleavened (roti and tortilla), flatbread with a pre-ferment (injera and kisra), gluten-free and sorghum bread with wheat. The quality of sorghum flour, dough, and bread can be improved by the addition of different ingredients and using novel and traditional methods. Furthermore, extrusion, high-pressure treatment, heat treatment, and ozonation, in combination with techniques such as fermentation, have been reported for increasing sorghum functionality.

Effects of Teff-Based Sourdoughs on Dough Rheology and Gluten-Free Bread Quality

Production of gluten-free bread (GFB) with good quality characteristics represents a technological challenge. Our study aimed to obtain nongluten bread from cereals and pseudocereals with applying single cultures of Pediococcus acidilactici, Pediococcus pentosaceus and Enteroccocus durans as sourdoughs. The effect of sourdoughs on the quality traits of gluten-free (GF) dough and GFB was explored. The structural and baking properties of GF dough composed of teff, rice, corn, and sorghum flours were improved by adding xanthan gum (0.6%), guar gum (1.0%) and carboxymethyl cellulose (1.0%). The tested strains reached 10⁸ cfu/g in teff flour and produced sourdoughs with a pleasant lactic aroma. The sourdough-fermented doughs were softer and more elastic compared to control dough and yielded reduced baking loss. Strain Enterococcus durans ensured the best baking characteristics of GF dough and the highest softness of the GFB during storage. Strain Pediococcus pentosaceus had the most pronounced positive effect on aroma, taste and aftertaste. Pan baking was found to be more appropriate to obtain stable shape and good-looking products. A careful starter culture selection is necessary for GFB development since a significant effect of strain specificity on dough rheology and baking characteristics was observed.

Olive Cake Powder as Functional Ingredient to Improve the Quality of Gluten-Free Breadsticks

The growing demand for high-quality gluten-free baked snacks has led researchers to test innovative ingredients. The aim of this work was to assess the feasibility of olive cake powder (OCP) to be used as a functional ingredient in gluten-free (GF) breadsticks. OCP was used by replacing 1, 2, and 3% of maize flour into GF breadstick production (BS1, BS2, BS3, respectively), and their influence on nutritional, bioactive, textural, and sensorial properties was assessed and compared with a control sample (BSC). BS1, BS2, and BS3 showed a higher lipid, moisture, and ash content. BS2 and BS3 had a total dietary fibre higher than 3 g 100 g⁻¹, achieving the nutritional requirement for it to be labelled as a “source of fibre”. The increasing replacement of olive cake in the formulation resulted in progressively higher total phenol content and antioxidant activity for fortified GF breadsticks. The L* and b* values decreased in all enriched GF breadsticks when compared with the control, while hardness was the lowest in BS3. The volatile profile highlighted a significant reduction in aldehydes, markers of lipid oxidation, and Maillard products (Strecker aldehydes, pyrazines, furans, ketones) in BS1, BS2, and BS3 when compared with BSC. The sensory profile showed a strong influence of OCP addition on GF breadsticks for almost all the parameters considered, with a higher overall pleasantness score for BS2 and BS3.

Rheological Characteristics of Model Gluten-Free Dough with Plantago Seeds and Husk Incorporation

The seeds and husk of Plantago origin are rich source of dietary fiber known for its medicinal use. Despite the use of both Plantago psyllium and Plantago ovata products due to their physicochemical and nutritional properties, only the effects of Plantago ovata husk have been studied. Their structure-forming properties may positively affect gluten-free bread quality only if an adequate dough hydration is used. The aim of the work is to analyze the effect of different Plantago products: Plantago psyllium seeds and Plantago ovata seeds and husk in quantities of 3, 6 and 9% share on the rheological profile of model gluten-free dough and bread and bread’s technological quality and shelf-life. The rheological parameters of the dough were determined with Mixolab protocols and uniaxial deformation test. Bread quality and its textural profile analysis after cooling and storage were determined. The addition of Plantago psyllium seeds weakened the dough. All additives contributed to a reduction in starch retrogradation, bread hardness and water loss during baking, and to the improvement of the doughs’ resistance to extension, dough energy and bread yield. This influence is strongest when the Plantago ovata husk was used. However, the consumer acceptance of the tested breads was low and, in this respect, the breads with the addition of seeds of both Plantago psyllium and ovata were considered to be better than the husk.

Gluten-Free Bread and Bakery Products Technology

Gluten, a protein fraction from wheat, rye, barley, oats, their hybrids and derivatives, is very important in baking technology. The number of people suffering from gluten intolerance is growing worldwide, and at the same time, the need for foods suitable for a gluten-free diet is increasing. Bread and bakery products are an essential part of the daily diet. Therefore, new naturally gluten-free baking ingredients and new methods of processing traditional ingredients are sought. The study discusses the use of additives to replace gluten and ensure the stability and elasticity of the dough, to improve the nutritional quality and sensory properties of gluten-free bread. The current task is to extend the shelf life of gluten-free bread and bakery products and thus extend the possibility of its distribution in a fresh state. This work is also focused on various technological possibilities of gluten-free bread and the preparation of bakery products.

