Modification of dough characteristics and baking quality based on whole wheat flour by enzymes and emulsifiers supplementation

Study on the Effect of Sorghum Flour Particle Size on the Storage Quality of Leavened Pancakes

Pancakes prepared with sorghum flour possess a high nutritional value, yet their quality is unstable and prone to degradation during storage. This instability can be attributed to the particle size of coarse cereal powder, which significantly influences the quality of flour products during storage. In this study, changes in the quality of these pancakes, prepared with varying particle sizes of sorghum flour, were meticulously analyzed during cold storage using advanced instruments such as a texture analyzer, nuclear magnetic resonance spectrometer, differential scanning calorimeter, X-ray diffractometer, and Fourier transform infrared spectrometer. Findings revealed that the hardness of leavened pancakes significantly increased over time. After a refrigeration period of 7 days, the hardness of wheat flour leavened pancakes increased by 56.60%. However, with a decrease in the particle size of sorghum flour, the increase in hardness diminished, thereby delaying the aging process of the pancakes. As the storage duration was extended, moisture migration within the pancakes occurred, and the sorghum flour pancakes with a smaller particle size exhibited a reduced moisture change rate, indicating an enhanced water holding capacity. In comparison to their wheat flour counterparts, sorghum flour leavened pancakes exhibited a substantial reduction in retrogradation enthalpy and crystallinity. The inclusion of sorghum flour effectively inhibited amylopectin recrystallization, thus slowing down the aging process of the pancakes. This inhibitory effect was more evident with decreasing sorghum flour particle sizes. Fourier transform infrared data indicated no significant alterations in absorption peaks across various wavelengths during cold storage. Although starch short-range orderliness increased with storage time, the use of sorghum flour with smaller particles reduced the degree of short-range orderliness in starch molecules throughout the cold storage period. Sorghum flour with a smaller particle size can inhibit water migration and amylopectin recrystallization, which subsequently delays pancake aging and enhances its quality stability during storage.

Improving the inhibitory resistance of xylanase FgXyn11C from Fusarium graminearum to SyXIP-I by site-directed mutagenesis

The aim of this study was to improve the inhibitory resistance of xylanase FgXyn11C from Fusarium graminearum to XIP in cereal flour. Site saturation mutagenesis was performed using computer-aided redesign. Firstly, based on multiple primary structure alignments, the amino acid residues in the active site architecture were identified, and specific residue T144 in the thumb region of FgXyn11C was selected for site-saturation mutagenesis. After screening, FgXyn11CT144F was selected as the best mutant, as it displayed the highest enzymatic activity and resistance simultaneously compared to other mutants. The specific activity of FgXyn11CT144F was 208.8 U/mg and it exhibited complete resistance to SyXIP-I. Compared with the wild-type, FgXyn11CT144F displayed similar activity and the most resistant against SyXIP-I. The optimal temperature and pH of the wild-type and purified FgXyn11CT144F were similar at pH 5.0 and 30 °C. Our findings provided preliminary insight into how the specific residue at position 144 in the thumb region of FgXyn11C influenced the enzymatic properties and interacted with SyXIP-I. The inhibition sensitivity of FgXyn11C was reduced through directed evolution, leading to creation of the mutant enzyme FgXyn11CT144F. The FgXyn11CT144F resistance to SyXIP-I has potential application and can also provide references for engineering other resistant xylanases of the GHF11.

Characterization of wheat dough and Chinese steamed bread using mealworm powder formulated with medium-gluten and whole wheat flour

BACKGROUND

Mealworm (Tenebrio molitor) larvae are nutritious edible insects and exhibit the potential to act as protein substitutes in food products. In this study, we added mealworm powder as a substitute to medium-gluten wheat and whole wheat flours to enhance the quality of baked products. We compared the pasting, farinograph and extensograph properties of medium-gluten wheat and whole wheat flours replaced with different concentrations of mealworm powder to explore the interactions between flour and mealworm powder.

