Optimizing Lactic Acid Bacteria Proportions in Sourdough to Enhance Antifungal Activity and Quality of Partially and Fully Baked Bread.

The organic acids produced by lactic acid bacteria (LAB) during the fermentation of sourdoughs have the ability to reduce the growth of different molds. However, this ability depends on the LAB used. For this reason, in this study, the proportions of different LAB were optimized to obtain aqueous extracts (AEs) from sourdough to reduce fungal growth in vitro, control the acetic acid concentration, and obtain a specific lactic to acetic acid ratio. In addition, the optimized mixtures were used to formulate partially baked bread (PBB) and evaluate the mold growth and bread quality during refrigerated storage. Using a simplex-lattice mixture design, various combinations of Lactiplantibacillus plantarum, Lacticaseibacillus casei, and Lactobacillus acidophilus were evaluated for their ability to produce organic acids and inhibit mold growth. The mixture containing only Lpb. plantarum significantly reduced the growth rates and extended the lag time of Penicillium chrysogenum and P. corylophilum compared with the control. The AEs' pH values ranged from 3.50 to 3.04. Organic acid analysis revealed that using Lpb. plantarum yielded higher acetic acid concentrations than when using mixed LAB. This suggests that LAB-specific interactions significantly influence organic acid production during fermentation. The reduced radial growth rates and extended lag times for both molds compared to the control confirmed the antifungal properties of the AEs from the sourdoughs. Statistical analyses of the mixture design using polynomial models demonstrated a good fit for the analyzed responses. Two optimized LAB mixtures were identified that maximized mold lag time, targeted the desired acetic acid concentration, and balanced the lactic to acetic acid ratio. The addition of sourdough with optimized LAB mixtures to PBB resulted in a longer shelf life (21 days) and adequately maintained product quality characteristics during storage. PBB was subjected to complete baking and sensory evaluation. The overall acceptability was slightly higher in the control without sourdough (7.50), followed by bread formulated with the optimized sourdoughs (ranging from 6.78 to 7.10), but the difference was not statistically significant (p > 0.05). The sensory analysis results indicated that the optimization was used to successfully formulate a sourdough bread with a sensory profile closely resembling that of a nonsupplemented one. The designed LAB mixtures can effectively enhance sourdough bread's antifungal properties and quality, providing a promising approach for extending bread shelf life while maintaining desirable sensory attributes.

Modified celluloses improve the proofing performance and quality of bread made with a high content of resistant starch.

BACKGROUND: Adding resistant starch (RS) to bread formulations is a promising way of increasing fiber content of white bread. However, the partial replacement of wheat flour (WF) by RS can lead to a decrease in technological quality. The objective of this study was to analyze the performance of hydroxypropylmethylcellulose and carboxymethylcellulose as improvers of wheat bread with a high level of replacement (30%) with maize RS. The levels of the modified celluloses were 1% and 1.5% (WF + RS basis), and a formulation without modified celluloses was used as control. Proofing time, loaf volume, crumb characteristics (porosity, texture), and bread staling parameters (hardness increase, moisture loss), among other attributes, were analyzed, and principal component analysis was applied to compare samples. RESULTS: The use of both modified celluloses was effective in improving the quality of breads. Specific volume and crumb porosity were enhanced, particularly at the 1.5% level. Breads with modified celluloses also allowed a higher retention of water and a better preservation of mechanical properties during storage. The principal component analysis projection graph for the first two principal components showed that samples with modified celluloses were clustered by the level of hydrocolloid addition rather than by the type of hydrocolloid used, although all the samples with modified celluloses were close to each other and distant from the control sample without hydrocolloids. CONCLUSION: The quality decrease resulting from the replacement of WF by a high level of RS can be greatly compensated by the use of structuring agents such as hydroxypropylmethylcellulose and carboxymethylcellulose. © 2022 Society of Chemical Industry.

Effect of Freezing Wheat Dough Enriched with Calcium Salts with/without Inulin on Bread Quality.

