Dough Fermentation Research Articles

Impact of Exopolysaccharides from Fructilactobacillus sanfranciscensis Ls5 on the Quality of Mantou: A Comparative Study of Fermentation Conditions

Lactic acid bacteria (LAB) and their exopolysaccharides (EPS) have the potential to enhance the quality of flour-based products. This study investigated the effect of EPS produced by Fructilactobacillus sanfranciscensis Ls5 on the quality of Mantou. LAB strains with high EPS production were isolated from traditional fermenters, and their characteristics and EPS properties were examined. Four different fermentation conditions (Blank, Yeast, Ls5-Yeast, and EPS-Yeast) were compared in terms of their effects on the physicochemical properties, in vitro digestion characteristics, and shelf-life of Mantou. The incorporation of Ls5 and its EPS into Mantou resulted in a lower dough fermentation pH, increased organic acid production, and enhanced fermentation activity. Additionally, the incorporation of Ls5 and its EPS led to significant improvements in the quality of the Mantou, including the extension of shelf-life, improved sensory evaluation, and a reduction in the sugar content. Additionally, there was an increase in resistant starch content during digestion in both types of Mantou, which could offer potential benefits to human glycemic health.

Intelligent monitoring of post-processing characteristics in 3D-printed food products: A focus on fermentation process of starch-gluten mixture using NIR and multivariate analysis

The production of three-dimensional (3D)-printed food products requires not only optimal 3D-printing adaptability but also appropriate post-processing characteristics. This study aimed to use near infrared (NIR) spectroscopy to predict the rheological properties of 3D-printed dough, enabling intelligent monitoring of the dough's fermentation process. Utilizing support vector machine (SVM) classification model, the fermentation stages can be classified as under-fermentation, complete fermentation, and over-fermentation. Employing preprocessing methods with Synergy Interval Partial Least Square-Competitive Adaptive Reweighted Sampling (SIPLS-CARS) algorithm, 27, 39, 23, and 27 key wavelengths were filtered from the raw NIR spectral data, corresponding to the prediction of storage modulus (G′), loss modulus (G″), complex viscosity (η∗), and loss factor (tan δ), respectively. Quantitatively, SVM (Support Vector Machine) regression outperformed Partial Least Squares (PLS) with Rc2 values (0.95, 0.94, 0.94) and Rp2 values (0.93, 0.93, 0.94) for G′, G″, and η∗. NIR spectra-based predictive models demonstrated superior performance compared to rheo-fermentation properties models. In summary, these findings show the potential of NIR spectroscopy as a rapid tool for predicting the fermentation progress of 3D-printed doughs.

Effect of Fermentation and/or Cooking on Some Nutritional Quality of Sorghum Meals Formulated with Different Ratios of Wheat and Pumpkin Flour

Sorghum cultivar (Tabat), defatted pumpkin seed pulp (DPSP), and wheat flour were used to prepare four meals to study the effects of component ratio and fermentation and/or cooking on various nutritional qualities. Before and after processing, the meals' chemical compositions, total calories, minerals, antinutrients, and in vitro protein digestibility (IVPD) were assessed. The addition of wheat and pumpkin flour resulted in a decrease in carbohydrates and antinutrients and an increase in ash, protein, fiber, fat, total and extractable minerals, and IVPD. After fermentation, the antinutrients were significantly (P ≤ 0.05) reduced, resulting in meals of excellent quality. Cooking the fermented dough afterward, nevertheless, revealed much greater improvement. The proportion of ingredients decreased the effect of cooking on chemical composition and led to a substantial (P ≤ 0.05) reduction in tannin and phytate, which was accompanied by a significant (P ≤ 0.05) increase in IVPD and mineral extractability. Meals were accepted more often than the control group (P ≤ 0.05). Out of all the formulations, the one with 10% wheat and 20% DPSP flours (M3) was found to be the most nutrient-dense and bioavailable.

