Health Functions of Egg Protein

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.

The effects of sucrose/NaCl combined pickling on the textural characteristics, moisture distribution, and protein aggregation behavior of egg yolk

Salted egg yolks have a tender, loose, gritty, and oily texture and are commonly employed as fillings in baked goods. This study investigated the formation mechanism of egg yolk gels using three different pickling methods: NaCl, sucrose, and mixed groups. The results revealed that of these pickling methods, egg yolks pickled with the mixture had the lowest moisture content (11.59% at 25°C and 10.21% at 45°C), almost no free water content, and the highest hardness (19.11 N at 25°C and 31.01 N at 45°C). Intermolecular force measurements indicated that pickling with the mixture mitigated the surface hardening effect of sucrose and facilitated protein cross-linking. Moreover, confocal laser scanning microscopy of the egg yolk gels pickled with the mixture displayed macromolecular aggregates and oil exudation, suggesting that this method partially disrupted the lipoprotein structure and notably promoted yolk protein aggregation and lipid release. Overall, egg yolks formed a dense gel via the mixed pickling method owing to the ionic concentration and dehydration effects. These findings show the impact of NaCl and sucrose in pickling egg yolks, providing a crucial foundation for developing innovative and desirable egg yolk products. PRACTICAL APPLICATION: This study introduces a novel pickling strategy that combines sucrose and NaCl for egg yolk processing. The egg yolk pickled using this method exhibited improved quality according to the evaluated textural characteristics, moisture distribution, and protein aggregation behavior. The findings may broaden the use of sucrose as a pickling agent for egg yolk processing and provide new ideas for developing and producing pickled eggs and other food products.

Quality of plant-based diets and frailty incidence: a prospective analysis of UK biobank participants

BACKGROUND

Substantial evidence supports the inverse association between adherence to healthy dietary patterns and frailty risk. However, the role of plant-based diets, particularly their quality, is poorly known.

OBJECTIVE

To examine the association of two plant-based diets with incidence of physical frailty in middle-aged and older adults.

DESIGN

Prospective cohort.

SETTING

United Kingdom.

SUBJECTS

24,996 individuals aged 40-70 years, followed from 2009-12 to 2019-22.

METHODS

Based on at least two 24-h diet assessments, we built two diet indices: (i) the healthful Plant-based Diet Index (hPDI) and (ii) the unhealthful Plant-based Diet Index (uPDI). Incident frailty was defined as developing ≥3 out of 5 of the Fried criteria. We used Cox models to estimate relative risks (RR), and their 95% confidence interval (CI), of incident frailty adjusted for the main potential confounders.

RESULTS

After a median follow-up of 6.72 years, 428 cases of frailty were ascertained. The RR (95% CI) of frailty was 0.62 (0.48-0.80) for the highest versus lowest tertile of the hPDI and 1.61 (1.26-2.05) for the uPDI. The consumption of healthy plant foods was associated with lower frailty risk (RR per serving 0.93 (0.90-0.96)). The hPDI was directly, and the uPDI inversely, associated with higher risk of low physical activity, slow walking speed and weak hand grip, and the uPDI with higher risk of exhaustion.

CONCLUSIONS

In British middle-age and older adults, greater adherence to the hPDI was associated with lower risk of frailty, whereas greater adherence to the uPDI was associated with higher risk.

Nutritional Values and Bio-Functional Properties of Fungal Proteins: Applications in Foods as a Sustainable Source

From the preparation of bread, cheese, beer, and condiments to vegetarian meat products, fungi play a leading role in the food fermentation industry. With the shortage of global protein resources and the decrease in cultivated land, fungal protein has received much attention for its sustainability. Fungi are high in protein, rich in amino acids, low in fat, and almost cholesterol-free. These properties mean they could be used as a promising supplement for animal and plant proteins. The selection of strains and the fermentation process dominate the flavor and quality of fungal-protein-based products. In terms of function, fungal proteins exhibit better digestive properties, can regulate blood lipid and cholesterol levels, improve immunity, and promote gut health. However, consumer acceptance of fungal proteins is low due to their flavor and safety. Thus, this review puts forward prospects in terms of these issues.

The Impact of Processing and Extraction Methods on the Allergenicity of Targeted Protein Quantification as Well as Bioactive Peptides Derived from Egg

This review article discusses advanced extraction methods to enhance the functionality of egg-derived peptides while reducing their allergenicity. While eggs are considered a nutrient-dense food, some proteins can cause allergic reactions in susceptible individuals. Therefore, various methods have been developed to reduce the allergenicity of egg-derived proteins, such as enzymatic hydrolysis, heat treatment, and glycosylation. In addition to reducing allergenicity, advanced extraction methods can enhance the functionality of egg-derived peptides. Techniques such as membrane separation, chromatography, and electrodialysis can isolate and purify specific egg-derived peptides with desired functional properties, improving their bioactivity. Further, enzymatic hydrolysis can also break down polypeptide sequences and produce bioactive peptides with various health benefits. While liquid chromatography is the most commonly used method to obtain individual proteins for developing novel food products, several challenges are associated with optimizing extraction conditions to maximize functionality and allergenicity reduction. The article also highlights the challenges and future perspectives, including optimizing extraction conditions to maximize functionality and allergenicity reduction. The review concludes by highlighting the potential for future research in this area to improve the safety and efficacy of egg-derived peptides more broadly.