Bread is a popular food that is widely consumed worldwide but has a short shelf life. Besides that, when incorporating prebiotics and calcium, aging mechanisms accelerate, further shortening the shelf-life. The objective of this work was to evaluate the effect of freezing storage on the rheological (loss tangent, tan δ) and thermal (glass transition temperature, Tg) properties of unfrozen dough, the fermentation times (tf), and the baking quality of wheat bread fortified with calcium and inulin. Formulations studied included wheat flour (control-C), flour with 1800 ppm Ca (calcium carbonate-CA, calcium citrate-CI or calcium lactate-LA), and flour with 2400 ppm Ca and 12% inulin (calcium carbonate-CA-In, calcium citrate-CI-In or calcium lactate-LA-In). Doughs were stored at −18 °C for 1, 7, 30 and 60 days. After storage, the rheological (oscillatory rheometry and texture profile analysis) and thermomechanical properties of the thawed doughs were measured. The quality parameters of breads determined consisted of specific volume (Vs), color, moisture, firmness, elasticity, and alveoli size characterization. Dough freezing neither changed viscoelasticity (tan δ) nor decreased hardness and adhesiveness up to the values observed for fresh wheat dough. The Tg of dough with calcium carbonate increased, while for samples with organic calcium salts, it (citrate and lactate) decreased. The tf of thawed dough significantly increased. The Vs of all breads did not change during the first 30 days but decreased after freezing the dough for 60 days (p < 0.05), probably due to the death of the yeasts. Crumb moisture decreased over time, and in all cases crumb C had the highest moisture content, suggesting a dehydration effect of the calcium salt. The firmness of CA, LA and C crumbs were similar and higher than that of CI (p < 0.05), suggesting a destabilizing effect of CI anion on gluten proteins. Inulin contributed to the depreciation of bread quality, mainly at 60 days of dough freezing storage. It can be concluded that during freezing storage, calcium improves the dynamic elasticity of the dough, although under extreme conditions it generates loaves of smaller volume. Principal component analysis (PCA) explained 66.5% of total variance. Principal component 1 (PC1) was associated with dough properties, and accounted for 44.8% of the total variance. In turn, PC2 was mainly related to baking quality parameters (fermentation time, browning index, firmness and springiness of crumbs), and explained 21.7% of the total variance. Fortification with calcium citrate should be recommended for dough freezing, as breads with softer crumbs were obtained under such conditions.

Technological, sensory, nutritional and bioactive potential of pan breads produced with refined and whole grain buckwheat flours.

The nutritional quality and bioactive potential of breads made with partial replacement of refined wheat flour (RWF) with 30% or 45% refined buckwheat flour (RBF) or whole buckwheat flour (WGBF) was assessed through mineral bioaccessibility, starch digestibility, dietary fiber content and bioactive potential by determining rutin and quercetin levels during processing. Moreover, technological quality and sensory acceptance were also evaluated. Breads made with 30% or 45% WGBF showed higher mineral and fiber contents compared to the control, while the formulations with RBF showed higher bioaccessibility. No changes were observed in the rutin levels of the dough before and after fermentation, but after baking, rutin and quercetin levels increased. The highest starch hydrolysis was found in the formulation containing 45% RBF. The formulations made with 30% RBF or 30% WGBF were well accepted by consumers. Our study shows interesting results, as few studies report the effect of processing on bioactive compounds.

Defining Amaranth, Buckwheat and Quinoa Flour Levels in Gluten-Free Bread: A Simultaneous Improvement on Physical Properties, Acceptability and Nutrient Composition through Mixture Design.

The study aimed to define the ideal proportions of pseudocereal flours (PF) in sensory-accepted gluten-free bread (GFB) formulations. The characteristics of GFB developed with PF (amaranth, buckwheat, and quinoa) were verified through a mixture design and response surface methodology. Three simplex-centroid designs were studied to analyze the effects of each PF and their interactions with potato starch (PS), and rice flour (RF) on GFB's physical and sensory characteristics, each design producing three single, three binary and six ternary GFB formulations. Results showed that using PF alone resulted in unacceptable GFB. However, the interactions between PF and RF improved the loaf specific volume and the crumb softness and also enhanced appearance, color, odor, texture, flavor, and overall liking. Moreover, the composite formulations prepared with 50% PF and 50% RF (flour basis) presented physical properties and acceptability scores like those of white GFB, prepared with 100% RF or a 50% RF + 50% PS blend (flour basis). Maximum proportions of PF to obtain well-accepted GFB (scores ≥7 for all evaluated attributes on a 10-cm hybrid hedonic scale) were defined at 60% for amaranth flour (AF), 85% for buckwheat flour (BF), and 82% for quinoa flour (QF) in blends with RF.

High ß-Glucans Oats for Healthy Wheat Breads: Physicochemical Properties of Dough and Breads.