RESULTS

Mealworm powder changed the pasting characteristics of medium-gluten wheat and whole wheat flours. After adding 20% mealworm powder, the pasting temperature of the medium-gluten wheat flour remained unchanged (approximately 89.9 °C), while the pasting temperature of whole wheat flour increased from 88.83 to 90.27 °C. Water absorption of medium-gluten and whole wheat flours exhibited a decreasing trend with increasing mealworm powder concentrations. Mealworm powder substitution resulted in stronger medium-gluten dough but exerted an opposite effect on the farinograph properties of whole wheat dough. Mealworm powder substitution decreased the stretching resistance of medium-gluten dough but increased that of whole wheat dough. With an increase in the concentration of mealworm powder, the specific volume of medium-gluten wheat steamed bread significantly increased from 1.69 mL g-1 (M0) to 3.31 mL g-1 (M10) whereas that of whole wheat steamed bread increased from 1.64 mL g-1 (M0) to 2.34 mL g-1 (M15). The addition of mealworm powder increased the protein, dietary fiber, lipid and sodium contents of steamed bread samples.

CONCLUSIONS

This study provides a reference for the rheological properties of medium-gluten wheat and whole wheat flours substituted with mealworm powder and supports the addition of insects as a protein source in food products. © 2023 Society of Chemical Industry.

Structure, nutritional composition, and functionality of xylanase/microwave radiation-pretreated tiger nut

In this study, tiger nut was pretreated with xylanase (Xyl), microwave radiation (MW), and a combination of both (MW + Xyl). The structure, nutritional composition, technofunctional, and antioxidant properties of the pretreated and untreated (control) tiger nut flour (TNF) were investigated. The Fourier transform infrared spectroscopic and X-ray diffractrometric spectra of the control and the pretreated samples are similar; however, there was a slight change in some peaks in the pretreated samples, indicating structural re-organization of macromolecules. Scanning electron microscopic images show reductions of surface erosion and formation of clusters in the MW + Xyl-treated TNF compared to the other pretreated samples. Pretreatment increased the protein, Ca, total phenolic content, and swelling capacity of TNF by 3.71-7.31%, 29.41-32.35%, 4.39-9.65%, and 1.59-6.75%, respectively. Meanwhile, 45.52-58.78% and 11.54-15.38% reductions in fat content and water absorption capacity, respectively, were recorded. Pretreatment of TNF with Xyl and MW + Xyl increased its soluble dietary fiber by 26.84% and 64.34%, respectively; however, a 3.31% reduction was recorded following MW treatment. The highest 2, 2-diphenyl-1-picrylhydrazyl scavenging activity (53.20%) was recorded in the MW + Xyl-treated TNF. These findings proved that pretreating TNF with microwave radiation and Xyl could improve its technological and nutritional qualities, enhancing its applicability in food systems.

Potential application of bioemulsifier RAG-1 as an anti-staling agent in flat bread quality

Bread undergoes physicochemical processes known as 'staling', which limits shelf life and quality. Despite the fact that several chemical emulsifiers have been employed to combat this issue, they may offer risks to human health. In this investigation, the effects of bioemulsan, a natural bioemulsifier (BE), on bread quality and staleness were examined. The yield of emulsan generated by Acinetobacter calcoaceticus RAG-1 was 1.49 g/L. The presence of clear zones around colonies, high emulsification value of 100%, and remaining surface tension below 40 mN/m after heating (at 250 °C for 15-20 min) verified emulsan thermal stability. BE-supplemented bread had a greater moisture percentage than the control, resulting in reduced crumb hardening and improved bread quality during storage as measured by moisture content. The first day after adding 0.5% emulsan, the hardness rose from 90.45 N (for the control) to 150.45 N. Texture analysis showed that although the hardness increased during storage, adding emulsan allowed obtaining bread with clearly softer crumb after 2 and 3 days of baking, especially at 0.5% level (from 215.6 N for the control to 150.5 N for 0.5% BE-enriched bread after 2 days, and from 425.7 to 210.25 N after 3 days). Based on the sensory evaluation results, emulsan did not lead to any unpleasant changes on bread organoleptic parameters. Therefore, using bioemulsifier RAG-1 as a green emulsifier and anti-staling agent found to be more promising.

