A Systematic Comparison of the Intrinsic Properties of Wheat and Oat Bran Fractions and Their Effects on Dough and Bread Properties: Elucidation of Chemical Mechanisms, Water Binding, and Steric Hindrance

Nutritional Composition, Physicochemical Properties, Antioxidant Activity, and Sensory Quality of Matricaria chamomilla-Enriched Wheat Bread

This study evaluates the effects of fortifying bread with different concentrations (3%, 10%, and 30%) of Matricaria chamomilla L. (MC) infusion and powder, derived from the plant's aerial parts (stem, leaf, and flower). UPLC/MS-MS analysis of MC infusion and powder ethanolic extract confirmed the presence of polyphenolic compounds, including flavonoids, contributing to enhanced antioxidant and enzyme inhibitory properties. The physicochemical, antioxidant, and sensory properties of the enriched breads were assessed. Hierarchical cluster analysis revealed that breads enriched with 30% MC powder (BP-MC 30%) and infusion (BI-MC 30%) exhibited superior overall quality compared with other formulations. The enriched breads showed increased protein, fiber, and antioxidant content. Specifically, BI-MC 30% demonstrated superior antioxidant activity, while BP-MC 30% provided the highest fiber content. Sensory evaluation indicated that the enriched breads retained sensory properties similar to those of the control bread, despite the nutritional improvements. These findings suggest that incorporating Matricaria chamomilla, particularly at 30%, enhances the nutritional profile and antioxidant properties of bread while maintaining sensory characteristics close to those of traditional bread. This research highlights the potential of using chamomile's aerial parts in the valorization of plant-based by-products for functional bakery product development.

Decoupling texture from nutritional composition in sugar and fat reduced pound cake: A physico-chemical approach to bakery formulations

Reducing sugars and fats in cakes often compromises sensory properties, limiting consumer acceptance. This study proposes that the textural changes from 30% fat replacement (using dietary fibres) can be balanced by adjusting the water-sugar mixture properties through a concurrent 30% sugar replacement. Specifically, key physico-chemical parameters were investigated to design cake reformulation: (i) the volumetric density of hydrogen bonds, Φw,eff, affecting protein denaturation and starch gelatinization; (ii) the molar volume density of effective hydroxyl groups in the sugar molecules, NOH,s/vs, influencing starch pasting properties; (iii) the Flory-Huggins water interaction parameter, χeff, describing the hygroscopic properties of sugar mixtures; and (iv) the volume fraction of flour, Φflour. These parameters were independently varied and tested against phase transitions, dough rheology (temperature sweeps) and cake properties. Results indicated that all physico-chemical parameters (Φw,eff, NOH,s/vs, χeff, and Φflour) effectively described key physical properties associated with phase transitions and batter rheology during heating, as well as final cake properties. Biopolymer phase transitions and the viscoelastic behavior of batters were primarily governed by Φw,eff, while cake properties depended on all physico-chemical parameters combined. Sensory tests with naïve consumers confirmed that properly modulating these parameters yielded cakes with sensory attributes comparable to the reference. Notably, cakes with enhanced sweetness, softness, and moistness were achieved despite the 30% sugar and fat reduction, positively influencing liking. Overall, this study highlights a formulation strategy that decouples texture from nutritional composition, enabling improved sensory properties while lowering calorie density.

Soluble fibres modulate dough rheology and gluten structure via hydrogen bond density and Flory-Huggins water interaction parameter

