Effects of short-term fermentation with lactic acid bacteria on egg white: Characterization, rheological and foaming activities

Explore the synergistic effects of Lactobacillus plantarum fermentation and tea polyphenols on the deodorization of egg white powder from the perspective of protein site competition

Spray drying often induces off-odors and diminishes the rehydration capacity of egg white powder (EWP), restricting its utility in food applications. In this study, the synergistic effects of the Lactobacillus plantarum fermentation treatment and the tea polyphenols (TP) addition on the flavor variations, protein structure, microstructure, and dispersion properties of EWP were investigated. The flavor results suggested that fermentation and TP reduced undesirable flavor substances (e.g. nonanal, decanal, and 3-methylbutanal), while the interaction between some volatile organic compounds produced by fermentation and protein flavor-binding sites was enhanced. Fermentation unfolded protein structures, increasing binding sites for TP and improving flavor-binding efficiency. Additionally, strong electrostatic repulsion introduced by fermentation improved the dispersion and stability of the EWP system. This approach provides a promising strategy for deodorizing and solubilizing EWP, advancing its potential in food processing.

Metabolomic and proteomic profiling reveals the formation mechanism of volatile flavor in egg whites during fermentation by Streptococcus thermophilus

In this study, the flavor of egg whites was significantly improved by lactic acid fermentation, and the metabolic networks of metabolites, volatile compounds, and enzymes were established using gas chromatography-mass spectrometry, metabolomic, and proteomic. Results indicate that among ten types of common lactic acid bacteria, Streptococcus thermophilus endowed egg white with the most pleasant flavor through increasing aldehydes, ketones, alcohols, esters, terpenoids, and aromatic compounds. Amino acid catabolism was the predominant pathway for generating most aldehydes, alcohols, acids, and esters. The changes in the organic acids and derivatives (mainly amino acids, peptides, and analogues) concentration during fermentation are attributed to the hydrolysis of egg white proteins by proteinases and peptidases, and the regulation of enzymes involved in amino acid biosynthesis and other reactions. This study provides a valuable reference for future investigations focusing on regulating the flavor release of egg whites.

Modification Effects of Microorganisms and Enzymes on Egg Components: A Review

In eggs, there are several components: eggshell (ES), eggshell membrane (ESM), egg white (EW), and egg yolk (EY). Many modification methods exist, such as thermal treatment, high pressure, freeze-thaw cycles, ultrasonic treatment, ozonation, phosphorylation, and acylation, all aimed at improving the functional properties of EW and EY. Additionally, microorganism and enzyme modifications have proven effective in enhancing the functional properties of EW and EY. ES and ESM are unique components of eggs. The eggshell is rich in calcium carbonate, while the eggshell membrane is rich in protein. The effective utilization of ES and ESM can help promote economic income in the poultry industry and benefit the environment. Research on the modification of ES and ESM has shown that microorganisms and enzymes have the potential to improve their functional properties. After modification, egg components can be utilized in the production of egg-based and other food products for improved performance. Furthermore, enzyme modification of egg components can produce bioactive peptides, which have the potential to treat specific diseases and may even be used in the biomedical field. This review primarily focuses on the effects of microorganisms and enzymes on the modification of egg components and summarizes the roles of microbial and enzymatic modifications in this context.

Lactic acid bacteria fermentation-induced egg white protein structure deformation influencing gelling properties, with membrane concentration as a strategy to improve texture

Egg white (EW), a rich protein source, holds promise for creating a high-protein, low-fat gel product. However, browning issues during heating and sterilization have hindered its wider application. In this study, lactic acid bacteria fermentation was employed to eliminate reducing sugar in EW, and its impact on the molecular structure and gelling properties was explored. The results revealed that fermentation would trigger protein structural unfolding and aggregation, evident from higher fluorescence intensity and enlarged protein particle diameters, resulting in the decrease in gelling hardness. In comparison, Streptococcus thermophilus-fermented EW (under 6 × 108 CFU/mL incubation rate, fermented for 6 h) exhibited the highest gel hardness, ascribed to the relatively weaker structure transformation, with high water holding capacity and stronger intermolecular hydrophobic interaction. To further enhance the gelling properties of fermented EW, membrane concentration treatment was applied, exhibiting superior characteristics in appearance, aroma, and taste. In summary, lactic acid bacteria fermentation and concentration are feasible solutions to improve appearance and texture of EW gels simultaneously. The research findings offer eco-friendly and practical strategies for enhancing the quality of EW gels, providing valuable theoretical insights for the development of innovative, texture-rich, and healthy nutritional foods.