Bread is a highly consumed food whose nutritional value can be improved by adding an oat flour (Avena sativa L.-variety Bonaerense INTA Calen-Argentina) to a high-industrial quality wheat flour (Triticum aestivum L.). This cultivar of oat contains high amounts of ß-glucans, which act as a prebiotic fiber. Wheat flour was complemented with different amounts of oat flour (5, 15, and 25%). A contribution of hydrophilic components from oat flour was evident in the oat-wheat mixtures. At the same time, the high content of total dietary fiber led to changes in the rheological properties of the dough. Mixtures with a higher proportion of oats showed an increase in alveographic tenacity (stiffer dough), higher stability, and a lower softening degree in farinographic assays. The dough showed significant increases in hardness and gumminess, without significant changes in cohesiveness, i.e., no disruption to the gluten network was observed. Relaxation tests showed that the blends with a higher oat content yielded 10 times higher stress values compared to wheat dough. Analysis of the oat-wheat breads showed improvements in nutritional parameters, with slight decreases in the volume and crust color. The crumb showed significant increases in firmness and chewing strength as the amount of oats added increased. Nutritional parameters showed that lipids, dietary fiber, and ß-glucans were significantly increased by the addition of oats. Sensory analysis achieved high response rates with good-to-very good ratings on the hedonic scale set. Thus, the addition of oats did not generate rejection by the consumer and could be accepted by them. Breads with wheat and oats showed nutritional improvements with respect to wheat bread, since they have higher dietary fiber content, especially in ß-glucans, so they could be considered functional breads.

Influence of pseudocereals on gluten-free bread quality: A study integrating dough rheology, bread physical properties and acceptability.

This study describes the use of the Mixture Design for simultaneals to improve the physical properties and acceptability of gluten-free bread (GFB) based on whole pseudocereals flour, as well as to define dough and bread instrumental predictors of the sensory quality of GFB. Three simplex-centroid designs were used to study the effects of each pseudocereal flour (amaranth - AF, buckwheat - BF, and quinoa - QF) blended with rice flour (RF) and potato starch (PS) on dough and bread properties. A total of 30 GFB formulations were produced and evaluated. Results reveal relationships between dough Mixolab parameters, such as C3 and C4, related to gelatinization and starch stability, with crumb moisture and firmness of GFB formulation, in which higher values of these parameters related to higher acceptability scores (>7 on a 10 cm hydroid hedonic scale). However, higher values of the secondary parameter C3-C4 was related to lower loaf-specific volume, impairing appearance and texture acceptability, as well as overall liking. The interaction effects between pseudocereal flour and RF increases dough consistency, bread volume, softness, and acceptability. Blends of 50% AF, BF, or QF with 50% RF results in GFB with high acceptability (overall liking of 8). The maximum pseudocereal proportions to obtain acceptable GFB (scores ≥ 7 for appearance, color, odor, texture, flavor acceptability and overall liking) were 60% AF, 85% BF, and 82% QF blended with RF. The combination of instrumental and sensory methods was useful to identify parameters capable of predicting the GFB quality, which may be useful for food scientists and producers to face the challenges regarding the development of healthier and better quality GFB to meet consumer needs.

Psyllium Improves the Quality and Shelf Life of Gluten-Free Bread.

Psyllium husk powder was investigated for its ability to improve the quality and shelf life of gluten-free bread. Gluten-free bread formulations containing 2.86%, 7.14%, and 17.14% psyllium by flour weight basis were compared to the control gluten-free bread and wheat bread in terms of performance. The effect of time on crumb moisture and firmness, microbial safety, and sensory acceptability using a 10-cm scale was assessed at 0, 24, 48, and 72 h postproduction. Crumb firming was observed during the storage time, especially for the control gluten-free bread, which had a crumb firmness 8-fold higher than that of the wheat bread. Psyllium addition decreased the crumb firmness values by 65-75% compared to those of the control gluten-free bread during 72 h of storage. The longest delay in bread staling was observed with a 17.14% psyllium addition. The psyllium-enriched gluten-free bread was well accepted during 72 h of storage, and the acceptability scores for aroma, texture, and flavor ranged from 6.8 to 8.3, which resembled those of wheat bread. The results showed that the addition of 17.14% psyllium to the formulation improved the structure, appearance, texture, and acceptability of gluten-free bread and delayed bread staling, resembling physical and sensory properties of wheat bread samples during 72 h of storage. Therefore, according to the obtained results, this approach seems to be promising to overcome some of the limitations of gluten-free breadmaking.

Technological and nutritional characterization of wheat breads added with eggplant flour: dependence on the level of flour and the size of fruit.

