Spray-dried Yolk Research Articles

Effect of lactic acid bacteria fermentation on spray-dried egg yolk powder: Powder characteristics, structural properties and gastrointestinal digestibility

Preparation of egg yolk powder with high solubility and high gastrointestinal digestibility is important for its effective utilization in the food industry. This study discovered that fermentation of egg yolks by lactic acid bacteria (LAB) resulted in a 54.3% increase in solubility, 110.6% increase in water dispersibility, and improved the stability of the dispersion to sedimentation. Fermentation resulted in smaller average particle size, enhanced hydrolysis of proteins and fats, and a more expansive protein structure in the egg yolk powder. Laser confocal microscopy showed increased hydrolysis of protein and fat in fermented egg yolk powder during simulated digestion, highlighting enhanced digestive properties due to LAB fermentation. This study validated the feasibility of LAB fermentation technology for modifying egg yolk powder, offering valuable insights for its processing and application in the food industry.

Extraction of Lipids and Functional Properties of Defatted Egg Yolk Powder Obtained Using a One-Step Organic Solvent Lipid Extraction Process.

A one-step organic solvent lipid extraction method was used to separate lipids from spray-dried egg yolk. Organic solvents tested were chloroform:methanol (CM, 2:1, v:v), methyl-tert-butyl ether (MTBE), or hexane:isopropanol (HI, 3:2, v:v). The resulting defatted egg yolk powder had between 21 and 30% more protein and between 22 and 25% less lipid than the initial spray-dried egg yolk powder (p < 0.05). The solubility of the powder decreased from 20% to 4% (p < 0.05) when CM was used as the organic solvent, likely due to protein denaturation by the chloroform. Gels made from MBTE and HI-extracted protein concentrates had similar hardness (p > 0.05) and were both harder than gels made using the initial egg yolk powder (p < 0.05). MTBE gels were springier, more cohesive, and gummier (p < 0.05) with similar resistance to the initial egg yolk powder (p > 0.05). The results of this study showed that the functionality of the protein in the defatted egg yolk powder was best retained when MTBE was used as the lipid extraction solvent.

Development of a novel dual-enzyme modification method for the functionality improvement of egg yolk powder

Spray dried egg yolk powder (EYP) is a kind of food ingredient with high nutritional value. However, its low solubility and insufficient emulsifying properties restrict its applications in the food industry. In this study, a new method of dual enzymatic hydrolysis (phospholipase and protease) was proposed to improve the functional properties of EYP including emulsifying properties, solubility, rehydration time and so on. The optimal conditions were determined to be 50 U/g (phospholipase A1 (PLA1)) and 250 U/g (neutral protease). Under these optimal conditions, the solubility of HYP (hydrolyzed EYP) treated by dual enzyme (61.30%) was significantly higher than that of unhydrolyzed EYP (16.49%) or HYP treated by single PLA1 (23.97%). Meanwhile, the emulsifying stability index (ESI) of HYP (hydrolyzed EYP) treated by dual enzymes was about 16/1.4 times larger than unmodified EYP/single PLA1 modified HYP. The increasing electronegativity and decreasing surface hydrophobicity/surface tension of HYP could be responsible for the above results. Scanning electron microscopy (SEM) revealed that dual-enzyme hydrolysis could promote the formation of fine HYP with pore structure, enabling it to rehydrate more effectively. In addition, the usage of protease could improve the radical scavenging activity of dual enzyme modified HYP by releasing antioxidant peptides. This study could provide new insights to promote the techno-functionality of EYP, thus optimizing its utilization as a high-performance emulsifier in the food industry.

Quantitative N-glycoproteomic analysis of egg yolk powder during thermal processing

The production of egg yolk powder often involves critical processes such as pasteurization and spray drying, however, these thermal processes will inevitably affect the functional properties of egg yolk (especially gelation and emulsification). The aim of this study was to elucidate the mechanism of the effect of pasteurized egg yolk (P-EY) and spray-dried egg yolk (SD-EY) on the functional properties through quantitative N-glycoproteomic. The results showed, compared with fresh egg yolk (F-EY), emulsifying property of mild heat-treated P-EY was slightly reduced while the gelation property did not undergo significant changes, whereas emulsifying activity (EAI) and gelation strength of vigorously heat-treated SD-EY were significantly reduced by 48.72 % and 35.73 %, respectively. During thermal processing in SD-EY, larger aggregate particles (particle size ∼10 um) were formed, and the surface hydrophobicity was reduced (93.0 %) and the zeta potential was enhanced (62.8 %). The results of quantitative N-glycoproteomic showed that 13 N-glycosylated proteins (APOB, vitellogenin, etc.) were down-regulated while only 2 N-glycosylated proteins were up-regulated; 21 N-glycosylation sites were down-regulated and 2 N-glycosylation sites were up-regulated in SD-EY, suggesting that covalent cross-linking of protein N-glycoproteins may have occurred in the process of spray-drying, which altered molecular physicochemical characteristics of the yolk solution that further affecting the processing properties of egg yolk.