Study on the effect of enzymolysis combined fermentation on reducing the off-flavor of egg white powder

BACKGROUND

The application of egg white powder (EWP) was subject to its off-flavor. In the present study, flavourzyme and lactic acid bacteria were used to treat egg white powder (EWP) and the mechanism effects of enzymolysis-fermentation were explored.

RESULTS

Compared with the control group, enzymolysis combined with fermentation treatment group (EW-EF) reduced the four-representative off-flavor compounds (geranyl acetone, 1-octen-3-ol, octanal and nonanal) by more than 62.66%. Fermentation produced esters with good flavor, and enzymolysis produced fresh amino acids. Characterization of protein structure indicated that fermentation decreased both fluorescence intensity and surface negative charges, accelerating the aggregation of proteins; enzymolysis promoted aggregation and degradation, improving the stability of the egg white proteins. Meanwhile, enzymolysis broke down the hydrophobic cavities bound to off-flavor compounds, releasing protein-bound off-flavor compounds and removing them through fermentation.

CONCLUSION

EW-EF had the best effect of off-flavor removal on EWP. The results of the present study could provide a green and effective method for improving the flavor of EWP. © 2024 Society of Chemical Industry.

Using salted egg white in steamed bread: Impact on functional and structural characteristics

Steamed bread has long been an important part of Chinese cuisine. This study investigated the effects of salted egg white (SEW) (5, 10, 15, and 20% w/w) on the quality of steamed breads. Findings revealed that SEW notably enhanced the bread's volume and texture, with a 20% inclusion significantly boosting water retention and rheological properties, albeit reducing bread's lightness. In addition, the H-bond absorption band intensity in the Fourier transform infrared spectroscopy (FTIR) analysis showed increased peak intensities with higher SEW levels, indicative of protein structure alterations. X-ray diffraction confirmed the presence of an amylose-lipid complex. Scanning electron microscope (SEM) and Confocal laser scanning microscope (CLSM) imaging depicted a smooth, consistent protein network with SEW addition. Consumer sensory evaluation responded favourably to the SEW15 steamed bread, suggesting its potential for food industry application. Overall, the study considers SEW an effective ingredient for improving steamed bread quality.

Emulsifying properties of egg proteins: Influencing factors, modification techniques, and applications

As an essential food ingredient with good nutritional and functional properties and health benefits, eggs are widely utilized in food formulations. In particular, egg proteins have good emulsification properties and can be commonly used in various food products, such as mayonnaise and baked goods. Egg protein particles can act as stabilizers for Pickering emulsions because they can effectively adsorb at the oil-water interface, reduce interfacial tension, and form a stable physical barrier. Due to their emulsifying properties, biocompatibility, controlled release capabilities, and ability to protect bioactive substances, egg proteins have become ideal carriers for encapsulating and delivering functional substances. The focus of this review is to summarize current advances in using egg proteins as emulsifiers. The effects of influencing factors (temperature, pH, and ionic strength) and various modification methods (physical, chemical, and biological modification) on the emulsifying properties of egg proteins are discussed. In addition, the application of egg proteins as emulsifiers in food products is presented. Through in-depth research on the emulsifying properties of egg proteins, the optimization of their applications in food, biomedical, and other fields can be achieved.

Understanding the nutritional benefits through plant proteins-probiotics interactions: mechanisms, challenges, and perspectives

The nutritional benefits of combining probiotics with plant proteins have sparked increasing research interest and drawn significant attention. The interactions between plant proteins and probiotics demonstrate substantial potential for enhancing the functionality of plant proteins. Fermented plant protein foods offer a unique blend of bioactive components and beneficial microorganisms that can enhance gut health and combat chronic diseases. Utilizing various probiotic strains and plant protein sources opens doors to develop innovative probiotic products with enhanced functionalities. Nonetheless, the mechanisms and synergistic effects of these interactions remain not fully understood. This review aims to delve into the roles of promoting health through the intricate interplay of plant proteins and probiotics. The regulatory mechanisms have been elucidated to showcase the synergistic effects, accompanied by a discussion on the challenges and future research prospects. It is essential to recognize that the interactions between plant proteins and probiotics encompass multiple mechanisms, highlighting the need for further research to address challenges in achieving a comprehensive understanding of these mechanisms and their associated health benefits.

