Physicochemical and functional properties of liquid whole egg treated by the application of Pulsed Electric Fields followed by heat in the presence of triethyl citrate

Target and Suspect Screening for Organic Additives in Six Classifications of Personal Care Products Using Liquid Chromatography-High-Resolution Mass Spectrometry

Personal care products (PCPs) are integral components of daily human existence, including a large number of chemicals intentionally added for functional attributes (e.g., preservatives and fragrances) or unintentionally present, such as plasticizers. This investigation aimed to optimize the methodology for target and suspect screening via liquid chromatography-high-resolution mass spectrometry, focusing on nine prevalent organic additives (comprising bisphenols A, F, and S, methyl, ethyl, propyl, and butylparaben, 5-chloro-2-methyl-4-isothiazolin-3-one, and 4-hydroxybenzoic acid). A total of 50 high-selling PCPs were purchased from the local online market as samples. In detail, PCP samples were classified into body washes, shampoos, hair conditioners, facial cleansers, body lotions, and moisture creams. For calibration, the quality assurance and quality control results demonstrated a coefficient of determination (R2) surpassing 0.999, with detection and quantification limits ranging from 2.5 to 100.0 ng/g. For recovery experiments, replicate recoveries (n = 5) ranged from 61 to 134%. In purchased PCP samples, five of the nine target compounds were detected via a target screening. Methylparaben exhibited the highest concentration (7860 mg/kg) in a facial cleanser, which is known as an endocrine-disrupting chemical. A total of 248 suspects of organic additives were screened in PCPs, leading to a tentative identification of 9. Confirmation (confidence level 1) via reference standards was achieved for three suspects, while six were tentatively identified with a confidence level of 2. This two-step extraction methodology utilizing methyl tert-butyl ether and isopropyl alcohol enabled simultaneous analysis of diverse chemical groups with distinct properties.

Improvement of foaming properties of ovalbumin: Insights into the synergistic effect of preheating and high-intensity ultrasound on physicochemical properties and structure analysis

Ovalbumin (OVA), characterized by its high concentration in eggs, possesses remarkable foaming properties. Nevertheless, OVA is highly sensitive to thermal changes and acid-base conditions, substantially hampering its application potential for foaming purposes within the food industry. This experiment aimed to examine the effects of preheating and high-intensity ultrasound (HIU) treatment at different powers on OVA foaming properties and explore the underlying mechanisms. The results revealed that OVA exhibited the highest foaming capacity (31.5 %) and foaming stability (96.7 %) under the treatment condition of 200w + 60°C. Additionally, significant improvements were observed in the content of free sulfhydryl groups (37.27 μmg/g), solution viscosity (142.33 mPa·s), and surface hydrophobicity (37.27 μg BPB) under this condition. The absolute value of the zeta potential (-10.28 mV) was significantly increased in the 200w + 60°C treatment group. Moreover, the polymer dispersity index of OVA (0.6045) was significantly reduced, resulting in improved dispersion than the control group. The structural analysis revealed significant changes in the α-helix and β-sheet content of OVA after treatment at 200w + 60 °C. The X-ray diffraction pattern exhibited sharper peaks, indicating a crystal structure, and the fluorescence peak displayed a slight blue shift along with increased hydrophobicity. Moreover, the preheating and HIU treatment induced a continuous uneven and irregular pore structure in OVA, which ultimately enhanced its foaming properties. In conclusion, the preheating and HIU treatment offers a novel approach to enhance the foaming properties of OVA.

Advances in pulsed electric stimuli as a physical method for treating liquid foods

There is a need for alternative technologies that can deliver safe and nutritious foods at lower costs as compared to conventional processes. Pulsed electric field (PEF) technology has been utilised for a plethora of different applications in the life and physical sciences, such as gene/drug delivery in medicine and extraction of bioactive compounds in food science and technology. PEF technology for treating liquid foods involves engineering principles to develop the equipment, and quantitative biochemistry and microbiology techniques to validate the process. There are numerous challenges to address for its application in liquid foods such as the 5-log pathogen reduction target in food safety, maintaining the food quality, and scale up of this physical approach for industrial integration. Here, we present the engineering principles associated with pulsed electric fields, related inactivation models of microorganisms, electroporation and electropermeabilization theory, to increase the quality and safety of liquid foods; including water, milk, beer, wine, fruit juices, cider, and liquid eggs. Ultimately, we discuss the outlook of the field and emphasise research gaps.

