Designer Egg: Improvement towards Modern Health Care
Introduction
Innovations in biotechnology and genetic engineering have revolutionized the agricultural sector, leading to the development of designer eggs with enhanced nutritional profiles and potential health benefits. These specialized eggs are engineered to contain specific nutrients, bioactive compounds, or therapeutic agents, offering promising prospects for improving human health and nutrition.
In the last decades people became highly aware of the connection between food and health that has led to the convergence of their attention on the nutritional quality of foods. The food industry has responded to the demand for foods of superior health benefits by modifying the nutritional profile of foods like eggs. Consumer awareness on the relationship between dietary lipid and the incidence of Coronary Heart Disease (CHD) changed their attitude towards food consumption. Consumers are always in search of newer products with potential health benefits.
Among various foods, egg is an important and easily available food delivering balanced essential nutrients to the body and egg is the best medium for incorporating health components in it. The designer food approach has been explored widely using egg in providing various essential nutrients to the human body, which are not usually present in required quantity. These are also called as Enriched eggs or Nutritional Enhanced Eggs Designer Eggs, Pre-Ovipositor Value Added Eggs, Health Promoting Designer Eggs or Enriched ω-3 Eggs.
Definition
Designer eggs are those in which the content has been modified from the standard egg in terms of high vitamin and minerals, lower cholesterol, high omega fatty acids & pharmaceutical compounds. Designer egg approach was started in 1934 by Cruickshank. He reported the modification of fatty acid composition in egg yolk by making feed interventions. Omega-3 fatty acids are proved to be beneficial in various disorders such as cardiovascular disease, hypertension, autoimmune, allergic, and neurological disorders. Sim and Sunwoo developed designer egg rich in omega-3 fatty acids and antioxidants by feeding hen with flax seed in which saturated fatty acid in yolk was replaced with 3-poly unsaturated fatty acid (PUFA) i.e. the yolk triglyceride is replaced by linolenic acid and yolk phospholipids are replaced by longer chain omega-3 fatty acids, such as eicosapentaenoic (EPA), dososapentaenoic and docosahexaenoic (DHA) acids. Fortification of omega-3 fatty acid not only increases the health benefits of designer egg but also reduces the cholesterol content of the egg by replacing saturated fatty acid in egg yolk.
Designer eggs were also developed by replacing yolk cholesterol with conjugated linoleic acid (CLA). CLA is studied for its various health related properties such as anti-adipogenic, anti-carcinogenic, anti-atherogenic and anti-inflammatory. Produced designer egg enriched with CLA by feeding hens with CLA rich diet and found that adding CLA to layers diets rich in omega-3 fatty acids produces CLA enriched eggs. CLA supplementation of egg also increased yolk moisture content, firmness and impaired the sensory quality of eggs.
Cholesterol content of the egg yolk can also be reduced by supplementing hen’s feed with chromium at 200–800 ppb concentration (13.9 to 33.7 % reduction. The pharmacological approach was also studied for reducing cholesterol level in egg by administering egg laying hens with cholesterol lowering drugs. US patent was issued for the method of reducing the cholesterol content of egg by supplementing hen with L-dihydroxyphenylalanine (L-DOPA). Selenium (Se), a micronutrient is essential for preventing cardiac muscle degeneration. Fortify the egg with increasing amount of Se, reduce the risk and prevalence of prostate and colon cancer and it also proved to have a role in prevention of cardiovascular diseases through antioxidant.
History of Designer Eggs
Cruickshank (1934) was one of the frist researchers document the ability to change the nutrient profile of the egg. In the late 80s, Sim, Jiang and their associates worked together to produce nutrient enriched eggs and developed designer egg, rich in n-3 fatty acids with antioxidants and patented this egg as ‘Professor Sim’s Designer Egg’. Later in 1997, Van Elswyk developed eggs enriched with conjugated linoleic acid (CLA). In Australia, Farell (1998) enriched the eggs with folic acid and iron. Other available designer eggs in the market include eggs enriched with vitamins. In Canada, Leeson and Caston, (2004) produced lutein and selenium enriched eggs which help in preventing eye disorders. In India, Narahari (2005) has also developed Herbal Enriched Designer Eggs (HEDE), which is not only rich in carotenoids, n-3 PUFA, selenium, trace minerals and vitamin E, but also rich in herbal active principles like Allicin, Betaine, Euginol, Lumichrome, Lumiflavin,, Lutein, Sulforaphane, Taurine and many other active principles of herbs, supplemented in the diets of hens.30 These eggs also contain natural sterols (phytosterols) like βsitosterol, Brassicasterol, Campesterol, Stigmasterol etc. which are cardiac friendly in nature
The egg is seen as a naturally occurring chemical store house that delivers very nutrient-dense food in a biological container (the egg shell) that is impervious to adulteration. It is endowed with all the necessary nutrients which can nourish an embryo to a chick. The phrase “Nature’s original functional food” has been used to describe eggs. Of the three dietary essentials – proteins, fats, and carbohydrates, the egg is composed largely of the first two. Due to their great biological value, high protein quality, and low cost and palatability, they are used as food on a global scale. Despite all of its benefits, it is frequently seen as a food high in cholesterol due to the lipid profile of the yolk. Due to this, people who are health conscious have developed a cholesterol phobia, which has resulted in a global decline in egg consumption, particularly in western nations. In light of the aforementioned facts, the idea of the “Designer Egg” has been developed with the intention of reducing the health-harming nutrients (such as cholesterol and triglycerides) and enriching it with the nutrients that are good for you, such as omega-3 fatty acids, antioxidants, vitamins, and minerals.