Legume protein fermented by lactic acid bacteria: Specific enzymatic hydrolysis, protein composition, structure, and functional properties

In recent years, with increasing emphasis on healthy, green, and sustainable consumption concepts, plant-based foods have gained popularity among consumers. As widely sourced plant-based raw materials, legume proteins are considered sustainable and renewable alternatives to animal proteins. However, legume proteins have limited functional properties, which hinder their application in food products. LAB fermentation is a relatively natural processing method that is safer than chemical/physical modification methods and can enrich the functional properties of legume proteins through biodegradation and modification. Therefore, changes in legume protein composition, structure, and functional properties and their related mechanisms during LAB fermentation are described. In addition, the specific enzymatic hydrolysis mechanisms of different LAB proteolytic systems on legume proteins are also focused in this review. The unique proteolytic systems of different LAB induce specific enzymatic hydrolysis of legume proteins, resulting in the production of hydrolysates with diverse functional properties, including solubility, emulsibility, gelability, and foamability, which are determined by the composition (peptide/amino acid) and structure (secondary/tertiary) of legume proteins after LAB fermentation. The correlation between LAB-specific enzymatic hydrolysis, protein composition and structure, and protein functional properties will assist in selecting legume protein raw materials and LAB strains for legume plant-based food products and expand the application of legume proteins in the food industry.

Comparison and evaluation of L. reuteri and L. rhamnosus-fermented egg yolk on the physicochemical and flavor properties of cookies

The study aims to explore an effective approach to improve the sensory quality and consumer satisfaction of cookies in the food industry. L. reuteri and L. rhamnosus were chosen to ferment egg yolk and their effects on dough properties and physicochemical properties, flavor, texture, color, and sensory acceptability of cookies were studied. Results show that the utilization of fermented egg yolk significantly decreased baking loss and increased spread factor of cookies. GC-MS analysis indicates different Lactobacillus species enhanced cookie flavor through unique mechanisms. Texture analysis shows cookies prepared with L. rhamnosus-fermented egg yolk had significantly lower hardness (1807.12 g) than control cookies (2028.34 g). Sensory evaluation reveals the L. reuteri-fermented egg yolk significantly improved the overall acceptability of cookies by enhancing appearance, flavor, and mouthfeel scores. These findings have practical implications for food manufacturers seeking to enhance their product's quality and appeal, thereby gaining a competitive edge in the market.

Substitution of sucrose by erythritol in angel cake: Effect on protein foaming, baking performance and digestion properties

Sugars played an important role in the processing of products such as cakes, however, their high-calorie character often posed a health risk to consumers. Therefore, this paper aimed to better investigate the effect of sugar substitutes on the improvement of egg white foaming properties and angle cake digestibility characteristics. It was demonstrated that the addition of erythritol improved the surface properties of egg whites, thus enhancing their foaming properties. Particularly, when the erythritol substitution was 50 %, the sugar-egg white complex structure unfolded and had the best foaming capacity. On this basis, the baking performance of angel cakes with sucrose replaced by erythritol was analyzed. When the erythritol substitution was lower than 50 %, the specific volume and the baking loss rate of the cakes were basically unchanged, and the texture and sensory taste of the cakes were all excellent. Finally, the gastrointestinal digestive kinetic analysis suggested that erythritol substitution for sucrose was beneficial for reducing blood glucose levels in vivo. Furthermore, for the MgCl2-based samples, both the degree of protein destruction after digestion was weakened and the glucose-lowering effect was better exerted. Overall, this study provided a new theoretical basis for the low-calorie sugar-substituted health food products development in the future.

