Effect of pre-treated wheat bran on semi-dried whole wheat noodles for extending shelf-life and improving quality characteristics

Research progress on processing and nutritional properties of fermented cereals

Fermented foods, especially those derived from cereals, are significant contributors to the diversification of global diets. As people pay increasing attention to food taste, flavor, and nutritional balance, conducting a comprehensive and integrated evaluation of the role of fermentation technology in cereals has become a top priority. This article reviews relevant research conducted in recent years, summarizing the fermentation conditions of cereals and focusing on the effects of fermentation on the nutritional value and health benefits of cereals, including its impact on basic components such as starch and dietary fiber. Fermentation can enhance the content of bioactive substances in cereals, playing a positive role in preventing chronic diseases such as type 2 diabetes, cancer, and hypertension. Finally, the article summarizes prospects for future market development of fermented cereal products, aiming to provide insights for improving the edible quality of fermented cereal-based products and developing functional fermented cereal products.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-06099-6.

Fermentation biotechnology applied to wheat bran for the degradation of cell wall fiber and its potential health benefits: A review

Consumption of wheat bran is associated with health benefits. However, the insoluble cell layer fiber and considerable levels of anti-nutritional factors limit bioavailability of wheat bran, which can be effectively improved through fermentation. To comprehensively elucidate the precise biotransformation and health benefits mechanisms underlying wheat bran fermentation. This review investigates current fermentation biotechnology for wheat bran, nutritional effects of fermented wheat bran, mechanisms by which fermented wheat bran induces health benefits, and the application of fermented wheat bran in food systems. The potential strategies to improve fermented wheat bran and existing limitations on its application are also covered. Current findings support that microorganisms produce enzymes that degrade the cell wall fiber of wheat bran during the fermentation, releasing nutrients and producing new active substances while degrading anti-nutrient factors in order to effectively improve nutrient bioavailability, enhance antioxidant activity, and regulate gut microbes for health effects. Fermentation has been an effective way to degrade cell wall fiber, thereby improving nutrition and quality of whole grain or bran-rich food products. Currently, there is a lack of standardization in fermentation and human intervention studies. In conclusion, understanding effects of fermentation on wheat bran should guide the development and application of bran-rich products.

Effect of sourdough on the quality of whole wheat fresh noodles fermented with exopolysaccharide lactic acid bacteria

In this study, the impact of exopolysaccharides (EPS)-positive strain Weissella cibaria (W. cibaria) fermented sourdough on the quality of whole wheat fresh noodles (WWNs) and its improvement mechanisms were studied. The optimal fermentation conditions were found to be 30% sucrose content, fermented at 25 °C for 12 h, which yielded the highest EPS, 28.06 g/kg, in the W. cibaria fermented sourdough with sucrose (DW+). During storage, the sourdough reduced polyphenol oxidase activities and delayed the browning rate of noodles. The DW+ increased the hardness by 11.98% from 2184.99 to 2446.83 g, and the adhesiveness increased by 19.60%, i.e., from 72.01 to 86.13 g∙s of the noodles. The EPS mitigated acidification of sourdough, prevented the disaggregation of glutenin macropolymers (GMP), and increased sourdough elastic modulus. In addition, scanning electron microscope and confocal laser scanning microscopy of noodles containing EPS sourdough also demonstrated the uniform distribution of gluten proteins. The starch granules were also closely embedded in the gluten network. Thus, the present work indicated that the EPS produced sourdough delayed browning and improved the WWNs texture, indicating its potential to enhance the quality of whole grain noodles.

The Quality Characteristics Comparison of Stone-Milled Dried Whole Wheat Noodles, Dried Wheat Noodles, and Commercially Dried Whole Wheat Noodles

To explore the quality differences between dried wheat noodles (DWNs), stone-milled dried whole wheat noodles (SDWWNs), and commercially dried whole wheat noodles (CDWWNs), the cooking quality, texture properties, microstructure, protein secondary structure, short-range order of starch, antioxidant activity, in vitro digestive properties, and estimated glycemic index (eGI) of the noodles were investigated. The results showed that the cooking loss of SDWWNs was significantly lower than that of CDWWNs. The springiness, cohesiveness, gumminess, chewiness, and resilience of SDWWNs reached the maximum, and the tensile strength was significantly increased. The continuity of the gluten network of SDWWNs was reduced, and more holes appeared. The protein secondary structure of the SDWWNs and CDWWNs was mainly dominated by the β-sheet and β-turn, and the differences in the starch short-range order were not significant. Prior to and after the in vitro simulated digestion, the DPPH radical scavenging activity, the hydroxyl radical scavenging activity, and the total reducing power of the SDWWNs were the highest. Although the digested starch content of SDWWNs did not differ significantly from that of CDWWNs, the eGI was significantly lower than that of the CDWWNs and DWNs. Overall, the SDWWNs had certain advantages, in terms of quality characteristics.