Effects of different protectants on the IgY content and physico-chemical properties of spray-dried egg yolk powder.

Egg yolk powder (EYP) with high immunoglobulin of yolk (IgY) content and good solubility is in great demand in the market of functional foods. In this article, the properties of spray-dried EYP with the addition of five protectants (maltodextrin, trehalose, mannitol, maltitol and sucrose) were investigated. All the protectants increased IgY activity and solubility of EYP. Among them, EYP with maltodextrin displayed the highest activity of IgY (27.11 mg/g), the highest solubility (66.39%) and the lowest surface hydrophobicity. Moreover, the average particle size of EYP with maltodextrin was the smallest (9.78 μm). The egg yolk particles obtained by adding the protectants are more uniformly distributed and have smaller particle size. Fourier-transform infrared spectroscopy confirmed the structural integrity of the proteins, indicating that the protectants addition enhanced the hydrogen bonding forces between the EYP protein molecules. The addition of protectants can significantly improve the IgY content, solubility and structural stability of EYP. © 2023 Society of Chemical Industry.

Subcritical fluid extraction treatment on egg yolk: Product characterization

In this study, the method of subcritical fluid-propane extraction (SPE) used to coproduce egg yolk oil (EYO) and low-fat egg yolk powder from spray-dried egg yolk powder (EYP) was investigated. Results showed that the optimum parameters were: extraction temperature of 313.15 K, extraction time of 120 min, and solid-liquid ratio of 1:9 (g/mL). Under this condition, the residual oil rate of EYP was 21.04%, which was much lower than that of ethanol extraction (39.24%). Scanning electron microscopy reveled that serious disruptions of egg yolk sphere extracted by SPE were observed, facilitating the EYO extraction. In addition, oil extracted by SPE had lower acid value and peroxide value than that of ethanol extraction. Moreover, the emulsifying properties and solubility of low-fat EYP obtained by SPE were similar to the original egg yolk powder. This study provides a new technique for coproducing high-quality oil and protein.

Antisecretory Factor (AF) egg-yolk peptides reflects the intake of AF-activating feed in hens

Summary Objective The aim of the present investigation was to determine the level of the active form of the endogenous protein Antisecretory Factor (actAF), and also the active form of AF immunoreactive molecules in the affinity purified egg yolk. Design Determination of AF in affinity purified egg yolk by means of in vivo and in vitro methods. Setting Sahlgrenska University Hospital and Chalmers University of Technology, both units located in Gothenburg, Sweden. The farm housing the egg-laying hens is situated some 10 miles west to Stockholm. Samples Egg yolk collected weekly from hens subjected to AF-stimulating feed for up to 18 weeks. Methods and main outcome measures The methods used were: a/ The in vivo rat ligated jejunal loop assay. b/ Two variations of ELISA, i.e. 1.An indirect ELISA using a polyclonal antibody against AF-16 antibodies. 2.A competitive enzyme immunoassay for detection of the peptide AF-16 and also related immunoreactive molecules. c/ Matrix-Assisted Laser Desorption Ionization Mass Spectrometry, (MALDI-MS). The numeric variables registered represents: a/ The rat jejunal ligated loop assay demonstrates the influence of AF on the in vivo secretory response (mg/cm) to cholera toxin challenge. The ligated loop is some 12–15 cm long and placed on the mid part of jejunum, and the cholera toxin induced secretion is registered after a 5 h long challenge period. b/ The indirect ELISA method demonstrates the relative concentration of immunogenic AF peptides/AF-16 peptides and also related immunoreactive compounds by means of absorbance values, while the values of the competitive immunoassay represent the concentration of AF-16 peptides including similar immunoreactive peptides in ng/ml. c/ The MALDI-MS method provide information about the concentration of the AF-16 peptide down to nanogram per ml. levels after mass spectrometry analysis of the sample. Results All methods revealed similar results by demonstrating a continuous increase over time in the collected egg yolk samples. Thus, low AF activity was registered in egg yolk collected in the period of 1–10 weeks of AF-stimulated feeding, significantly higher AF values was registered in yolk collected between 10 and 15 weeks of feeding, while maximal AF concentration was determined after 15 weeks of feeding. Thus, in the period between 15 and 18 weeks of stimulated AF-feeding, no further increase of the endogenous AF activity could be registered despite continuous AF-stimulated feeding. Conclusion During the period of AF-stimulated feeding of the egg laying hens the registration of AF concentration in the affinity purified egg yolk samples must be continuously registered over time. The various methods used for determination of AF concentration in the affinity purified egg yolk might all serve as tools in order to achieve the optimal concentration of active AF. Together, these methods will provide information about the optimal AF concentration in the final product consisting of spray dried egg yolk (Salovum®) used for disease treatment.