Soluble fibres are gaining increasing interest for functional food applications like bread, but their interaction with gluten and effects on dough rheology are not fully elucidated. This study hypothesized that soluble fibres influence gluten structure and dough rheology by acting as plasticizers and humectants. Plasticizing properties depend on the effective number of hydrogen bonding sites available in the fibre molecule (N OH,s ). Humectant properties are related to the water interaction parameter derived from analysis of the sorption behaviour. Oligo-fructoses, inulins, polydextrose and a glucose syrup were added individually and in mixtures to wheat dough to test the hypothesis. PCA and multi-linear regressions showed that the G' from temperature sweeps increased with an increase in the effective volume fraction of hydrogen bonding sites (Φ w , e f f ) in the solvent and in the water interaction parameter (χ eff ). The enhanced G' corresponded to a reduction in tan(δ), indicating an increased elastic behaviour. The parametersΦ w , e f f and χ eff also explained the changes in phase transitions during heating, i.e. Tonset and Tpeak of starch gelatinization (R2 > 0.9). Image analysis of the gluten network revealed that fibre structure and physico-chemical properties influenced the gluten network by altering branching rate, lacunarity, and protein strand width. Comparing inulins and polydextrose of similar molecular weights (Mw) indicated that interactions with gluten were influenced more by N OH,s than Mw. High Mw inulins, with a linear structure, promoted junctions in the gluten network through hydrogen bonds, and possibly phase separation in gluten-rich and inulin-rich phases. In contrast, the more hydrophilic, branched polydextrose reduced junction formation in the gluten network due to fewer N OH,s . This study provides new insights into the physico-chemical properties of soluble fibres and their role in wheat dough functionality.

Home-made vs industry-made: Nutrient composition and content of potentially harmful compounds of different food products

Many consumers perceive industrially processed foods as lower in quality and potentially harmful to health, with concerns about poor nutrition, additives, and harmful compounds formed during processing. Epidemiological studies have highlighted risks associated with "ultra-processed foods," but empirical comparisons between industrial (IND) and home-made (HM) foods are scarce. This study aimed to compare nutritional values and harmful compounds in IND vs. HM versions of four common foods: plumcake, fish sticks, tomato sauce, and cereal bars. The HM foods were prepared using similar recipes to their industrial counterparts, avoiding technologies and ingredients not available at home. The analysis revealed identical nutritional compositions between the IND and HM versions. Acrylamide (AA) and Maillard reaction (MR) products, considered potentially harmful, showed comparable levels across the food pairs, though HM versions showed slightly higher levels in some cases. AA was undetectable in IND plumcake and HM cereal bars, while HM fish sticks had higher AA content than the industrial version. These findings indicate that homemade foods do not necessarily offer superior nutritional quality or lower levels of harmful compounds compared to industrial products. The classification of food products quality based on processing or industrial ingredients alone is not a reliable indicator of their healthiness.

Impact of compositionally diverse cereal flour water extracts on the gas cell size distribution and extensional rheology of model gluten-starch doughs

The role of water-extractable (WE) cereal flour constituents, and particularly WE proteins, in determining bread dough gas cell stability and bread specific volume (SV) remains ill-understood. We investigated the impact of compositionally diverse cereal flour aqueous extracts on bread SV, dough extensional rheology, and dough gas cell size distribution. To this end, aqueous extracts from wheat, rye, and defatted oat flours were either used as such, or their composition was modified by dialyzing out (i) low molecular mass constituents or (ii) both low molecular mass constituents and enzymatically hydrolyzed carbohydrates. These modifications generated wheat, rye, and oat extracts with increasing protein purities. Incorporating wheat or rye extracts in model gluten-starch (GS) doughs increased bread SV by 12-18%, regardless of modification, suggesting that not WE carbohydrates but probably proteins drive this effect. Dough extensional rheology and gas cell size distribution data could not explain these bread SV increases. It is hypothesized that wheat/rye WE proteins stabilize gas cells in dough by adsorbing at their interfaces. Incorporating oat extracts in GS dough led to a 50% decrease in bread SV. This was associated with oat extract-containing doughs having a lower strain hardening index, a lower gas cell number density, and a more heterogeneous gas cell size distribution. That similar effects were observed irrespective of the modification type suggests that oat WE proteins may be responsible for the adverse impact on dough and bread properties. Future efforts will focus on investigating direct gas cell stabilization effects by WE cereal flour constituents.

