Effect of potassium carbonate on rheological properties of dough and its mechanism

Effects of acidification by traditional Jiaozi starter and neutralization with alkali (Na2CO3) on whole wheat dough properties

BACKGROUND

Whole wheat steamed bread has been recommended for its potential nutritional benefits to human health. Given the positive role of both organic acid and alkali in improving dough development and product quality, the present study investigated the effects of neutralization by addition of alkali (Na2CO3) after dough acidification with traditional Jiaozi starter on the properties of whole wheat dough.

RESULTS

The population of yeast and lactic acid bacteria and the acidification level of the dough increased significantly after fermentation with Jiaozi. Incorporation of alkali greatly improved the leavening capacity of the remixed dough and the quality of steamed bread. Jiaozi fermentation and alkali addition changed the water distribution patterns (T2) and affected the secondary structures of gluten protein, starch crystallinity and pasting properties. The storage modulus (G') of the dough increased significantly with the alkali addition, which could be attributed to the promoted cross-linking of the gluten structure and the altered hydration state of the macromolecules.

CONCLUSION

The results of the present study indicate that a combination of Jiaozi fermentation and alkali addition could improve the technological properties of whole wheat dough and the quality of steamed bread. The results will help us to further explore the potential application of moderate acidification and alkali addition in the production of leavened whole wheat products. © 2024 Society of Chemical Industry.

Effects of improver on the quality of frozen Chinese sweet rice wine dough: Water status, protein structure and flavor properties

In the study, a sweet wine koji (YQ-5) was successfully selected to make frozen Chinese sweet rice wine dough (F-CD) for flavor enrichment. Subsequently, the effects of single improver (SI: xanthan gum, potassium carbonate, antifreeze protein, diacetyl tartaric esters of monoglycerides and composite improver (XPADG: Four improvers mixed in proportion) on the texture, rheological properties, microstructure, water status, protein secondary structure, volatile flavor substances and sensory properties of F-CD during frozen storage were investigated. The results indicated that XPADG slowed the increase in freezable water and water mobility in the dough, giving dough the most stable rheological properties and minimizing the damage of freezing to the secondary structure and microstructure of proteins. Besides, GC-QTOF/MS analysis showed that XPADG may facilitate the retention of flavoring substances in F-CD after storage for 6 days. Finally, the sensory evaluation showed that XPADG imparted good sensory properties to the product after freezing for 6 days.

Improvement in Noodle Quality and Changes in Microstructure and Disulfide Bond Content through the Addition of Pepper Straw Ash Leachate

Every year, a significant amount of pepper stalks are wasted due to low utilization. The ash produced from pepper stalks contains a significant amount of alkaline salts, which are food additives that can enhance the quality of noodles. Therefore, utilizing natural pepper straw ash to improve the quality of noodles shows promising development prospects. In this study, pepper straw ash leachate (PSAL) was extracted and added to noodles. The quality of the noodles gradually improved with the addition of PSAL, with the best effect observed at a concentration of 18% (PSAL mass/flour mass). This addition resulted in a 57.8% increase in noodle hardness, a 55.43% increase in chewiness, a 19.41% rise in water absorption rate, and a 13.28% increase in disulfide bond content. These alterations rendered the noodles more resilient during cooking, reducing their tendency to soften and thus enhancing chewiness and palatability. Incorporating PSAL also reduced cooking loss by 57.79%. Free sulfhydryl groups decreased by 5.1%, and scanning electron microscopy revealed a denser gluten network structure in the noodles, with more complete starch wrapping. This study significantly enhanced noodle quality and provided a new pathway for the application of pepper straw resources in the food industry.

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.

