Crumb Softness Research Articles

Impact of Raw, Roasted and Dehulled Chickpea Flours on Technological and Nutritional Characteristics of Gluten-Free Bread

The main objective of this study was to develop a healthy rice-based gluten-free bread by using raw, roasted, or dehulled chickpea flours. All breads containing chickpea flours showed a darker crust and were characterized by an alveolar (porosity 41.5–51.4%) and soft crumb (hardness 5.5-14.1 N). Roasted chickpea flour bread exhibited the highest specific volume, the softest crumb, and the slowest staling rate. Enriching rice-based breads with the chickpea flours resulted in increased protein (from 9.72 to 12.03–13.21 g/100 g dm), ash (from 2.01 to 2.45–2.78 g/100 g dm), fat (from 1.61 to 4.58–5.86 g/100 g), and total phenolic contents (from 49.36 up to 80.52 mg GAE/100 g dm), and in reduced (~10–14% and 13.7–17%, respectively) available starch levels and rapidly digestible starch compared to rice bread. Breads with roasted chickpea flour also showed the highest in vitro protein digestibility. The results of this study indicated that the enrichment of rice-based gluten-free breads with chickpea flours improved the technological and nutritional quality of the breads differently according to the processed chickpea flour used, also allowing recovery of a waste product.

Antioxidant, flavor profile and quality of wheat dough bread incorporated with kiwifruit fermented by β-glucosidase producing lactic acid bacteria strains

This study aimed to investigate the effect of incorporation of kiwifruit substrate fermented by 3 high β-glucosidase producing lactic acid bacteria (LAB) of Lactobacillus harbinensis (M12, M24) and Pediococcus pentosaceus (J28) on physicochemical and rheo-fermentation properties during proofing of wheat dough. Quality, sensory evaluation, antioxidant content and activity, and flavor profiles of bread was evaluated. Results revealed that LAB strains adequately adapted (J28>M12>M24) and produced enzymes during substrate fermentation. In dough, incorporation of fermented substrate increased acidity, soluble dietary fiber, β-glucosidase and α-amylase activity and gas retention during proofing, in a strain dependent manner (J28>M12>M24). The subsequent breads exhibited higher specific volume and had softer crumbs. Furthermore, total flavonoid, total phenolic, antioxidant activity, flavor content and intensity increased in breads incorporated with fermented substrate. Overall sensory acceptance was in order, bread containing substrates fermented by J28 (KFB-J28)> M12 (KFB-M12)> M24 (KFB-M24)> wheat bread (WB)> bread containing unfermented substrate (KFB). Changes observed were attributed to biotransformation by β-glucosidase which increasingly degraded dietary fibers into soluble dietary fiber, increased acidity, released glycosylated aroma compounds and phenolic compounds in substrate. When incorporated in dough, fermented kiwifruit substrates stabilized gluten network, increased yeast metabolism and gas retention during proofing. Subsequently, KFB-J28, KFB-M12, and KFB-M24 had higher antioxidant content and activity, higher flavor content and intensity, better quality and were more accepted compared to WB and KFB. This suggested the potential role played by β-glucosidases through LAB fermentation on functionally enriching and adding value to kiwifruit substrate as a novel functional ingredient in bakery industry.

High nutritional value muffins produced with wholemeal rye (Secale cereale L.) and wholemeal bean (Phaseolus vulgaris L.) flour mix

The combination of flours from cereal and legume results in less caloric products, with high contents of fiber, proteins, ash and antioxidants. Thus, this study aimed at developing muffins made with different proportions of wholemeal rye flour (WRF) and wholemeal common black bean flour (WBF). Physicochemical and physical analyses were performed to characterize starches, flours and the muffins. Sensory analysis was also carried out. WRF had the highest values for L* value, moisture and ash contents, whereas WBF had more proteins and lipids, and heterogeneous particle size distribution. The formulation with the highest acceptability grade with total replacement of whole wheat flour, was that containing 70% WRF and 30% WBF (F2). This sample was characterized as high-quality muffin, chocolate flavor, chocolate odor, light and soft crumb. Its texture was defined as low hardness, chewiness and high cohesiveness. It was concluded that the F2 formulation had a high dietary fiber content (20%), low lipid content (8%), containing 32% resistant starch, 9% protein and 51.43 mg GAE 1001 g-1 of total phenolic content, being considered an excellent nutritional food option.

