Chinese Steamed Bread Research Articles

Processing, physicochemical and nutritional properties of steamed bread fortified with Chinese Huai-shan Yam

Chinese Huai-shan Yams (HSY) is a source of diverse nutrients, such as allantoin, resistant starch, and non-starch polysaccharides, which is the homology of medicine and food in China. Chinese Steamed Bread (CSB) has gained popularity recently. HSY powder was added to wheat flour to make nutritionally fortified CSB. Three flour improvers were used to enhance the dough thermo-mechanical properties, dough rheology, and physical properties of CSB fortified with HSY powder (up to 30 %). The results showed that the combination of 6 % gluten, 0.3 % xanthan gum, and 100 U/kg TGase can greatly improve the quality of CSB fortified with HSY powder (30 %). The specific volume was increased from 2.00 to 2.97 cm3∙g−1 which was 16.7 % higher than the standard CSB with pure wheat flour, while the hardness, adhesiveness, gumminess, and chewiness were decreased to some extent. During storage, the hardness of the improved CSB was significantly suppressed and the enthalpy was significantly decreased. More importantly, the estimated glycemic index of CSB containing HSY and the improved group decreased from 75.4 to 68.1 and 64.8 respectively. The findings indicated the feasibility of formulating HSY-fortified foods with enhanced nutritional quality.

Characterizing the Internal Structure of Chinese Steamed Bread during Storage for Quality Evaluation Using X-ray Computer Tomography

Chinese steamed bread (CSB) is a traditional food of the Chinese nation, and the preservation of its quality and freshness during storage is very important for its industrial production. Therefore, it is necessary to study the storage characteristics of CSB. Non-destructive CT technology was utilized to characterize and visualize the microstructure of CSB during storage, and also to further study of quality changes. Two-dimensional and three-dimensional images of CSBs were obtained through X-ray scanning and 3D reconstruction. Morphological parameters of the microstructure of CSBs were acquired based on CT image using image processing methods. Additionally, commonly used physicochemical indexes (hardness, flexibility, moisture content) for the quality evaluation of CSBs were analyzed. Moreover, a correlation analysis was conducted based on the three-dimensional morphological parameters and physicochemical indexes of CSBs. The results showed that three-dimensional morphological parameters of CSBs were negatively correlated with moisture content (Pearson correlation coefficient range−0.86~−0.97) and positively correlated with hardness (Pearson correlation coefficient range−0.87~0.99). The results indicate the inspiring capability of CT in the storage quality evaluation of CSB, providing a potential analytical method for the detection of quality and freshness in the industrial production of CSB.

Effects of Wheat Flour Substitution with High‐Amylose Corn Flour on the Quality of Dough and Chinese Steamed Bread

AbstractIn order to increase the nutritional value of Chinese steamed bread (CSB), high‐amylose corn flour (HACF) is used to partially replace wheat flour (WF) in the preparation of CSB. In CSB prepared with 0–50% HACF, the study examines the thermomechanical characteristics of the dough, starch–gluten network, quality, and in vitro digestibility. According to Mixolab data, the addition of HACF reduces dough stability and increases the thermal stability of pasting. In doughs with HACF concentrations >30%, scanning electron microscopy observations reveal that the starch–gluten connections are weaker and the network structure is discontinuous. The addition of HACF reduces the specific volume and increases the hardness, gumminess, and chewiness of the CSB. Compared with the WF‐CSB, the content of resistant starch increases from 12.01% to 28.49% in the HACF‐CSB, whereas there is a reduction in the glycemic index from 94.39 to 57.55. In summary, the addition of 30% HACF can increase the resistance of CSB and enhance its nutritional value without unduly reducing the desirable organoleptic qualities.

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.