The influence of non-starch polysaccharides on the formation mechanism of wheat dough

The study examined the effects of oat β-glucan (OβG), chitosan (CTS), araboxylan (AX), and fructosan (FOS) on wheat dough formation. Adding 0-7 % OβG, AX, and FOS increased SS content, enhancing gluten stability. D-AX and D-FOS showed higher β-sheet structures, higher air retention and gluten network, smaller pores and denser structures, higher elastic and viscosity moduli. Excessive OβG and CTS could reduce the dough stability, and β-turn and β-sheet ratios, respectively. Therefore, B-7AX and B-7FOS exhibited lower hardness indices during storage, leading to a smoother appearance and more orderly gas chamber distribution. The study provides a theoretical foundation for using non-starch polysaccharides in flour-based products.

Effect of high pressure homogenization on in vitro digestibility and colon fermentability of pea protein-rich bread designed for elderly consumers

Enrichment of staple foods with proteins can be a solution to tackle protein-energy malnutrition in the elderly. For instance, bread can be enriched with pea proteins that are cheap, sustainable and easily digestible. Non-conventional technologies, such as high pressure homogenization (HPH), can improve the digestibility of plant proteins. To characterize the health functionality of pea-enriched bread, a functional bread tailored to elderly consumers was developed by substituting 5% wheat flour with untreated or HPH-treated pea protein concentrate. Protein digestibility and colon fermentability were assessed by mimicking elderly in vitro gastrointestinal and gut microbiota conditions and compared with adult conditions. Bread reformulation with pea proteins affected physical and chemical properties and produced an increase in hardness, which is one of the key features for the acceptability of bread by the elderly. The highest hardness value was observed for pea protein bread, followed by HPH-treated pea protein bread and wheat bread. In vitro protein digestibility and fermentability were affected by reformulation and by physiological digestive conditions, with lower digestibility under elderly conditions compared to adult ones. The obtained results may contribute to a better understanding of food digestibility under different gastrointestinal conditions and its dependence on physiological and formulation factors, and ultimately would help to design age-tailored foods.

Role of particle size in modulating starch digestibility and textural properties in a rye bread model system

In cereal products, the use of flour containing clusters of intact cells has been indicated as a potential strategy to decrease starch digestion. Rye possesses more uniform and thicker cell walls than wheat but its protective effect against starch digestion has not been elucidated. In this study, rye flours with three different particle sizes, large (LF) (∼1700 μm), medium (MF) (∼1200 μm), and small (SF) (∼350 μm), were used to produce model bread. The textural properties of these breads were analysed using Textural Profile Analysis (TPA). The starch digestibility of both the flour and the bread was measured using Englyst's method, while the presence of intact cell clusters was examined using Confocal Laser Scanning Microscopy (CLSM). Additionally, the disintegration of bread digesta during simulated digestion was assessed through image analysis. CLSM micrographs revealed that bread made with MF and LF retained clusters of intact cells after processing, whereas bread made with SF showed damaged cell walls. Starch digestibility in LF and MF was lower (p ≤ 0.05) than that in SF. Bread produced with MF and LF exhibited the least (p ≤ 0.05) cohesive and resilient texture, disintegrated more during digestion, and exhibited higher starch digestibility (p ≤ 0.05) than bread made with SF. These results highlight the central role of bread texture on in vitro starch digestibility.

Lupin as Ingredient in Durum Wheat Breadmaking: Physicochemical Properties of Flour Blends and Bread Quality

