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

The study examined the effects of oat ß-glucan (OßG), chitosan (CTS), araboxylan (AX), and fructosan (FOS) on wheat dough formation. Adding 0-7 % OßG, AX, and FOS increased SS content, enhancing gluten stability. D-AX and D-FOS showed higher ß-sheet structures, higher air retention and gluten network, smaller pores and denser structures, higher elastic and viscosity moduli. Excessive OßG and CTS could reduce the dough stability, and ß-turn and ß-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.

Insight into konjac glucomannan-retarding deterioration of steamed bread during frozen storage: Quality characteristics, water status, multi-scale structure, and flavor compounds.

Konjac glucomannan (KGM), a water-soluble hydrocolloid, holds considerable potential in the food industry, especially for improving the quality and nutritional properties of frozen products. This study explored the alleviative effect of KGM on the quality characteristics, water status, multi-scale structure, and flavor compounds of steamed bread throughout frozen storage. KGM significantly improved the quality of steamed bread by slowing down the decrease in water content and the increase in water migration while maintaining softness and taste during frozen storage. Notably, KGM also delayed amylopectin retrogradation and starch recrystallization, thus preserving the texture and structure of the steamed bread. At week 3, the microstructure of the steamed bread with 1.0 % KGM remained intact, with the lowest free sulfhydryl content. Additionally, heat map analysis revealed that KGM contributed to flavor retention in steamed bread frozen for 3 weeks. These results indicate that KGM holds promise as an effective cryoprotectant for improving the quality of frozen steamed bread.

Effects of heterotrophic Euglena gracilis powder on dough microstructure, rheological properties, texture, and nutritional composition of steamed bread.

This study investigated the effects of incorporating different levels of Euglena gracilis microalgae powder (MP) on the dough properties, rheology, and quality attributes of Chinese steamed bread (CSB) for the first time. Moderate levels of MP (2%) reinforced the gluten network and improved protein structure, while higher levels (4-8%) adversely affected the gluten network and rheological properties. The addition of MP decreased the specific volume, pore number, and pore density of CSB, but increased pore size, hardness, and chewiness. It also imparted a yellow color to the CSB and slowed down moisture loss during storage. Notably, MP effectively increased the protein and lipid content of CSB, enhancing its nutritional value. The results suggest that optimizing the MP level is crucial to achieve nutritional enhancement while maintaining desirable texture and sensory attributes. An addition of 2% MP can strike a balance between nutrition and the overall quality of the final product.

Incorporating whole soybean pulp into wheat flour for nutrient-enriched steamed bread: Exploring the impact on physical and nutritional characteristics.

This research explored the impact of incorporating various levels of whole soybean pulp (WSP) (10%, 20%, 30%, 40%, and 50%) into wheat flour on the physical and nutritional qualities of steamed bread. In comparison with the traditional steamed bread, the substitution of up to 20% WSP did not significantly alter the specific volume, hardness, and chewiness of the steamed bread. Additionally, the crumb texture of the steamed bread with 20% WSP maintained small and uniform pores, with optimal springiness and cohesiveness. Nutritionally, the substitution of 10%-50% WSP enhanced total dietary fiber, total phenolics, and protein by 9.40%-89.79%, 14.96%-116.31%, and 3.45%-34.36%, respectively. Isoflavones in the steamed bread increased markedly from 22.92 µg/g to a range of 140.12-997.12 µg/g. The expected glycemic index showed a decrease from 90.24 to between 85.85 and 70.75, whereas amino acid scores improved from 59.22 to a range of 64.58-65.08, with lysine (Lys) scores notably increasing from 59.22 to between 64.96 and 88.80. In conclusion, partially replacing wheat flour with WSP is an effective method for enhancing the nutritional profile and addressing the essential amino acid imbalance in steamed bread. PRACTICAL APPLICATION: This study partially replaced flour with WSP to improve the steamed bread's nutritional quality. The optimal substitution level was determined to be 20% WSP, which improves the bread's nutritional value without significantly impacting its physical qualities. Furthermore, WSP is produced from soaked soybeans through hot water milling. This process simplifies soybean processing, lowers energy consumption and costs, and reduces pollution. It also effectively retains essential nutrients, such as protein, dietary fiber, polyphenols, and soy isoflavones, ensuring the full utilization of soybeans.