The effect of different drying methods on some physico-chemical, functional and protein structure properties of liquid egg white fermented by Lactobacillus rhamnosus GG

This research aims to understand the effect of Lactobacillus rhamnosus GG fermentation on egg white powder. In this study, some physico-chemical, functional, textural, and protein structure properties of microwave (MD) and oven dried (OD) egg white powders were determined. The fermentation process decreased the pH value (5.92, 5.82) and foaming capacity (20.83%, 27.20%) of MD and OD groups. The highest yield (11.61%) and emulsion capacity values (78.17%) were observed in fermented oven dried group. While MD group (703.22 g) had the lowest hardness value, OD group (3301.35 g) exhibited highest hardness value. The denaturation peaks of the samples were ranged between 61.00 °C and 80.43 °C. Scanning electron microscopy images of all sample groups showed broken glass structure. This study suggests that fermentation (L. rhamnosus GG) can effectively improve the quality properties of egg white powder and thus fermented egg white powders could be used in the food industry.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05766-4.

Investigation on physicochemical properties, sensory quality and storage stability of mayonnaise prepared from lactic acid fermented egg yolk

In this research, the physicochemical properties, sensory quality, and storage stability of mayonnaise prepared from egg yolk fermented for different times (0, 3, 6, and 9 h) have been investigated. Compared with control mayonnaise (3.50 μm and 92.88%), mayonnaise prepared from fermented egg yolk possessed significantly lower particle size (3.32-3.41 μm) and higher emulsion stability (97.26-98.72%). Meanwhile, texture, color, and gas chromatography-mass spectrometry (GC-MS) analysis revealed that the fermented egg yolk significantly enhanced the firmness, consistency and cohesiveness, lightness and redness, and flavor profile of mayonnaise. Sensory evaluation showed that mayonnaise with 3 h-fermented egg yolk exhibited the highest sensory scores. And the microscopic and appearance characteristics revealed that fermented egg yolk endowed mayonnaise with a more stable appearance after 30 days of storage. These results indicated that lactic acid fermentation of egg yolk is a feasible way to improve consumer acceptability and shelf life of mayonnaise.

Research advance of non-thermal processing technologies on ovalbumin properties: The gelation, foaming, emulsification, allergenicity, immunoregulation and its delivery system application

Ovalbumin (OVA) is the most abundant protein in egg white, with excellent functional properties (e.g., gelling, foaming, emulsifying properties). Nevertheless, OVA has strong allergenicity, which is usually mediated by specific IgE thus results in gut microbiota dysbiosis and causes atopic dermatitis, asthma, and other inflammation actions. Processing technologies and the interactions with other active ingredients can influence the functional properties and allergic epitopes of OVA. This review focuses on the non-thermal processing technologies effects on the functional properties and allergenicity of OVA. Moreover, the research advance about immunomodulatory mechanisms of OVA-mediated food allergy and the role of gut microbiota in OVA allergy was summarized. Finally, the interactions between OVA and active ingredients (such as polyphenols and polysaccharides) and OVA-based delivery systems construction are summarized. Compared with traditional thermal processing technologies, novel non-thermal processing techniques have less damage to OVA nutritional value, which also improve OVA properties. OVA can interact with various active ingredients by covalent and non-covalent interactions during processing, which can alter the structure or allergic epitopes to affect OVA/active components properties. The interactions can promote OVA-based delivery systems construction, such as emulsions, hydrogels, microencapsulation, nanoparticles to encapsulate bioactive components and monitor freshness for improving foods quality and safety.

Addition of NaCl or Sucrose on the Protein Content, and Functional and Physicochemical Properties of Egg Whites Liquid under Heat Treatment

In this study, differences in the protein content and functional and physicochemical properties of four varieties of egg white (EW) were studied by adding 4-10% sucrose or NaCl and then heating them at 70 °C for 3 min. According to a high-performance liquid chromatography (HPLC) analysis, the percentages of ovalbumin, lysozyme and ovotransferrin rose with an increase in the NaCl or sucrose concentration; however, the percentages of ovomucin and ovomucoid decreased. Furthermore, the foaming properties, gel properties, particle size, α-helixes, β-sheets, sulfhydryl groups and disulfide bond content also increased, whereas the content of β-turns and random coils decreased. In addition, the total soluble protein content and functional and physicochemical properties of black bone (BB) chicken and Gu-shi (GS) EWs were higher than those of Hy-Line brown (HY-LINE) and Harbin White (HW) Ews (p < 0.05). Subsequently, transmission electron microscopy (TEM) confirmed the changes in the EW protein structure in the four varieties of Ews. As the aggregations increased, the functional and physicochemical properties decreased. The protein content and functional and physicochemical properties of Ews after heating were correlated with the concentration of NaCl and sucrose and the EW varieties.