Effects of coarse cereals on dough and Chinese steamed bread - a review

Chinese steamed breads (CSBs) are long-established staple foods in China. To enhance the nutritional value, coarse cereals such as oats, buckwheat, and quinoa have been added to the formulation for making CSBs. This review presents the nutritional value of various coarse cereals and analyses the interactions between the functional components of coarse cereals in the dough. The addition of coarse cereals leads to changes in the rheological, fermentation, and pasting aging properties of the dough, which further deteriorates the appearance and texture of CSBs. This review can provide some suggestions and guidelines for the production of staple and nutritious staple foods.

Dough Rheological Behavior and Bread Quality as Affected by Addition of Soybean Flour in a Germinated Form

This study analyzes the possibility of using soybeans as an addition to the main ingredients used to make bread, with the aim of improving its quality characteristics. To maximize the nutritional profile of soybeans they were subjected to the germination and lyophilization process before being used in bread making. The addition levels of 5%, 10%, 15%, and 20% germinated soybean flour (GSF) on dough rheology and bread quality were used. From the rheology point of view, the GSF addition had the effect of decreasing the values of the creep and recovery parameters: J_Co, J_Cm, μ_Co, J_max, J_Ro, J_Rm, and J_r. At the same time, the rheological parameters λ_C and λ_R increased. The GSF addition did not affect dough homogeneity as may be seen from EFLM analysis. Regarding the quality of the bread, it may be concluded that a maximum of 15% GSF addition in wheat flour had a desirable effect on loaf volume, porosity, elasticity, and sensory properties of the bread. The bread samples with GSF additions showed a higher brightness and a less pronounced red and yellow tint. When the percentage of GSF in wheat flour increased, the value of the firmness parameter increased and the value of the gumminess, cohesiveness, and resilience parameters decreased. The addition of GSF had a desirable influence on the crumb structure of the bread samples. Thus, taking into account the results of the determinations outlined above, it can be stated that GSF addition in wheat flour leads to bread samples with good quality characteristics.

Purification and characterization of a fungal laccase expressed in Kluyveromyces lactis suitable for baking

Laccase enzyme can replace chemical additives to improve texture properties and the volume of bread. Laccase encoding gene from Phlebia brevispora, a native fungus from Misiones, Argentina, was expressed in the generally recognized as safe yeast Kluyveromyces lactis. To improve laccase activity, medium conditions were optimized. The use of iron sulfate at a concentration of 1 mM led to optimum laccase activity (1289 U·L^-1 ) on the fourth day of incubation. SDS-PAGE analysis revealed that the molecular mass of purified laccase was about 180 kDa. Optimum pH for the enzyme was 4 and optimum temperature was 40°C. Laccase exhibited high stability at low pH and high temperature. The application of recombinant laccase to bread decreased hardness, gumminess, and chewiness and increased bread volume. Based on these results, recombinant laccase from P. brevispora with improved yield is a good option for application as an improver of the physicochemical quality of bread at the industrial level. Besides, it will allow us to advance toward our goal of developing healthy alternatives for the bakery industry. No previous work has been reported concerning the heterologous expression of the laccase gene native to the province of Misiones, Argentina, with an aim for application in baking. PRACTICAL APPLICATION: Healthy bakeries became a trend in recent years. The use of the laccase enzyme increases the specific volume and decreases the hardness of bread, being thus an alternative for the replacement of chemical additives in the bakery industry.

Research of the influence of xanthan gum on rheological properties of dough and quality of bread made from sprouted wheat grain

The effect of microbial polysaccharide xanthan in the amount of 0.1-0.4% on the rheological characteristics of the dough from sprouted wheat grain and quality indicators of bread was studied. It was found that when xanthan gum is added, the dough's spreading and adhesion strength decreases, and the dough's resilience-elastic and plastic-viscous characteristics improve. Bread made from sprouted wheat grains with the addition of experimental dosages of xanthan has better structural-mechanical and physicochemical properties, as evidenced by higher indicators of crumb compressibility, specific volume, and moisture compared to the control sample. To obtain bread with the best quality indicators, it is recommended to use 0.3% xanthan.

