1. Composition Sample Lab scale Pilot scale
Dry Matter
(g/100g Wet Weight )
Egg Yolk 50.88 ± 0.27 50.54 ± 0.52
Plasma 22.36 ± 1.15 22.36 ± 1.92
Granule 45.47 ± 0.74 a
51.39 ± 1.39 b
Protein
(g/100g Dry Matter)
Egg Yolk 31.84 ± 0.40 30.15 ± 0.37
Plasma 21.84 ± 0.60a
18.83 ± 1.26b
Granule 57.62 ± 9.17b
67.64 ± 1.63b
Lipid
(g/100g Dry Matter)
Egg Yolk 56.50 ± 2.85 62.37 ± 0.93
Plasma 70.61 ± 5.90a
75.71 ± 1.00b
Granule 31.70 ± 1.04a
23.01 ± 2.79b
Cholesterol
(g/100g Dry Matter)
Egg Yolk 0.74 ± 0.1 0.80 ± 0.20
Plasma 0.40 ± 0.08 0.31 ± 0.36
Granule 0.27 ± 0.16 0.24 ± 0.11
B9/Folate
(μg/100g Dry Matter)
Egg Yolk 399 ± 10a
658 ± 151a
Plasma Not Detected Not Detected
Granule 1474 ± 42b
2079 ± 307c
Experiments were repeated on 3 separate occasions. Values are mean ±SD.
Did you know vitamin B9 is essential during pregnancy in
reducing the incidence of neural tube defects? This
vitamin exists in both synthetic (folic acid) and natural
(folate) forms. However, recent studies indicated the
excess intake of synthetic folic acid for the population as a
whole may not necessarily be beneficial. Conversely, the
natural forms of folate are known to have no adverse
effects. Egg yolk has been reported as an excellent
source of folate (Strandler et al., 2011) with high
bioavailability (House et al., 2003) with folate principally
restricted to the yolk fraction. Thereby, research on
separation of natural vitamin folate from egg yolk would
be an interesting attempt to expand the use of egg yolk or
its fractions for industrial purposes.
Scaling-up a process for the preparation of folate-enriched protein extracts from hen egg yolks
Our study aimed to establish simple and non-toxic
method to prepare a folate-enriched extract and further
we are scaling-up the fractionation of native hen egg yolk.
Introduction
Nassim Naderi1*, James D.House1,2 and Yves Pouliot1
1 Institute of Nutraceuticals and Functional Foods (INAF), Department of Food Science and Nutrition, Université Laval, Québec, QC, Canada, G1V 0A6.
2 Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB, Canada, R3T 2N2.
Fractionation of egg yolk
Yolk is separated from albumen, chalazae and vitelline membrane and diluted with water (1:1 v/v).
Diluted egg yolk separated into two fractions of plasma (water-soluble) and granule (precipitate).
The fractionated method was modified from the procedures described by Laca et al. (2010).
Fractionation process was later scaled-up at pilot scale by using a tubular bowl centrifuge.
References
Compositional analysis
• Lipids (total): By mojonnier method.
• Protein content (Total N): By using nitrogen
gas analyzer system (LECO FP-528).
• Folate: Extracted and detected by HPLC
system (fluorescence; Ex290/Em360 nm)
(House et al. 2002) .
• Cholesterol: Extracted by Dispersive liquid-
liquid microextraction method (Daneshfar et
al. 2009). The detection was done by HPLC
system (UV, 210 nm).
• Protein profile: By SDS-PAGE using linear
gradient polyacrylamide gels (4–20%; Bio-
Rad, Canada).
Methodology
Centrifugation
Lab-scale (10,000g ; 4°C ; 45 min)
Pilot-scale (40,000g ; 23°C ; 10 min)
Synthetic Natural
Objective
Plasma
Granule
Results & Discussion
Composition of egg yolk and its fractions
Analysis show that plasma is mainly contains water and lipid
whereas granule composed of vitamin B9 and protein.
