Chinese Steamed Bread Research Articles

Effects of fermentation on the rheological characteristics of dough and the quality of steamed bread

During the production of steamed bread, fermentation is a critical step to obtain a final product with the desired characteristics. The quality of the final steamed bread is significantly affected by the properties of the dough. This study investigated the effects of fermentation on the rheological properties, state of water, microstructure of the dough, and the quality of steamed bread. After fermentation, the steamed bread dough exhibited higher stickiness, and was more easily to break during uniaxial extension. Biaxial extension tests revealed a significant decrease in biaxial extensional viscosity from 110,118 (0 min) to 11,544 Pa·S (80 min) at the strain rate of 0.04/S. The properties of the dough matrix were closely related to the fermentation time and the quality of the steamed bread is significant affected by the fermentation time. The results is valuable to provide theoretical basis for steamed bread making under precise control. Practical applications Fermentation is a key step in the production of steamed bread. This study (a) investigated the rheological properties of Chinese steamed bread dough during fermentation, including dough stickiness, uniaxial extensibility, and biaxial extension; (b) evaluated the effects of fermentation on the microstructure of fermented dough and steamed bread quality; and (c) investigated the relationship between the fermentation process and the quality of steamed bread. The information provided in this work will serve as the basis for further study on physical properties of fermented dough. The results is very valuable to provide theoretical basis for determining quality during the industrial production of steamed bread. This potentially leads to improved quality of steamed bread under precise control.

Physicochemical and sensory properties of steamed bread fortified with purple sweet potato flour

Whole purple sweet potato flour (PSP) is rich in various nutrients such as anthocyanins and dietary fiber. Chinese steamed bread (CSB) is a fermented food eaten by Chinese populations. Freeze-dried PSP was incorporated into CSB formulations up to 50%. The physicochemical and sensory properties of the resulting CSB were studied. The results showed that PSP addition up to 50% increased the antioxidant activities of CSB, while reducing the glycemic response. The total polyphenol/anthocyanin contents of CSB increased with increasing PSP level, although a portion of these polyphenols were lost during CSB production. PSP addition up to 50% had little effect on the water activity and water content of CSB and increased the hardness, while decreasing the specific volume. CSB with 5–10% PSP improved the overall sensory acceptance. PSP can be used in CSB up to 10% with wheat flour to enhance the functional properties of CSB without compromising eating quality.

Application of Lactobacillus as Adjunct Cultures in Wheat Dough Fermentation.

The purpose of this study was to evaluate the potential use of Lactobacillus from traditional Chinese sourdoughs of different regions as original adjunct cultures in the steamed bread making process. The effects of Lactobacillus on dough and steamed bread were evaluated. Some differences were obtained in the parameters of fermented dough (organic acid content, rheofermentative parameters, pH, and total titratable acidity [TTA]) and steamed bread (hardness, specific volume, organic acid content, shape, color, pH, TTA and sensory score) made with five different Lactobacillus strains (Pediococcus pentosaceus, Lactobacillus fermentum, Weissella confusa, Lactobacillus crustorum, and Pediococcus acidilactici). Steamed bread made with P. pentosaceus showed a significant increase in specific volume (from 2.19 to 2.41) and a decrease in hardness (from 3,158 g to 2,301g). Dough leavened by L. fermentum showed significantly higher amounts of lactic acid and acetic acid than dough inoculated with W. confusa, which had values similar to those of the control. The dough fermented by P. pentosaceus exhibited the most gas production (1,811 mL), which is an important index of streamed bread quality. Our research provides a reference for making steamed bread with Lactobacillus. PRACTICAL APPLICATION: Probiotic Lactobacillus is widely used to produce fermenting foods and has been used in bread processing to improve the quality and characteristics of bread. Steamed bread is one of the most popular fermented foods in northern China. However, there is little information about the application of Lactobacillus in Chinese steamed bread. This study explored the potential use of Lactobacillus to improve the characteristics and quality of steamed bread.

Application of near-infrared spectroscopy for screening the potato flour content in Chinese steamed bread.

