Breadmaking performance and technological characteristic of gluten-free bread with inulin supplemented with calcium salts

The fortification of gluten-free bread containing inulin with different organic and non-organic calcium sources was investigated. Calcium lactate, calcium citrate, calcium chloride and calcium carbonate were used as calcium sources. Gluten-free bread composed of corn starch, potato starch, salt, yeast, pectin, sugar and sunflower oil was used as a reference. The calcium salts were supplemented to the gluten-free formula to provide equal content of elementary calcium (Ca⁺²). The Mixolab^? device was used to analyse the behaviour of gluten-free dough subjected to a dual mechanical shear stress and temperature constraint. Calcium salts significantly modified the dough behaviour during heating and cooling. The addition of calcium carbonate and calcium citrate provoked an increase in dough consistency during heating and cooling compared with the other salt-enriched samples. The specific volume and texture parameters of gluten-free breads varied with the calcium salt used, but calcium carbonate and calcium citrate showed improved values. The higher calcium content of the enriched breads, compared with the control, confirmed the fortification. Sensory evaluation of the calcium-fortified breads confirmed that calcium carbonate followed by calcium citrate was the most recommended salt for obtaining calcium fortification of gluten-free breads.     

Technological,nutritional and sensorial characteristics of wheat bread fortified with calcium salts

The aim of this paper was to carry out a comprehensive study of wheat flour breads fortified with different sources of calcium, which includes: technological, nutritional and sensorial characteristics. Calcium salts (lactate: LA, carbonate: CA, and citrate: CI) at two fortification levels (20% and 50%) were analysed. Only the LA fortified breads were harder with lower specific volume and the LA 50% showed the higher chewiness value. The crust colour of the CI 50% breads presented the lower browning index. In vitro nutritional studies showed that calcium content on digest and dialysate was significantly higher in all fortified breads. The CI 20% and all the 50% fortifications showed a better contribution of bioaccessible calcium. Sensorial general quality was not significantly different between fortified and Control breads.     

Effect of calcium and vitamin D2 fortification on quality characteristics of dahi

Two levels (500 and 600 ppm) of calcium (calcium phosphate and calcium citrate) along with vitamin D₂ (600 IU/L) were fortified in milk for dahi preparation. pH, water‐holding capacity and syneresis of fortified dahi were not affected significantly (P > 0.05). However, acetaldehyde content decreased and setting time increased upon fortification. Microbial count significantly (P < 0.05) decreased in calcium phosphate‐fortified dahi, whereas no difference was observed in calcium citrate‐fortified dahi. Firmness and viscosity decreased in calcium phosphate‐fortified dahi, whereas it increased in calcium citrate‐fortified dahi as compared to control. All dahi samples showed good sensory acceptability.     

Effect of different iron compounds on wheat and gluten‐free breads

BACKGROUND: Iron fortification of bread often results in sub‐optimal quality of the final product due to undesirable changes in the physical characteristics and sensory properties of the bread. In this study both the form of iron (soluble, insoluble or encapsulated) and the type of bread (wheat or gluten‐free) were varied in order to investigate the effect of iron and gluten on the product characteristics. RESULTS: The effect of iron on the quality characteristics of the breads investigated depended on iron type, but not on iron solubility. Colour, crust firmness, specific volume, cell number and uniformity as well as aroma were the attributes that were mainly affected in iron‐enriched wheat bread. In some cases, specific volume was 30% lower than that of the control sample, while cell uniformity was significantly lower, as low as 50% of the control sample in some fortified samples. In gluten‐free breads, differences between unfortified and fortified samples included colour, crust firmness, cell number, ‘moisture’ odour, metallic taste and stickiness. In some cases, the sensory scores were better for fortified samples. CONCLUSIONS: Differences due to iron fortification were less pronounced in gluten‐free compared to wheat breads. The choice of the appropriate iron compound which will not cause adverse quality changes is still a challenge. Copyright © 2010 Society of Chemical Industry     