Effects of Salecan on the gelatinization and retrogradation behaviors of wheat starch

The retrogradation behavior of native wheat starch (WS) is undesirable for starchy food. Adding polysaccharides is a secure and effective method to improve starch properties. Herein, the effects of Salecan, a novel microbial polysaccharide, on WS's gelatinization and retrogradation behaviors were investigated. Results showed that Salecan increased peak, trough, and final viscosities while decreasing WS paste's breakdown and setback values, suggesting Salecan inhibited the short-term retrogradation of WS. The rheological results showed Salecan increased the viscosities of the gelatinized samples, and its storage moduli decreased initially and then increased when Salecan was added more than 10 g/kg. Moreover, Salecan significantly reduced the WS gel hardness during long-term storage. SEM and XRD results showed Salecan improved the microstructure and reduced the crystallinities of retrogradation WS gels, respectively. Furthermore, the application of Salecan in Chinese steamed bread showed Salecan could inhibit moisture migration and maintain the texture of prepared bread during chilled storage, demonstrated by LF-NMR and TPA, respectively. In summary, Salecan could inhibit the retrogradation of WS, and the recommended optimal added level is 10 g/kg of WS weight, which would be helpful for the development of starchy food with a longer shelf-life.

Physicochemical properties and molecular structure of starches from different wheat varieties and their influence on Chinese steamed bread.

Starch is one of the key factors for the texture of Chinese steamed bread (CSB). In this study, the molecular structures and physicochemical properties of starches from 11 wheat varieties with amylose content (AC) of 1.75%-28.79% were investigated. Northern style CSB was made using these wheat varieties to explore the structure-property-quality relationship of starches. AC was negatively correlated with the pasting and gelatinization properties. The relative crystallinity (RC) had a negative correlation with AC but a positive correlation with gelatinization. The molecular structure results from the fluorophore-assisted capillary electrophoresis spectrophotometer indicated that the length of short amylopectin chains (βAp,i ) was positively correlated with hot paste and cool paste viscosities. The amount of medium amylopectin chains (hAp,iii ) was positively correlated with peak and breakdown viscosities but negatively correlated with setback viscosity. The hAp,iii had positive correlations with gelatinization temperatures and RC. The amount of long amylopectin chains (hAp,v ) had a positive correlation with peak temperature. For the CSB texture, βAp,i had negative correlations with hardness and chewiness, whereas had a positive correlation with resilience. The hAp,iii was negatively correlated with springiness and resilience. The hAp,v was negatively associated with resilience. PRACTICAL APPLICATION: Starch has a vital role in wheat flour products. Clarifying the structure-property-quality relationship of starches will help illuminate the role of starch molecular structure in CSB production and provide valuable information for the control of CSB quality. It also provides a significant reference for wheat breeding.

Effect of frozen storage on the quality and amylopectin structure of Chinese steamed bread made from different wheat cultivars

The physicochemical properties of wheat flour and the chain-length distributions of amylopectin from eleven cultivars were studied. Chinese steamed bread (CSB) was made by a one-step fermentation procedure using these flours to explore the effects of frozen storage on the qualities of CSB and starch molecular structures. The results indicated that the protein and wet gluten had significant effects on the fermentation rheological properties of wheat dough and CSB qualities. The amylose content and amylopectin structure had important influences on the pasting properties of wheat flour and the firming of CSB. Water loss and migration in CSB during freezing, accompanied by the starch retrogradation, depended on the amylose content and amylopectin structure. After 60-day of frozen storage at −18 °C, the amylopectin extracted from CSB showed decreased fractions of B1 and B2 chains while the long B3 chain and average chain length increased. Moreover, short amylopectin chains were negatively correlated with the hardness of CSB (P < 0.01). These results confirmed that the structure-property relationships of wheat flour have crucial influences on the qualities of CSB, which would benefit our selection of wheat materials for the frozen food industry and provide a reference for wheat breeding.

Microbiota structure of traditional starters from around the Tai-hang mountains and their influence on the fermentation properties, aroma profile and quality of Chinese steamed bread.