Near-infrared (NIR) spectroscopy combined with chemometrics was used as a technique to predict the potato flour content in Chinese steamed bread (CSB). The inner core of CSB was chosen as the measuring position for acquiring the NIR spectra. Spectra between 4000 and 10,000cm-1 were analysed using a partial least-squares regression. The coefficient of determination (R CV 2) and the root mean square error of cross-validation in the calibration set were found to be 0.7940-0.8955 and 4.22-5.93, depending on the pre-treatment of the spectra. The external validation set gave an R2 and a ratio to performance deviation of 0.8865 and 3.07. Reasonable recovery (93.1-102.5%) and good intra-assay (3.3-8.3%) and inter-assay (7.6-17.2%) precision illustrated the feasibility of this method. The result of this study reveals that NIR spectroscopy could be used as rapid tool to determine the potato flour content in CSB (> 20%).

Identification of Key Aroma Compounds in Type I Sourdough-Based Chinese Steamed Bread: Application of Untargeted Metabolomics Analysisp.

Untargeted metabolomics is a valuable tool to analyze metabolite profiles or aroma fingerprints of different food products. However, less attention has been paid to determining the aroma characteristics of Chinese steamed breads (CSBs) by using this approach. The aim of this work was to evaluate the key aroma compounds and their potential generation pathway in Chinese steamed bread produced with type I sourdough by a metabolomics approach. Based on the aroma characteristics analysis, CSBs produced with type I sourdough and baker’s yeast were clearly distinguishable by principal component analysis (PCA) scores plot. A total of 13 compounds in sourdough-based steamed breads were given the status of discriminant markers through the untargeted metabolomics analysis. According to the odor activity values (OAVs) of discriminant aroma markers, ethyl acetate (fruity), ethyl lactate (caramel-like), hexyl acetate (fruity), (E)-2-nonenal (fatty) and 2-pentylfuran (fruity) were validated as the key volatile compounds in the breads produced with type I sourdough as compared to the baker’s yeast leavened steamed bread. The metabolite analysis in proofed dough indicated that esters are mainly generated by the reaction between acid and alcohol during steaming, and aldehydes are derived from the oxidation of palmitoleic acid and linoleic acid during proofing and steaming.

Effect of oatmeal on texture, water mobility, and starch retrogradation properties of Chinese steamed bread

AbstractBackground and objectivesThe study aimed to characterize the effect of oatmeal on the texture, water mobility, and starch retrogradation properties in Chinese steamed bread (CSB). Oatmeal substitution was set as 0%, 10%, and 30%.FindingsWith the addition of oatmeal in CSB, higher hardness and chewiness and lower resilience were observed compared to the control (p < 0.05); CSB with addition of oatmeal exhibited a lower rate of increase in hardness than that of the control. Oatmeal increased the water holding capacity of CSB and restricted water migration, which resulted in a lower content of immobilized water (S22, 76.72%–77.03%) and higher content of free water (S23, 1.01%–1.07%) in NMR. Results from differential scanning calorimetry, X‐ray diffraction, and fourier transform infrared suggested that with the increase in oatmeal, the enthalpy and the relative crystallinity of CSB reduced. The addition of oatmeal retarded a stable and ordered state of starch structure formed in CSB during storage at room temperature. Oatmeal decreased the starch retrogradation rate constant k and CSB with 30% of addition of oatmeal had the lowest k value (10.1), indicating its inhibitory effect on the formation of starch crystals.ConclusionsOur findings revealed that oatmeal could increase the free water of CSB and restrict water migration, thus retarding starch retrogradation in CSB.Significance and noveltyOatmeal could effectively inhabit water migration and starch retrogradation of CSB, consequently inhibiting the staling, and there could be a potential utility of oatmeal in the development of flour‐based food products.

Influences of alkali on the quality and protein polymerization of buckwheat Chinese steamed bread

The effects of alkali (NaHCO3 or Na2CO3) on the quality and protein polymerization of buckwheat Chinese steamed bread (CSB) were investigated. The alkali addition increased the specific volume of CSB, for NaHCO3 from 1.84 ml/g (control) to 2.66 ml/g. Image analysis showed that alkali increased the pore area fractions. The addition of Na2CO3 exhibited a greater pore count and lower pore average size. The texture properties were improved with the increase of crumb hardness and resilience. The extractability of protein in sodium dodecyl sulfate containing medium (SDSEP) decreased. Furthermore, SDS–PAGE showed an obvious decrease in the intensity of protein bands with lower molecular weight, while intensity of higher molecular protein bands increased. This demonstrated that alkali addition promoted protein aggregation in buckwheat CSB. In addition, the content of degydroalanine and lanthionine increased and free SH decreased, which indicated alkali addition prompted protein to form dehydroalanine-derived and disulfide cross-linkings.