Effects of cereal flour types and sourdough on dough physicochemical properties and steamed bread quality.

Coarse cereals have been promoted for their health benefits, and sourdough is used to improve their steamed bread sensory acceptance. However, grains vary in dough physiochemical properties and steamed bread-making performance. This study investigated the effects of yeast and sourdough fermentation on the biochemical, textural, and flavor properties of dough and steamed bread of eight grain types. Results indicated that sourdough dough had a lower pH and higher total titrable acidity compared with yeast group. The texture of sourdough-steamed bread was significantly improved with reduced hardness and enhanced springiness. Microstructure revealed that sourdough resulted in starch surface corrosion and less amylopectin recrystallization. Aldehydes, alcohols, and esters are more dominant in sourdough group than yeast group. Foxtail millet and sorghum steamed breads exhibited the highest performances in texture, flavor, and sensory evaluation. This could provide a theoretical basis for producing coarse cereal products with desirable quality.

Effect of sorghum bran addition on antioxidant activities, sensory properties, and in vitro starch digestibility of Chinese southern-style steamed bread.

BACKGROUND: Chinese steamed bread (CSB) is one of the most important staple foods in China and is also popular in South-East Asia. Developing functional CSB could improve people's resistance to inflammatory and non inflammatory diseases. This work investigated the effect of sorghum bran addition on antioxidant activities, sensory properties, and in vitro starch digestibility of Chinese southern-style steamed bread (CSSB). RESULTS: In this study, the enhanced CSSB with 0-200 g kg-1 of fine black and tannin (sumac) sorghum bran addition was developed. A small change in phenol content and antioxidant activity was observed at various stages in the processing procedure before steaming. Moreover, a high retention of antioxidant phenolics CSSB with sorghum bran addition was observed. Sorghum bran addition significantly increased the total phenol content and antioxidant activity of CSSB by 4.5-10 times, on average, relative to control. Sorghum bran addition significantly also increased the content of resistant starch, and significantly decreased in vitro starch digestibility in CSSB; these effects were likely due to the joint inhibitory effect of tannins and ferulic acid on starch digestibility. Interestingly, the sorghum bran breads scored higher or similar to control in sensory color preference and overall appearance, but lower on most textural and mouthfeel attributes. CONCLUSION: Sorghum bran addition significantly increased the antioxidant activity of CSSB and significantly decreased starch digestibility. Moreover, the color and appearance properties were maintained or improved. However, the sensorial textural attributes were negatively impacted by the sorghum bran substitutions. Strategies to improve the texture of bran-fortified breads would likely enhance their consumer acceptability. © 2024 Society of Chemical Industry.

Effects of Wickerhamomyces anomalus Co-Fermented with Saccharomyces cerevisiae on Volatile Flavor Profiles during Steamed Bread Making Using Electronic Nose and HS-SPME-GC-MS.

Steamed bread is a traditional staple food in China, and it has gradually become loved by people all over the world because of its healthy production methods. With the improvement in people's living standards, the light flavor of steamed bread fermented by single yeast cannot meet people's needs. Multi-strain co-fermentation is a feasible way to improve the flavor of steamed bread. Here, the dynamic change profiles of volatile substances in steamed bread co-fermented by Saccharomyces cerevisiae SQJ20 and Wickerhamomyces anomalus GZJ2 were analyzed using the electronic nose (E-nose) and headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The five detectors of the E-nose rapidly detected the changes in volatile substances in different dough or steamed bread with the highest response value in co-fermented dough. A total of 236 volatile substances were detected in all the samples using HS-SPME-GC-MS, and alcohols were the most variable component, especially Phenylethyl alcohol. Significantly, more alcohols and esters were upregulated in co-fermented dough, and the addition of W. anomalus GZJ2 improved the key volatile aroma compounds of steamed bread using the relative odor activity value method (ROAV), especially the aldehydes and alcohols. Moreover, these key volatile aroma compounds can be quickly distinguished using the W2S detector of the E-nose, which can be used for the rapid detection of aroma components in steamed bread.

