Composition of Shell Waste from Egg Breaking Plants

Abstract Eleven samples of egg shell waste were obtained from egg breaking plants. This waste was conveyed directly from the breaking machines. It included the shells, membranes, and adhering albumen. Two of the eleven samples were centrifuged to remove free albumen; and two samples were washed repeatedly with distilled water to remove all adhering albumen. This waste material contained an average of 29.1% moisture as it came from the breakers and 16.2% moisture when centrifuged. After drying and grinding, various chemical analyses were made. The average gross composition (dry basis) of the regular samples was 91.1% ash, 7.56% protein, and 0.24% lipid. These samples averaged 90.9% calcium carbonate. Centrifuging and washing reduced protein levels to 5.31% and 5.15% respectively. The elemental composition for regular samples was 36.4% calcium, 0.002% iron, 0.097% potassium, 0.398% magnesium, 0.152% sodium, 0.091% sulfur, and 0.116% phosphorus. The percent of calcium increased with centrifuging and with washing. Determinations for 17 amino acids were made. Levels of certain amino acids in the regular shell waste were 0.28% methionine, 0.41% cystine, 0.35% lysine, and 0.34% isoleucine. The amino acid levels were reduced by centrifuging and by washing. These results suggest that utilization of egg shell waste or “meal” as a feed ingredient.