Steamed bread is a popular staple food in China, and the significant regional differences of the microbiota in traditional starters make the flavor and quality of steamed bread highly variable along with long preparation times. Therefore, analyzing the microbial flora of traditional starters and their influences on the flavor and quality may help to solve the problems mentioned earlier, and it may also be conducive to potentially meet consumer needs and permit industrialization of this traditional fermented food. One hundred and thirty-two fungal and 50 bacterial species were identified in five traditional starters, each with a different dominant genus. The fermentation properties of dough showed that total titratable acid, dough volume and gas production increased and the pH decreased with fermentation time. The traditional starters improved the quality of Chinese steamed bread (CSB) including the crumb structure, specific volume and sensory attributes. Thirty-three aroma compounds with a VIP (variable importance for the projection) > 1 were identified as characteristic aroma compounds. The correlations among the microbiota, aroma and qualities of CSB showed a greater contribution from the bacteria, which was consistent with the predictions of metabolic pathways in the sequenced genomes. The quality of CSB fermented with traditional starters was improved induced by their different microbial profiles, and bacteria made a greater contribution than fungus to the aroma and qualities of CSB. © 2023 Society of Chemical Industry.

Research on the aroma properties and microbial succession patterns in the processing of Chinese yellow sticky rice jiuqu steamed bread

To investigate the aroma properties and microbial succession patterns of Chinese steamed bread (CSB) prepared with yellow sticky rice and Baijiu Qu, several important stages were determined in processing, including yellow sticky rice, fermented rice, fermented juice, sourdough, and steamed bread by solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS) and high-throughput sequencing (HTS). The composition of volatile compounds varied significantly in different stages. The highest content of 2-methyl-butane (9.69%) and hexanal (6.34%) was detected in yellow sticky rice while the high content of ethanol (39.60%–42.14%), phenylethyl alcohol (9.01%–15.70%) and 3-methyl-1-butanol (8.91%–10.19%) endowed other samples sweet, rose and brandy aroma. Bacterial community mainly consisted of Chloroplast (10.83%–70.20%) and Weissella (0.43%–51.49%), and fungal community was primarily composed of Saccharomyces (1.22%–64.25%). Phenylethyl acetate was positively related to Saccharomyces, and phenylethyl alcohol and 1-hexanol were positively related to Lactobacillus. This paper provided a new prospect for the industrialization of traditional Chinese steamed bread.

A novel strategy inspired by steaming Chinese steamed bread for preparation of tannin-furanic rigid bio-foam

Tannin-furanic rigid foam material has been receiving extensive attention due to its renewable, easy-preparation, lightweight, thermal insulation, and flame retardancy, that been considering a potential flame-retardants and thermally-insulating materials in construction field. The most fashionable approaches for tannin-furanic foam manufacturing, currently, are the self-blowing expansion with the aid of blowing agent with/without extra heating, and foaming via mechanical stirring in presence of non-environmentally friendly crosslinker. Herein, a novel and green strategy was proposed for tannin-furanic rigid foam preparation without blowing agent and additional crosslinker by steam-driven foaming. The performance of steam-driven tannin-furanic based foam (SDTF) was evaluated systematically and a possible foaming mechanism was suggested. The results indicated that a totally different surface but similar microstructure morphology of SDTF was developed, which displayed a larger cell size and thicker cell wall than standard tannin-furanic-formaldehyde foam (STF). A much lower pulverization ratio (approximately 4.6%) was reached for SDTF with respect to STF even though its compression strength was only less than half. An excellent thermal insulation performance was verified by the thermal conductivity of SDTF, only approximately 0.0286 W/m·K, which is considered ultra-low value that the STF cannot reach or seldom reach after STF modification or/and special structure design. The flame retardancy of SDTF was investigated by LOI and ignition experiment, which demonstrated a strong flame resistance and self-extinguishing nature, rendering it superior to STF. This preparation strategy provides a promising sustainable and environmentally friendly method for fabrication of green tannin-furanic foam for industry applications.

Radio-frequency treatment of medium-gluten wheat: effects of tempering moisture and treatment time on wheat quality.

Wheat and wheat flour are important raw materials of staple foods. Medium-gluten wheat is now the dominant wheat in China. In order to expand the application of medium-gluten wheat, radio-frequency (RF) technology was used to improve its quality. Effects of tempering moisture content (TMC) of wheat and RF treatment time on wheat quality were investigated. No evident change in protein content after RF treatment, but a reduction in wet gluten content of the sample with 10-18% TMC and RF treatment for 5 min, was observed. By contrast, protein content increased to 31.0% after RF treatment for 9 min in 14% TMC wheat, achieving the requirement of high-gluten wheat (≥30.0%). Thermodynamic and pasting properties indicated that RF treatment (14% TMC, 5 min) can alter the double-helical structure and pasting viscosities of flour. In addition, the results of textural analysis and sensory evaluation for Chinese steamed bread showed that RF treatment for 5 min with different TMC (10-18%) wheat could deteriorate wheat quality, while the wheat (14% TMC) treated with RF for 9 min had the best quality. RF treatment for 9 min can improve wheat quality when the TMC was 14%. The results are beneficial to the application of RF technology in wheat processing and improvement of wheat flour quality. © 2023 Society of Chemical Industry.