Mitigating effect of fucoidan versus sodium alginate on quality degradation of frozen dough and final steamed bread.

The impact of fucoidan (FD) and sodium alginate (SA) addition (0.3, 0.6, and 0.9 g/100 g wheat flour, dry basis) and freezing time on the rheology, water, structural characteristics of dough, and the quality of end steamed bread was explored in this study. The results showed FD was more effective in improving the textural characteristics of frozen dough compared with SA. Meanwhile, the freezable and free water content of SA dough were lower than those of FD dough, with the most pronounced effect observed at 0.9%. Adding SA increased the storage modulus, loss modulus, and disulfide bond content of the dough. The addition of FD induced a denser gluten protein network with fewer pores. Furthermore, the addition of FD reduced the hardness and chewiness of steamed bread and increased its specific volume and lightness. Overall, FD could alleviate the quality deterioration of frozen dough and the corresponding steamed bread.

Applicability of wheat brewer's spent grain in steamed bread-making based on physicochemical and visual profiles assessment of doughs and breads.

Brewer's spent grain (BSG), one of the main byproducts of brewing, has been widely used in the food industry due to its high nutritional components of dietary fiber, proteins, polysaccharides, and polyphenols. This study investigated the influence of wheat brewer's spent grain (WBSG) on the physicochemical properties of dough and steamed bread-making performance. The incorporation of WBSG in wheat flour significantly increased water absorption, development time, and degree of softening while decreasing the stability time of blending dough. Excessive WBSG up to 20% restricted the dough formation. WBSG contributed to the remarkable increase of pasting viscosities, pasting temperature, and immobilized water proportion in doughs. For all doughs, storage moduli (G') were higher than viscous moduli (G″). WBSG addition resulted in higher moduli values and the formation of highly networked gluten structure, finally leading to the lower specific volume, spread ratio, and elasticity of bread. Lightness (L*) of bread decreased with increasing WBSG while redness (a*) and total color difference (ΔE) augmented. Low WBSG addition (≤5%) could endow steamed bread with the appearance of a chocolate-like color and pleasant malt flavor, which is acceptable for most consumers. Nevertheless, the improvement of nutritional and functional characteristics of steamed bread incorporated with WBSG should be more focused in the future.

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.

Quality analysis of dough and steamed bread under various freezing conditions.

Freezing is a crucial step in the process of frozen foods. In this study, the effects of different freezing methods, including liquid nitrogen immersion freezing (LF), quick-freezing machine freezing (QF), packaging immersion freezing (PF), and ultralow temperature refrigerator freezing (UF), and freezing time (0, 15, 30, and 60 days) on the textural properties, dynamic rheological properties, water distribution, and structure of dough and the quality of end steamed bread were evaluated. Freezing resulted in a decline in the physicochemical properties of dough. UF- and QF-doughs had higher storage modulus and loss modulus, compared with PF- and LF-doughs. LF enhanced the textural attributes of the dough, resulting in reduced hardness and increased springiness. At 15 days of freezing, QF- and LF-doughs exhibited a compact and continuous structure with a smooth surface. Additionally, the correlation analysis elucidated that the weight loss rate and the bound water content of the dough had discernible impacts on the texture of both the dough and the resulting steamed bread. Overall, LF demonstrated a relatively high freezing efficiency and effectively maintained the quality of the dough for up to 15 days of freezing. These results offer valuable insights for the applications of freezing methods and time in frozen foods.

Synergistic enhancement of anthocyanin stability and techno-functionality of colored wheat during the steamed bread processing by selectively hydrolyzed soy protein.