The nutritional composition of a designer egg may differ from a regular egg in terms of important fatty acids, cholesterol, vitamins, minerals, antioxidants, etc. The simplest way to describe them is as “Nutritionally enhanced, Value added, Supplemental eggs.” The egg is a great vehicle for adding various health-promoting ingredients, therefore the possibilities for designing eggs are endless. By nutritionally manipulating the laying hens’ diet, it would be easy to alter the various nutrients in an egg.A typical designer egg may have six times as much omega-3 fatty acids as compared to a standard egg and up to 40% less cholesterol.
Chromium supplements make it simple to control cholesterol, the biggest egg restriction. The egg and yolk cholesterol will both be markedly reduced by adding chromium supplements from 250-1000 ppb. Copper supplementation is another method of lowering the amount of cholesterol in yolk. When varying amounts of copper were added to the feed of laying hens, the blood and yolk cholesterol levels decreased. Incorporating up to 300 mg/kg of copper into the food of chickens will aid in lowering plasma and yolk cholesterol.
Microbiological feed additive has capacity to improve the host’s health and well being. Effect of probiotic is mediated via improved nutrition utilization, digestive enzyme secretion, appetite stimulation, improvement of gut health, and immune regulation. Additionally, aid in increasing daily feed consumption and retaining calcium and nitrogen. Adding multi-strain probiotics at a rate of 0.5 g/kg of feed to the diet of laying hens can enhance egg production and considerably lower yolk cholesterol. In accordance with the same line, adding probiotics (Rhodobacter capsulatus) in layers at a rate ranging from 0.01 to 0.04% will also lower yolk triglycerides and cholesterol.
Garlic supplementation in the feed of laying hens for more than 16 weeks at various levels, ranging from 0 to 10%, will considerably cut blood and yolk cholesterol. Also, PUFA supplementation in the diet of layers will result in a decrease in cholesterol levels in the diet of layers.
As omega-3 fatty acids are not produced by the human body, they are essential for a variety of bodily processes, including regulating triglyceride, LDL, and HDL levels, preventing cardiovascular disease, lowering blood cholesterol, reducing inflammation, and boosting the immune system. Commercial table eggs contain a high proportion of omega-6 fatty acids but are a poor source of omega-3 fatty acids. Various dietary sources of omega-3 fatty acids are fish and fish oils (salmon, mackerel, menhaden, halibut, and herring), plants (flax seed or linseed, soy and walnut), vegetable oils (canola and safflower oil) as well as marine algae. The richest source out of all is flaxseed oil, which is followed by fish and soybean oil. Eggs from layer birds were markedly enhanced with essential omega-3 fatty acids (ALA, EPA, and DHA) after dietary supplementation of flaxseed oil at various levels of 0%, 1.5%, and 3% and fish oil at rates of 0%, 2%, 3%, and 4%. The organoleptic quality of omega-3 eggs tends to be similar to regular table eggs although in some cases panellists are able to detect fishy taint in eggs, which decreases the overall egg acceptability.
Alteration in pigment content of eggs can be achieved by dietary manipulation. The yolk colour is the indicator of pigment content of egg and varied with dietary supplementation such as plants (marigold, chilli or corn) and blue green algae (Spirulina). These feeds have lutein and zeaxanthin in it which gives the colour to yolk. These compounds will improve eye health by protecting the macula from degenerative, oxidative and photochemical damage. Dietary manipulation makes it possible to improve the level of iodine, selenium, chromium without affecting the calcium and phosphorous level in eggs.
Everyone in today’s world must deal with a lot of stress. These stresses are mediated through oxidative reactions, which produce a lot of free radicals and peroxides inside the body. The best safeguard against such stresses comes from dietary antioxidants. The antioxidant chemicals like vitamin E, vitamin A, selenium have a protective impact against heart diseases as well. A further solution is to design the eggs with a higher antioxidant content.In the layer’s ration, adding vitamin E or fish oil causes a linear, dose-dependent rise in the concentration of α-tocopherol. Supplementing with vitamin E not only boosted the amount of α-tocopherol, but it also maintained the high concentration of ω-3 fatty acids. As a result, eggs now have a superior four-week shelf life and maintain their freshness longer.