Effect of Fermentation on the Quality of Dried Hollow Noodles and the Related Starch Properties

Crumbly dough fermentation was applied to produce dried hollow noodles, with Lactobacillus plantarum, Koji and yeast as the main fermenting agents. The cooking, textural and digestive properties of the noodles were studied, followed by the morphological, crystalline and thermal properties of the starch. The results show that, compared to unfermented noodles, the optimal cooking time of Koji pre-fermented noodles (KJHN) decreased from 460 s to 253 s, and they possessed a higher percentage of weakly bound water and degree of gelatinization at the same cooking time. After cooking, KJHN had a softer texture and higher starch digestibility. In addition, the physicochemical properties of the KJHN and Lactobacillus plantarum pre-fermented noodles (LPHN) showed a decrease in pH and amylose content, and an increase in reducing sugars content. The starch extracted from KJHN and LPHN had significant superficial erosion and pore characteristics, and the gelatinization enthalpy, relative crystallinity and short-range order were all increased. These changes in the starch properties and the quality characteristics of noodles resulting from Koji fermentation might provide a reference for the development of easy-to-cook and easy-to-digest noodles.

Effects of Lactobacillus plantarum and Saccharomyces cerevisiae co-fermentation on the structure and flavor of wheat noodles

BACKGROUND

Although traditional fermented noodles possess high eating quality, it is difficult to realize large-scale industrialization as a result of the complexity of spontaneous fermentation. In present study, commercial Lactobacillus plantarum and Saccharomyces cerevisiae were applied in the preparation of fermented noodles.

RESULTS

The changes in the structural characteristics and aroma components of noodles after fermentation were investigated via scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), low-field magenetic resonance imaging, electronic nose, and simultaneous distillation and extraction/gas chromatography-mass spectrometry (GC-MS) analysis. SEM images revealed that co-fermentation of the L. plantarum and S. cerevisiae for 10-40 min enhanced the continuity of the gluten network and promoted the formation of pores. FTIR spectra analysis showed that the co-fermentation increased significantly (P < 0.05) the proportion of α-helices of noodles gluten protein, enhancing the orderliness of the molecular structure of protein. After fermentation for 10-40 min, the signal density of hydrogen protons increased from the surface to the core, indicating that the water in the noodles migrated inward during a short fermentation process. The results of multivariate statistical analysis demonstrated that the main aroma differences between unfermented and fermented noodles were mainly in hydrocarbons, aromatic compounds and inorganic sulfides. GC-MS analysis indicated that the main volatile compounds detected were 2, 4-di-tert-butylphenol, bis (2-ethylhexyl) adipate, butyl acetate, dibutyl phthalate, dioctyl terephthalate, bis (2-ethylhexyl) phthalate, pentanol and 2-pentylfuran, etc. CONCLUSION: Co-fermentation with L. plantarum and S. cerevisiae improved the structure of gluten network and imparted more desirable volatile components to wheat noodles. © 2022 Society of Chemical Industry.

Impact of Fermented Wheat Bran Dietary Fiber Addition on Dough Rheological Properties and Noodle Quality

This study aimed to evaluate the effect of fermented wheat bran dietary fiber (FWBDF) on the rheological properties of the dough and the quality of noodles and to compare it with the effect of the unfermented WBDF (UWBDF). WBDF was fermented with Auricularia polytricha. The results showed that adding UWBDF/FWBDF increased the storage modulus G' and loss modulus G” of the dough, converted α-helices and β-turns into β-sheets and random coils, respectively, inhibited water flow, increased cooking loss, and decreased the maximum resistance in the noodles. The formed gluten network had a more random and rigid structure, resulting in the deterioration of the quality of noodles. Furthermore, the number of α-helices and the peak proportions of weakly bound water A₂₂ increased but the number of β-sheets and cooking loss decreased in the FWBDF group compared with the UWBDF group. FWBDF (≤4%) improved the hardness of noodles, while UWBDF decreased it. These changes indicated that fermentation could reduce the destructive effects of WBDF on the quality of noodles, providing a new perspective on balancing dietary fiber-rich and high-quality foods.

Changes in physicochemical properties of rice flour by fermentation with koji and its potential use in gluten-free noodles

To use rice flour as an ingredient in gluten-free noodles, improved texture properties such as increased hardness and reduced adhesiveness are required. We investigated the physicochemical characteristics of rice flour obtained by fermenting japonica rice with koji, determined the pasting and textural properties of the resulting gel, and suggested a method for producing gluten-free noodles. Koji-fermented rice flour was obtained by fermenting rice grains for 24 and 48 h. Koji fermentation reduced the protein and ash content of the rice and lowered the pH. The change in amylose content was not significant, but the short-to-long-chain ratio of amylopectin increased. Changes in the structural and compositional characteristics facilitated swelling of the rice flour and starch leaching. Variations in the gelatinization and hydration properties of the rice flour increased its peak viscosity and gel hardness, and reduced its gel adhesiveness. Noodles made from koji-fermented rice flour have improved physical features, such as modified textural properties resulting from a gel texture and increased whiteness, indicating that koji-fermented rice flour is a desirable noodle ingredient for gluten-free foods.