Exploring the Addition of Mango Peel in Functional Semolina Sourdough Bread Production for Sustainable Bio-Reuse

Mango, a tropical fruit celebrated for its delightful fragrance and high nutritional value, generates significant waste during processing, with approximately 35–60% of the fruit being discarded. However, this waste contains valuable components, such as fibre, carotenoids, polyphenols, and other bioactive compounds. In an effort to repurpose mango peel, this study dehydrated it to create mango peel powder (MPP), which was then incorporated into sourdough bread to produce functional breads with enhanced nutritional value. Semolina was replaced with MPP at levels of 5% (MPP-5) and 10% (MPP-10) (w/w). After dehydration, the mango peel had a yield of 22%, and the procedure used did not cause any organoleptic changes. The bread fermentation process was conducted at 30 °C for 8 h. During dough fermentation, the pH was monitored, showing a value of 4.14 ± 0.02 in the MPP-10 dough. Overall, the MPP-10 bread received a higher score (6.51) than the control (CTR) bread (5.6) and the MPP-5 bread (6.11). The total phenolic content of the fortified breads ranged from 44.760 to 98.931 mg gallic acid equivalents (GAE)/g, and the antiradical activity ranged from 15.213 to 29.461 mmol trolox equivalent antioxidant activity (TEAC)/100 g, depending on the percentage of enrichment.

Assessment of the Suitability of Flour Obtained from Mountain Rye Grain Milling and the Method of Dough Fermentation for the Production of Rye Bread.

Currently, there is an increase in consumer interest in food produced from raw materials from organic farming, which has an impact on the greater attention paid to the possibility of increasing the cultivation of old cereal species. One of the cereals that is suitable for these trends is mountain rye, which is a premise for undertaking research on the usefulness of this cereal grain in food production. Therefore, the aim of the study was to compare the baking value of flour with different milling yields obtained from milling mountain rye grain. The research material consisted of rye grain (Secale montanum Guss.), which was milled, and 6 different rye flours were obtained. The flour was tested for selected quality parameters such as moisture, crude protein content, total ash content, and acidity. Doughs were prepared and fermented using a single-phase method carried out in two different variants, with or without the addition of lactic acid. The obtained rye breads were quality assessed and subjected to organoleptic and consumer evaluations. The use of the fermentation method with dough acidification with lactic acid allowed us to obtain breads with a better specific volume and acidity compared to those obtained from dough without acidification. Breads baked from dough prepared using the method of non-acidification with lactic acid had better porosity of the crumb. In the quality classification, breads made from low-extract flour turned out to be the best, and breads baked from dough made using the non-lactic acid acidification method were more generally accepted by panelists. As confirmed by research, mountain rye grain is a raw material for the production of flour with good baking value, which depends on the preparation of the grain and milling method. The quality of rye bread made from mountain rye flour depends on the flour yield, the baking value of the flour, and the method used for dough fermentation for bread baking.

Effects of four kinds of improver on fermentation characteristics of gluten-free rice dough.

Rice is commonly utilized as a wheat bread substitute due to its low allergenicity. However, rice bread faces challenges in processing efficiency and the formation of a cohesive gel network structure, resulting in suboptimal taste Hence, this study compared four improvers-trypsin, whey protein (WPC), hydroxypropyl methyl cellulose (HPMC), and molecularly distilled monoglycerides (GMSs). The impacts of the four improvers on the processing attributes of rice dough were comprehensively assessed across fermentation, moisture content analysis, rheology, heat stability, and pasting characteristics. The findings indicated that the incorporation of trypsin, HPMC, and WPC resulted in 107%, 61%, and 1% increases in gas production of fermented rice dough, respectively, while reducing the regrowth values to 564.00±7.21, 176.67±0.58, and 611.00±3.61cP. Notably, the air-holding capacity of HPMC-fermented rice dough exhibited a 7% enhancement. All four types of improvers raised the enthalpy of melting (ΔH) and the difference in melting point (ΔT) of fermented rice doughs, with trypsin enhancing ΔH by 44% and ΔT by 40%. GMS, HPMC, and WPC increased the degree of water incorporation in fermented doughs. This study could serve as a benchmark for enhancing the fermentation attributes of rice dough and establish a groundwork for the future advancement of gluten-free dietary options. PRACTICAL APPLICATION: The thorough analysis conducted in this experiment provides a theoretical framework for rice dough preparation during the fermentation process, addressing the dietary needs of individuals with coeliac disease and those following a gluten-free diet. This study also paves the way for the development of improved gluten-free rice products in future research pursuits.