Yoghurt as a starter in sourdough fermentation to improve the technological and functional properties of sourdough-wheat bread

The incorporation of yoghurt as a starter in sourdough wheat bread, to improve technological and nutritional properties, was investigated. Two bread dough matrices were considered: endosperm wheat flour and blended with whole-grain flour. Two fermentation’s types were performed, two-stage sourdough bread and yeast bread fermentation. Compared with yeast dough, yoghurt-sourdough fermentation promoted considerable changes in chemical composition, particularly when whole-grain flour was conjoined with wheat flour: higher protein proteolysis degree, increase of peptide and free amino nitrogen content, solubilization of phenolic compounds (46–53%), increase of DPPH radical scavenging (54–65%) and ferric-reducing power (85–88%), were observed. As a baking ingredient, yoghurt-sourdough improved the bread crumb softness (15–12%) and delayed the staling (40–35%). Nutritionally, the glycemic index was reduced (18–32%) while protein digestibility (6–12%) and free amino acids bioavailability (50–100%) were enhanced. The addition of yoghurt and sourdough fermentation techniques offered a promising tool to improve wheat bread's technological and functional properties.

Delving into the Role of Dietary Fiber in Gluten-Free Bread Formulations: Integrating Fundamental Rheological, Technological, Sensory, and Nutritional Aspects

The evidenced relevance of dietary fibers (DF) as functional ingredients shifted the research focus towards their incorporation into gluten-free (GF) bread, aiming to attain the DF contents required for the manifestation of health benefits. Numerous studies addressing the inclusion of DF from diverse sources rendered useful information regarding the role of DF in GF batter’s rheological properties, as well as the end product’s technological and nutritional qualities. The presented comprehensive review aspires to provide insight into the changes in fiber-enriched GF batter’s fundamental rheological properties, and technological, sensory, and nutritional GF bread quality from the insoluble and soluble DF (IDF and SDF) perspective. Different mechanisms for understanding IDF and SDF action on GF batter and bread were discussed. In general, IDF and SDF can enhance, but also diminish, the properties of GF batter and bread, depending on their addition level and the presence of available water in the GF system. However, it was seen that SDF addition provides a more homogenous GF batter structure, leading to bread with higher volumes and softer crumb, compared to IDF. The sensory properties of fiber-enriched GF breads were acceptable in most cases when the inclusion level was up to 7 g/100 g, regardless of the fiber type, enabling the labeling of the bread as a source of fiber.

Assessment of the Starch-Amylolytic Complex of Rye Flours by Traditional Methods and Modern One.

The properties of the starch-amylolytic complex of commercial low-extract rye flour were determined based on the traditional method, such as falling number and amylograph test as well as differential scanning calorimetry (DSC). The starch, pentosans and protein had a significant effect on the thermal properties of the tested rye flours. Based on the falling number, it was revealed that rye flours were characterized by medium and low alpha-amylase activity. The falling number and amylograph test are not sufficient methods to determine the suitability of currently produced rye flours for bread making. The gelatinization process of the rye flour starch could be evaluated by the DSC test, which, together with the falling number and amylograph test, may allow a better way to evaluate the usefulness of rye flours for bread making. Many significant correlations between parameters determined by DSC endotherm and quality parameters of rye bread, such as volume and crumb hardness, were reported. Breads made from flour with higher enthalpy in DSC were characterized by higher volume and softer crumb.

Impact of Ferment Processing Parameters on the Quality of White Pan Bread

A controlled fermentation process using straight-grade wheat flour, commercially milled from a grist of Canada Western Red Spring (CWRS) wheat and English wheat, and fresh yeast (Saccharomyces cerevisiae) was found to be effective for developing a naturally derived product (ferment) that could be used for processing bread with the minimum use of dough improvers. The effects of ferment storage, fermentation time, and fermentation temperature on the quality of ferment and bread were evaluated to establish optimal conditions to produce a mature ferment. Trials were conducted on a pilot scale for greater relevance to industrialized bakeries. Ferment was assessed for total titratable acidity (TTA), pH, and viscosity. Breads made with ferment were evaluated for processing parameters, dough properties, and bread quality and compared to a control prepared without ferment. During fermentation, maximum TTA levels in the ferment were achieved at 100 min, then decreased by the end of fermentation, and increased by 24 h of storage at 4 °C. Viscosity was stable during fermentation but decreased by 24 h of storage. Inclusion of ferment resulted in reduced mixing times and improved dough extensibility and crumb softness. Specific loaf volume was not impacted; a slight reduction in crumb brightness and crumb structure was detected. Fermentation for 240 min at 35 °C was determined as optimal with a storage time for 24 h.