Effect of low lactose dairy powder addition on the properties of gluten-free batters and bread quality

Different low lactose dairy ingredients including sodium caseinate (SC), milk protein isolate (MPI), whey protein isolates (WPIS and WPIM) and whey protein concentrate (WPC) were tested in a gluten-free bread formulation and compared to controls with the addition of no dairy ingredient (C) and one dairy ingredient containing lactose, skim milk powder. Rheological characterisation (frequency sweep and creep-recovery) of the batters at 90% water level (WL) suggested that the addition of WPIS, WPIM and WPC significantly decreased G′ and G″ values. SC and MPI had the opposite effect with a significant increase in both these parameters being found (p < 0.05). The WL of the batters was adjusted in order to obtain the same consistency of the batter C at 90% WL. A Power Law model was used to predict the new WL based on single frequency measurements of G* for each sample. The baking analysis demonstrated that the correction of the WL did not show a strong impact in the quality of the breads. Nevertheless, whey proteins demonstrated the ability to increase significantly the specific volume of the breads and decrease the hardness over time (p < 0.05). SC had a negative impact on the specific volume, which led to an increase in crumb hardness (p < 0.05).     

Effect of Iron Fortification on Physical and Sensory Quality of Gluten-Free Bread

The scope of the present study was to investigate the effects of different iron compounds on the physical and sensory characteristics of gluten-free breads (GFBs) that were iron fortified (40 mg/kg solid compound) using different iron compounds. Differences among unfortified and fortified samples were observed in colour, crust firmness, and in the following sensory attributes: pore number, smell of ‘moisture’, metallic taste and stickiness. Elemental iron was more stable and thus adverse changes to product by its addition were not noticed. The results are useful in understanding the limitations of iron fortification and thus help designing more acceptable iron-fortified GFBs.     

Folate fortification of white and whole-grain bread by adding Swiss chard and spinach. Acceptability by consumers

The aim of this work was to study the effect of bread-making on the content of endogenous folate of white and whole-grain bread fortified with either Swiss chard or spinach at 20 g/100 g and 40 g/100 g measured by HPLC (H4-folate and 5-CH3-H4-folate); and to assess the sensory acceptability of folate-fortified breads compared to non-fortified breads. The fortification of breads with 20 g/100 g and 40 g/100 g vegetables significantly (p < 0.001) increased the total folate content (from 19.9 to 57.9 μg/100 g in white bread and from 37.4 to 75.5 μg/100 g in whole-grain bread). Moreover, 40 g/100 g Swiss chard- and spinach-fortified breads obtained higher scores in overall acceptability than 20 g/100 g fortified or control bread for both white and whole-grain breads. The consumption of two servings (56 g each) per day of 40 g/100 g fortified bread would meet the daily folate requirements by 14.3–21.8% in adults and 9.6–14.5% in some special states like women of child-bearing age.     

Effect of quinoa,chia and millet addition on consumer acceptability of gluten-free bread

There is an increasing demand for gluten-free foods; however, standard gluten-free foods are deficient in nutrients. This study investigated the use of alternative grains (chia, millet and quinoa) in gluten-free breads to evaluate their sensory properties (fresh and following a partial bake method). A sensory trial (n = 98) asked participants to consider six fresh bread samples made from chia, millet and quinoa, using 9-point hedonic scales and check-all-that-apply. A second sensory trial (n = 89) was then completed using par-baked bread samples of the different formulations. The sensory properties and the acceptability of the bread were significantly affected by the chia and quinoa flour. The millet flour did not change the acceptability of the bread. Furthermore, the partial baking method (after 90 days of frozen storage) did not significantly affect the acceptability of the breads made with chia, millet and quinoa, but it did affect the acceptability of the control bread prepared with brown rice flour. Overall, millet flour could be incorporated into gluten-free breads made following a partial baking method without affecting consumer acceptability. Future studies should use a trained panel to evaluate how the breads differ based on the partial baking method.     