The popularity of adding pulse flours to baked goods is growing rapidly due to their recognised health benefits. In this study, increasing amounts (3, 7, 10, and 15%) of white lupin flour (Lupinus albus L.) and of protein concentrate from narrow-leaved lupin (Lupinus angustifolius L.) were used as replacements for durum wheat semolina to prepare bread, and their effects on the physicochemical properties of the flour blends, as well as the technological and sensory qualities of bread, were evaluated. The addition of protein concentrate from narrow-leaved lupin and white lupin flour increased the water binding capacity and the leavening rate compared to pure semolina. A farinograph test indicated that the dough development time had a slight but significant tendency to increase with the addition of lupin flour and protein concentrate of narrow-leaved lupin, while had a negative effect on the stability of dough. The alveograph strength decreased (225, 108, and 76 × 10-4 J for dough made with semolina, 15% of protein concentrate from narrow-leaved lupin, and 15% of white lupin flour, respectively), whereas there was an upward trend in the P/L ratio. Compared to re-milled semolina, the samples with lupin flour and protein concentrate from narrow-leaved lupin had low amylase activity, with falling number values ranging from 439 s to 566 s. The addition of the two different lupin flours lowered the specific volumes of the breads (2.85, 2.39, and 1.93 cm3/g for bread made from semolina, from 15% of protein concentrate from narrow-leaved lupin, and from 15% of white lupin flour, respectively) and increased their hardness values (up to 21.34 N in the bread with 15% of protein concentrate from narrow-leaved lupin). The porosity of the loaves was diminished with the addition of the two lupin flours (range of 5-8). The sensory analysis showed that the addition of white lupin flour or protein concentrate from narrow-leaved lupin did not impart any unpleasant flavours or odours to the bread. To conclude, the use of lupin in breadmaking requires adjustments to strengthen the gluten network but does not require a deflavouring process.

Functional and Nutritional Characteristics of Natural or Modified Wheat Bran Non-Starch Polysaccharides: A Literature Review

Wheat bran (WB) consists mainly of different histological cell layers (pericarp, testa, hyaline layer and aleurone). WB contains large quantities of non-starch polysaccharides (NSP), including arabinoxylans (AX) and β-glucans. These dietary fibres have long been studied for their health effects on management and prevention of cardiovascular diseases, cholesterol, obesity, type-2 diabetes, and cancer. NSP benefits depend on their dose and molecular characteristics, including concentration, viscosity, molecular weight, and linked-polyphenols bioavailability. Given the positive health effects of WB, its incorporation in different food products is steadily increasing. However, the rheological, organoleptic and other problems associated with WB integration are numerous. Biological, physical, chemical and combined methods have been developed to optimise and modify NSP molecular characteristics. Most of these techniques aimed to potentially improve food processing, nutritional and health benefits. In this review, the physicochemical, molecular and functional properties of modified and unmodified WB are highlighted and explored. Up-to-date research findings from the clinical trials on mechanisms that WB have and their effects on health markers are critically reviewed. The review points out the lack of research using WB or purified WB fibre components in randomized, controlled clinical trials.

Bread Products from Blends of African Climate Resilient Crops: Baking Quality, Sensory Profile and Consumers' Perception

With food insecurity rising dramatically in Sub-Saharan Africa, promoting the use of sorghum, cowpea and cassava flours in staple food such as bread may reduce wheat imports and stimulate the local economy through new value chains. However, studies addressing the technological functionality of blends of these crops and the sensory properties of the obtained breads are scarce. In this study, cowpea varieties (i.e., Glenda and Bechuana), dry-heating of cowpea flour and cowpea to sorghum ratio were studied for their effects on the physical and sensory properties of breads made from flour blends. Increasing cowpea Glenda flour addition from 9 to 27% (in place of sorghum) significantly improved bread specific volume and crumb texture in terms of instrumental hardness and cohesiveness. These improvements were explained by higher water binding, starch gelatinization temperatures and starch granule integrity during pasting of cowpea compared to sorghum and cassava. Differences in physicochemical properties among cowpea flours did not significantly affect bread properties and texture sensory attributes. However, cowpea variety and dry-heating significantly affected flavour attributes (i.e., beany, yeasty and ryebread). Consumer tests indicated that composite breads could be significantly distinguished for most of the sensory attributes compared to commercial wholemeal wheat bread. Nevertheless, the majority of consumers scored the composite breads from neutral to positive with regard to liking. Using these composite doughs, chapati were produced in Uganda by street vendors and tin breads by local bakeries, demonstrating the practical relevance of the study and the potential impact for the local situation. Overall, this study shows that sorghum, cowpea and cassava flour blends can be used for commercial bread-type applications instead of wheat in Sub-Saharan Africa.