To improve the stability of anthocyanins and techno-functionality of purple and blue wheat, the selectively hydrolyzed soy protein (reduced glycinin, RG) and ß-conglycinin (7S) were prepared and their enhanced effects were comparatively investigated. The anthocyanins in purple wheat showed higher stability compared to that of the blue wheat during breadmaking. The cyanidin-3-O-glucoside and cyanidin-3-O-rutincoside in purple wheat and delphinidin-3-O-rutinoside and delphinidin-3-O-glucoside in blue wheat were better preserved by RG. Addition of RG and 7S enhanced the quality of steamed bread made from colored and common wheat, with RG exhibited a more prominent effect. RG and 7S suppressed the gelatinization of starch and improved the thermal stability. Both RG and 7S promoted the unfolding process of gluten proteins and facilitated the subsequent crosslinking of glutenins and gliadins by disulfide bonds. Polymerization of α- and γ-gliadin into glutenin were more evidently promoted by RG, which contributed to the improved steamed bread quality.

Characteristic aroma compounds during the fermentation of Chinese steamed bread fermented with different starters.

The characteristic aroma compounds of Chinese steamed bread (CSB) fermented with different starters were studied using HS-SPME-GC/MS, aroma recombination and omission experiments. The dynamic changes of the microbiota and their function and metabolites during fermentation were analyzed using metagenomics and non-targeted metabolomics. Forty-nine volatile flavor compounds were identified, while 5 characteristic aroma-active compounds were investigated in CSB fermented with commercial dry yeast (AQ-CSB), and 10 were investigated in CSB fermented with traditional starter (NY-CSB). Microbial structure and function analysis showed that Saccharomyces cerevisiae dominated during AQ-CSB fermentation and contributed >95% to its KEGG pathways, while Pediococcus pentosaceus, unclassified Pediococcus, Lactobacillus plantarum, Lactobacillus brevis and unclassified Lactobacillus were predominant in NY-CSB and together had an ~96% contribution to these pathways. NY-CSB showed higher metabolic activity during fermentation, and the characteristic metabolites were mainly involved in carbohydrate, amino acid and lipid metabolism. The characteristic aroma compounds were identified and increased the understanding of the contributions of the microbiota. This may be useful for designing starter cultures that produce CSB with desirable aroma properties.

Inulin with different degrees of polymerization as a functional ingredient: Evaluation of flour, dough, and steamed bread characteristics during freezing.

In the study, the effects of short-chain inulin (OP), natural inulin (OH), and long-chain inulin (OHP) at substitution levels of 3%, 6%, and 9%, as well as freezing of 0, 15, and 30 days, on the farinograph and extensograph characteristics of flour, the rheological properties, water distribution, and microstructure of dough, as well as the quality of the final steamed bread, were investigated. The findings revealed that inulin led to a reduction in the water absorption of the dough while increasing its stable time. Furthermore, inulin delayed the alteration of freezable water within the frozen dough. Notably, the addition of inulin resulted in a more cohesive and evenly arranged network structure within the frozen dough. Steamed bread supplemented with 6% OP, 6% OH, and 3% OHP consistently dislayed a higher specific volume and spread ratio. These findings offer valuable insights into the utilization of inulin in frozen wheat foods.

Effect of Fucoidan on Structure and Bioactivity of Chinese Steamed Bread.

Fucoidan refers to a group of sulphated polysaccharides obtained from brown seaweed, with numerous biological activities. In this study, fucoidan was fortified into Chinese steamed bread (CSB) at different concentrations (0, 1%, 3% and 5%) and the effect of fucoidan on the dough properties, structure properties and bioactivity were investigated. The results showed that fucoidan could change the viscosity of unfermented dough, and a high concentration of fucoidan could remove the free radicals produced by the SH-SS exchange reaction (GS-) in the dough, which significantly reduced the content of disulfide bond and reduced the expanded volume of fermented dough (p < 0.05). In addition, fucoidan forms a physical barrier on the surface of starch particles and hinders the reaction between protein-to-protein; therefore, fucoidan increased the hardness, gumminess and chewiness in CSB, and reduced the specific volume in CSB. Furthermore, the fucoidan-fortified CSB samples were found to have both the ability to significantly reduce the predicted glycemic index (pGI) (p < 0.05) and improve antioxidant activity (p < 0.05). Collectively, these findings could provide a theoretical basis for the applications of fucoidan as a functional component in fermented foods.