Effect of L-calcium lactate, zinc lactate, and ferric sodium EDTA on the physicochemical and functional properties of liquid whole egg

The study aimed to evaluate the physicochemical and functional properties of liquid whole egg (LWE) with L-calcium lactate (L-Ca), zinc lactate (L-Zn), and sodium ferric EDTA (NaFeEDTA), and to compare with NaCl addition to determine the application potential of these mineral supplements. Results showed that salts addition significantly influenced the foaming, emulsifying, and gelling properties of LWE, which was possible through affecting the pH, particle size, surface hydrophobicity, apparent viscosity, and solubility. The addition of all the four salts reduced pH but increased the d_4,3 diameter of LWE. Additionally, the addition of 200 mM L-Ca and 6 mM L-Zn significantly improved the emulsifying capacity by 41.73% and 13.6%, the foaming capacity by 26.57% and 10%, and the protein solubility by 13.89% and 12.70%, respectively. In the meantime, mineral supplements tend to produce lower hardness gel, especially with 25 mM L-Ca and 8 mM L-Zn, and the hardness was decreased from 2401.13 to 1138.29 and 1175.59 g, respectively. A relative decrease in hardness was desirable in gelled egg products. Moreover, the addition of NaCl and L-Ca showed a higher redness and yellowness, but the addition of NaFeEDTA showed an undesirable color in dark brown, which may be not accepted by the public. In summary, L-Ca and L-Zn had great potential for application in LWE, which was more appropriate than adding NaCl. This study provides a basis for improving the functional properties of LWE products in the future. PRACTICAL APPLICATION: The addition of L-Ca and L-Zn to liquid whole egg (LWE) could improve the foaming and emulsifying capacity of LWE as well as produce a lower hardness gel, which may be more conducive to the production of cake, custards, and meat products. Meantime, it is more in line with people's pursuit of a healthy diet.

Improvement of Foaming Characteristics and Stability of Sterilized Liquid Egg with Egg White Hydrolysate (EWH)

A pasteurized liquid egg leads to protein denaturation and degradation of processing properties, whereas non-pasteurized eggs may have food safety risks. If the negative impact of the pasteurization process on liquid eggs can be reduced, for example, the loss of stability and foamability, companies will be willing to purchase pasteurized eggs, thereby reducing food safety risks. Therefore, in this study, specific hydrolyzation conditions were used to produce egg white hydrolysate (EWH) with a lower molecular mass of amino acid and peptide fragments, and the effects of various concentration of EWH refilling on pasteurized liquid egg properties were investigated. The results showed that up to 30.1% of EWH was hydrolyzed by protease A and papain. Adding 1% (w/w) EWH can improve the negative charge potential value, surface tension, viscosity, and weight loss analysis of the sample. In addition, the cake structure and the appearance was acceptable to consumers. Therefore, to ensure its efficient use in the baking industry and considering the cost and stability, 1% (w/w) EWH was chosen as the best concentration.

Determining Sonication Effect on E. coli in Liquid Egg, Egg Yolk and Albumen and Inspecting Structural Property Changes by Near-Infrared Spectra

In this study, liquid egg, albumen, and egg yolk were artificially inoculated with E. coli. Ultrasound equipment (20/40 kHz, 180/300 W; 30/45/60 min) with a circulation cooling system was used to lower the colony forming units (CFU) of E. coli samples. Frequency, absorbed power, energy dose, and duration of sonication showed a significant impact on E. coli with 0.5 log CFU/mL in albumen, 0.7 log CFU/mL in yolk and 0.5 log CFU/mL decrease at 40 kHz and 6.9 W absorbed power level. Significant linear correlation (p < 0.001) was observed between the energy dose of sonication and the decrease of E. coli. The results showed that sonication can be a useful tool as a supplementary method to reduce the number of microorganism in egg products. With near-infrared (NIR) spectra analysis we were able to detect the structural changes of the egg samples, due to ultrasonic treatment. Principal component analysis (PCA) showed that sonication can alter C-H, C-N, -OH and N-H bonds in egg. The aquagrams showed that sonication can alter the properties of H₂O structure in egg products. The observed data showed that the absorbance of free water (1412 nm), water molecules with one (1440 nm), two (1462 nm), three (1472 nm) and four (1488 nm) hydrogen bonds, water solvation shell (1452 nm) and strongly bonded water (1512 nm) of the egg samples have been changed during ultrasonic treatment.

Effect of citric acid addition on functional properties of pasteurized liquid whole eggs

The aim of this study was to examine the influence of different concentrations of citric acid (0, 300, 400 and 500 mg/L) on the physical and functional properties of pasteurized liquid whole eggs (LWE) over 4 weeks of storage. The properties tested include pH, conductivity, colour, particle size, rheological, and textural properties, as well as protein solubility, foaming and emulsification. The 4 weeks of storage had a statistically significant (P < 0.05) effect on every tested parameter, while the addition of citric acid had a statistically significant (P < 0.05) effect on pH, conductivity, L^* and b^* values, protein solubility, emulsion activity index, emulsion capacity, emulsion stability, and an increase in foaming and texture parameters, but not on rheological parameters. Citric acid addition and a storage period of 4 weeks resulted in a change of pH and an increase in protein solubility. It also led to a lower foaming capacity and a larger drainage of the system, which causes a lower power (work load) requirement to break formed gels. Apparent viscosity did not change significantly in the samples with citric acid.