Effects of Xanthan gum and Potassium carbonate on the quality and flavor properties of frozen Jiuniang doughs

Chinese Jiuniang (CJ) is a flavorful and nutritious food, but underutilized in frozen dough (FD) production. In addition, frozen storage can harm FD's gluten structure and degrade quality and flavor. Therefore, the impacts of two excellent protective agents (XG-Xanthan Gum; PC-Potassium Carbonate) on frozen Jiuniang dough (F-JD) quality and flavor during dynamic freezing were investigated. The results suggested that adding XG conferred F-JD with good processing stability, maintained the bound water levels, stabilized rheological properties, diminished ice crystal damage to the protein structure, and inhibited the increase in frozen water content during the freezing process. In contrast, although PC reduced free water production during freezing, it increased dough hardness and offered less protein protection than XG. Additionally, GC-QTOF/MS analysis showed that adding XG during freezing increased the relative content of pleasant flavor compounds like Phenylethyl Alcohol and decreased undesirable ones like Hexanal. Moreover, PC lowered the relative content of undesirable flavor substances (Formic acid) but reduced the relative content of beneficial flavor compounds (1-Hexanol). Importantly, the study confirmed that XG maintained the new F-JD product's storage quality during dynamic freezing. In conclusion, this study broadens CJ's application possibilities and provides new insights into mechanisms for preserving F-JD's quality and flavor.

Milling of buckwheat hull to cell-scale: Influences on the behaviors of protein and starch in dough and noodles

Superfine grinding of insoluble dietary fiber (IDF) is a promising method to improve the product quality by regulating the interaction between protein and starch. In this study, the effects of buckwheat-hull IDF powder, at cell-scale (50-10 μm) and tissue-scale (500-100 μm), on the dough rheology and noodle quality were investigated. Results showed that cell-scale IDF with higher exposure of active groups increased the viscoelasticity and deformation resistance of the dough, due to the aggregation of protein-protein and protein-IDF. Compared with the control sample, the addition of tissue-scale or cell-scale IDF significantly increased the starch gelatinization rate (β, C3-C2) and decreased the starch hot-gel stability. Cell-scale IDF increased the rigid structure (β-sheet) of protein, thus improving the noodle texture. The decreased cooking quality of cell-scale IDF-fortified noodles was related to the poor stability of rigid gluten matrix and the weakened interaction between water and macromolecules (starch and protein) during cooking.

Lutein fortification of wheat bread with marigold powder: impact on rheology, water dynamics, and structure

BACKGROUND

Demands for foods conducive to eye health have been on the increase in the global healthcare sector. Marigold powder as a major source of lutein was utilized to produce lutein-fortified breads for ocular health. The physicochemical characteristics of the doughs and breads were investigated in terms of rheology, water mobility, and protein secondary structures.

RESULTS

The incorporation of marigold powder decreased the water absorption of doughs without significantly altering thermomechanical properties. With a range of fortification levels (1-3%), marigold powder led to decreased storage and loss modulus of doughs by weakening their gluten network, which was supported by their T₂ relaxation times. The resistance of the doughs weakened with increasing levels of marigold powder, while their extensibilities significantly incremented. Fourier transform infrared spectral deconvolution revealed the changes in wheat protein structures upon marigold powder incorporation, in which the proportion of β-turn increased at the expense of β-sheet ratio. The breads with marigold powder displayed increased specific volume from 4.034 to 4.368 mL g^-1 , accompanied by softer textures. The baking process led to heat-induced losses in lutein concentration of less than 10% within the crumb and approximately 30% in the crust.

CONCLUSION

The use of marigold powder induced changes in protein secondary structure and extensional features of doughs, contributing to increased loaf volume and softer texture. Overall, this study provides fundamental information on the rheological and structural effects of marigold powder in a wheat bread system, consequently encouraging the food industry to utilize marigold power as a functional food ingredient. © 2023 Society of Chemical Industry.