Eggplant (Solanum melongena L.) is the third solanaceous of horticultural importance in the world, after potato and tomato. In the agricultural production of this vegetable, there are post-harvest losses and waste generation. Reduction of these inconveniences can be avoided by obtaining ingredients with high nutritional value for food processing, as breadmaking. Changes in wheat dough and bread quality due to the incorporation of eggplant flour were studied. Different levels (5, 7.5, 10%) of replacement with flour from Large eggplant were analysed. The optimum level of eggplant flour (7.5%) was used for comparison technological performance of eggplant-wheat breads elaborated with flour from eggplants of different size: small size eggplant (Baby, BE) and large size eggplant (Large, LE). Dough was characterized through farinographic (water absorption, development time, stability, softening degree) and fermentation parameters (maximum volume of fermented dough, fermentation time). Technological quality (specific volume, hardness, elasticity, number of crumb alveolus, colour of crust and crumb) and sensory analysis of breads were evaluated. Proximal composition and antioxidant activity of flour and breads were studied. Water absorption, development time and softening degree increased, while bread volume, elasticity and the area occupied by alveoli decreased with the presence of eggplant flour. Breads also became darker. Breads with 7.5% of BE, presented a harder crumb with lower luminosity than those with LE. Both type of breads were well accepted by consumers; nevertheless, BE was the bread that contains higher amount of compounds with antioxidant activity and therefore it is recommended for formulation of functional breads.

Mixture Design Applied to the Development of Chickpea-Based Gluten-Free Bread with Attractive Technological, Sensory, and Nutritional Quality.

The aim of the study was utilized chickpea to create appealing, nutritious, and palatable gluten-free bread (GFB). The performance of chickpea flour (CF) in single and composite GFB formulations was studied with a mixture design and response surface methodology. Six simplex-centroid designs for 3 ingredients were used to identify the ideal proportions of CF in various blends with cassava starch (CS), maize starch (MS), potato starch (PS), and rice flour (RF) achieving the best physical properties. For each design, 3 single, 3 binary, and 3 ternary formulations were prepared. The results showed that CF alone is suitable for bread production, resulting in GFB with higher volume and crumb firmness and lower crumb moisture than single formulations of other raw materials. However, the interactions between CF and PS or CS enhanced the loaf volume and decreased the crumb firmness values. The GFB prepared with only CF was accepted (overall acceptability score of 7.1- on a 10-cm scale). Nevertheless, the composite formulations prepared with CF75:PS25 or CF75:CS25 (flour basis) received overall acceptability scores of 8.2, like those of their white GFB, prepared with RF50:PS50 blend (flour basis), and wheat bread counterparts, used as positive controls. Compared to white GFB, both composite formulations presented nearly a twofold increase in ash and protein contents and a threefold increase in total fiber content. These results show that blends of CF75:PS25 or CF75:CS25 can be used to develop GFB with a good physical and sensory properties, as well as an enhanced nutritional composition. PRACTICAL APPLICATION: Gluten-free bread (GFB) made with 75% chickpea flour (CF) blend with 25% potato or cassava starch showed improved total minerals, protein and dietary fiber content and bread quality characteristics. Therefore, CF is a valuable ingredient for food technologists in manufacturing better-tasting and healthy GFB, which is important for consumers with gluten-related disorders since GFB often lack nutrition content, appearance, texture, and mouthfeel.

Management of freezing rate and trehalose concentration to improve frozen dough properties and bread quality

Abstract Bread is one of the most consumed foods in the world, and alternatives have been sought to extend its shell life, and freezing is one of the most popular methods. The purpose of this study was to evaluate the effect of freezing rate and trehalose concentration on the fermentative and viscoelastic properties of dough and bread quality. Dough was prepared and trehalose was added at three concentrations (0, 400, 800 ppm); dough was pre fermented and frozen at two freezing rates then stored for 42 days. Frozen dough samples were thawed every two weeks. CO2 production and elastic and viscous modulus were determined. In addition, bread was elaborated and specific volume and firmness were evaluated. High trehalose concentrations (400 and 800 ppm) produced dough with the best viscoelastic and fermentative properties. Greater bread volume and less firmness were observed when a slow freezing rate (-.14 °C/min) was employed.

Improvement of gluten-free bread properties by the incorporation of bovine plasma proteins and different saccharides into the matrix.

The aim of this work was to improve the quality of gluten-free bread, incorporating plasma bovine proteins concentrated by ultrafiltration and freeze-dried with saccharides (inulin and sucrose). The influence of these compounds on textural properties and final bread quality was assessed. The textural studies revealed that with the addition of proteins and inulin, homogeneous and smaller air cells were achieved improving the textural properties while the bread hardness was comparable with breads with gluten. The volume of gluten-free breads increased with increasing proteins and inulin concentrations, reaching a maximum at a protein concentration of 3.5% (w/w). The addition of the enhancers improved moisture retention of the loaves after cooking and an increase of lightness of crumb with respect to the control was observed. The sensory analysis found no statistically significant difference in sensory attributes evaluated with respect to the control, so these ingredients do not negatively affect the organoleptic properties of bread.