Lexicon development and quantitative descriptive analysis of Chinese steamed bread

Instrumental analysis showed that steamed breads made with Chinese traditional sourdoughs from different origins had different aroma components. However, the analysis of flavor characteristics of Chinese steamed breads (CSBs) using human olfactory perception was rarely reported. In this study, eleven CSBs made of different Chinese traditional sourdoughs were collected to develop a lexicon and a quantitative descriptive analysis (QDA) method suitable for the sensory evaluation of CSBs. A terminology lexicon consisting of 14 flavor attributes (the odors of cellar, sweet, alkaline, sour aromatic, butyric acid, sourdough, overripe and yeasty; the tastes of sweet, sour and acetic acid; the after-tastes of bitter, sweet and sour) was developed by 11 trained panelists. The QDA method was conducted to evaluate the intensities of CSB flavor attributes. Cluster analysis indicated that eight CSBs were divided into four categories: CSBs made of Shangqiu, Tanghe and Xi'an sourdoughs had a unique property of sour, CSBs fermented by Heze and Zhenping sourdoughs had rich sensory attributes, CSBs made with Minqin, Taian, Zhumadian, Weinan and Nanyang sourdoughs had bland flavor, and CSB fermented by Angel yeast had a prominent characteristic of sweet. QDA method was accurate and applicable for analyzing flavor characteristics of CSB.

Zinc concentration and bioavailability of Chinese steamed bread prepared from foliar zinc-biofortified wheat grain.

Increasing the concentration of zinc (Zn) in a widely consumed staple food, such as Chinese steamed bread (CSB), is a promising strategy for alleviating Zn malnutrition in humans. The aim of this study, which was based on a 2-year field experiment, was to evaluate the effectiveness of spraying Zn fertilizer combined with commonly applied (i) pesticides and/or (ii) KH2 PO4 (PK) to increase the concentration of Zn and its bioavailability in wheat grain and the CSB derived from it. All the foliar Zn applications (foliar Zn alone or combined with pesticides and PK) significantly increased the concentration of Zn in grain and derived CSB by 69.1% and 63.1%, respectively. Milling caused an 86-88% loss of Zn, while the process of producing CSB caused an 11-26% increase in the concentration of Zn. A net gain of 2.5-8.3 mg Zn kg-1 of CSB was achieved owing to foliar applications of Zn. The concentration of phytic acid (PA) decreased dramatically during milling (89-90%) and the production of CSB (69-72%). As a result, the Zn bioavailability was greater in the CSB than in grain. Foliar applications of Zn also increased the estimated Zn bioavailability of CSB to be as high as 5.5-7.8 mg, which is adequate for human nutrition. Enrichment with Zn had no adverse effects on the quality of CSB. The mixture of foliar Zn with pesticides and PK represents a useful approach to improve the bioavailable Zn of CSB without altering its quality. © 2023 Society of Chemical Industry.

Effect of the addition of microwave, roasting pre‐treated pea flour on dough properties, sensory attributes, and nutritional profiles of steamed bread

SummaryFood fortification with whole or de‐hulled pulse flours is a challenge since food products usually have inferior structure and sensory characteristics. In this study, wheat flour was substituted with whole or de‐hulled pea flour (20 wt%) processed under pre‐treatments of microwave and roasting to prepare novel Chinese steamed bread (CSB), respectively, and the effect on pasting property of the dough, and its influence on physical quality, sensory attributes, and nutritional profile (amino acids, dietary fibre, and mineral micronutrients) of the resulting CSB was investigated. The addition of pretreated pea flour increased the peak, retraction and final viscosity of the dough and increased the specific volume and decreased the hardness of the final product due to the enhanced pasting characteristics, compared to the control. Microwave and roasting presented different patterns affecting gas cell structure, amino acid composition, dietary fibre content, and essential minerals, depending to a large extent on the milling fraction. Among all the treatments, microwave‐treated de‐hulled pea flour was more effective in modifying the cellular structure, improving amino acid composition and dietary fibre content of the resultant CSBs. This study offers useful knowledge for creating functional CSB that satisfies the needs for both sensory appeal and nutritional balance.