QTL mapping for the textural property traits of northern-style Chinese steamed bread by using recombinant inbred lines of wheat

Textural property is one of the most important factors influencing the quality of northern-style Chinese steamed bread (CSB). We detected quantitative trait loci (QTLs) for the textural properties of CSB by using 184 recombinant inbred lines derived from a cross between two Chinese winter wheat (Triticum aestivum L.) varieties, Linmai6 and Tainong18. Eighteen putative QTLs were detected on 14 chromosomes: 1B, 1D, 2A, 2B, 2D, 3A, 3B, 4A, 4B, 5B, 6A, 6B, 7B, and 7D. Six textural quality traits, one QTL for hardness (QHa-4A), three QTLs for springiness (QSp-3B, QSp-4B, and QSp-5B), seven QTLs for cohesiveness (QCo-6A, QCo-7B.1, QCo-7B.2, QCo-3A, QCo-1D, QCo-2B.1, and QCo-2B.2), four QTLs for resilience (QRe-2D, QRe-2A, QRe-7D, and QRe-1B), two QTLs for gumminess (QGu-6B, and QGu-3B), and one QTL for chewiness (QCh-7D) were detected. The contributions of the QTLs ranged from 6.19% to 15.74%. The present study enhances understanding of the genetic basis for the textural properties of northern-style CSB and provides the basis for gene mapping of these traits.

Microbiota succession and metabolite changes during the traditional sourdough fermentation of Chinese steamed bread

ABSTRACTThis study was conducted to evaluate the changes in microbial communities and metabolites during the Chinese traditional sourdough fermentation. A gradual decrease in pH values was observed throughout the fermentation process. A considerable increase in LAB and yeasts counts was noticed during the primary stage of fermentation with the corresponding increase in amino acids, glucose, lactic acid and acetic acid. During the secondary fermentation stage, LAB count started decreasing slowly, while yeast count still increased, and reached to the maximum value. However, glucose, amino acid, lactic acid and acetic acid contents decreased slightly. PCR-DGGE results identified nine bacteria, six yeasts and one mold species during the whole fermentation process. Saccharomyces cerevisiae and Lactobacillus sanfranciscensis were the predominant species. These results would help to understand the LAB and yeasts influence on the metabolic process during the fermentation of steamed bread by Chinese traditional sourdoughs.

Microbial diversity in traditional type I sourdough and jiaozi and its influence on volatiles in Chinese steamed bread

The aim of this work was to investigate the microbial diversity of jiaozi (n = 7) and type I sourdoughs (n = 8) by culture-dependent and culture-independent analysis and explore the effect of these starter cultures on the generation of volatiles in steamed breads. Both starter cultures significantly varied in terms of their pH, TTA and moisture content (P < 0.001); however, no significant difference in cell density of presumptive lactic acid bacteria (LAB) and yeast (P > 0.05) was found. The culture-dependent and culture-independent approaches revealed that Weissella cibaria and Lactobacillus sanfranciscensis were predominant in the microbiota of jiaozi and type I sourdoughs, respectively. Saccharomyces cerevisiae and Candida humilis were the most common yeast species in all samples. A total of 36 volatile compounds were detected in all steamed breads. The products fermented with jiaozi had a relative high concentration of volatiles synthesized by amino acid metabolism. However, products fermented with type I sourdough were dominated by acids, furans, aldehydes and their corresponding alcohols. The principal component analysis distinguished the two starter cultures, based on the abundance of bacterial species as well as the total volatile composition of their respective steamed breads. We conclude that the production of volatile compounds strongly correlated with the microbiota involved in fermentation.