Total phenolic and total flavonoid content,antioxidant activity and sensory evaluation of pseudocereal breads

The aim of the study was to investigate the effect of adding (in two different doses 15% and 30%) pseudocereal (buckwheat, amaranth and quinoa) flour on the antioxidant properties and sensory value of breads. Buckwheat flour had the highest phenolic content (7.25 ± 0.23 mg/g dw). The content of total flavonoids in flours was about 2–4 fold higher when compared to breads. The addition of buckwheat flour to wheat bread, particularly in higher dose, was more effective in enhancing antioxidant activity, as evaluated by means of FRAP and DPPH, which increased by 2.36 fold, and 3.64 fold respectively, in comparison with other pseudocereal flours (amaranth, quinoa), which caused, in higher doses, the changes of above parameters within the ranges 1.20–1.79 fold, and 0.60–1.71 fold. Analysis of sensory results of breads showed that addition of buckwheat flour to the dough might improve subjective properties of bread and increase acceptable quality attributes such as taste, colour or odour. All these observations suggest that addition of buckwheat flour into bread can improve antioxidant as well as sensory properties of bread. Bread fortified with pseudocereal flours, and especially with buckwheat flour, may be placed on the market as a functional food.     

Effect of dietary fibre enrichment on selected properties of gluten-free bread

The enrichment of gluten-free baked products with dietary fibre seems to be necessary since it has been reported that coeliac patients have generally a low intake of fibre due to their gluten-free diet. In the present study different cereal fibres (wheat, maize, oat and barley) were added at 3, 6 and 9 g/100 g level into a gluten-free bread formulation based on corn starch, rice flour and hydroxypropyl methyl cellulose (HPMC). Doughs were evaluated based on consistency, viscosity and thermal properties. Results showed that maize and oat fibre can be added to gluten-free bread with positive impact on bread nutritional and sensory properties. All breads with 9 g/100 g fibre increased the fibre content of control by 218%, but they were rated lower than those with 3 and 6 g/100 g fibre due to their powdery taste. The formulation containing barley fibre produced loaves that had more intense color and volume comparable to the control. During storage of breads a reduction in crumb moisture content and an increase in firmness were observed. The micrographs of the crumb showed the continuous matrix between starch and maize and/or oat fibre obtaining a more aerated structure.     

Antihypertensive properties of aqueous extracts of vegetable leaf‐fortified bread after oral administration to spontaneously hypertensive rats

This study investigated the potential cardiovascular health benefits of leavened bread produced from wheat flour that contained 1%, 2% and 3% additions of leafy vegetable powders obtained from Amaranthus viridis (AO), Solanum macrocarpon (SM) or Telfairia occidentalis (TO). Dried breads were extracted with water at 60 °C followed by analysis for total polyphenolic content (TPC), as well as in vitro inhibitions of angiotensin‐converting enzyme and renin activities. HPLC analysis of the bread extracts indicated the presence of mainly rutin, gallic acid, myricetin and caffeic acid. TPC of the vegetable‐fortified breads was significantly (P < 0.05) higher (5.8–7.6 mg gallic acid equivalent, GAE/g) than that of control bread (5.5 mg GAE/g). Oral administration of 100 mg dried extract/kg body weight to spontaneously hypertensive rats led to reductions (up to 42 mmHg) in systolic, diastolic and mean arterial blood pressure in comparison with 20 mmHg for the control bread.     