Effect of Alkali on the Microbial Community and Aroma Profile of Chinese Steamed Bread Prepared with Chinese Traditional Starter.

Alkali is an indispensable additive in Chinese steamed bread (CSB) production. This work aimed to evaluate the key roles of alkali in the microbial community of dough fermented using Chinese traditional starter (CTS) and the aroma profiles of CSB. The dominant fungi in CTS and fermented dough were members of the phylum Ascomycota and the genus Saccharomyces. Pediococcus, Companilactobacillus, and Weissella were the dominant bacterial genera in CTS and fermented dough. Adding alkali could retain the types of dominant yeasts and LAB derived from CTS, decrease the relative abundance of Companilactobacillus crustorum and Weissella cibaria, and increase that of Pediococcus pentosaceus, in fermented dough. Principal component analysis (PCA) indicated that adding alkali decreased the content of sourness-related volatiles in CSB fermented by CTS. Correlation analysis showed that Pediococcus and Weissella in fermented dough were positively correlated with the lipid oxidation flavor-related compounds in CSB, and Lactobacillus was positively correlated with sourness-related aroma compounds. Synthetic microbial community experiments indicated that CSB fermented by the starter containing P. pentosaceus possessed a strong aroma, and adding alkali weakened the flavor intensity. Alkali addition could promote the formation of ethyl acetate and methyl acetate with a pleasant fruity aroma in W. cibaria-associated CSB.

Exploration of microbial profile of traditional starters and its influence on aroma profile and quality of Chinese steamed bread.

Chinese steamed bread (CSB) is a popular staple food in China with traditional ethnic characteristics. CSB with traditional starters has good flavor and texture but is unstable and requires a long preparation time. Therefore, it is necessary to analyze the traditional starters (ST) and their influence on the flavor and quality of steamed bread to meet people's requirements as a staple food. The count of yeast, lactic acid bacteria and total microbial population significantly varied in different traditional starters; Saccharomyces and Lactobacillus were the predominant genera. Among the tested samples, fungi were found in ST from Shijiazhuang (SJ), Handan (HD) and Langfang (LF), while bacteria were found in ST from Tangshan (TS) and SJ at sub-predominant levels. In terms of the bread quality, the highest specific volume and porosity were in XT-CSB (Xingtai); the highest height/diameter ratio was in SJ-CSB; and the highest sensory score was in TS-CSB. A total of 26 aroma compounds (VIP > 1; variable importance for predictive components) were identified to discriminate CSB fermented with different starters, which were separated by stepwise canonical discriminant analysis using two functions. The correlation analysis among microbiota, aroma compounds and bread quality showed a higher contribution of bacteria than of fungi. Differences in microbial profiles caused different aroma profiles and quality of CSB; and the CSB fermented with traditional starters were sufficiently separated by stepwise canonical discriminant analysis based on aroma compounds. © 2023 Society of Chemical Industry.

Empirical and Theoretical Bases of Good Steamed Bread Production.

Chinese steamed bread (CSB) is a main staple food in China, accounting for 40% of wheat flour usage in China. Due to its health benefits, CSB is gaining popularity across the world. In this review, the effects of gluten proteins (particularly glutenins and gliadins) on the quality of CSB are summarized from the literature. Requirements of appropriate rheological parameters in different studies are compared and discussed. Along with the increasing demand for frozen storage food, there are obvious increases in the research on the dynamics of gluten proteins in frozen dough. This review also summarizes the factors influencing the deterioration of CSB dough quality during frozen storage as well as effective measures to mitigate the negative effects.

Effect of Enyzmes on the Quality and Predicting Glycaemic Response of Chinese Steamed Bread.

