Mineral, amino acid, and hormonal composition of chicken eggshell powder and the evaluation of its use in human nutrition

Abstract

Chicken eggshell powder (ESP) might be an attractive source of Ca for human nutrition. To study its nutritional value, we analyzed minerals, amino acids, and hormones in commercially available Slovakian ESP. The mineral composition was compared with three Dutch ESP samples that differed in feed and housing, a Japanese ESP, refined CaCO3, and an oyster shell supplement. Chicken eggshell powder contains high levels of Ca (mean +/- SD/g EPS: 401+/-7.2 mg) and Sr (372+/-161 microg) when compared with recommended or estimated daily intakes for humans 51 to 70 yr of age. Levels of potentially toxic Pb, Al, Cd, and Hg were very low as were levels of V, B, Fe, Zn, P, Mg, N, F, Se, Cu, and Cr. Large differences in the levels of F, Se, Cu, Cr, and Sr in the Dutch and Slovakian ESP indicated a strong influence of feed and environment. The small protein fraction of ESP contains high levels of Gly and Arg. Furthermore, small amounts of transforming growth factor-beta1 (0.75 to 7.28 ng/g ESP), calcitonin (10 to 25 ng/g ESP), and progesterone (0.30 to 0.33 ng/g ESP) were detected. Estradiol-17beta and calcitriol were below the detection limit of the methods used. Compared with ESP, refined CaCO3 was found to contain increased levels of Cd, and the oyster shell supplement showed increased levels of Al and Cd. Therefore, ESP seems to have a beneficial composition with about 39% of elemental Ca, relevant amounts of Sr, and low levels of Al, Pb, Cd and Hg. It may be used as a Ca source in human nutrition.

Physicochemical study of CaCO3 from egg shells

“…It is also used as a base for medicinal and dental preparations, buffering and dissolution aid in dispersible tablets, as well as food additive and calcium supplement 3,6,14 .…”

Casca de ovo como fonte de cálcio para humanos: composição mineral e análise microbiológica

“…O micromineral Fe foi detectado apenas em cinco amostras, atingindo o teor máximo de 6,25µg g -1 (Tabela 1). Estudos prévios relatam teores variados, de 1,5 até 23µg g -1 de Fe na casca de ovo, denotando que a concentração deste mineral pode variar nas cascas (SCHAAFSMA et al, 2000;VILAR et al, 2010;KÜÇÜKYILMAZ et al, 2012).…”

“…A casca de ovo de galinha, que contém cerca de 40% de Ca na forma de carbonato de cálcio (CaCO 3 ), poderia ser uma opção de baixo custo e fácil obtenção para atender as necessidades nutricionais da população (SCHAAFSMA et al, 2000;ROVENSKÝ et al, 2003). Anualmente, cerca de 6 milhões de toneladas de cascas de ovo são geradas nas residências e em empresas alimentícias de todo o mundo (OLIVEIRA et al, 2013).…”

“…No entanto, somente alguns estudos avaliaram a composição mineral deste produto, utilizando número expressivo de amostras (SCHAAFSMA et al, 2000;KÜÇÜKYILMAZ et al, 2012;BRUN et al, 2013).…”

“…O sistema de criação das poedeiras é um possível fator de influência sobre a composição mineral de cascas de ovo (SCHAAFSMA et al, 2000;KÜÇÜKYILMAZ et al, 2012). Atualmente, a maioria dos ovos disponíveis para comercialização provém de galinhas poedeiras criadas em granjas no sistema intensivo (confinadas em gaiolas), sendo que a variação mais perceptível destes encontra-se na coloração das cascas (classificados em brancos e vermelhos).…”