Modeling Microwave Heating of Frozen Chinese Fast Foods Based on Dielectric Properties

Abstract Chinese steamed bread with chicken, which is a typical Chinese fast food, is popular among consumers. The model simulated a frozen combination consisting of six chicken nuggets and two Chinese steamed breads with the dynamic change of dielectric properties on the turntable. The temperature-dependent dielectric and thermo-physical properties of chicken meat were measured as a function of temperature from −5°C to 95°C. A mathematical model of the dielectric properties, specific heat and thermal conductivity with temperature dependence was inputted in the model as the material parameters. 7.5 rpm was observed to be the optimal rotation speed. Simulated temperature profiles were compared with experimental temperature profiles after 90 s of microwave (MW) heating at 700 W. The simulated results were consistent with the corresponding experimental results. The developed model can be applied in food products to identify the cold and hot spots to ensure quality in terms of temperature uniformity.

Chinese steamed bread: Packaging conditions and starch retrogradation

AbstractBackground and objectivesThe starch retrogradation of Chinese steamed bread (CSB) under different packaging conditions (sealed package [SP], vacuum package [VP], and thermal‐vacuum package [T‐VP]) was compared in the present study. Parameters including moisture content, moisture migration, starch granule structure, and starch retrogradation were monitored by NMR, SEM, XRD, and FT‐IR.FindingsDuring storage, T‐VP steamed bread kept higher water content and had longer shelf life compared to SP and VP. T‐VP hindered the interactions among water molecules, gluten, and starch, thus relatively increasing the mobility of water molecules represented by T23 in NMR tests compared to SP. T‐VP decreased the speed of CSB starch granules getting narrowing in SEM, maintaining a good taste of steamed bread. Results from FT‐IR and XRD suggested a lower retrogradation rate of CSB starch with T‐VP as compared to SP and VP, and the retrogradation of CSB starch was affected by free water during storage.ConclusionsThermal‐vacuum package could delay the speed of water desorption, blocked the interaction among water molecules, gluten and starch and slowed the adhesion between starch granule, thus retard starch retrogradation of CSB.Significance and noveltyThermal‐vacuum package technology as an anti‐retrogradation packaging system for CSB preservation could extend the shelf life of CSB for at least 84 days at room temperature.

Effects of bran hydration and autoclaving on processing quality of Chinese steamed bread and noodles produced from whole grain wheat flour

Background and objectivesConsumption of Chinese steamed bread (CSB) and noodles made from whole grain wheat flour (WWF) is encouraged due to their important nutritional elements in the outer seed layers that benefit human health. However, the use of WWF is limited because of the poor processing quality and less attractive product properties of dark color, rough texture and coarse crumb structure. Three Chinese wheat cultivars, Zhongmai 895, Yumai 49, and Zhoumai 27, were used to investigate the potentials of bran hydration and autoclaving treatments for the improvement of WWF functionality in making CSB and noodles.FindingsBran particle size, hydration, and autoclaving treatment of WWF significantly affected the quality of dough, CSB, and noodles made from it. Farinograph water absorption and stability of WWFs with fine bran were larger than those with coarse bran. WWFs with coarse bran compared with fine bran exhibited inferior color and higher water retention capacity (WRC), and produced CSB with better texture and crumb structure and noodles with less smoothness and poor appearance. Prehydration of bran decreased dough water absorption and increased dough stability. WWFs containing bran hydrated to 40% moisture content produced CSB with the best texture and crumb structure, and the highest total score. Bran hydration merely induced negative effects on smoothness of noodles made with fine bran. Autoclaving of bran significantly improved texture and crumb structure of CSB made from WWFs with bran hydrated to 40% moisture. Autoclaved bran with 20% moisture contributed to higher total score of CSB. However, bran hydration and autoclaving resulted in darker color of noodle sheet made from WWFs.ConclusionsHydration and autoclaving of bran could be an effective way to improve the processing quality of CSB made from WWFs, but there was little improvement in eating quality of noodles made from WWFs.Significance and noveltyThis is the first research to show that hydration and autoclaving of bran could be an effective way to improve the processing quality of CSB made from WWFs. These results provide useful information for the incorporation of wheat bran to make fiber‐rich CSB.

Effects of green tea powder on the quality attributes of hard red winter wheat flour and Chinese steamed bread

SummaryThe effects of green tea powder (GTP) on the properties of hard red winter (HRW) flour and Chinese steamed bread were investigated. GTP was blended with HRW flour at levels of 0.00, 1.00, 2.00, 3.00 and 4.00 g GTP/100 g wheat flour. With the addition of GTP, the maximum torque of flour became stronger. The resilience and degree of green colour of steamed bread increased, while hardness and chewiness decreased, with the addition of GTP. The addition of 1.00% GTP did not significantly affect the specific volume, but remarkably influenced the hardness and resilience of steamed bread. In steamed bread formulated with GTP, the antioxidant activity was 0.84 mm TE per g at 1.00% of GTP and increased with GTP levels. The steamed bread had a pleasant flavour, and the degree of overall liking of steamed bread increased with GTP levels to the maximum used in this work.