Effect of Mealworm Powder Substitution on the Properties of High-Gluten Wheat Dough and Bread Based on Different Baking Methods

Mealworms (Tenebrio molitor) are protein-rich edible insects that have been regarded as novel food ingredients. In this study, high-gluten wheat flour was formulated with dried mealworm powder at various levels (0%, 5%, 10%, 15%, and 20%) to study its influence on the pasting, farinograph, and extensograph properties and microstructure of the dough. A subsequent decrease in the pasting parameters was observed due to starch dilution. The water absorption, dough development time, and dough stability time decreased gradually from 71.9% to 68.67%, 13.6 min to 10.43 min, and 14.1 min to 5.33 min, respectively, with the increase in the substitution of mealworm powder from 0% to 20%. The farinograph characteristics corresponded to a weak gluten network formed through the dilution of gluten by the replacement of wheat flour with a non-gluten ingredient. The stretch ratio of the high-gluten dough increased gradually from 4.37 (M0) to 6.33 (M15). The increased stretching resistance and extensibility of the dough with 5% and 10% mealworm powder indicated that mealworm powder can act as a plasticizer in the gluten network, which might contribute to the decreased strength and increased elasticity and flexibility of the dough network. The bread made with three different baking methods showed similar increases in specific volume and decreased hardness up to the 10% substitution level, owing to the increased elasticity and flexibility of the dough. The GB/T 35869-2018 Rapid-baking method, GB/T 14611-2008 Straight dough method, and automatic bread maker method exhibited the highest specific volumes of 3.70 mL/g, 3.79 mL/g, and 4.14 mL/g when the wheat flour was substituted with 10% mealworm powder. However, 15% and 20% mealworm powder substitution markedly reduced the bread quality owing to the dilution effect and mealworm powder phase separation. These results provide a perspective on the relationship between the rheological properties of mealworm powder-substituted high-gluten dough and application suggestions for insect food development in the food industry.

Effect of Partial Substitution of Flour with Mealworm (Tenebrio molitor L.) Powder on Dough and Biscuit Properties

Mealworm (Tenebrio molitor L.) is a type of edible insect rich in protein that has become popular as a protein-alternative ingredient in flour-based products to improve the nutritional properties of baking products. The mealworm powder substitution affected the pasting, farinograph, extensograph properties of wheat flour and the texture, nutritional, and sensory properties of the resulting soda biscuit. The pasting parameters (peak viscosity, trough viscosity, breakdown viscosity, final viscosity, and setback viscosity) and the water absorption decreased with the increased mealworm powder substitution level, which was ascribed to the dilution effect of mealworm powder. The farinograph parameters remained similar up to 15% substitution level. The extensograph results showed that mealworm powder substitution decreased the elastic properties of wheat dough as indicated by the consistently decreased extensibility, stretching energy, and stretching resistance, resulting in a significantly decreased baking expansion ratio of the soda biscuit. The protein, lipid, and dietary fiber content of the biscuits increased accordingly with the increased mealworm powder substitution level. The protein content of the soda biscuit was gradually increased from 9.13/100 g for the control (M0) to 16.0/100 g for that supplemented with 20% mealworm powder (M20), accompanied with the significantly increased essential amino acid content. Meanwhile, the fat and dietary fiber content of M20 exhibited 20.5 and 21.7% increase compared to those of M0. The score of the sensory attributes showed no significant difference up to 15% substitution level. The results demonstrated the 15% mealworm powder substitution level would not significantly affect the farinograph property, microstructure of wheat dough, and sensory acceptability.

Effects of soybean oil on rheological characteristics of dough under high hydrostatic pressure

In order to improve the stability of dough with soybean oil, this paper explored the effect of soybean oil addition on the rheological characteristics of dough under high hydrostatic pressure. The results showed that, compared with the dough without soybean oil, the β-sheet, disulfide bonds content and gauche-ganche-ganche in the dough increased by 4.23%, 0.85 μmol/g and 4.16% respectively when the dough was added with 6% soybean oil, which improved the degree of cross-linking polymerization of gluten protein and the stability of gluten network. Meanwhile, the dough had the highest elastic modulus and the lowest maximum creep compliance (6.85 Pa^-1 ×10^-4 ), indicating that 6% soybean oil significantly increased the elasticity and hardness of the dough. The results of short-range ordered structure and paste properties showed that with the addition of soybean oil, the ordered structure and paste viscosity decreased with the increase of soybean oil.