I also authorize Chattogram Veterinary and Animal Sciences University (CVASU) to lend this thesis to other institutions or individuals for the purpose of scientific research. I would like to express my thanks and grateful feelings to everyone who has helped and supported me in various ways during my Masters in Biochemistry under the Department of Physiology, Biochemistry and Pharmacology, Chattogram Veterinary and Animal Sciences University. CVASU Chattogram Veterinary and Animal Sciences University et al Et alii/ et aliae/ et alia.
The aim of the present study was to measure the physical properties and nutritional value of different chicken egg powders such as Brown egg and White egg. On the other hand, brown egg contained a higher amount of high-density lipoprotein (HDL) (21.58 mg/100gm) than white egg.
Introduction
Dried egg powder (egg white and egg yolk) is widely used in food preparation because it is microbiologically safe and easy to transport compared to unshelled or liquid eggs. Dried egg powder is also relatively easier to store, handle, measure and achieve uniformity and longer shelf life of the product (Caboni et al., 2005). In addition, spray-dried egg powder is of great importance to the food industry with regard to handling and hygienic aspects.
The properties of eggs are very delicate and the final quality of the dried product can be significantly affected by the drying conditions (Koç et al., 2011). For the production of egg powder, most research in the literature was related to the spray drying method and process conditions (Caboni et al., 2005; Lechevalier et al., 2007).
Review of Literature
- Egg Composition and Formation - Anatomy & Physiology
- Nutrient composition of eggs
- Macronutrients
- Micronutrients
- Antinutritional Factors
- Egg Nutraceuticals
- Antimicrobials
- Antioxidant Activities
- Anti-Cancerous Molecules
- Immunomodulatory Activities
- Antihypertensive Activities
- Conclusion
Egg yolk is mainly of hepatic origin, while the egg white is synthesized and secreted after ovulation of the mature yolk in the chicken's oviduct (Nys et al., 2011). These lipids are concentrated only in the egg yolk (Figure 2.2) and a small portion can remain tightly associated with vitelline films (Trziska et al., 1982) (Shinn et al., 2016). Indeed, protein is an important source of ovostatin, ovomucoid, ovo inhibitor and cystatin (Back et al., 1982).
Interestingly, some of these bioactive peptides are produced specifically after limited proteolysis of denatured egg proteins (Vilcacundo et al., 2018), after boiling. Conversely, some valuable immunomodulatory activities may derive from egg yolk ovotransferrin and vitellogenin hydrolysates (Liu et al., 2017) after partial degradation by digestive proteases.
Materials and Methods
Egg collection and sample preparation
- Collection of eggs
- Samples preparation for nutritional composition analysis
Chemical analysis of egg powder
- Determination of moisture content
- Determination of ash content
- Protein determination
- Crude fat determination
- Crude Fiber Determination
- Determination of total carbohydrates
The protein content of the feed was obtained by estimating the nitrogen content of the material and multiplying the nitrogen factor by 6.25. Determination of the amount of nitrogen in the condensing flask can be done by several methods. The most common method is the titration of ammonia with a standard solution of N/10 HCl in the presence of a mixed indicator.
The filtrate was placed in separating funnels and then the separated mixture was dried to measure the extract and the percentage of fat was estimated. Procedure: The dried sample was taken in a thimble and the top of the thimble was plugged with a wood of grease-free cotton. The anhydrous petroleum ether was poured through the sample into the tube into the flask.
At the end of the extraction period, the casing was removed from the apparatus and distilled from petroleum ether allowing it or collected in a Soxhlet tube. When the ether reached a small volume, it was poured into a small, dry beaker (previously weighed) through a small funnel containing cotton. Ether was evaporated on a steam bath at low heat, then dried at 100°C for 1 h, cooled and weighed.
It was estimated by digesting a known amount of fat-free food sample by boiling it in a weak solution of acid (1.25% H2SO4) for 30 minutes followed by boiling in a weak solution of alkali (1.25% NaOH) for 30 minutes at constant volume and then draw ash from the residue obtained. At the end of this period the mixture was filtered through a muslin cloth and the residue was washed with hot water until free from acid. It was given as the difference between 100 and the sum of the other nearby components.
Determination of mineral contents
- Determination of Sodium (Na + )
- Determination of Chloride Ion (Cl - )
- Determination of Calcium (Ca ++ )
- Determination of magnesium (Mg 2+)
- Determination of phosphorus (P)
- Determination of Potassium (K + )
- Determination of Iron (Fe)
- Determination of Zinc (Zn)
- Determination of Copper (Cu)
- Determination of Manganese (Mn 2+ )
- Determination of Selenium (Se 2- )
The intensity of the color formed is directly proportional to the amount of chloride present in the sample. Principle: The method is based on the specific binding of calaghite, a metallochromic indicator, and magnesium at alkaline pH with the shift resulting in absorption. The intensity of the chromophore formed is proportional to the concentration of magnesium in the sample.