The impact of dough hydration level on gluten-free bread quality: A case study with chickpea flour

The effects of dough hydration level on the physical properties and acceptability of gluten-free bread (GFB) made with chickpea flour were studied. Nine GFB samples were prepared with water levels ranging from 100 to 180% on a flour weight basis. Chickpea GFB required higher hydration levels than rice flour and starchy based products, and improvement on bread quality was observed at 150% water content level, which contributed to the increase in loaf-specific volume, crumb softness and porosity, as well as improving texture, flavor, and overall acceptability (≥8 on 10-cm hybrid hedonic scale), resulting in a promising alternative for meeting consumer demands for tasty and healthy innovative gluten-free products. • Effect of dough hydration level on the chickpea gluten-free bread was investigated. • Nine products with water levels ranging from 100 to 180% flour weight basis. • Increasing the water content improves chickpea gluten-free bread quality. • Water content of 150% resulted in bread with better texture and acceptability. • Promising alternative for tasty and healthy innovative gluten-free bread.

The impact of incorporating coarse wheat farina containing intact endosperm cells in a bread recipe on bread characteristics and starch digestibility

Intact or broken wheat kernels containing clusters of intact cells can be used in wheat bread recipes to lower starch digestibility but result in very dense bread crumb. We hypothesized that a smaller wheat milling fraction [i.e. coarse farina (CF; average diameter 705 μm)] that still contains intact cells can result in lower starch digestibility without a substantial deleterious effect on bread quality. We thus studied the impact of different levels of CF incorporation on bread characteristics and starch digestibility. A portion of the CF cell walls seemingly retained integrity throughout the bread making process. Bread volume and crumb softness linearly decreased with increasing levels of CF, yet remained acceptable. Unexpectedly, the extent and rate of in vitro starch digestion were not influenced by CF incorporation. In the complex bread crumb matrix, the reduced starch digestibility as a result of the inclusion of intact CF cells in the recipe may well be counterbalanced by increased starch digestibility as a result of the presence of a less elaborated gluten network and thus weaker gluten-starch interactions. Overall, modulation of starch digestibility in wheat bread is an inherently difficult task and incorporation of clusters of intact cells only appears effective at reducing starch digestibility when very large particles at plant tissue level are added.

Effects of bread making methods, lupin variety and gluten powder on the quality of bread enriched with high percentage of lupin flour

SummaryLupin is an economical source of protein, fibre and bioactive compounds, and to obtain these health and nutritional benefits lupin flour has been used in bread production. However, addition of more than 10% lupin flour markedly reduces bread quality mainly due to gluten dilution. The main aim of this research was to retain lupin bread quality enriched with higher percentages of lupin flour (20%) by addition of vital gluten powder (0%, 2%, 3.5% and 5%), investigating the effects of lupin variety (Lupinus albus and L. angustifolius) and two baking systems (rapid and sponge & dough). Impact on bread staling qualities was also determined through texture analysis of samples over a 72‐h storage period. Compared to lupin bread with nil gluten addition, significant improvements in loaf volume and crumb texture were observed with addition of gluten powder especially at 5% which increased loaf volume by an average of 20% across lupin sources and baking methods, and crumb softness by 30–50%. Differences were observed between the lupin flour sources. L. angustifolius had a reduced weakening effect when blended with the base flour compared with L. albus. The Sponge & Dough process was found to be more suitable to the inclusion of lupin flour than the rapid process.