Denaturation of Spray-dried Egg Yolk During Processing and Storage

Denaturation of Spray-dried Egg Yolk During Processing and Storage

Cashew Nut Shell Liquid Supplementation and the Effect on Lipid Oxidation and Color in Fresh and Spray-Dried Eggs

In this study, the effect of dietary cashew nut shell liquid (CNSL) on the lipid stability and coloring of fresh and spray-dried yolks during storage was evaluated. Birds were fed according to the following treatments: diet without antioxidant and diets containing 0.25, 0.50, 0.75, or 1.00% CNSL. The fresh and spray dried yolks were stored for 60 and 180 days, respectively, and analysis of lipid oxidation and color were performed. For fresh yolks, 0.50% CNSL had the best results to prevent the damage of lipid oxidation, favoring the coloring during refrigerated storage for 60 days. For spray-dried yolks, the best results of lipid stability and yellowness was with 0.75% CNSL. Thus, the cashew nut shell liquid is a potential natural antioxidant for fresh and spray-dried yolk submitted to storage, when added in the laying diet. Practical Applications In recent years, the application of synthetic antioxidants in foods has become increasingly restricted due to the several studies indicating their potential toxic effects to the body. Thus, recent research has focused on the isolation and identification of effective antioxidants of natural origin. Thus, this paper is the first about the application of cashew nut shell liquid in eggs. The lipid oxidation in fresh and spray-dried yolks reduces with cashew nut shell liquid. This study indicates that cashew nut shell liquid is potential natural antioxidant when added in laying diets.

Effect of anacardic acid on oxidative and color stability of spray dried egg yolk

The effect of anacardic acid on lipid stability and coloration of spray dried yolks was evaluated. The yolks were added to antioxidants, according to the treatments: no added antioxidant, with 100 mg/kg butylated hydroxytoluene and with 50, 100, 150 and 200 mg/kg anacardic acid. The yolks was dehydrated according to the following conditions: inlet temperature of drying air (130 °C), feed flow rate of yolk (0.5 L/h) flow of hot air (3,5 m3/min) and pressurized air flow (30 L/min). After drying, yolks were stored for 180 days, and the analysis of lipid oxidation and color performed each 45 days. In regression analysis to assess anacardic acid-dose effect, there was a linear decrease in lipid oxidation in all storage periods with the increased acid dose. According to the means test, at 0, 90, 135 and 180 days, the concentrations of 150 and 200 mg/kg anacardic acid were more effective in retarding the lipid oxidation. The anacardic acid inclusion provided higher yellowness in the yolks, which decreased linearly with storage. Thus, the dose of 150 mg/kg anacardic acid had the best results among treatments studied to prevent the damage of lipid oxidation in the yolk, favoring the coloring.

Influence of Spray Drying on Amino Acid Composition and the Immunological Value of Egg Yolk Preparations.

There was estimated nutrition and immunological quality of spray-dried egg yolk preparations.There was observed increase concentration of total protein, IgY and amino acid composition in finalproducts.

In-Vitro and In-Vivo Binding Activity of Chicken Egg Yolk Immunoglobulin Y (IgY) against Gliadin in Food Matrix