Development, evaluation and application of propidium monoazide (PMA) based methodologies on viable cell quantification of Pediococcus acidilactici in rice noodles products

Pediococcus acidilactici provides a special taste during dough fermentation, but its improper presence will accelerate the spoilage of rice noodles products. In this study, propidium monoazide (PMA) based methodologies on viable cells quantification of P. acidilactici were developed, evaluated and applied in rice noodles products. Prior to qPCR and RT-qPCR detection, PMA treatment was included to effectively remove the residual DNA from membrane-compromised (dead) cells. Firstly, considering the influence of food component and PMA on qPCR result determination, 4 standard curves corresponding Ct value to P. acidilactici cell number were established in 4 different rice noodle products, respectively. The 4 standard curves were subsequently applied for viable cell quantification of P. acidilactici. Secondly, mimicking the storage conditions of rice noodles products and growth states of P. acidilactici, planktonic and biofilm (early, mediate, mature) cells in 4 types of rice noodles products stored at −20 °C and 4 °C were taken into consideration to evaluate the efficiency of PMA-qPCR for viable cell quantification. Thirdly, stress response gene expression in P. acidilactici was monitored by PMA-RT-qPCR and compared with culturable and viable cell number quantification. The PMA-qPCR method with specific standard curves for 4 types of rice noodle products was applicable for viable cell quantification of P. acidilactici in planktonic and biofilm (early, mediate, and mature) states. The planktonic and biofilm cells of P. acidilactici maintained high and stable in both culturable and viable cell number in different growth states, rice noodles products, and low temperature conditions, but acquired significantly different gene expression levels. The findings provided viable cells quantification methods and an alarm for P. acidilactici contamination risk in instant rice noodles products.

SELECTION OF LACTIC ACID BACTERIA FOR RYE BREAD SOURDOUGH

Lactic acid bacteria are widely used to produce diverse type of fermented products. One of conventional applications for lactic acid bacteria is inclusion into sourdough for bread baking. These microorganisms play a key role in dough fermentation of rye flour or wheat and rye mixture since the yield of stable and well-leavened rye dough is possible only in acidic environment. Lately, despite the development of accelerated baking technologies and technological improvements, which in some cases eliminate the need for sourdough, interest in the tradition of making bread using sourdough as a source of flavoring, nutrient and health-enhancing compounds is constantly growing across the globe. It is natural therefore that focus of the researchers is centered on seeking new strains of lactic acid bacteria attractive as potential constituents of rye bread sourdough. Screening of strains-candidates to be included in the consortia for rye flour fermentation was conducted among collection cultures (23 strains), isolates from rye flour samples (154 strains) and among craft rye dough cultures for spontaneous fermentation kindly provided by private households of Minsk, Turov, Zhitkovichi (21 strains). Identification of lactic acid bacteria following examination of morphological, cultural, physiological and biochemical characteristics of the cultures and guided by the data of MALDI TOF mass spectrometry indicated that the compared microorganisms represented genera Lactiplantibacillus, Limosilactobacillus, Pediococcus, Weissella, Lactococcus. The majority of lactic acid bacteria isolated from rye flour samples belonged to genera Lactiplantibacillus and Pediococcus. Representatives of genera Lactiplantibacillus and Levilactobacillus prevailed among domestic variants of rye bread sourdoughs. Evaluation of acidogenic capacity of analyzed cultures upon 16 h fermentation in water-flour suspension by Neumann technique and organoleptic assessment of the obtained solutions sorted out for further studies 10 strains of lactic acid bacteria referred to species Levilactobacillus brevis (4 strains) Lactiplantibacillus plantarum (3 strains) and singular strains of species Lactiplantibacillus paraplantarum, Limosilactobacillus fermentum, Weissella cibaria. Glycosyl-hydrolases produced by lactic acid bacteria constituting starter cultures largely determine biochemical processes during fermentation of flour mixtures. Chromogenic substrates o-nitrophenyl-β-D-galactopyranoside, o-nitrophenyl-α-D-galactopyranoside, 4-nitrophenyl-β-D-glucopyranoside were used in 1 mmol concentration to assay activities of β-galactosidase, α-galactosidase, β-glucosidase, respectively. It was found that all tested bacteria of species Levilactobacillus brevis and Limosilactobacillus fermentum were characterized by synthesis of proteins with α-galactosidase and β-galactosidase activities in the course of growth on media with glucose and maltose. β-glucosidase activity was revealed in all representatives of species Lactiplantibacillus plantarum, Levilactobacillus brevis and Lactiplantibacillus paraplantarum. Amylolytic activity was detected in two Lactiplantibacillus plantarum strains, whereas bacteria of species Weissella cibaria displayed a weak β-glucosidase activity. An important criterion to select microbial constituents for dough fermentation is antagonistic activity toward contaminating microbiota. Antagonistic response of lactic acid bacterial cultures to causal agents of bread spoilage was demonstrated, including epidemiologically significant fungi of genera Fusarium, Aspergillus, Penicillium, etc. Analysis of obtained data has enabled to compose microbial consortia promising for further elaboration of technologies for producing active bread-making starter formulas with upgraded biotechnological properties and enhanced alimentary, nutritional and biological value.