Enzymatic modifications of gluten protein: Oxidative enzymes

Oxidative enzymes treat weak flours in order to restore the gluten network of damaged wheat flour and reduce the economic and technological losses. The present review concentrates on oxidative exogenous enzymes (transglutaminase, laccase, glucose oxidase, hexose oxidase) and oxidative endogenous enzymes (tyrosinase, peroxidase, catalase, sulfhydryl oxidase, lipoxygenase, lipase, protein disulfide isomerase, NAD(P)H-dependent dehydrogenase, thioredoxin reductase and glutathione reductase) and their effects on the rheological, functional, and conformational features of gluten and its subunits. Overall, transglutaminase is used in wheat-based foods through introducing isopeptide bonds (ε-γ glutamyl-lysine). Glucose oxidase, hexose oxidase, peroxidase, sulfhydryl oxidase, lipase, and lipoxygenase form disulfide and nondisulfide bonds through producing hydrogen peroxide. Laccase, tyrosinase, and protein disulfide isomerase form cross-links between tyrosine and cysteine residues by generating radicals. Thioredoxin reductase and glutathione reductase create new inter disulfide bonds. The effect of oxidative enzymes on the formation of covalent cross-linkages were substantially more than non-covalent bonds in gluten structure.

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.

Development of a Breadfruit Flour Pasta Product

Breadfruit (Artocarpus altilis) is grown throughout the tropics. Processing the perishable starchy fruit into flour provides a means to expand the use of the fruit. The flour can be used to develop new value-added products for local use and potential export. The purpose of this investigation was to develop a pasta product using breadfruit flour, test the sensory qualities of the breadfruit pasta product by sensory evaluation, and evaluate the nutritional composition. 'Ma'afala', a popular and widely distributed Polynesian cultivar was used for the study. Nutritional labeling shows that the breadfruit pasta product is high in carbohydrates (73.3%/100 g) and low in fat (8.33/100 g). Sensory evaluation indicates that 80.3% of the panelists (n = 71) found the pasta acceptable while 18.3% disliked the pasta. The breadfruit pasta product can provide a nutritious, appealing and inexpensive gluten-free food source based on locally available breadfruit in areas of the world where it can be easily grown.

INVESTIGATION OF THE WATER-RETAINING CAPACITY OF THE PROTEIN-HYDROCARBON COMPLEX OF RYE-WHEAT DOUGH WITH ADDITION OF POLYFUNCTIONAL FOOD SUPPLEMENT “MAGNETOFООD”

Under modern conditions, creation of new high effective technologies of bread is connected with a necessity of solving a problem of the products quality at the discrete work of enterprises: at processing raw materials (flour) with decreased properties in ecologically unfavorable regions, manufacturing products with prolonged storage terms, high consumption characteristics, diet destination, for treating-prophylactic nutrition. The development of innovative technologies of bakery products of rye-wheat flour is based on revelation of conceptual approaches, connected with creation of new functional technological properties of dough systems and ready products. That is why in bread technologies there are searched new raw material sources, food supplements-improvers, able to raise consumption characteristics, storage terms, food value; to enrich a ready product with functional ingredients and so on. The water-retaining capacity (WRC) – is one of main functional-technological parameters of food raw materials and ready products, because it favors the output, prime cost and quality characteristics of bakery products. For increasing WRC of rye-wheat dough, there is proposed the polyfunctional food supplement “Magnetofood”. For reasoning the mechanism of its interaction with polymer matrixes of lipo- and glucoproteids of rye-wheat flour and WRC mechanism of the food supplement “Magnetofood” in rye-wheat dough – there was investigated the influence of “Magnetofood” on processes of hydration, dissolution and water-retention of rye-wheat flour. It was established, that introduction of the food supplement “Magnetofood” in rye-wheat flour in amounts: 0,10; 0,15; 0,20 % of a flour mass increases its solubility and WRC: solubility – by 4,5 – 12,5 %; WRC – in 1,1 – 1,3 times, respectively. The rational dose of the food supplement “Magnetofood” is experimentally determined -– 0,15 % of a flour mass. There was investigated the influence of the food supplement “Magnetofood” on a quantity of bound water by experimental samples of rye-wheat flour at temperatures from 30 to 70 оС. It was established, that the temperature growth in experiments results in increasing the quantity of bound water for all experimental samples. Addition of “Magnetofood” in amounts: 0,10; 0,15; 0,20 % of a flour mass favors the increase of bound water in 1,2 – 1,5 times, comparing with the control (without “Magnetofood”). The received experimental data may be used at developing the technology of rye-wheat bread, enriched with the polyfunctional food supplement “Magnetofood”; and also at developing innovative technologies of food system systems (especially, meat, confectionary, milk ones). The results of the study may be used for developing recipes and technologies of food products for increasing their output, water-retaining and stabilizing capacities.

