In the present demanding market, where a constant search for foods with high benefit-quality ratio is increasingly taking place, the innovation possibilities often lie in the most common and versatile everyday foods, such as the egg.
Used in almost every aspect of the gastronomy, from confectionery to soups, an egg is an important ally for all chefs and kitchen households. An egg alone is one of the most nutritious and appreciated foods on the planet. It is a high protein and low carb intake food, excellent for those who want a simple, easy and healthy snack, such as the common hard-boiled version. In fact, a whole egg contains a relevant amount of several important vitamins and minerals.
The nutritious egg – the forgotten superfood?
Along with milk, eggs contain the highest biological value for protein. One egg has only 75 calories but 7 grams of high-quality protein, 5 grams of fat, and 1.6 grams of saturated fat. According to the reference daily intake (RDI) nutrient values for a healthy adult, a large egg has vitamin A (19% RDI), responsible for immune system and good vision maintenance and a set of B vitamins, such as riboflavin (42% RDI), pantothenic acid (28% RDI), pyridoxine (9% RDI), folate (11% RDI) and cobalamin (46% RDI), essential for cell division processes and mental health.
Egg yolks are one of the few foods that naturally contain vitamin D (15% RDI), essential for strong bones and muscles, as well as overall health. In fact, the majority of the egg’s vitamins and minerals are located within the yolk. Vitamin E, iron, selenium and omega-3 fatty acids are also found in relevant concentrations in the egg.
The high quality proteins of the egg, essentially albumins, mucoproteins and globulins, contain a set of essential amino-acids like leucine, tryptophan, methionine and other non-essential aminoacids, which will act as precursor molecules in human metabolism. It is also noteworthy the high concentration of choline (60% RDI), an essential vitamin-like nutrient involved in the metabolism of molecules necessary for good neural-muscle function and its control in humans. For muscle building and fitness athletes the ingestion of these nutrients is of extreme importance for cell regeneration and muscle growth.
Cholesterol is perhaps the most controversial nutrient in the egg, one large egg containing more than two thirds of the RDI for this nutrient, currently set at 300 mg. However, several recent studies showed that there is no significant correlation between the egg’s cholesterol and an increase of blood harmful LDL cholesterol levels in healthy humans. The ingestion of one whole egg a day, preferably hard-boiled, is recurrently suggested by nutritionists and medical specialists as an important incorporation in one’s diet.
The egg market
From over the 75 million tons of eggs produced worldwide, the Asia-Pacific region represents the biggest market for egg and egg products, being India, Indonesia, Japan and China the key players due to its population and economic growth over the last decades. China alone is responsible for almost 40% of both worldwide production and consumption. North and Latin American regions are also important markets regarding egg products, with USA leading the charts, followed by Mexico and Brazil.
In the European context, according to the last stats of the European Commission for Agriculture and Rural Development, more than 7 million tons of eggs were produced in 2018 within the economic space, where 7 of the 28 members, France, Germany, Spain, Italy and UK, were responsible for over 80% of the total production. If the Russian and Turkey markets were to be included (European countries not in EU) the Economic European Space market would represent twice its actual numbers regarding the egg production and consumption. The Portuguese case represents a modest percentage, with only 0,1 million tons of eggs produced for consumption in the last year. Although lifestyle tendencies such as veganism or higher healthcare awareness are rising in popularity, these do not seem to be threatening the growing tendency of the egg market, especially in the Asian continent.
From farm to table
An average person consumes 180 eggs per year. The majority of these eggs (about 50%) are produced by enriched feed hens in cages followed by barn-raised hens (26%), free range hens (14%) and organic feed hens (5%). The difference between all these eggs raising hens are concerned to their diet and growth space.
Eggshell size, form and specially color are commonly associated by consumers as main characteristics for egg quality, however, this is only dependent on the hens’ breed, size and feed.
Whiter breeds tend to lay white eggs while darker ones tend to lay browner eggshells. As for the yolk, the same applies, being the hens’ diet the major factor responsible for its color. While grain-fed chickens produce pale-yellow yolks, hens fed with rich pigmented and nutritious food from insects, vegetables, fruits and grasses produce deep orange yolks. The real egg quality is given by the age of the hen and its feeding over the growing process, where older hens tend to lay thinner eggshells and shorter shelf-life eggs than younger and nutrient controlled-feed hens.
Applications beyond breakfast
From cosmetic industry to medicine, the egg components are used in a wide range of areas for remarkably different goals. Nowadays it is easy to find different forms of whole egg, yolk or egg white in retail stores, ranging from solid to concentrated, crystalized, frozen or deep-frozen states. From the yolk is extracted its oil, consisting mainly of triglycerides and other elements, such as lecithin, cholesterol, biotin and xanthopylls. This non-allergic oil becomes free from egg proteins and is therefore allowed for use in cosmetics or dermatological products for hair fall, eczemas or dermatitis. The natural pigments (xanthopylls) present in the yolk, lutein (E161b) and zeaxanthin (E161h), are also of high interest for the pharmaceutical and food industry for their attractive yellow and orange colors.
Lecithin (E322) was actually first isolated from the egg yolk in 1846 by the French chemist and pharmacist Theodore Gobley. This product is currently in high demand due to its emulsifying, lubricant and stabilizing properties, which were commonly obtained with the use of soybean oil. However, EU legislation has been inciting the use of allergen-free natural lecithin food sources, minimizing the use of soybean. Lecithin is also a molecule used in a variety of pharmaceutical and cosmetic products due to its stabilizing capacities and choline enrichment.
Eggs are also used as ingredients for alcoholic drinks, as in the case of the famous eggnog, or as clarifying agents for superior category wines and rich broths. In the pharmaceutical sector, the egg has been used for over 70 years in the manufacturing of flu vaccines due to its concentration of albumins, mucoproteins and other globulins. The eggshells are also a valuable resource for organic agriculture as a source of natural calcium.
The numerous shapes that the egg can assume are a clear representation of its high acceptance and versatility, with verified health benefits at an affordable price.
Miranda, J. M. et al, (2015), Egg and Egg-Derived Foods: Effects on Human Health and Use as Functional Foods, Nutrients, vol. 7, 706-729.
Garcés-Rimon M. et al., (2015) Egg protein hydrolysates: New culinary textures, International Journal of Gastronomy and Food Science, vol. 3, 17-22.
Wu Jianping et al., (2014) Eggs and Egg product processing, Food Processing: Principles and Applications, published by John Wiley & Sons, 2nd edition, chapter 19, 437-455.
R&D leader at CFER for the development of highly innovative food products and food technologies. MSc in Microbiology with background studies in Cell and Molecular Biology. João has a high interest in the study of yeast spoilage of foods, with focus in wine natural contaminants and other high tolerant weak-acids yeast strains.