Lactic acid bacteria‐fermented Chlamydomonas reinhardtii as an innovative ingredient to produce microalgae‐enriched steamed bread

AbstractBackground and ObjectivesChlamydomonas reinhardtii (C. reinhardtii) is recognized as a sustainable source of high‐quality protein. This study aimed to assess the potential application of C. reinhardtii for producing microalgae‐fortified steamed bread. To reduce the inherent green color and volatile compounds of the microalgae, lactic acid bacteria (LAB) fermentation was applied as a pretreatment method for C. reinhardtii. Subsequently, both unfermented (unFC) and fermented C. reinhardtii (FC) were added to steamed bread formulations (4%, 8%, 12%, and 16% wheat flour substitution).FindingsThe results showed that the incorporation of unFC into steamed bread had a dose‐dependent negative impact on the dough fermentation performance and the quality of steamed bread, including volume, texture, and sensory attributes, rendering the steamed bread unacceptable. Fermentation altered the amino acid profile of C. reinhardtii, caused the color to shift from green to red (a*, −14.7 vs. 7.0), and reduced unpleasant volatile components. Further, fermentation reduced the negative impact of microalgae incorporation, especially at substitution levels of 4% and 8%, which manifested as an increased dough fermentation volume and improved bread volume with reduced crumb firmness of the steamed bread. However, in sensory analysis, the steamed bread that contained 4% FC had an overall acceptability similar to the control sample.ConclusionsMicroalgae‐enriched steamed bread could be produced by incorporating up to 4% FC to improve its nutritional profiles while maintaining overall sensory acceptability by the consumers.Significance and NoveltyLAB fermentation of C. reinhardtii is a feasible strategy to address the sensory and structural challenges that hinder the incorporation of algae into food products.

Monitor and classify dough based on color image with deep learning

To address subjective, time-consuming, and labor-intensive manual methods for monitoring and classifying fermenting dough, an automated and non-destructive method is proposed. Deep learning model YOLOv8s and extracted features including dough surface area, contrast, and homogeneity from RGB color images were employed to monitor fermenting dough. The features were input to a stacked ensemble model (SEM) with base models SVM, AdaBoost, KNN, and RF, with AdaBoost as meta-learner to classify fermenting dough into under-fermented, fermented, and over-fermented. SEM demonstrated a high dough classification rate of 83%, with specific rates of 75% for under-fermented, 71% for fermented, and 90% for over-fermented dough. Results reviewed that combining dough surface area and texture features is effective for monitoring dough, and can be used in adjusting chamber conditions. Furthermore, SEM showed great ability in classifying fermenting dough. The proposed method offers a promising solution for improved bread quality and consistency in bread-making.