The present study investigates the individual and interactional effects of α-amylase (6 and 10 ppm), xylanase (70 and 120 ppm) and cellulase (35 and 60 ppm) on the physicochemical characteristics and nutritional quality of Chinese steamed bread (CSB) incorporated with 15% oat bran. As a result, the single enzyme can significantly improve the specific volume and texture of CSB. Compared to the single enzyme, the combined enzymes improved the specific volume of CSB up to the highest value (2.51 mL/g) and decreased the hardness to the minimum value (233.61 g) when the concentration was 6, 70 and 35 ppm. With respect to chemical and nutritional properties, the addition of single enzyme had no great changes, while the combined enzymes (6, 70 and 35 ppm) significantly (p &lt; 0.05) decreased the total starch from 37.52 to 34.11% and hence increased the area under the reducing sugar release curve during 2 h in vitro digestion (AUC) from 344.61 to 371.26. Consequently, enzymes combination can significantly improve the quality of oat bran CSB whereas reduce the nutritional value of oat bran CSB.

Subtle differences in starch fine molecular structure are associated with large differences in texture and digestibility of Chinese steamed bread

Chinese steamed bread (CSB) is a staple food for a large number of people in China, but it has a high glycemic index, which is nutritionally undesirable. Developing a CSB with more slowly digestible starch has been achieved, but current processes for this result in a product with poor sensory appeal. In this study, the relations among starch chain-length distribution, starch digestibility and texture of CSBs made from 10 different wheat flour varieties were investigated, the long-term aim being to develop CSBs with an optimal combination of slow starch digestibility and desirable texture. Although there were only small differences among the CLDs of different wheat flours, they were strongly correlated to the differences of both starch digestibility and textural attributes of CSB. A slower starch digestion rate was associated with relatively longer amylose intermediate to long chains, lower amounts of amylopectin short chains and higher amounts of amylose short chains. A softer CSB texture was related to a relatively higher amount of amylopectin long chains and shorter amylopectin short chains. A higher springiness/resilience of CSB was associated with more amylopectin long chains, longer amylose intermediate to long chains, fewer amylose long chains, and smaller average chain length of amylopectin short chains. A higher cohesiveness of CSB was developed with a higher amount of amylopectin long chains. These results suggest that it is feasible to produce CSB with both slow starch digestibility and desirable texture, by choosing the wheat flour with optimized starch structures. Small variance of wheat starch chain-length distribution can cause a significant difference of starch digestibility and texture of Chinese steamed bread. • Small differences exist among wheat starch chain-length distributions. • Slower starch digestibility associated with higher amounts of amylose short chains. • A softer texture of Chinese steamed bread related to more amylopectin long chains. • Higher springiness of Chinese steamed bread related to fewer amylose long chains.

Preparation and characterisation of plant and dairy-based high protein Chinese steamed breads (mantou): Microstructural characteristics and gastro-small intestinal starch digestion in vitro

The effects of dairy and plant protein addition on microstructural characteristics and in vitro gastro-small intestinal starch digestion characteristics of Chinese steamed breads (CSBs) were studied. Breads containing rennet casein (RC) and a mixture of soy protein isolate and milk protein concentrate (SM) at two different levels (RC I, RC II; SM I, SM II) were prepared. Microstructural characteristics of the undigested and digested control (100% wheat flour) bread and high protein steam bread (HPCSB) versions were compared through scanning electron microscopy. The compact microstructure of HPCSBs displayed a network of proteins wrapped around starch granules and had fewer air cells compared to the control. The addition of both proteins influenced the microstructure of HPCSBs, which in turn affected their textural and starch digestion properties. The in vitro starch digestion of control CSB and HPCSBs confirmed that the addition of proteins is capable of lowering the starch hydrolysis (%). The highest starch hydrolysis was observed for the control wheat bread, followed by SM1 > RC I > SM II and RC II at the end of the small-intestinal digestion. The estimated glycaemic indices (eGI) for all HPCSBs were statistically lower than the control CSB. In comparison to control CSB, the microstructure of HPCSBs appeared more irregular, less porous, and compact during gastric and small intestinal digestion.