Effect of Bioprocessing on Techno-Functional Properties of Climate-Resilient African Crops, Sorghum and Cowpea

Sorghum and cowpea are very compatible for intercropping in hot and dry environments, and they also have complementary nutritional compositions. Thus, the crops have the potential to improve food security in regions threatened by climate change. The aim of this study was to investigate different enzymes (carbohydrate-degrading, proteases and phytases) and lactic acid bacteria (LAB) fermentation to improve the techno-functional properties of sorghum and cowpea flours. Results show that sorghum carbohydrates were very resistant to hydrolysis induced by bioprocessing treatments. Most of the protease treatments resulted in low or moderate protein solubilization (from ca. 6.5% to 10%) in sorghum, while the pH adjustment to 8 followed by alkaline protease increased solubility to 40%. With cowpea, protease treatment combined with carbohydrate-degrading enzymes increased the solubility of proteins from 37% up to 61%. With regard to the techno-functional properties, LAB and amylase treatment decreased the sorghum peak paste viscosities (from 504 to 370 and 325 cPa, respectively), while LAB and chemical acidification increased cowpea viscosity (from 282 to 366 and 468 cPa, respectively). When the bioprocessed sorghum and cowpea were tested in breadmaking, only moderate effects were observed, suggesting that the modifications by enzymes and fermentation were not strong enough to improve breadmaking.

Impact of Native Form Oat β-Glucan on the Physical and Starch Digestive Properties of Whole Oat Bread

To investigate the effect of oat bran on bread quality and the mechanism of reducing the glycemic index (GI) of bread, wheat bran (10%, w/w, flour basis), oat bran (10%), and β-glucan (0.858%) were individually added to determine the expansion of dough, the specific volume, texture, color, GI, starch digestion characteristics, and α-amylase inhibition rate of bread. The results showed that the incorporation of wheat bran and oat bran both reduced the final expanded volume of the dough, decreased the specific volume of the bread, and increased the bread hardness and crumb redness and greenness values as compared to the control wheat group. The above physical properties of bran-containing bread obviously deteriorated while the bread with β-glucan did not change significantly (p < 0.05). The GI in vitro of bread was in the following order: control (94.40) > wheat bran (69.24) > β-glucan (65.76) > oat bran (64.93). Correspondingly, the oat bran group had the highest content of slowly digestible starch (SDS), the β-glucan group had the highest content of resistant starch (RS), and the control group had the highest content of rapidly digestible starch (RDS). For the wheat bran, oat bran, and β-glucan group, their inhibition rates of α-amylase were 9.25%, 28.93%, and 23.7%, respectively. The β-glucan reduced the bread GI and α-amylase activity by intertwining with starch to form a more stable gel network structure, which reduced the contact area between amylase and starch. Therefore, β-glucan in oat bran might be a key component for reducing the GI of whole oat bread.

Dry Heating of Cowpea Flour below Biopolymer Melting Temperatures Improves the Physical Properties of Bread Made from Climate-Resilient Crops

Improving the technological functionality of climate-resilient crops (CRCs) to promote their use in staple foods, such as bread, is relevant to addressing food and nutrition security in Africa. Dry heating of cowpea flour (CPF) was studied as a simple technology to modulate CPF physicochemical properties in relation to bread applications. For this purpose, the melting behavior of cowpea starch and proteins in CPF was first studied and modeled using Flory–Huggins theory for polymer melting. Next, dry-heating conditions were investigated based on the predicted biopolymer melting transitions in CPF to be well below starch and protein melting. The pasting properties (i.e., peak viscosity, final viscosity, breakdown and setback) of CPF could be selectively modulated depending on temperature-time combinations without altering the thermal behavior (i.e., melting enthalpies) of CPF. Water-binding capacity and soluble solids decreased with the increased severity of the temperature-time combinations. Dry-heated CPF added to CRC-based bread significantly improved crumb texture. In particular, dry heating at 100 °C for 2 h provided bread with the highest crumb softness, cohesiveness and resilience. The positive effects on the crumb texture could be largely related to enhanced starch integrity, as indicated by a reduction in breakdown viscosity after treatment. Overall, dry heating of CPF under defined conditions is a promising technology for promoting the use of CPF as a techno-functional and protein-rich ingredient in bread-type products.