Enhanced butanol production from dough and okara waste through co-fermentation

Biobutanol production from waste via fermentation emerges as a promising solution for a sustainable waste-energy nexus. However, maximizing the resource potential of waste-derived feedstock for fermentation remains a hindrance to biobutanol production in the industry. To address this issue, co-fermentation of food processing waste, dough and okara, by Clostridium sp. strain BOH3 was explored to enhance biobutanol production. Results indicated that strain BOH3 generated 15.9 ± 0.90 g/L of butanol and 25.4 ± 1.43 g/L of acetone-butanol-ethanol solvents from 80 g/L co-substrate containing 85 % dough and 15 % okara, which represented a remarkable enhancement of butanol and solvent production with a notable increase of 91.6 % and 108.2 %, respectively, compared to sole fermentation of 80 g/L dough waste. In contrast, the sole fermentation of okara produced negligible amounts of solvent with acid as the dominant product due to the unsuitable carbon-to-nitrogen ratio intrinsic to okara for fermentation. Meanwhile, co-fermentation accelerated the acidogenesis-to-solventogenesis phase transition by balancing the carbon-to-nitrogen ratios and elevating the activity of amylase and butanol dehydrogenase by 1.7 folds when compared with the sole fermentation of dough waste. Findings in this study provided an effective co-fermentation strategy as well as the associated mechanistic insights regarding enhanced biobutanol production from dough and okara waste, promisingly contributing to sustainable waste-to-energy management.

Retention of bioactive compounds during technological steps of the production of bread enriched with roasted buckwheat hulls

The retention of bioactive compounds in the blend of wheat and rye flours and 4% roasted buckwheat hulls, dough before and after fermentation, and obtained bread were determined. In parallel, the content of Maillard reaction products (MRPs) and antioxidant capacity (AC) during technological steps of bread production were studied. The dough formation and fermentation process increased the content of phenolic acids and flavonoids and reduced the content of tocopherols, and no changes in glutathione as compared to the blend were noted. Moreover, the increased level of available lysine and AC were observed after dough fermentation. The baking process resulted in further increased phenolic acids, and flavonoids and decreased the tocopherols and glutathione contents. The bread was characterized by the highest values of parameters related to MRPs, such as the content of fluorescent intermediary compounds and final browning index compared to other analyzed steps.

Closing the Fibre Gap-The Impact of Combination of Soluble and Insoluble Dietary Fibre on Bread Quality and Health Benefits.

Dietary fibre (DF) is important for overall health and disease prevention. However, the intake of DF in Westernised countries is below the recommended level, largely due to the excessive consumption of low-fibre foods. Fortifying staple foods, such as bread, with dietary fibre ingredients is one approach to closing the fibre gap in our diet. However, incorporating purified and chemically modified fibre ingredients into food is challenging. This study unveils interactions between soluble-fermentable (arabinoxylan), insoluble-fermentable (resistant starch type IV) and insoluble-unfermentable (cellulose) fibre ingredients and their impact on bread quality using Response Surface Methodology. This resulted in an optimised mixture of these fibre ingredients that can coexist within a bread matrix while maintaining quality characteristics comparable to white wheat bread. The partial replacement of flour with fibre ingredients led to an interference with the gluten network causing a reduction in gluten strength by 12.4% and prolonged gluten network development time by 24.4% compared to the control (no fibre addition). However, the CO2 retention coefficient during dough fermentation was not affected by fibre ingredient inclusion. The fibre content of the white bread was increased by 128%, with only a marginal negative impact on bread quality. Additionally, the fibre-fortified bread showed a lower release of reducing sugars during in vitro starch digestion. This study illustrates the synergy of different types of fibre ingredients in a bread system to advance in closing the fibre gap.

Moderate regulation of wheat B-starch ratio: Improvement of molecular structure, spatial conformation, aggregation behavior of reconstituted fermented doughs and its processing suitability

Aiming to investigate the changes and effects of different particle sizes of wheat A/B starch during dough fermentation, the present study reconstituted A/B starch fractions in ratios of 100:0, 75:25, 50:50, 25:75, and 0:100, further blended with gluten and subjected to slight (20 min), medium (30 min), and high (60 min) fermentation processes by yeasts. Results showed that fermentation gas production promoted gluten network extension, inducing starch granule exposure and dough surface roughness. Also, fermentation fractured protein intermolecular disulfide bonds and decreased α-helix and β-folded structure content, contributing to GMP, LPP, and SPP content decreases. Moreover, moderately increasing the B-starch ratio in the dough can improve gluten network stability, continuity, and air-holding capacity. The 25A-75B steam bread exhibited optimal processing suitability (better morphology, texture, and quality) due to its higher GMP and polymer protein content with lower free sulfhydryl and monomeric protein content. Further, conformational relationships indicated the key indicators influencing dough products' properties were free sulfhydryl content, GMP content, protein molecular weight distribution, and secondary structure. The obtained findings contributed to understanding the effect of wheat starch granule size distribution on dough processing behavior, and future targeted breeding for wheat cultivars with high B-starch content for improved fermentation pasta product qualities.