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

BackgroundThe development of gluten-free breads has attracted great attention as a result of better diagnoses of relationship between gluten-free products and health. The market demand for gluten-free products is increasing day by day due to growing number of celiac disease cases. Development of gluten-free bread remains a technological challenge due to the key role of gluten in the breadmaking process and in bread structure, appearance, texture and shelf life.Scope and approachThis review covers recent advances in the application of hydrocolloids in dough handling, technological and nutritional properties of gluten-free breads, which affect its quality and value.Key findings and conclusionsGluten-free breads results from the combination of different ingredients and hydrocolloids required to building up network structures responsible for bread quality. Various gluten-free formulations have applied hydrocolloids to mimic the viscoelastic properties of gluten. In addition, the impact of different hydrocolloids on the characteristics of dough and bread quality is known to be highly dependent on raw materials, the nature and quantity of hydrocolloids. Hydrocolloids improve the texture, increase the moisture content and extend the overall quality of bread. The results of the reviewed studies indicate that some of those products were acceptable and presented similar or better sensory attributes than control formulations and some were even comparable to their wheat-based counterparts. Based on successful applications of hydrocolloids, it is suggested that novel nutritious ingredients, combined with hydrocolloids can be added to gluten-free bread formulations to improve the quality of life.     

Effects of protein and transglutaminase on the preparation of gluten-free rice bread

Effects of transglutaminase (TGase) and proteins such as whey protein, caseinate, and soy protein on the preparation of gluten-free rice breads using non-waxy rice flour were investigated. Rice flour (about 12% moisture content) was prepared from dry milling of dried grain after rice got soaked. Unlike general dry milled flour, newly developed rice flour increased water binding capacity (WBC), swelling power, and peak viscosity. Soy protein increased WBC but other proteins slightly decreased with the increase of levels. Lightness decreased and yellowness increased with the addition of whey and soy protein. All pasting viscosities decreased with the addition of protein. The TGase improved the network structure of rice batter. The 2^nd proof time of rice batter with protein was shortened by 4–9 min with the addition of TGase. The specific volumes of rice breads with whey and soy protein also increased. TGase and protein additions decreased the hardness of rice bread. Sensory test showed that roasted flavor, volume, air cell homogeneity, and overall quality were significantly different (p<0.05) with protein and TGase additions.     

In situ dextran synthesis by Weissella confusa Ck15 and Leuconostoc pseudomesenteroides DSM 20193 and their effect on chickpea sourdough bread

This work evaluated, for the first time, the impact of in situ dextran (with different branching degree) produced by Weissella confusa Ck15 and Leuconostoc pseudomesenteroides DSM 20193 strains on the technological properties of chickpea–wheat sourdough bread prepared with three levels of chickpea flour (20, 30 and 40 g/100 g). In addition Lactiplantibacillus plantarum F8 strain (not dextran producing) and a control without sourdough fermentation were used. Specific volume, crumb hardness and moisture content of breads were evaluated during six days of storage. At the increase of chickpea flour from 20 to 40 g/100 g in the samples, the lowest decrease in bread volume (15%) occurred when W. confusa Ck15 was used. Moreover, these breads showed the lowest crumb hardness at each chickpea flour percentage, 46, 80 and 98 N. Hence, in situ dextran synthesis by W. confusa Ck15 might counteract negative effects caused by gluten-free chickpea flour on technological properties of bread.     

Sourdough fermented by Lactobacillus plantarum FST 1.7 improves the quality and shelf life of gluten-free bread

Lactobacillus plantarum FST 1.7 has been recently shown to produce antifungal compounds, which improve the shelf life of wheat bread. In the present study, this strain was investigated for its ability to improve the quality and shelf life of gluten-free bread. Effects of incorporation of sourdough fermented by strain FST 1.7 into a gluten-free bread mixture were compared to those obtained with sourdough fermented by the non-antifungal strain Lactobacillus sanfranciscensis TMW 1.52 as well as to those obtained with chemically or non-acidified batters. Fundamental rheological tests revealed that the addition of sourdough to the gluten-free mix led to an increase in firmness and increase in elasticity overtime (P < 0.05). Bread characteristics such as pH, total titratable acidity, and crumb hardness (5-day storage) were evaluated. Results showed that the biologically acidified gluten-free breads were softer after 5 days than the chemically acidified gluten-free breads (P < 0.001). Antifungal challenge tests employing conidial suspensions of Fusarium culmorum were carried out using the sourdough, non-acidified batter and bread. The rate of mould growth for the fungal species used was retarded by L. plantarum FST 1.7 when compared to the controls. In conclusion, the results of this study indicate that L. plantarum FST 1.7 can be used to produce gluten-free bread with increased quality and shelf life.     