Technological properties, shelf life and consumer preference of spelt-based sourdough bread using novel, selected starter cultures

The goal of this work was to investigate the use of selected starter cultures to obtain a spelt-based sourdough bread with improved technological, sensory and shelf-life characteristics. Two consortia were set up, containing a yeast strain (either a commercial Saccharomyces cerevisiae strain or a maltose-negative Kazachstania unispora strain) and two strains of Lactic Acid Bacteria (LAB), belonging to Weissella cibaria and Pediococcus pentosaceus species. The ability to grow in co-culture was investigated, and no inhibitions were recorded between the LAB and yeasts, that grew in proportions deemed desirable for sourdoughs. The performance of the two consortia was assessed in a spelt-based sourdough bread, and the leavening behavior, bread volume and crumb softness, shelf life and consumer preference were assessed. The product obtained with the consortium containing S. cerevisiae had superior crumb texture that was maintained through 5 d of storage, and was well accepted by the consumers. Furthermore, both consortia improved the mold free shelf-life when challenged with common cereal contaminants. The data showed that selected starter cultures have a good potential in improving the quality of bakery products obtained with flours that have a poor technological performance, such as spelt, but interesting nutritional properties and sustainable cultivation.

Rejuvenated Brewer's Spent Grain: EverVita Ingredients as Game-Changers in Fibre-Enriched Bread.

Brewer’s spent grain (BSG) is the main side-stream of brewing. BSG is a potential source for nutritionally enriched cereal products due to its high content of fibre and protein. Two novel ingredients originating from BSG, EverVita FIBRA (EVF) and EverVita PRO (EVP), were incorporated into bread in two addition levels to achieve a ‘source of fibre’ (3 g/100 g) and a ‘high in fibre’ (6 g/100 g) nutrition claim for the breads. The impact of those two ingredients on dough and bread quality as well as on nutritional value was investigated and compared to baker’s flour (C1) and wholemeal flour (C2) breads. The addition of EVF performed outstandingly well in the bread system achieving high specific volumes (3.72–4.66 mL/g), a soft crumb texture (4.77–9.03 N) and a crumb structure comparable with C1. Furthermore, EVF barely restricted gluten network development and did not influence dough rheology. EVP increased the dough resistance (+150%) compared to C1 which led to a lower specific volume (2.17–4.38 mL/g) and a harder crumb (6.25–36.36 N). However, EVP increased the nutritional value of the breads by increasing protein content (+36%) and protein quality by elevating the amount of indispensable amino acids. Furthermore, a decrease in predicted glycaemic index by 26% was achieved and microbial shelf life was extended by up to 3 days. Although both ingredients originated from the same BSG, their impact on bread characteristics and nutritional value varied. EVF and EVP can be considered as game-changers in the development of bread fortified with BSG, increasing nutritional value, and promoting sustainability.

Impacts of the baking heating rate on the water mobility, starch microstructure and mechanical properties of degassed crumb during staling

In this study, the impacts of different heating rates (HRs) from 6 to 40 °C/min were investigated in terms of the 1H proton water mobility, starch microstructure, texture, soluble amylose (AM), amylopectin (AP) retrogradation and AM crystallization during staling. A degassed breadcrumb baked in a miniaturized baking system was used to ensure better time-temperature control during baking. Proton nuclear magnetic resonance (1H NMR) data showed that the evolution of the proton T2 relaxation time decreased with increasing HR during staling. The amount of soluble AM, AP retrogradation degree, AM crystallization degree and crumb firmness tend to increase at higher HR. Environmental scanning electron microscopy (ESEM) observations showed that most starch granules in crumbs treated at higher HR exhibited strong deformation and disruption. These results confirmed that the increase in crumb firmness during staling with increasing HR was related to a higher level of starch disruption. This yielded a higher degree of separation between the AM and AP, which resulted in more pronounced water trapping in the starch crystals. The resulting dehydration of the matrix (gluten network, with AM gel surrounding of starch granules) yielded a loss in crumb softness, and crumb baked at higher HR tended to have a firmer texture and faster staling.