Protein profile of egg yolk and its fractions
Substitution
Fractio
n Protein name
* MW
(kDa)
*
1 2 3 4 Std
MW (kDa)
Y Apovitellenin VIa 221
Y/P ϒ-livetin, apovitellenin VI 203
Y/P apovitellenin Va 122 202
Y/G Apovitellenin3+4 110
Y ApovitelleninVb 93
Y Apovitellenin V 85 115
Y/G Apovitellenin5+6 78
Y/P α-livetin 73 73
Y/P Apovitellenin IV 68
Y Apovitellenin IIIa 62 48
Y/G Phosvitin 59
Y/P α-livetin, Apovitellenin III 55 34
Y/G Apovitellin 7 47 27
Y/P β- livetin 36
Y/P β- livetin 33 17
Y/G Apovitellin 8 31
Y Apovitellenin IIa 21 6
Y Apovitellenin II 20
Y/P Apovitellenin I 17
Y/P Apolipoprotein CII 5
SDS-PAGE profile of proteins of egg yolk fractions: (1) Yolk;
(2) Plasma fraction; (3) Granule fraction; (4) commercial phosvitin;
(Std) MW standard.
*All protein lanes are identified and named according to Guilmineau et al. (2005).
Y P G
• The presented scaled-up fractionation process allows obtaining two egg yolk
fractions: granules, and watery fraction (plasma).
• Granules have shown to contain 2x higher proteins, 2x lower lipids and 3x less
cholesterol compare to native egg yolk.
• HPLC analysis revealed that all folate separated in granule fraction with a
concentration factor of 3 compare to native egg yolk.
• Granule fraction mainly composed of HDLs and phosvitin.
• One of the main approaches to the development of the egg industry is fractionation
of egg components and move forward new innovative applications. In this way, egg
yolk granules could be exceptionally promising for applications in food industry, or
Pharmaceutical.
Conclusion References
1. House, J. D., et al. 2003. Journal of Agricultural and Food Chemistry, 51,
4461-4467.
2. Guilmineau et al. 2005. Journal of Agricultural and Food Chemistry.
53:9329–9336.
3. Laca, A., et al. 2010. Food Hydrocolloids, 24, 434-443.
4. Naderi, N., et al. 2014, Journal of Food Engineering,141, 85-92.
5. Strandler, H. S., et al. 2011. European Food Research & Technology,
233, 923-930.
Acknowledgement
Nassim Naderi is supported by a scholarship from the FAST training
program, an initiative of NSERC-CREATE Funding program.
B9
Fraction Protein name
*
MW
(kDa)
*
1 2 3 4 Std
MW (kDa)
Y Apovitellenin VIa 221
Y/P
ϒ-livetin, apovitellenin
VI
203
Y/P apovitellenin Va 122 202
Y/G Apovitellenin3+4 110
Y ApovitelleninVb 93
Y Apovitellenin V 85 115
Y/G Apovitellenin5+6 78
Y/P α-livetin 73 73
Y/P Apovitellenin IV 68
Y Apovitellenin IIIa 62 48
Y/G Phosvitin 59
Y/P
α-livetin, Apovitellenin
III
55 34
Y/G Apovitellin 7 47 27
Y/P β- livetin 36
Y/P β- livetin 33 17
Y/G Apovitellin 8 31
Y Apovitellenin IIa 21 6
Y Apovitellenin II 20
Y/P Apovitellenin I 17
Y/P Apolipoprotein CII 5
Figure 2. SDS-PAGE profile of proteins of EY fractions in NR and R conditions: (1
(2, 7) Plasma fraction; (3, 6) Granule fraction; (4 and 5) commercial phosvitin; (Std
*All protein lanes are identified and named according to Guilmineau et al. (2005).
Y P G
SDS polyacrylamide gel electrophoresis of yolk and
fractions separated at pilot-scale shows that granule
fraction mainly composed of HDLs whereas, plasma
fraction contains mostly LDLs.