is basically digestible because the pH of your stomach is low enough...
Peptic digestibility of raw and heat-coagulated hen's egg white proteins at acidic pH range.
Yoshino K, Sakai K, Mizuha Y, Shimizuike A, Yamamoto S.
Source
Department of Nutrition, School of Medicine, The University of Tokushima, Japan.
Abstract
Allergenicity in food proteins is generally dependent on their heat stability and resistance to digestive enzymes together with the presence of IgE-recognizing epitopes on the molecules. Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting, we assessed peptic digestibility of raw and heat-coagulated hen's egg white proteins at acidic pH range (1.5-4.0). Ovalbumin in raw egg white was slightly digested by pepsin at pH 1.5 and pH 2.0, and was almost resistant to the enzyme at pH 2.5 and over, which was altered in heat-coagulated egg white at the pH range from 1.5 to 2.5 where the protein was well digestive against the enzyme. Peptic digestibility of ovomucoid in raw egg white was good at the pH range from 1.5 to 2.5, but almost non-existent at pH 3.0 and over where the improvement of the digestibility of the protein was not found even in heat-coagulated egg white. As the stomach in new born infants shows a low amount of secretary pepsin and an out of optimum pH of peptic activity, low digestibility of ovalbumin and ovomucoid in raw and heat-coagulated egg white at over pH 3.0 is supposed to be responsible for their allergenicity and delayed outgrowth from hen's egg allergy in patients with delayed maturation of stomach functions.
Comp Biochem Physiol B. 1991;100(1):1-9.
Egg white proteins.
Stevens L.
Source
Department of Biological and Molecular Sciences, University of Stirling, Scotland, UK.
1. Egg white proteins are the principal solutes present in egg white, making up approximately 10% of its weight. 2. They are globular proteins and most have acidic isoelectric points. 3. Many are glycoproteins with carbohydrate contents ranging from 2 to 58%. 4. Of the major egg white proteins, lysozyme is the only one having catalytic activity, but many have specific binding sites, e.g. for vitamins such as biotin, riboflavin and thiamin, or for metal ions such as FeIII. 5. A major group are those showing proteinase inhibitory activity, and they include ovomucoid, ovoinhibitor, cystatin and ovostatin. 6. The synthesis of egg white protein occurs in the oviduct, and is hormonally controlled either by oestrogens or progesterone. 7. Extensive studies have been carried out in the genes coding for egg white proteins.
PMID:
1756612
[PubMed - indexed for MEDLINE]