The impact of magnetic field-assisted freeze-thaw treatment on the quality of foxtail millet sourdough and steamed bread.

Foxtail millet and sourdough are used to make foxtail millet sourdough steamed bread to improve the flavor and taste. Compared with the conventional freeze-thaw treatment (CFT), the effect of magnetic field-assisted freeze-thaw treatment (MFT) on the storage quality of foxtail millet sourdough and steamed bread is explored. The results showed that compared with CFT, MFT shortened the phase transition time of dough; decreased the water loss rate, the water mobility, and the freezable water content; increased the fermentation volume; stabilized the rheological properties; and minimized the damage of freezing and thawing to the secondary structure and microstructure of the gluten. In addition, an analysis of the specific volume, texture, surface color, and texture structure showed that MFT was beneficial to slowing the deterioration of the steamed bread texture. Finally, MFT effectively inhibited the growth and recrystallization of ice crystals during freezing and thawing, improving the quality of millet dough and steamed bread.

The Effect of Carboxymethyl Cellulose Sodium on the Proofing Tolerance and Quality of Frozen Dough Steamed Bread.

This study investigated the effects of dough proofing degree (1.1, 1.3, 1.5, and 1.7 mL/g) and carboxymethyl cellulose sodium (CMC-Na) on the quality of frozen dough steamed bread (FDSB). As the dough proofing degree was increased from 1.1 to 1.7 mL/g, the specific volume of FDSB initially increased and then decreased, with the maximum at 1.3 mL/g, and then dramatically decreased at 1.5 and 1.7 mL/g, accompanied by a harder texture and secession of crust and crumb, which were the detrimental effects brought by over-proofing. The optimal amount of CMC-Na effectively alleviated the deterioration associated with over-proofing, and the proofing tolerance of FDSB was increased from 1.3 mL/g to 1.7 mL/g. Fermentation analysis showed that CMC-Na significantly improved the extensibility and gas-holding capacity of the dough by increasing the maximum height of the dough (Hm) and the emergence time (T1) of Hm. Frequency sweep tests indicated that CMC-Na improved the plasticity of proofed dough by increasing loss factor tan δ. Significant reductions were found in peak viscosity and complex modulus G* in pasting properties tests and temperature sweep measurements, respectively, suggesting that CMC-Na influenced starch gelatinization and dough stiffening during steaming, which promoted the extension of the network structure, thus facilitating gas expansion and diffusion. These property changes theoretically explained the improvement in the proofing tolerance of FDSB by CMC-Na.

Effects of different thawing methods on physical and physicochemical properties of frozen dough and quality of corresponding steamed bread.

The thawing method is critical for the final quality of products based on the frozen dough. The effects of ultrasound thawing, proofer thawing, refrigerator thawing, water bath thawing, ambient thawing, and microwave thawing on the rheology, texture, water distribution, fermentation characteristics, and microstructure of frozen dough and the properties of steamed bread were investigated. The results indicated that the ultrasound thawing dough had better physicochemical properties than other doughs. It was found that ultrasound thawing restrained the water migration of dough, improved its rheological properties and fermentation capacity. The total gas volume value of the ultrasound thawing dough was reduced by 21.35% compared with that of unfrozen dough. The ultrasound thawing dough displayed a thoroughly uniform starch-gluten network, and an enhanced the specific volume and internal structure of the steamed bread. In conclusion, ultrasound thawing effectively mitigated the degradation of the frozen dough and enhanced the quality of steamed bread.

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.