Unraveling chemical changes associated with the sensory quality of Chinese steamed bread as altered by wheat flour type

Chinese steamed bread (CSB) is an important staple of the Chinese people, and its flavor profile is mostly affected by wheat varieties among others. This study selected wheat flour made from three different wheat varieties and investigated their contribution to the CSB flavor profile in terms of metabolism. Thirteen aroma-active compounds identified by GC-O were determined as the main contributors to the different aroma profiles of three CSBs. 350 sensory trait-related metabolites were obtained from five key modules via weighted gene co-expression network analysis. It was found that the sensory characteristics of CSBs made of different wheat flour were significantly different. The higher abundance of lipids in Yongliang No.4 (YL04) wheat flour was converted to large number of fatty acids in fermented dough, which led to the bitterness of CSB. Besides, the abundance in organic acids and fatty acids contributed to the sour, milky, wetness and roughness attributes of YL04-CSB. More fatty amides and flavonoids in Jiangsu Red Durum wheat flour contributed to the fermented and winey attributes of CSB. Carbohydrates with higher abundance in Canadian wheat flour was involved in sugar-amine reaction and glucose conversion, which enhanced the sweetness of CSB. In addition, fatty acids, organic acids, amino acids, and glucose were crucial metabolites which can further formed into various characteristic compounds such as hexanal, hexanol, 2,3-butanediol, acetoin, and 2,3-butanedione and thus contributed to the winey, fresh sweet, and green aroma properties. This study is conductive to better understand the evolution of the compounds that affect the quality and aroma of CSBs.

Evaluation of the addition of cassava flour fermented with lactic acid bacteria on the sensorial and nutritional properties of a baked product

Due to the existing uncertainties regarding the fermentation of non-traditional flours with lactic acid bacteria for the partial replacement of wheat flour in baked products, this research focused on evaluating the substitution of 10 %, 15 % and 20 % of wheat flour in white bread with cassava fermented dough. Cassava flour was fermented with L. plantarum at a concentration of 1 × 106 CFU/g for 32 h at 32 °C. This dough was added in different percentages of partial substitution to a baked product to analyze its impact on the sensory and nutritional properties. The results reveal a more balanced proximate composition in those supplemented products, obtaining a higher amount of protein, fiber and ash, as well as better physical properties such as hardness. Sensory evaluation shows no significant difference, indicating that the sensory properties were not affected in a statistically significant manner after the replacement. Therefore, fermenting cassava flour is advantageous for wheat flour substitution in baked products.

Characteristics of whole wheat steamed bread production by two-stage fermentation procedure with Jiaozi as starter

Given the beneficial role of biological acidification in improving the quality of cereal-based products, this study evaluated the applicability of Jiaozi as a starter for whole wheat dough fermentation and steamed bread quality improvement. During the first 12 h of dough fermentation, yeast and lactic acid bacteria (LAB) populations increased significantly, resulting in rapid carbohydrate consumption and acidification of the dough. The lactic/acetic acid molar ratio was approximately 3.3, which was within the recommended fermentation quotient (FQ). Compared with the unfermented dough and the dough fermented for 12 h, the dough fermented for 6 h had an improved protein network structure, and the steamed bread made from it also showed the best quality. At a low leavening temperature of 28 °C, satisfactory specific volume and height/diameter ratio were obtained. The dough with an inoculation amount of 50% of the fully fermented dough showed the highest CO2 production capacity. Compared with yeast, the whole wheat steamed bread produced by Jiaozi using the two-stage fermentation process showed higher specific volume, resistant starch (RS) content and protein digestibility. The results showed that the use of Jiaozi as a starter has great potential for application in improving the quality of whole wheat steamed bread.