Chicken egg yolk immunoglobulin Y (IgY) is a promising alternative for the prevention of enteric gliadin absorption, the predisposing factor of celiac disease (CD). IgY antibody was produced from the egg yolk of Single Comb White Leghorn chickens during the immunization period for the development of an oral immunotherapeutic agent. Here, we report the potential use of spray dried IgY antibody formulation using sugar protectants (mannitol, sorbitol, or microcrystalline cellulose powder (MCCP)). The long-term stability of the spray dried egg yolk powder formulated with 37.5% mannitol (EYP-M) preserved IgY antibody activity at 99.9%, which was significantly higher than that with other protectants (p < 0.05). In a dissolution test, the EYP-M shows 82.4% IgY activity after 2 h in simulated gastric fluid (SGF). A competitive ELISA at 50% inhibition (IC(50)) shows that 1.6 mg/mL EYP-M bound to 7.6 mg/mL and 10.5 mg/mL gliadin in SGF without and with food matrix conditions, respectively, whereas in simulated intestinal fluid, the formulation bound to 10 mg/mL gliadin, regardless of a food matrix. In-vivo study: BALB/c mice fed with EYP-M and gliadin at a ratio of 1:5 (w/w) demonstrated that gliadin absorption in the gastrointestinal tract was minimal at <1%. Thus, EYP-M containing IgY antibody may be used in CD patients to eliminate the effects of ingested toxic gliadin.

Influence of Pasteurization, Spray- and Freeze-Drying, and Storage on the Carotenoid Content in Egg Yolk

A liquid chromatography-atmospheric pressure chemical ionization mass spectrometry [LC-(APCI)MS] method was developed to identify and quantify the carotenoids present in fresh, pasteurized, and freeze- and spray-dried egg yolk in two independent batches. The egg yolk powders in each batch were stored in the dark for 6 months at -18 or 20 degrees C. Carotenoids were isolated by solvent extraction without saponification and analyzed by HPLC using a C(30) column coupled to a photodiode array and mass detector. The most abundant carotenoids were all-E-canthaxanthin, all-E-lutein, all-E-zeaxanthin, 9-Z-canthaxanthin, and beta-apo-8'-carotenoic acid ethyl ester. Pasteurization of the egg yolk caused no critical changes in the carotenoid content. On the contrary, drying to a dry matter of 98-99% led to higher carotenoid contents, induced by a denaturation of binding proteins, and a destabilization of the cell matrix. After the 6 months of storage, the contents of all main carotenoids in the egg yolk powder were significantly lower. The synthetic carotenoids canthaxanthin and beta-apo-8'-carotenoic acid ethyl ester showed a higher retention rate, and the greatest losses occurred within the first 8 weeks. Statistical tests (ANOVA, P < 0.05) also proved that after 26 weeks, the egg yolk powders stored at -18 degrees C showed only a slightly higher retention of carotenoids when compared to the powders stored at 20 degrees C.

Production of phospholipids from spray-dried egg yolk by consecutive in situ solid phase extraction with acetone and ethanol

Egg yolk lipids were extracted and fractionated into neutral lipids and phospholipids using acetone followed by ethanol as eluting solvents to a column consisting of spray-dried egg yolk. This technique, named in situ solid phase extraction, can be performed with spray-dried egg yolk due to the properties of this material. The effect of temperature, flowrate and scale has been studied. Results suggest that the methodology is suitable for industrial implementation.

In situ solid phase extraction of lipids from spray-dried egg yolk by ethanol with subsequent removal of triacylglycerols by cold temperature crystallization

ln situ solid phase extraction of lipids from spray-dried egg yolk by ethanol combined with subsequent removal of triacylglycerols from the ethanolic extract by cold temperature crystallization is described. By this procedure a lipid product is obtained which contains 86 g/l00 g phospholipids, 4 g/l00 g triacylglycerols and 10 g/100 g cholesterol. About 80% of spray-dried egg yolk phospholipids are recovered in this product. The product may serve as a source of phospholipids for specialized dietetic applications due to their relative high contents of both n-3 and n-6 long-chain polyunsaturated fatty acids. The procedure which requires no mechanical extractor and filtering device is amenable to scale up since recovery is not affected by changes in column volume or flow rate. This suggests the possibility of profitable industrial exploitation.

Determination of cholesterol oxidation products in the supercritical carbon dioxide extract of egg yolk powder: Comparison with conventional liquid solvent extraction methods

Neat SC-CO2 extraction was compared with the conventional Folch and the Bligh and Dyer (B&D) extraction, as a sample preparation technique for the determination of cholesterol oxidation products (COPs) in spray-dried egg yolk. Total lipids could be extracted in analytical scale (2 g sample) using four dynamic extraction steps of 30 min each, at 40 °C and 51,700 kPa. The recovery of total COPs in the SC-CO2 extract (35 µg COPs g–1 extract) was not statistically different with respect to the Folch and B&D extract. SC-CO2 extraction showed important advantages, such as the elimination of chlorinated solvents and the reduction of sample manipulation and preparation time. The formation of artifacts of COPs due to the acidic properties of CO2 during the sample preparation did not reach a significant extent.