Study on gel properties of lysozyme-free egg white before and after Lactiplantibacillus plantarum fermentation

BACKGROUND

Isolation of lysozyme from egg white (EW) using ion exchange resin adsorption method generates large quantities of lysozyme-free egg white (LFEW) with poor gelling property. To maximize the applications of LFEW, the effect of Lactiplantibacillus plantarum fermentation on the gel properties of LFEW was investigated in this study.

RESULTS

The fermentation efficiency of LFEW with lysozyme removed was significantly improved, and the sugar removal rate (2 g kg^-1 Lactiplantibacillus plantarum, 37 °C, 7 h) was more than 90%. Removal of lysozyme resulted in increased stability and surface hydrophobicity of EW. After Lactiplantibacillus plantarum fermentation, the stability of EW decreased, and the average particle size and surface hydrophobicity increased. In addition, by comparing the gel properties of EW and LFEW before and after fermentation at different pH, it was found that the hardness, elasticity, and water holding capacity (WHC) of EW gel increased significantly. The removal of lysozyme effectively improved the WHC and springiness of the EW gel and promoted the formation of a denser network structure with smaller pores. After Lactiplantibacillus plantarum fermentation treatment, LFEW gel hardness decreased, with loose and porous network structure, no browning occurred after autoclaving.

CONCLUSION

This study provided the direction and theoretical basis for producing a fermented LFEW gel with pleasing texture and appearance. © 2022 Society of Chemical Industry.

Fermented egg-milk beverage alleviates dextran sulfate sodium-induced colitis in mice through the modulation of intestinal flora and short-chain fatty acids

Fermented egg-milk beverage (FEMB) can alleviate the symptoms of intestinal diseases by regulating intestinal flora and supplying nutrition. This study investigated the protective effect of FEMB on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. The results showed that FEMB relieved the UC mice's pathological abnormalities and colonic inflammation, and restructured the intestinal flora composition simultaneously. After FEMB treatment for 14 days, the body weight of the mice rose and the disease activity index (DAI) value decreased. Furthermore, the length and form of colons in the UC mice were notably restored. Inflammatory cells decreased or disappeared, and goblet cells and crypt were enriched and modified. 16S rRNA gene sequencing results demonstrated that FEMB treatment could increase the abundance of beneficial bacteria in the cecum content of mice, including unclassified_f_Lachnospiraceae and Lactobacillus. Moreover, probiotics that can increase the content of short-chain fatty acids (SCFAs) may contribute to inflammation alleviation. An increase in amino acids was observed in our experiment, which may benefit nutritional supplements. In conclusion, FEMB treatment can alleviate the damage of DSS-induced colitis in Balb/c mice. This study provides a theoretical basis for both the relief of inflammation and the application of FEMB.

Effects of short-term fermentation with lactic acid bacteria on the characterization, rheological and emulsifying properties of egg yolk

Lactic acid bacteria fermentation is a safe and green technology that can modify the function of food ingredients (including proteins). In this article, egg yolks were subjected to fermentation with commercial lactic acid bacteria for 0, 3, 6 and 9 h, respectively. After fermentation treatment, the microbial composition has changed obviously (Streptococcus thermophilus increased significantly). The free sulfhydryl group (SH) contents and surface hydrophobicity of egg yolk proteins were significantly reduced. The rheological results indicated that the treated egg yolks possessed a decreased apparent viscosity. Correspondingly, the emulsifying activity of egg yolk was enhanced from 9.07 to 19.55, 23.40 and 24.61 m²/g for 3, 6 and 9 h of fermentation, respectively. And the emulsifying stability reached the maximum after 3 h of fermentation. This study investigated the relationship between structure and properties of yolk proteins, and showed that lactic acid fermentation endued egg yolk with better emulsifying properties.