Color, antioxidation, and texture of dough and Chinese steamed bread enriched with pitaya peel powder

AbstractBackground and objectivesIntake of phytochemicals such as betalains, polyphenols, and dietary fiber is health beneficial. Pitaya peel, a by‐product during fruit processing, is usually discarded. In this study, pitaya peel powder (PPP) was added to the dough of Chinese steamed bread (CSB) as a bioactive ingredient.FindingsTotal betacyanins, free phenolics, and DPPH radical scavenging capacity of the dough and CSB increased with increasing the PPP level from 0% to 9%. Color properties of the dough and CSB were significantly affected by the PPP level. Moreover, steaming led to significant decreases in the betacyanin content, redness, and free phenolic content of CSB. The addition of PPP led to a stiffer and less extensible dough. With increasing the level of PPP, the hardness of CSB was increased, but its specific volume, cohesiveness, springiness, and elasticity were reduced. With 3% PPP, the CSB had similar sensory scores to the control.ConclusionsHealthy and colorful CSB with high phytochemicals and antioxidant capacity as well as acceptable texture can be produced by the addition of 3% PPP.Significance and noveltyPPP can be used as a bioactive ingredient, and its level significantly affects the color, antioxidative, rheological, and sensory properties of dough and CSB.

Simple synthesis of nitrogen-doped porous carbon from Chinese steamed bread flour and its catalytic application for hydrogen evolution reaction

A cost-effective green synthesis method for nitrogen-doped porous carbon from Chinese steamed bread flour by successive hydrothermal treatment and pyrolysis is reported. The hydrothermal treatment remarkably enhances the strength of the resulting pyrolyzed carbon materials, enabling the facile fabrication of robust monolithic nitrogen-doped porous carbon with the yield of 44.33%. This nitrogen-doped porous carbon exhibits 3-dimensional porous structure which is mainly mesoporous and high surface area. The thin and 3-dimensional self-supported working electrode is made from the synthesized nitrogen-doped porous carbon without using any other current collector or polymeric binder. The hydrogen evolution reaction electrocatalytic activity in 0.5 M H2SO4 reveals the achievement of the low overpotential of ∼220 mV at 10 mA cm−2, a Tafel slope of ∼77 mV dec−1, a nearly 100% Faradaic yield, an excellent stability, and a low charge transfer resistance. The self-supported electrode exhibits higher electrocatalytic activity than the powder-state supported on graphite felt electrode. Its hydrogen evolution reaction electrocatalytic activity is better than that of the reported non-metal heteroatom-doped carbon catalysts and comparable to that of some metal catalysts in acidic media. The use of flour enables the cheap and facile fabrication of carbon electrode with tunable pore sizes and surface areas, making flour-based carbon electrodes highly promising.

Sensory evaluation of Chinese white salted noodles and steamed bread made with Australian and Chinese wheat flour

