Effects of Processing (Raw, Frying and Boiling) on the Nutritional Composition of White Chicken Eggs

Abstract

Nutritional value of chicken egg is widely accepted but because the egg cannot be consumed raw, various processing methods are utilized. The aim of this study is to determine the effect of processing methods (raw, cooking and frying) on the nutritional composition of chicken egg. The egg samples used in the study were collected from Eke Awka market while the AOAC methods were used in the analysis. The nuts were cooked for 20 minutes at temperature of 100°C and also fried using vegetable oil for 15min. the proximate, mineral and vitamin compositions of the raw and processed egg samples were determined using standard AOAC method. The result revealed that there was no significant (p>0.05) difference in fat, total protein and fiber compositions of chicken egg. Processing method affected the moisture content as it decreased from 58.00% in raw egg to 25.80% in cooked egg and 10.60% in fried egg, protein content reduced from 22.52% in raw egg to 21.52% in cooked egg and 8.33% in fried egg respectively. The ash content was increased from 1.09% in raw sample to 3.86% in fried egg and 4.00% in cooked egg. The crude fiber also increased from 0.90% in raw sample to 1.19% in cooked sample and 5.30% in fried samples. The fat content was increased from 1.50% in raw sample to 5.70% in cooked egg and 8.33% in fried egg. Finally, the carbohydrate increased from 15.99% in raw egg to 41.79% in cooked egg and 56.22% in fried egg sample. Calcium decreased from 189.57mg/100g down to 160.72 in fried egg and 29.00mg/100g in cooked egg. Iron was highest in fried egg (3.30mg/100g) while cooked eggs have the lowest value (2.90mg/100g). The magnesium content was reduced by cooking and frying from 240.68mg/100g down to 48.64 in fried and 46.50mg/100g in cooked egg, while Zinc and phosphorus were increased from 11.00 and 0.45mg/100g in raw egg up to 13.10 and 1.16mg/100g for cooked egg and 21.80 and 1.33mg/100g for fried egg. It was also discovered that; Vitamin B2 decreased from 0.68mg/100g down to 0.57 in fried egg and 0.53mg/100g in cooked egg. Vitamin C decreased from 13.11mg/100g down to 5.32 in fried egg and 3.08mg/100g in cooked egg, while vitamin E and D were increased from 17.00 and 0.94mg/100g in raw egg up to 15.74 and 0.95mg/100g for cooked egg and 18.70 and 1.12mg/100g for fried egg. From the tests carried out and the result obtained, it was discovered that chicken egg cooked for 60 minutes at a constant temperature of 100°C gave better results in terms of nutrient retention. Processing treatments showed significant effects on the chemical composition of egg.