Supplementation of common white bread by coriander leaf powder

Coriander leaves are widely used worldwide as a very common garnish in almost all types of Western, Oriental, and Arabic culinary. It is rich in the beneficial components of antioxidants, trace elements, and essential oils. Bread enriched with coriander leaf powder is therefore likely to have greater acceptability to consumers compared to unfortified bread. In the present study the antioxidant and sensory analyses along with baking and staling characteristics of such breads at supplementation levels of 1.0, 3.0, 5.0, and 7.0%(w/w) on wheat flour have been investigated. Results show that supplementation with coriander leaf powder bettered the crumb moisture content with only a little increase in crumb firmness. A substantial improvement in sensory characteristics was observed with the supplemented breads. A sharp increase in antioxidant content was an important beneficial fortification effect observed in the fortified breads. Coriander leaf content between 3.0 and 5.0% was found to be the optimum supplementation level that offered the best compromise for highest acceptability of the fortified breads.     

Influence of in-situ synthesized exopolysaccharides on the quality of gluten-free sorghum sourdough bread

The majority of gluten-free breads on the market are of poor sensory and textural quality. Exopolysaccharides (EPS) formed from sucrose during sourdough fermentation can improve the technological properties of gluten-free breads and potentially replace hydrocolloids. In this study, the influence of in situ formed EPS on dough rheology and quality of gluten-free sorghum bread was investigated. Dextran forming Weissella cibaria MG1 was compared to reuteran producing Lactobacillus reuteri VIP and fructan forming L. reuteri Y2. EPS containing bread batters were prepared by adding 10% and 20% of sourdough. As control served batters and bread containing sourdoughs fermented without sucrose and batters and bread without sourdough addition. The amount of EPS formed in situ ranged from 0.6 to 8.0 g/kg sourdough. EPS formed during sourdough fermentation were responsible for the significant decrease in dough strength and elasticity, with in situ formed dextran exhibiting the strongest impact. Increased release of glucose and fructose from sucrose during fermentation enhanced CO? production of yeast. Organic acids in control sourdough breads induced hardening of the bread crumb. EPS formed during sourdough fermentation masked the effect of the organic acids and led to a softer crumb in the fresh and stored sorghum bread. Among EPS, dextran showed the best shelf life improvements. In addition to EPS, all three strains produced oligosaccharides during sorghum sourdough fermentation contributing to the nutritional benefits of gluten-free sorghum bread. Results of this study demonstrated that EPS formed during sourdough fermentation can be successfully applied in gluten-free sorghum flours to improve their bread-making potentials.     

Impact of emulsifiers on the quality and rheological properties of gluten-free breads and batters

The effects of the emulsifiers lecithin (LC), di-acetyl tartaric ester of monoglycerides (DATEM), distilled monoglycerides (DM) or sodium stearoyl lactylate (SSL) were studied in a gluten-free (GF) batter and bread formulation. Three different levels, i.e. low, medium, and high, were evaluated and compared to a control bread with no emulsifier. The rheological properties of the emulsifiers at their optimum level as well as their effect on starch retrogradation were investigated. Standard baking tests were carried out and the breads were tested over 5 days of storage. Rheological tests suggested that LC reduced the elasticity of the batter and increased the batter consistency during gelatinisation (P < 0.05). A significant increase in the specific volume was found with the addition of the various emulsifiers (P < 0.05). Higher volumes were found for breads with DM whereas lower specific volumes were obtained for the breads with DATEM. With regards to cell size and distribution, significant differences were found across the emulsifiers and the levels used (P < 0.05). Crumb staling revealed significant time effects as well as an increase in the shelf-life by the addition of high levels of DM and SSL. The retrogradation of starch over 5-days did not seem to be affected by the addition of emulsifiers. Overall this study demonstrated that the addition of emulsifiers at their respective optimum level enhanced the quality of the GF breads.