Rheological behaviour of spray-dried egg yolk/xanthan gum aqueous dispersions

This paper provides information on the microstructure of, and reports particle size distributions and rheological results for, aqueous dispersions of spray-dried egg yolk and xanthan gum prepared on a laboratory scale using two types of homogenisers. Laser light scattering results demonstrated that higher energy input during homogenisation yielded a dispersion with a lower average particle size and a wider polydispersity, slightly influencing the linear dynamic viscoelastic functions due to the low concentration of egg yolk particles. These dispersions exhibited weak gel properties at the composition studied. The mechanical spectrum and the corresponding relaxation spectrum were dominated by the xanthan/gum-water matrix which controls the structure of the continuous phase. This fact explained the lack of any wall depletion effects. Several controlled-rate and controlled-stress rotational rheometers and a capillary rheometer were used to obtain information on flow properties. The shear rate dependence of steady state viscosity was determined through twelve decades, and was fitted using the Carreau equation. The kinetics of structural recovery after steady-state shear was studied by start-up at the inception of shear and flow interrupted experiments under controlled shear history. The results were analysed in terms of the ratio of a time-dependent amount of overshoot to the amount of overshoot of the original sample, using the addition of two first order equations. Additionally, combined steady state flow properties at fixed shear stress/oscillatory shear experiments were also used. The increase of the storage modulus with time, checking a linear viscoelastic response, tracked the structural recovery after steady shear. Laser light scattering of sheared samples helped gain a better understanding of the role of egg yolk particles on the rheology of these dispersions.

Supercritical carbon dioxide extraction of phospholipids from dried egg yolk without organic modifier

Phospholipids (PL) were successfully extracted from dried egg yolk by using neat supercritical carbon dioxide (SC-CO 2) on a microscale. The spray-dried egg yolk powder was extracted with SC-CO 2 at a density of 1.06 g/ml (517 bar, 40°C), which was the maximum of density achievable with the apparatus. The extraction yield obtained by SC-CO 2 (67 g of extract per 100 g of sample) can be compared with the conventional Bligh and Dyer extraction method (63 g of extract per 100 g of sample), which involves a chloroform/methanol/water mixture as an extraction solvent. The solvent extract contained 29% of PL, while the neat SC-CO 2 extract consisted of 26% PL. HPLC analysis coupled with an evaporative light scattering detector (ELSD) showed no significant selectivity in the SC-CO 2 extraction of the PL components. The extraction with neat SC-CO 2 appears to be a valid alternative for the extraction of PL for analytical purpose.

Identification and quantification of aminophospholipid-linked Maillard compounds in model systems and egg yolk products.

While the Maillard reaction of free amino acids and proteins is a well-established process, no defined structures from the nonenzymatic browning of aminophospholipids in foodstuffs have been described so far. Phosphatidylethanolamine (PE)-linked glucosylamines (Schiff-PE), Amadori products (Amadori-PE), 5-hydroxymethylpyrrole-2-carbaldehydes (Pyrrole-PE), and carboxymethyl (CM-PE) as well as carboxyethyl (CE-PE) derivatives were detected and quantified by liquid chromatography- electrospray mass spectrometry (LC-(ESI)MS). Model incubations of soy-PE and D-glucose were employed to firmly establish the LC-(ESI)MS procedure. Analyses of spray-dried egg yolk powders and lecithin products derived therefrom show one-fourth of the native D-glucose content of egg yolk to be transformed to Amadori-PE, corresponding to a PE derivatization quota of 11-15.5 mol %. Schiff-PE and Pyrrole-PE were present only in low amounts, no CM-PE and CE-PE could be identified in any of the investigated samples. The high glycation rate of egg yolk PE will influence the emulsifying properties and perhaps even the oxidation resistance of the respective products.

Influence of reduced-cholesterol yolk on the viscoelastic behaviour of concentrated O/W emulsions

A stress-controlled Carri-Med rheometer was used to carry out dynamic oscillatory experiments within the linear viscoelastic region on mayonnaise emulsions prepared with low-in-cholesterol egg yolk protein concentrates. Spray-dried egg yolk as well as yolk protein concentrates prepared by extracting with 20:80 ethanol/water or supercritical carbon dioxide were used. The type of egg product varied, while the composition of the emulsions was held constant. The method of lipid extraction influenced both the emulsion droplet size and the viscoelastic parameters. The small deformation properties of the emulsions are interpreted in connection with the interdroplet interactions as they are affected by the presence of yolk protein concentrates.