Effect of preservatives on the shelf-life and sensory characteristics of pasteurized liquid whole egg stored at 4°C

The study focused on the effects of traditional (benzoate-sorbate and triphosphates) and alternative (nisin, Laktocid, Defence JB, and Galimax Flavor) food preservatives on the microbiological quality and sensory properties of pasteurized liquid whole eggs (LWE). The LWE samples with the addition of a test preservative and a control were stored at 4°C for 45 D. The selected microbiological parameters, sensory attributes, and color space parameters were determined. The results were statistically analyzed by means of factorial ANOVA, followed by the Tukey post hoc test. The multivariate method of principal component analysis based on the correlation matrix was employed to assess the relationships between pH and sensory characteristics of LWE. Total plate counts at the end of storage differed significantly, being the lowest in samples with benzoate-sorbate (1.69 ± 0.12 log cfu.g-1) and Laktocid (2.12 ± 0.12 log cfu.g-1). The final counts of lactic acid bacteria on day 45 were lower in the samples with benzoate-sorbate, triphosphates, nisin, and Laktocid (maximum 1.01 ± 1.44 log cfu.g-1). The amounts of yeasts at the end of storage did not differ among samples with different preservatives; none were detected in any samples with the exception of Defence JB (1.28 ± 1.90 log cfu.g-1). The lowest final mold count was observed in LWE with Laktocid (0.92 ± 1.29 log cfu.g-1). In conclusion, Laktocid showed great potential as a preservative; it had however a negative impact on pH value and the sensory properties of LWE.

Effects of Ultrahigh Temperature Pasteurization on the Liquid Components and Functional Properties of Stored Liquid Whole Eggs

Ultrahigh temperature (UHT) pasteurization is often used to sterilize liquid whole eggs in egg processing enterprises in China. Although this treatment generates satisfactory sterilization effect, there are few studies on the processing characteristics and physical and chemical properties of the liquid whole eggs treated by UHT pasteurization. We compared the physical and chemical properties (i.e., foaming ability and stability, emulsification ability and stability, viscosity, thiol content, gel strength, and color) of unsterilized eggs and liquid whole eggs pasteurized with UHT over five weeks of storage. The emulsifying properties of sterilized liquid whole eggs were initially low and decreased further with the storage time. The emulsification stability index of UHT-pasteurized liquid whole eggs was higher than that of unsterilized eggs and increased by 21.9%, from 7.850 to 9.567. The foaming ability of UHT-pasteurized and unsterilized liquid whole eggs increased by 33.38% and 15.48%, respectively. The viscosity, gel strength, and soluble protein content were higher in UHT-pasteurized liquid whole eggs than those in unsterilized liquid whole eggs and increased further with storage time. Our results demonstrate that UHT pasteurization preserves and improves the processing characteristics and shelf life of liquid whole eggs.

Modifying the Functional Properties of Egg Proteins Using Novel Processing Techniques: A Review

Egg proteins can be used in a wide range of food products, owing to their excellent foaming, emulsifying, and gelling properties. Another important functional property is the susceptibility of egg proteins to enzymatic hydrolysis, as protein digestion is closely related to its nutritional value. These functional properties of egg proteins are likely to be changed during food processing. Conventional thermal processing can easily induce protein denaturation and aggregation and consequently reduce the functionality of egg proteins due to the presence of heat-labile proteins. Accordingly, there is interest from the food industry in seeking novel nonthermal or low-thermal techniques that sustain protein functionality. To understand how novel processing techniques, including high hydrostatic pressure, pulsed electric fields, ionizing radiation, ultraviolet light, pulsed light, ultrasound, ozone, and high pressure homogenization, affect protein functionality, this review introduces the mechanisms involved in protein structure modification and describes the structure-functionality relationships. Novel techniques differ in their mechanisms of protein structure modification and some have been shown to improve protein functionality for particular treatment conditions and product forms. Although there is considerable industrial potential for the use of novel techniques, further studies are required to make them a practical reality, as the processing of egg proteins often involves other influencing factors, such as different pH and the presence of other food additives (for example, salts, sugar, and polysaccharides).

Pulsed electric field processing of egg products: a review

Thermal processing ensures safety and enhances the shelf-life of most of the food products. It alters the structural-chemical composition, modifies heat labile components, as well as affects the functional properties of food products. This has driven the development of non-thermal food processing techniques, primarily for extending the shelf-life of different food products. These techniques are currently also being evaluated for their effects on product processing, quality and other safety parameters. Pulsed electric field (PEF) is an example of non-thermal technique which can be applied for a variety of purpose in the food processing industry. PEF can be used for antimicrobial treatment of various food products to improve the storability or food safety, for extraction and recovery of some high-value compounds from a food matrix or for stabilization of various food products through inactivation of some enzymes or catalysts. Research on the application of PEF to control spoilage or pathogenic microorganisms in different egg products is being currently focused. It has been reported that PEF effectively reduces the activity of various microorganisms in a variety of egg products. However, the PEF treatment also alters the structural and functional properties to some extent and there is a high degree of variability between different studies. In addition to integrating findings, the present review also provides several explanations for the inconsistency in findings between different studies related to PEF processing of egg products. Several specific recommendations for future research directions on PEF processing are well discussed in this review.