AbstractBackground and objectivesChinese white salted noodles (CWSN) and steamed bread (CSB) are staple foods and represent approximately 65% of wheat consumption in China. Sensory evaluation was used to measure the quality attributes of selected Australian wheat varieties and Chinese commercial wheat for Chinese white salted noodle and northern style steamed bread. Descriptive parameters for Chinese sensory evaluation are described and tested using a Chinese‐trained expert sensory panel.FindingsThe results showed that flour from selected Australian wheat varieties had better gluten properties, dough mixing characteristics and starch properties compared with the commercial Chinese wheat flours evaluated. Improved sensory evaluation scores in noodle firmness, stickiness, elasticity, smoothness, and flavor resulted in a significantly higher total quality score (p &lt; 0.05) for all Australian wheat flours and blends (60% and 74% extraction) compared with the two Chinese wheat flours for CWSN. Sensory evaluation scores for steamed bread from the Australian wheat variety Mace (60% and 74% extraction) were equal to the best Chinese gold standard flour (49% extraction) and significantly higher (p &lt; 0.05) than Chinese flour of 69% extraction. The Australian flours with protein content 9%–10.5% produced higher quality white salted noodles and steamed bread than the higher protein 12.0% Chinese flours. The highest scoring noodles at 78.5–79.5 points were Australian Mace, and Mace and Zen blends. The highest scoring Chinese steamed bread at 85.7 points was Mace at 60% extraction.ConclusionsThe features of the Australian 60% extraction flours were higher noodle firmness, elasticity, and smoothness scores and improved flavor compared with the 49% extraction Chinese gold standard flour. Noodle sensory evaluation results showed significantly higher (p &lt; 0.05) total scores for the Australian flours compared with noodles made with the two high‐quality Chinese wheat flours. The features of Australian 60% extraction flour were ideal for steamed bread characteristics: mouthfeel, stickiness, texture, and elasticity/firmness. Steamed bread made from Mace flour (60% and 75% extraction) showed a significantly higher total score compared with steamed bread made from Chinese wheat flour (69% extraction). The demand for improved wheat quality in China is growing, and future research is needed to investigate quality of newly released Australian and Chinese wheat varieties.Significance and noveltyThis research contributes to defining sensory quality testing methods and quality characteristics for Chinese white salted noodles and steamed bread. Mace and Zen blends were tested for sensory quality by a Chinese expert sensory panel.

Effect of chia seed on glycemic response, texture, and sensory properties of Chinese steamed bread

Chia (Salvia hispanica) seed is a source of diverse bioactive components with various potential health effects. Chinese steamed bread (CSB) is a traditional staple among Asian population. In this report, intact white chia seeds replaced wheat flour for northern-style CSB formulation at various levels up to 300 g/kg. The impact of seed replacement on in vitro starch digestion, expected glycemic index (eGI), expected glycemic load (eGL), volumetric properties, colour, texture, and sensory quality of the CSB were studied. Chia seed addition reduced the eGI and eGL of CSB by up to 25% and 48%, respectively. Chia seeds increased the hardness of CSB and reduced the specific volume of CSB by up to 211% and 27%, respectively. Sensory analysis showed that the overall acceptance of CSB was not affected by chia seed addition. It may be concluded that intact chia seed addition up to 300 g/kg can nutritionally enhance CSB without compromising the eating quality.

The Effect of Oat Bran on the Dough Rheology and Quality of Chinese Steamed Bread

The present study investigates the effects of incorporating oat bran (OB) into Chinese steamed bread (CSB). Different levels (5%, 10% and 15%) of OB were used to replace wheat flour in the manufacture of CSB. The rheological properties of the dough were measured (water absorption (WA), development time, mixing tolerance, extensibility and stickiness). The addition of OB significantly increased WA, development time and stickiness, whereas decreased extensibility of dough. The physical properties of CSB were determined using specific volume, loaf height, moisture, and texture analysis. The nutritional quality of the bread was also analysed using an in vitro digestion method mimicking intestinal digestion. The results illustrated that the incorporation of OB into wheat flour decreases specific volume and softness of CSB. The addition of OB decreased the glycaemic response of steamed bread. This study illustrates the potential addition of OB to improve the nutritional quality of CSB.

Impact of in situ formed exopolysaccharides on dough performance and quality of Chinese steamed bread

This study investigated the impact of in situ exopolysaccharides (EPS) on the properties of dough and quality of Chinese steamed bread (CSB). Sourdoughs were fermented with dextran-producing Weissella confusa QS813, with and without sucrose addition at 20 °C and 35 °C, respectively. The highest EPS content and lowest titratable acidity value were obtained in sucrose-enriched sourdough fermented at 20 °C (WS20+). Addition of WS20 + significantly improved proofing performance and induced glutenin macropolymer (GMP) particle agglomeration of dough. Microstructure results revealed a more continuous, connected network in WS20 + dough and better crumb structure in the corresponding CSB. The quality of CSB was enhanced upon addition of WS20+. Low EPS yield in sourdough without sucrose negatively affected dough and CSB quality. Increased acidification in sucrose-enriched sourdough fermented at 35 °C masked the beneficial effects of EPS. Therefore, both high EPS generation and mild acidification contributed to the beneficial effect of W. confusa sourdough on CSB quality.