Incorporation of white tea extract in nano-liposomes: optimization, characterization, and stability

BACKGROUND

In the present study, an extraction method affected by sonication intensity (40%, 70% and 100%), sonication time (5, 10 and 15 min) and different solvents (ethanol, methanol and a combination of ethanol/methanol) was optimized to extract the white tea with the greatest polyphenolic compounds using a response surface methodology. To prepare the nano-liposomal vesicles, phospholipids and cholesterol in various proportions (60:0, 40:20, 30:30 and 20:40) were applied based on thin-film hydration and ultrasound method. The nano-capsules enriched in bioactive compounds were examined through particle characteristics, encapsulation efficiency, morphological analysis, thermal properties and Fourier transform infrared spectroscopy.

RESULTS

The observations showed that the extraction yield highly depended on the type of solvent with varying permeability, sonication time and power. The highest total phenolic content (68.38 mg GA g^-1 ) and free radical scavenging activity (77.65%) were observed for the following optimal conditions: 70% for sonication intensity, 15 min for sonication time and methanol as solvent. Characteristics of nanoliposomes within a compositional ratio of lecithin/cholesterol (40:20) and with a zeta potential of -56 ± 0.01 mV, as well as white tea extract (WTE) samples with an average particle diameter of 82.20 ± 0.08, microencapsulation efficiency of 76.5% ± 0.081, polydispersity index of 0.06 ± 0.02 and span value of 0.69 ± 0.03. are used as the optimal formulation for microencapsulation of antioxidant WTE. The results demonstrated an increment in thermal stability of liposomal WTE samples compared to other samples.

CONCLUSION

The findings of the present study indicated that nano-liposomes comprise an effective technology for coating the WTE, as well as to increasing its stability and thermal properties. © 2021 Society of Chemical Industry.

The dough-strengthening and spore-sterilizing effects of mannosylerythritol lipid-A in frozen dough and its application in bread making

Biosurfactants have been put into applications in breadmaking industry, while the effects of mannosylerythritol lipid-A (MEL-A) on gluten network of frozen dough, bread quality and microbial spoilage were firstly investigated in this study. Rheology and differential scanning calorimetry (DSC) analysis showed that MEL-A significantly improved the rheological properties of frozen dough and reduced the content of frozen water. Further experiments showed that MEL-A promoted the formation of aggregates by interacting with gluten protein, and strengthened the gluten network through molecular weight distribution measurement and microstructure observation, effectively avoiding the destruction of ice crystals. A series of bread assessments illustrated MEL-A improved the loaf volume, gas retention ability and textural property. In addition, MEL-A (1.5%) killed 99.97% of the vegetative cells of Bacillus cereus and 75.54% of the spores, and at the same time had a slight inactivation effect on yeast. These results indicate that MEL-A has broad application prospects in the baking industry and the storage stage of flour products.

Biochemical characterization of a GH10 xylanase from the anaerobic rumen fungus Anaeromyces robustus and application in bread making

Anaeromyces robustus is an anaerobic rumen microorganism which can produce plant cell wall degrading enzymes. In this study, a new GH10 xylanase gene xylAr10 from A. robustus was identified, cloned and expressed in Pichia pastoris GS115. The recombinant protein ArXyn10 was characterized after being purified by Ni-NTA. The optimal pH and temperature of ArXyn10 was determined at 5.5 and 40 °C, respectively. ArXyn10 was stable at the pH range of 4.0-8.0, and could maintain high stability from 35 to 45 °C. The hydrolysis products released from beechwood xylan by ArXyn10 showed chromatographic mobility similar to xylobiose and xylotriose according to thin-layer chromatography analysis. It was shown that the addition of 7.5 mg of ArXyn10 in 100 g high-gluten wheat flour during bread making could increase the reducing sugar content by 10.80%, indicating that xylo-oligosaccharides were produced. With the addition of ArXyn10, the hardness and chewiness of the bread decreased and the quality was improved. The new discovered xylanase ArXyn10 have potential application prospect in bread making.