INVESTIGATION OF THE WATER-RETAINING CAPACITY OF THE CARBOHYDRATE COMPLEX OF RYE-WHEAT DOUGH WITH ADDITION OF POLYFUNCTIONAL FOOD SUPPLEMENT “MAGNETOFООD”

Today in Ukraine the share of low-quality bakery products is near 20–25 %, because they often don’t correspond to quality standards and sanitary norms, because of being produced of flour with low bakery properties. That is why new raw material sources, functional ingredients and so on are searched for in bread technologies. For using new raw material and food supplement types, it is necessary to know their functional-technological properties (FTP) that allows to prognosticate the behavior of powder-like raw materials and food supplements in food masses at technological processing and storage of ready products. The water-retaining capacity (WRC) is one of main functional-technological parameters of carbohydrate-containing raw materials, because it favors the outcome, structural-mechanical properties and quality characteristics of ready products. The authors introduced “Magnetofood” polyfunctional food supplement for increasing WRC of rye-wheat dough. For grounding the mechanism of forming supramolecular groups in carbohydrate food systems: Magnetofood-polysacharide-water, there was studied the influence of “Magnetofood” food supplement on processes of hydration, swelling and water-retention by rye-wheat starch and rye-wheat flour. It was established, that introduction of “Magnetofood” food supplement in rye-wheat starch and flour in amounts: 0,10; 0,15; 0,20 % to the mass of starch or flour increases swelling and water-retaining capacity (WRC) of starch and flour: swelling in 1,3–1,5 and 1,5–2,25 times, respectively; WRC in 1,10–1,15 and 1,1–1,3 times, respectively. The rational dose of “Magnetofood” food supplement – 0,15 % to the mass of dry raw material was experimentally set. There was studied the influence of “Magnetofood” food supplement on rheological properties of water suspensions of rye-wheat starch and flour at different temperatures and different speeds of shift. It was established, that adding “Magnetofood” in amount 0,15 % favors increasing the effective viscosity of suspensions of experimental samples of starch and flour at temperatures: (23±2) ºС and (40±2) ºС comparing with control samples in average by 29,0 % – for starch and by 22,0 % – for flour at 23 °С and by 16,0 % – for starch and by 10,0 % – for flour at 40 °С. There was studied the dynamics of changing viscosity of colloid solutions of starch and flour, enriched with “Magnetofood” in amount 0,15 % to the mass of dry raw material in the keeping process at different temperatures and shift speed 9 s-1. There was established the increase of viscosity of suspensions of rye-wheat starch and flour in the process of infusion (especially at adding “Magnetofood”) that is connected with continuing hydration and swelling process. It was demonstrated, that the temperature increase of the colloid system from (23±20) ° С to (40±2) °С favors the increase of its viscosity – both at the initial moment and in infusion process during 30 min in average by 20,0–25,0 % at the expanse of the aforesaid processes. Moreover, adding “Magnetofood” accelerates and intensifies the processes of swelling and hydration of experimental samples of rye-wheat starch and flour comparing with control ones. The received experimental data may be used at elaborating the technology of rye-wheat bread, enriched with “Magnetofood” food supplement; and also at elaborating innovative technologies of carbohydrate food systems. The results of this study may be used at elaborating recipes and technologies of carbohydrate-containing food products for increasing their viscosity, water-retaining and stabilizing capacities.

INVESTIGATION OF THE MOISTURE-RETAINING POWER OF RYE-WHEAT GLUTEN AND FLOUR WITH POLYFUNCTIONAL FOOD SUPPLEMENT “MAGNETOFООD”