Soybean by-products and modified cassava starch for improving alveolar structure and quality characteristics of gluten-free bread

There is a global trend towards assuring more sustainable application of ingredients in food development, with emphasis in the nutrients recovering from agro-industrial by-products. Soybean extruded–expelled meal (SF) was explored to take an advantage from its nutrients; and its behaviour with pregelatinised cassava starch (PGS) and hydration levels (WC) as a contribution to technological improvement in gluten-free (GF) bread-making. The aim of this work was to study the effects of different levels of SF, PGS and WC on alveolar structure and final quality characteristics of GF bread formulation. A Box–Behnken experimental design and surface response methodology were applied. The final quality of GF breads was significantly affected by the addition of SF, PGS and WC, being the SF and WC the components with major impact. Lower levels of PGS and SF showed higher specific loaf volume with a softer crumb, faster recuperation of resilience and springiness, and less susceptibility to being disintegrated. The colour intensity and the uniformity of the alveolar crumb structure were enhanced by SF addition. Optimisation carried out to improve the physical and textural characteristics of bread, rendered a formulation with PGS 15.0 g × 100 g−1, SF 6.0 g × 100 g−1 and WC 160 g × 100 g−1. A size portion of GF bread (50 g) would increase 1.4- and 3.7-fold the protein and fibre intake, respectively. The addition SF and PGS with the adequate hydration level is promising for producing GF bread with an improved technological and nutritional profile, and could be useful to add value to an industrial by-product and reduce manufacturing cost.

Fructo-oligosaccharides, hydrolyzed soy protein and yeast (Saccharomyces sp.) extract as potential cryoprotectans in gluten-free frozen dough and bread quality.

People with celiac disease, wheat allergy, and non-celiac gluten sensitivity required bakery products without gluten. However, gluten-free bread has a high rate of starch retrogradation during shelf life, resulting in loss of softness in the bread crumbs. The inclusion of frozen doughs for gluten-free bread can provide a feasible solution to increase product supply with high technological and sensory quality, providing fresh bread with uniform characteristics. The biggest challenge in the frozen dough for gluten-free bread is related to the high amount of water added to the dough (70-120 % - flour basis) because the ice crystals formed during the freezing step can cause damage to yeast. The use of cryoprotectants in the dough is an alternative for preserving yeast during freezing and cold chain maintenance. This study aimed to evaluate the behavior of fructo-oligosaccharide, hydrolyzed soy protein, and yeast extract as a cryoprotectant in the gluten-free frozen dough and the evaluation of bread quality. Through the Response Surface Methodology, using a Simplex-Centroid Mixture Design, the cryoprotectants were evaluated up to a concentration of 5 % (flour basis) with freezing of the dough for 7 days at -18 °C. The results showed that with the use of cryoprotectants, there was an increase in volume increase of the doughs, in the specific volume of the bread, and the softness of the crumb. The use of 69 % fructo-oligosaccharide and 31 % hydrolyzed soy protein, without the yeast extract, was considered as the optimal formulation for the tested cryoprotectants, with a probability of 79.60 % of success obtained by the desirability function. These levels promoted a better biopreservation of yeast fermentation power and resulting in an improved crumb softness and specific volume at 46 and 40 %, respectively, compared to the standard sample.

Improving the quality of gluten-free bread by a novel acidic thermostable α-amylase from metagenomics data

Development of gluten-free products is important due to their role in gluten related disorders and health improvement. α-Amylase enzymes have shown to have a positive effect on wheat bread quality. This study aimed to screen in-silico a novel acidic-thermostable α-amylase (PersiAmy2) from the sheep rumen metagenome to increase the quality of gluten-free bread. The PersiAmy2 was cloned, expressed, purified and characterized. The enzyme was highly stable at a wide range of pH, temperature and storage conditions. The PersiAmy2 had excellent activity in the presence of ions, inhibitors, and surfactants. Utilization of the acidic thermostable PersiAmy2 in gluten-free bread resulted in a softer crumb, higher specific volume, porosity, moisture content and caused a darker crust color. The rheological measurement showed a solid-elastic behavior in batters. Also the addition of this enzyme reduced the firmness. From the results of this study it can be concluded that the PersiAmy2 can be used to improve the quality of gluten-free bread.

Type and Amount of Legume Protein Concentrate Influencing the Technological, Nutritional, and Sensorial Properties of Wheat Bread

Plant protein concentrates are used to enhance the nutritional quality of bread and to respond to the demand of consumers with respect to increased protein intake. In the present study, bread samples were produced using pea protein concentrate (PP) and soy protein concentrate (SP) substituting wheat flour by 5%, 10%, and 15%. The protein levels were between 1.2- and 1.7-fold (PP) and 1.1- and 1.3-fold (SP) higher than the control bread. The incorporation of 10% and 15% PP allowed for the achievement of a “high protein” claim. Water absorption was correlated with the protein contents of the breads (r = 0.9441). The decrease in bread volume was higher for the PP than SP incorporations, and it was highly negatively correlated with the protein content (r = −0.9356). Soy breads had a softer crumb than pea breads. The total change in crumb colour was higher in the PP than SP breads. The soy breads had an overall acceptability between 6.3 and 6.8, which did not differ (p > 0.05) from the control. PP breads were statistically less liked (p < 0.05). The results underlined that the choice of the type and amount of protein concentrates influenced the bread properties differently.