Principle: Inorganic phosphate reacts with ammonium molybdate in the presence of sulfuric acid to form a phosphomolybdic complex which is measured at 340 nm. Principle: Sodium tetraphenyl boron reacts with potassium to produce a fine haze of potassium tetraphenyl boron. The intensity of the turbidity is directly proportional to the concentration of potassium in the sample.
The intensity of the color formed is proportional to the iron concentration in the sample. Principle: Zinc in an alkaline medium reacts with Nitro-PAPS to form a purple colored complex. The intensity of the complex formed is directly proportional to the amount of zinc present in the sample.
Intensity of the complex formed is directly proportional to the amount of copper present in the sample. This color reaction was developed for the colorimetric determination of manganese (Hashmi et al., 1969). The released iodine bleaches the violet color of blue B to colorless leucoform and the absorbance is measured at 620 nm (Narayana and Mathew, 2006).
Determination of Vitamin content
- Determination of Riboflavin (Vit B2)
- Determination of retinol and carotene (Vit-A) using TFA
- Determination of tocopherol (Vit -E)
- Determination of Cholesterol
- Determination of Triglycerides
- Determination of High Density Lipoprotein (HDL)
Difference from standard Abs × Standard conc. mg/l) 3.4.2 Determination of retinol and carotene (Vit-A) using TFA. After reading the intensity of the yellow color due to carotenes, the light petroleum is evaporated and the residue dissolved in chloroform before the color reaction is carried out. During the reaction of sample and TFA, a blue color is observed indicating the presence of retinol in the sample.
The blue color is transient, so if a color appears, it should be observed within 2 seconds of adding the reagent (Makhumula et al., 2007). Mix well with a vortex mixer, mechanical shaking for 10 minutes, centrifuge the tubes for 10 minutes at 3000 RPM. Tocopherols are first extracted into xylene and absorbance read at 480 nm to measure tocopherols.
A correction for the tocopherols is made after adding ferric chloride and reading at 520 nm (Baker and Frank, 1968). Then start with the blank then add 0.33ml ferric chloride solution, mix, set the wavelength to 520 nm and 1.5 min after mixing read the absorbance (A520) of the sample and the standard against the blank Calculation:. The indicator quinonimine is formed from hydrogen peroxide 4-aminophenazone in the presence of phenol and peroxidase.
The indicator is a quinonimine formed from hydrogen peroxide 4 aminophenazone and 4 chlorophelol under the catalytic influence of peroxidase. Principle: Low-density lipoproteins and chylomicron fractions are quantitatively precipitated by phosphotungstic acid in the presence of magnesium ions. After centrifugation, the cholesterol concentration is determined in the HDL fraction that remains in the supernatant.
Results
- Overall weight distribution of different types of chicken egg
- Nutritional composition of white and brown chicken egg
- Mineral composition of different types of chicken egg
- Vitamin Contents in different white and brown egg yolk
Table 4.2 shows the approximate protein composition between white and brown eggs from commercial chickens. There were no significant differences between white and brown eggs in terms of crude protein, fat, ash, moisture, carbohydrates and energy value. The content of calcium, magnesium, chlorine, zinc, manganese, selenium differs significantly between different types of dried egg yolk.
Carotene is higher in brown egg than in white egg, while retinol is higher in white egg. There was no significant difference between white egg and brown egg in terms of cholesterol and high-density lipoprotein, except triglycerides (P < 0.05).
Discussion
Conversely, the moisture content found higher in this study in both parts of dried egg than the previous study. Yolk essentially has a hepatic origin, while egg white is synthesized and secreted after ovulation from mature yolk in the hen's oviduct (Mann, 2008). In the present study, the overall mineral content was higher in the egg yolk than the egg white.
In addition, the egg yolk contains more iron than the egg white, which is different from the previous study. This study shows that both calcium and potassium are high in brown egg powder, egg white and white egg yolk powder. In addition, the magnesium content is higher in brown egg white and yolk than in white egg white and yolk powder.
In this study, selenium content is higher in brown egg white powder and yolk powder than in white egg. In this study, the manganese content is higher in white egg yolk powder than in brown egg. Although the vitamin content was not significantly different between the brown and white eggs, the retinol content was higher in the white egg, while the carotene content was higher in the brown egg.
In the study, both cholesterol and triglycerides were found higher in white egg than brown egg and conversely high density lipoprotein (HDL) was found higher in brown egg. We can suggest that egg albumen powder can be a good choice for people suffering from protein deficiencies, while egg yolk powder can be considered a good fat source. It is worth noting that the content of fat-soluble vitamins (Vitamin A, D, E, K) in egg yolk is highly dependent on the hen's diet (Rehault, 2019).
Conclusion
Strength & Weakness
Strength of the study
Weakness of the study
Recommendations & future projection
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Effect of processing and storage on the chemical quality markers of spray-dried whole egg. The composition of the egg fat and depot of the bird as affected by the intake of large amounts of different fats. The effect of diet on the chemical composition, nutritional value and hatchability of the egg.
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