The moisture-retaining power (WRP) of dough is one of main functional technological parameters, because it influences the output, structural-mechanical properties and quality characteristics of bread and bakery products. For increasing WRP of rye-wheat dough, the polyfunctional food supplement “Magnetofood” is offered. For determining, what component of rye-wheat dough plays the leading role in absorbing and retaining water – there was studied the influence of the polyfunctional food supplement “Magnetofood” on water-absorbing and water retaining power of rye-wheat gluten and rye-wheat flour. It was established, that adding the food supplement “Magnetofood” in amount 0,15 % for the mass of rye-wheat gluten and rye-wheat flour increases their water-retaining power by 2,0 % and by 2,5 % respectively. There were studied water binding forms in gluten and flour at implementing the food supplement “Magnetofood” by the indicator method and one of differential-thermal analysis (DTA). There were established the quantity ratios of free and bound moisture in gluten and flour with food supplement “Magnetofood”. It was established, that model systems, based on rye-wheat gluten and rye-wheat flour, enriched with “Magnetofood” supplement, demonstrate the increase of the amount of free and bound moisture in 1,3 and in 0,35 times in experimental samples of model systems based on gluten, respectively; in 1,2 and 0,29 times in experimental samples of model systems, based on flour, respectively. DTA method established the increase of the total content of adsorptively and osmotically bound moisture in experimental samples of model systems based on rye-wheat gluten and rye-wheat flour at adding the food supplement “Magnetofood”: – adsorptively bound moisture grows: from 15, 3% to 19,7% (samples of model systems based on rye-wheat gluten) and from 18,3% to 25,4% (for samples of model systems based on rye-wheat flour); – osmotically bond water grows: from 10, 3% to 14, 4% (for samples of model systems based on rye-wheat gluten) and for 14,5% to 17,0% (for samples of model systems based on rye-wheat flour). It was revealed, that the increase of the moisture-retaining power of rye-wheat gluten and rye-wheat flour, enriched with the food supplement “Magnetofood” is explained by the “cluster-loop-chain” model of hydration of gluten proteins at “Magnetofood” nanoparticles. The obtained experimental data may be used at elaborating the technology of rye-wheat bread, enriched with the polyfunctional food supplement “Magnetofood”; and also at elaborating innovative technologies of food systems with proteins as gliadin, glutenin and so on. The results of this study have the theoretical and practical interest for the world scientific society, because they may be used for decelerating hardening processes, prolongation of storage terms, increase of output and improvement of quality parameters of bread and bakery products.

Sensory, digestion, and texture quality of commercial gluten-free bread: Impact of broken rice flour type

This research investigated the effects of two varieties of broken rice (Khouzestan and Lenjan) from warm and dry regions, and two (Hashemi and Tarom) from mild and humid regions on different parameters including dough rheology, digestibility, and quality (color, specific volume, textural properties, and sensorial properties) of a commercial gluten-free bread (GFB). Furthermore, the rice varieties' hydration properties, gelatinization temperatures, and starch-granule morphology were assessed. Significant differences were observed in the varieties' proximate composition and hydration properties from both climate zones. The granules' average size was 3.17-4.9 µm. The specific volume of the breads showed no correlation with either the damaged starch content or the amylose content, but had a significant negative correlation with hardness (r = -.923, p < .05). The crumb hardness of bread was positively correlated with water-binding capacity and was affected by elastic modulus of dough. Results of predicted glycemic index were in accordance with total carbohydrates. Khouzestan received the highest score in sensory evaluation test. Based on the outcomes for bread-quality attributes, Khouzestan from the warm and dry region, which is a cheaper rice variety in Iran, was the most appropriate variety for GFB production. Moreover, it was determined that the rice varieties currently used in commercial manufacture of gluten-free bread do not necessarily yield the highest-quality bread.

PRACTICAL APPLICATIONS

Gluten-free breads (GFBs) are generally used by Coeliac patients. In comparison to wheat bread, the quality of GFBs is lower. Rice is one of the main ingredients of GFBs' formulation, thence by determining the quality-related features of the rice, improvement in the final product could be achieved. In addition, by implementing the cheap and the broken rice variety, the price of the final product could be decreased and be more affordable for the patients.

Possible association between celiac disease and bacterial transglutaminase in food processing: a hypothesis

The incidence of celiac disease is increasing worldwide, and human tissue transglutaminase has long been considered the autoantigen of celiac disease. Concomitantly, the food industry has introduced ingredients such as microbial transglutaminase, which acts as a food glue, thereby revolutionizing food qualities. Several observations have led to the hypothesis that microbial transglutaminase is a new environmental enhancer of celiac disease. First, microbial transglutaminase deamidates/transamidates glutens such as the endogenous human tissue transglutaminase. It is capable of crosslinking proteins and other macromolecules, thereby changing their antigenicity and resulting in an increased antigenic load presented to the immune system. Second, it increases the stability of protein against proteinases, thus diminishing foreign protein elimination. Infections and the crosslinked nutritional constituent gluten and microbial transglutaminase increase the permeability of the intestine, where microbial transglutaminases are necessary for bacterial survival. The resulting intestinal leakage allows more immunogenic foreign molecules to induce celiac disease. The increased use of microbial transglutaminase in food processing may promote celiac pathogenesis ex vivo, where deamidation/transamidation starts, possibly explaining the surge in incidence of celiac disease. If future research substantiates this hypothesis, the findings will affect food product labeling, food additive policies of the food industry, and consumer health education.