Antistaling properties of encapsulated maltogenic amylase in gluten-free bread.

Staling of bakery products especially gluten‐free products is a challenge on the development of these products. For retarding staling of gluten‐free bread, maltogenic amylase (MAase) at concentrations of 8.2, 45, and 82 mg/ml was encapsulated into beeswax (BW) at 1%, 2.5%, and 4% levels. Results showed the treatment with 8.2 mg/ml MAase and 2.5% beeswax had the highest encapsulation efficiency (42.04%) and chosen for subsequent experiments. The size of encapsulated particles was 362.70 nm and had a zeta potential of −15.35 mV. Surface morphology of encapsulated MAase was almost spherical with layered appearance. The free and encapsulated MAase with the activity of 5.2 µmol/min were used in gluten‐free batter and breads, respectively. In the rheological tests, batters containing free and encapsulated MAase showed lower cross over point than control batter (without enzyme or wall material) (59 and 53 Hz, respectively). Encapsulated MAase contained bread had darker crust, whiter and softer crumb, and more aerated structure in comparison with free MAase loaded one. Both breads containing MAase as free or encapsulated had higher moisture content and water activity in crust and crumb than control bread. However, bread with free MAase had softer crumb after four days of storage, and bread with encapsulated MAase had higher sensorial acceptability than other breads after 2 and 4 days of storage.

Lime juice and enzymes in clean label pan bread: baking quality and preservative effect.

Clean label breadmaking is a challenge for the bakery industry, considering the removal of additives, especially preservatives. Through dough acidification and theuse of enzymes, shelf-life of breads may be extended in terms of sensory quality and preservation against microbiological deterioration. This study aimed to evaluate the effect of lime juice (0, 10.2 or 20.4g.100g-1, flour basis, f.b.) on technological characteristics and preservation of clean label pan breads, with and without enzymes (0.0015 and 0.0050g.100g-1 of phospholipase and fungal xylanase, f.b., respectively). The technological parameters of dough (high-speed mixing time, temperature, pH before and after proofing) and pan bread (specific volume, firmness, crust and crumb color, aw, pH and mold occurrence) were evaluated. Doughs with lime juice required a longer mixing time, and produced breads with lower volume, firmer crumb, lighter crust and lower mold occurrence, when compared to the market standard. Pan breads with 10.2g.100g-1 of lime juice and enzymes showed a higher volume and softer crumb, compared to those with only lime juice. Thus, the joint use of lime juice and enzymes may be suitable for clean label pan breads, maintaining a soft crumb and longer shelf life without additives.

Effect of added psyllium and food enzymes on quality attributes and shelf life of chickpea-based gluten-free bread

A 24 full factorial design with four center points was used to investigate the effects of chickpea flour (CF), psyllium (PSY), cyclodextrin glycosyltransferase (CGTase), and transglutaminase (TGase) on dough Mixolab® parameters and fresh and stored gluten-free bread (GFB) physical properties. Results show that CF and PSY have the greatest effects on the investigated variables. CF increases the loaf-specific volume and crumb firmness values of fresh GFB, effects of increased starch stability (C4) and tendency to starch retrogradation (C5). Both PSY and PSY- CF interactions reduce the loaf-specific volume and increase the crumb firmness of GFB during storage, effects of an increased initial consistency (C1). CF - CGTase interaction reduced crumb firmness during storage, and TGase had no effect. High CF-levels (75 and 100 g/100 g flour weight basis, fwb) combined with low PSY-levels (4.5 and 5.5 g/100 g fwb) resulted in favorable dough consistency for increasing loaf volume and crumb softness. Results also show that the combination of 75 CF and 5.5 PSY (g/100 g fwb) produces a GFB with good physical properties and appearance, reaching values comparable to commercially available fresh and stored GFB.