By
Dr Rafael Frascino Cassaro (PhD)
| Reviewed by
Dr Rafael Frascino Cassaro (PhD)
Page last updated:
19/10/2023 |
Next review date:
19/10/2025
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The contents of this article are fact-based except otherwise stated within the article.
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Author bio
Dr Rafael Frascino Cassaro PhD is a Chemist with expertise in Food Technology, extraction of essential oils from food sources, organocatalysis, extraction by supercritical CO2 and organic chemistry. He writes and reviews content on these topics.
Dr Rafael Frascino Cassaro’s Highlights:
- PIPE-FAPESP Project Coordinator for the company Bioativos Naturais Ltda involving the extraction of essential oils from food sources, with supercritical CO2.
- PhD in Chemistry with research in supercritical fluid reactivity.
- Bachelor of Environmental Chemistry at University of São Paulo State (UNESP)/Brazil
Professional Experience:
Dr Rafael Frascino Cassaro’s Experience:
Dr Rafael coordinated a PIPE-FAPESP Project (Company Research and Innovation Project) for the company Bioativos Naturais Ltda, involving the extraction of essential oils with supercritical CO2 from food sources such as turmeric, ginger, hops, orange bagasse, pepper rose, cupuaçu pie, among others.
Dr Rafael has worked on a project, involving studies of the influence of pre-treatment on the recovery of crude food extracts by extraction with supercritical CO2 (Supercritical Fluid Extraction or SFE) and with pressurized liquids (ethanol and water) for food sources, aimed at obtaining oleoresins; determination of global yield and chemical composition of crude extracts. As a postdoctoral fellow for the Food Engineering department at the University of Campinas/Brazil
Dr Rafael Frascino Cassaro has worked as a substitute Professor at the University of São Paulo State (UNESP) on General Chemistry and Thermodynamics II disciplines for the Food Engineering course.
Education:
- 2009 Bachelor in Environmental Chemistry at the State University of São Paulo, Brazil
- 2015 PhD in Chemistry with research in supercritical fluid reactivity University of São Paulo, Brazil
- 2017 Post Doctoral in Food Engineering Research: Influence of Biomass Pre-Treatment on Supercritical CO2 Extraction: Preservation of High Added Value Assets and Reduction of Process Costs at the State University of Campinas, Brazil
The main publications of Dr Rafael Frascino Cassaro are:
RC Bazito, RF CASSARO, LC OLIVEIRA, RA Gariani, CAO Nascimento. (2013). Proline derivatives as organocatalysts for the aldol reaction in conventional and non-conventional reaction media. Green Processing and Synthesis 2, 43-50
TS Bastos, SB Rodriguez Reartes, MS Zabaloy, RF Cassaro, RC Bazito. (2019).Phase Behavior for the System Carbon Dioxide plus p-Nitrobenzaldehyde: Experimental and Modeling JOURNAL OF CHEMICAL AND ENGINEERING DATA 64 (5), 2116-2125
GH Sakae, LM Takata, AS Paulino, RC Bazito, RF Cassaro, C Princival, .(2013). A high enantioselective Proline-based helical polymer catalyst for aldol type reaction. Blucher Chemistry Proceedings 1 (2), 214-214
You can view some of Dr Rafael’s work below and links to his professional profile.
Research Gate: https://www.researchgate.net/profile/Rafael-Cassaro-2
Fapesp: https://bv.fapesp.br/pt/pesquisador/680718/rafael-frascino-cassaro/
Google Scholar: https://scholar.google.com/citations?user=ToO7HIcAAAAJ&hl=en
Linkedin: https://www.linkedin.com/in/rafael-frascino-cassaro-4a156a37/?originalSubdomain=br
ORCID: https://orcid.org/0000-0002-3729-2858
close
Reviewer bio
Dr Rafael Frascino Cassaro PhD is a Chemist with expertise in Food Technology, extraction of essential oils from food sources, organocatalysis, extraction by supercritical CO2 and organic chemistry. He writes and reviews content on these topics.
Dr Rafael Frascino Cassaro’s Highlights:
- PIPE-FAPESP Project Coordinator for the company Bioativos Naturais Ltda involving the extraction of essential oils from food sources, with supercritical CO2.
- PhD in Chemistry with research in supercritical fluid reactivity.
- Bachelor of Environmental Chemistry at University of São Paulo State (UNESP)/Brazil
Professional Experience:
Dr Rafael Frascino Cassaro’s Experience:
Dr Rafael coordinated a PIPE-FAPESP Project (Company Research and Innovation Project) for the company Bioativos Naturais Ltda, involving the extraction of essential oils with supercritical CO2 from food sources such as turmeric, ginger, hops, orange bagasse, pepper rose, cupuaçu pie, among others.
Dr Rafael has worked on a project, involving studies of the influence of pre-treatment on the recovery of crude food extracts by extraction with supercritical CO2 (Supercritical Fluid Extraction or SFE) and with pressurized liquids (ethanol and water) for food sources, aimed at obtaining oleoresins; determination of global yield and chemical composition of crude extracts. As a postdoctoral fellow for the Food Engineering department at the University of Campinas/Brazil
Dr Rafael Frascino Cassaro has worked as a substitute Professor at the University of São Paulo State (UNESP) on General Chemistry and Thermodynamics II disciplines for the Food Engineering course.