A more recent development is the enrichment of bioactive components in eggs. Supplementation of sprouted alfalfa and flax seed increased several plant bioactive compounds, including isolariciresinol, daidzein and equol. Utilizing fermented buckwheat extract in layer diets increased the amount of GABA and L-carnitine in the yolk. L-carnitine is essential for the oxidation of mitochondrial fatty acids, whereas GABA has a number of beneficial impacts on mammalian physiology, such as lowering anxiety, controlling blood pressure, boosting immunity, and having antihypertensive effects.
With the advancement of biotechnology, we can produce genetically modified chickens which then produce the eggs containing the desired compound e.g., insulin for the treatment of diabetic patients and variable antibodies that could be used in treatment of microbial toxins and snake venoms. Antibodies could be produced in the albumin of eggs by transgenic hens. Egg yolk antibodies (EYA) are the antibodies in the yolk and can be generated by injecting hens intramuscularly or subcutaneously with a particular antigen that produces IgY antibodies. Eggs could be used as a source of immunogens to strengthen people’s immune systems, especially those of youngsters, against a variety of diseases.EYA could be employed as an antibacterial and antiviral agent in both humans and animals, as well as to treat rotavirus, corona, and E. coli-related enteric illnesses in calves and pigs and to prevent the spread of rabies.For these reasons, designer eggs can be employed as a source of immunoglobulins that can be used as immunotherapeutic agents to improve immune system capabilities.
However, the efficiency of nutrient transfer from diet to eggs reaches a limit beyond which further enrichment of nutrients in eggs is not possible. Enrichment often has a higher cost of production, so retailers and consumers must pay a higher price for it. As a result, the health benefits of designer eggs must be conveyed through suitable labels on final packaging. Designer eggs are currently gaining popularity on the global market under various trade names, but the Indian market is more encouraging in metropolises and the southern region due to a greater population of non-vegetarian. However, rising public health consciousness and purchasing power offer optimism for the market’s expansion.
Varieties of Designer Eggs:
- Shell colour –Regional consumer preferences determine the shell color F. Kuhl estimated that half of the designer eggs on the market are brown shelled.
- Yolk colour-Yolk color can vary from virtually white to orange depending on the deposition of xanthophylls from the feed. Sources of supplemental xanthophylls include corn gluten meal, alfalfa, marigold, peppers and spirulina.
- High vitamin content –particularly vitamin A and E. Although, the vitamin content of eggs varies with the diet of hen but the hen may also differ in transferring the different vitamins with different efficacy. It is highest for vitamin A (60-80%), vitamin B12, riboflavin, biotin and pantothenic acid (40-50%), vitamin D3 and vitamin E (15-25%). So the attention should be there for the economic production of high vitamin eggs.
- High mineral content –Increasing the micro mineral contents of yolk & albumin especially selenium, iodine, zinc, copper and chromium by dietary supplementation. Iodine deficiency exists in India, so eggs could be a good source for its supplementation. Selenium level in eggs can be increased by incorporating the selenium yeast in diet of hens.
- Alteration in the pigment content –The yolk colour is the indicator of pigment content of egg and varied with dietary supplementation such as plants viz., marigold, chilli or corn, blue green algae spirulina. Recently in a study, it was found that high intake of carotenoids reduced the macular degeneration, a major cause of blindness in the elderly.
- Low cholesterol- An average sized egg contains approximately 200-220 mg of cholesterol. Supplementation of chromium to laying hen diets at concentrations of less than 1 ppm have shown to lower egg cholesterol and also improve the interior of the egg. The low cholesterol eggs can be obtained by feeding a all-vegetarian diet rich in protein and fiber fortified with vitamin E.
- Fats & fatty acids profile – The omega-3 essential PUFA include linolenic acid and its derivatives EPA (Eicosapentanoeic acid) and DHA. High content of this fatty acid also increases the keeping quality and shelf life of the eggs. Studies have also been conducted on the egg having the lower saturated and unsaturated fatty acid ratio by feeding the hen with canola oil.
- Pharmaceutical operations –through biotechnology genetically modified chickens are produced which then produce the eggs containing the desired compound e.g., insulin for the treatment of diabetic patients.
Specific antigen injects into hen body
Antibody formation starts and flow in blood, then concentrate in egg.
Collection of antibody from the egg and use it in human health care.
Biological compounds – chicken can also produce antibodies that can neutralize the antigens of bacteria, viruses etc. These antibodies circulate in the blood and transferred to eggs for the protection of chicks.
In India, NABARD-supported Kisan Jyoti Farmers Club (KJFC), WAYFARM like groups are producing designer egg containing Omega-3 Fatty Acids.
Conclusion
Designer eggs provide options for consumers who want eggs with different nutritional benefits or properties than generic eggs. A generic shell egg provides a nutrient dense, high quality, inexpensive source of protein as well as a variety of essential vitamins and minerals, with other functional components. By feeding hens special diets, eggs can offer functions above and beyond the excellent nutrition that they already provide.
Designer Egg
Compiled & Shared by- This paper is a compilation of groupwork provided by the Team, LITD (Livestock Institute of Training & Development)
Image-Courtesy-Google
Reference-On Request