Effect of fermentation on nutrient composition, antinutrients, and mineral bioaccessibility of finger millet based Injera: A traditional Ethiopian food

Finger millet, like other cereals, contains high amounts of antinutrients that bind minerals, making them unavailable for absorption. This study explores the effect of traditional fermentation on nutritional, antinutritional, and subsequent mineral bioaccessibility (specifically iron, zinc, and calcium) of finger millet based Injera. Samples of fermented dough and Injera prepared from light brown and white finger millet varieties were analyzed for nutritional composition, antinutritional content, and mineral bioaccessibility following standard procedures. With some exceptions, the proximate composition of fermented dough was significantly affected by fermentation time. Compared to unfermented flour, the phytate and condensed tannin content significantly (p < 0.05) decreased for fermented dough and Injera samples. A strong decline in phytate and condensed tannin content was observed in white finger millet Injera as fermentation time increased, compared to light brown finger millet based Injera. The mineral bioaccessibility of Injera prepared from finger millet and maize composite flour increased with fermentation time, leading to a significant increase in bioaccessible iron, zinc, and calcium, ranging from 15.4–40.0 %, 26.8–50.8 %, and 60.9–88.5 %, respectively. The results suggest that traditional fermentation can be an effective method to reduce phytate and condensed tannin content, simultaneously increasing the bioaccessibility of minerals in the preparation of finger millet based Injera.

Assessment of the technological, physicochemical and microbiological characteristics of the fermented dough used to produce &lt;i&gt;O’moabu&lt;/i&gt; in the Eastern region of Burkina Faso

O'moabu is a traditional dough made from fermented cereal dough by the Gourmachema tribe in the East Region of Burkina Faso. The technological, physicochemical and microbiological characteristics of this food, have been poorly documented. This study aimed to evaluate the characteristics of the fermented dough used in the production of O'moabu. Data on production technology were collected through a survey. Physicochemical, microbiological and biochemical analyses were conducted using standard methods. The assessment enabled the generation of a typical production diagram for O'moabu. Concerning physicochemical characteristics, pH ranged from 5.57 ± 0.02 to 6.08 ± 0.02, while titratable acidity varied between 0.41 ± 0.01 and 1.04 ± 0.01 g lactic acid/100 g. Regarding microbiological characteristics, total aerobic mesophilic flora ranged from 1.1x105 ± 27 to 4.6x107 ± 10 CFU/g, yeasts from 5x102 ± 37 to 9.5x104 ± 33 CFU/ g and lactic acid bacteria from 1x104 ± 25 to 6.7x105 ± 27 CFU/g. Morphological and biochemical tests showed that the yeast isolates belonged to the genera Saccharomyces sp. (50%), Candida sp. (18.75%), Torulaspora sp. (25%) and Kluyeverommyces sp. (6.25%). The lactic acid bacteria belonged to the genera Lactobacillus sp. (37.5%), Streptococcus sp. (12.5%), Leuconostoc sp. (25%) and others genera (25%). These yeasts and lactic acid bacteria work in symbiosis to ferment O'moabu dough.

New insights into crumb formation in model systems: Effects of yeast metabolites and hydration level by means of multiwave rheology

The solidification of wheat dough is induced by a complex sequence of polymer transition processes. The extend of the polymer transitions is thereby strongly dependent on the hydration level of each constituent. Further, yeast metabolites, resulting from the fermentation of dough, are hypothesized to impact the functionality of dough's polymers in their thermal transitional behavior. Hence, the aim of this work was to elucidate the occurrence of polymer transitions in dependency of (i) the amount of water available for hydration and (ii) the presence of yeast metabolites. An approach of reduced complexity was chosen to reveal the interactions during the hydrothermal treatment by multiwave SAOS rheology together with basic physicochemical characterization methods (DSC, 1H NMR). By excluding single dough polymers from the solidification cascade, their functionality in the polymeric system was elucidated. In combination with a non-invasive yeast inactivation method, sophisticated information on the dependence of the matrix solidification on the matrix hydration level and presence of yeast metabolites were established. Water shortage was shown to limit the extend of starch gelatinization, resulting in a reduced overall matrix solidification, whereas the extend of gluten polymerization was not affected by water shortage. In contrast, a water surplus favored the progression of starch gelatinization, which was also shown to be induced indirectly by yeast metabolites. Therefore, the water availability and accessibility of starch were shown to be decisive for the solidification of the dough matrix. The knowledge obtained contributes to the elucidation of the impact of baker's yeast on the dough matrix.