Education:
- 2009 Bachelor in Environmental Chemistry at the State University of São Paulo, Brazil
- 2015 PhD in Chemistry with research in supercritical fluid reactivity University of São Paulo, Brazil
- 2017 Post Doctoral in Food Engineering Research: Influence of Biomass Pre-Treatment on Supercritical CO2 Extraction: Preservation of High Added Value Assets and Reduction of Process Costs at the State University of Campinas, Brazil
The main publications of Dr Rafael Frascino Cassaro are:
RC Bazito, RF CASSARO, LC OLIVEIRA, RA Gariani, CAO Nascimento. (2013). Proline derivatives as organocatalysts for the aldol reaction in conventional and non-conventional reaction media. Green Processing and Synthesis 2, 43-50
TS Bastos, SB Rodriguez Reartes, MS Zabaloy, RF Cassaro, RC Bazito. (2019).Phase Behavior for the System Carbon Dioxide plus p-Nitrobenzaldehyde: Experimental and Modeling JOURNAL OF CHEMICAL AND ENGINEERING DATA 64 (5), 2116-2125
GH Sakae, LM Takata, AS Paulino, RC Bazito, RF Cassaro, C Princival, .(2013). A high enantioselective Proline-based helical polymer catalyst for aldol type reaction. Blucher Chemistry Proceedings 1 (2), 214-214
You can view some of Dr Rafael’s work below and links to his professional profile.
Research Gate: https://www.researchgate.net/profile/Rafael-Cassaro-2
Fapesp: https://bv.fapesp.br/pt/pesquisador/680718/rafael-frascino-cassaro/
Google Scholar: https://scholar.google.com/citations?user=ToO7HIcAAAAJ&hl=en
Linkedin: https://www.linkedin.com/in/rafael-frascino-cassaro-4a156a37/?originalSubdomain=br
ORCID: https://orcid.org/0000-0002-3729-2858
In this brief guide, we will answer the question “Is a white egg yolk safe to eat?”, and will discuss why egg yolk can be white, what factors affect yolk color and if there are nutritional differences between them.
Is a white egg yolk safe to eat?
Yes, white egg yolk is safe to eat. While consumers often associate a well-colored egg yolk, typically golden yellow to orange, with healthiness and quality, and may perceive pale or non-uniform colored egg yolks as inferior products from unhealthy hens, this is not necessarily the case.
The color of an egg yolk is more a matter of consumer preference than an indicator of egg quality. Yolk color is one of the most easily controlled factors that affect the commercial quality of eggs. Across regions, some preferences and standards shape consumer choices.
For instance, in Europe, deeply colored yolks are preferred, whereas lighter hues are favored in the United States when it comes to table eggs. However, this preference is not universally shared as the baking industry specifically demands more intensely pigmented yolks.
What factors affect the color of egg yolk?
The color of a yolk is mainly influenced by a hen’s diet. By adjusting what the hen eats, it becomes possible to change the yolk’s color. The pigments responsible for yolk color come from their food, specifically carotenoids and chlorophyll. Carotenoids like carotene and xanthophyll create deep yellow yolks, while chlorophyll leads to darker orange-red yolks.
In the past, people believed that yolk color was determined by a particular hen breed. However, it is now widely accepted that there is no connection between yolk color and any specific breed of hen. (3)
How do foodstuffs affect the color of egg yolk?
Various food items lead to distinct yolk colors: rice, white oats, barley, wheat, and their by-products, along with meat, milk, and fish meal, typically produce pale yellow or nearly white yolks, yellow maize and green foods result in deep yellow yolks.
Young green foods rich in chlorophyll tend to yield dark orange-red yolks, cabbage gives rise to a brighter orange-red hue, and beetroot contributes to a dark yellow yolk color. Conversely, linseed imparts a greenish tinge to the yolks. (3)
What is the nutritional profile of egg yolk?
Egg yolks contain approximately 16% protein, 32% lipids, and 50% water. One-third of these lipids are phospholipids, with phosphatidylcholine being the dominant type, comprising approximately 80% of them. A medium-sized boiled egg weighing about 50 grams provides 78 calories. It contains 6.29 grams of protein, 0.56 grams of carbohydrates, and 5.3 grams of total fat.
Out of the total fat content, roughly 1.6 grams are saturated fats, while monounsaturated fats make up around 2 grams and polyunsaturated fats contribute to approximately 0.7 grams with approximately 186 milligrams of cholesterol Eggs are a rich source of micronutrients, encompassing vital minerals like calcium, iron, magnesium, phosphorus, potassium, sodium, and zinc.
Additionally, they provide an array of essential vitamins including thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, vitamin A, vitamin E, vitamin D, and vitamin K. Eggs provide a wealth of essential proteins, fats, vitamins, minerals, and bioactive compounds.
These components’ specific composition and quantity can vary depending on factors such as the egg’s strain, the hen’s age, diet, and environmental conditions. (4)
Why is organic egg yolk usually paler?
Egg yolks from organically raised hens appear lighter in color compared to those from conventional farming. This color difference is attributed to the presence of carotenoids in the hen diet.
Conventional hen diets often incorporate sources of carotenoids like corn gluten, alfalfa, saponified extracts from marigold flower, or paprika fruit, or even synthetic carotenoids such as astaxanthin or canthaxanthin to enhance the yolk color. These synthetic pigments can be utilized in conventional egg production to control and maintain yolk color at a consistent level.
However, in organic egg production, these additives are prohibited and hens in free-range and organic systems, with access to vegetation or provided plant-based forage, have ample access to carotenoids, especially when compared to hens in conventional systems, although this availability might decrease during winter making the yolk even more pale. (1, 5)
Is there a nutritional difference between yoke colors?
There likely isn’t a significant link between yolk color and its nutritional value, apart from the fact that higher carotene deposition leads to increased Vitamin A activity in the yolk. (3)
Conclusion
In this brief guide, we answered the question “Is a white egg yolk safe to eat?”, and discussed why egg yolk can be white, what factors affect yolk color and if there are nutritional differences between them.
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References
3.-
FRENCH, M. H. Quality in Egg Yolks. The East African Agricultural Journal, v. 4, n. 2, p. 102-104, 1938.