M.G. Smits1, T. Huppertz2, A.C. Alting2 and J. Kiers2
1European Camel Research Society, Johanniterlaan 7, 6721 XX Bennekom, The Netherlands.
2NIZO Food Research, PO Box 20, Ede, The Netherlands
ABSTRACT
Samples of Dutch fresh raw, tunnel-frozen and home-frozen whole camel milk and raw whole bovine milk were studied with respect to composition and drying properties. Furthermore, the protein fraction of the milk was characterised in more detail by liquid chromatography and gel electrophoresis. Digestibility of the proteins of camel milk and bovine milks was studied under stimulated physiological conditions.
Camel milk contained less protein, fat and lactose than bovine milk, which is in agreement with literature data. Spray-drying of raw whole camel milk did not cause noticeable damage to its protein fraction and camel milk powder had a higher solubility than powder prepared from bovine milk. Characteristics of caseins and whey proteins in camel milk differed significantly from those in bovine milk, both in terms of molecular mass and hydrophobicity. The whey protein β-lactoglobulin, which is the main allergen in bovine milk, could not be detected in camel milk. Several unidentified proteins were characterised in camel milk.
Digestibility of camel milk proteins was comparable to that of bovine milk proteins, with the caseins being almost fully digested after simulated gastric digestion; whey proteins were resistant to gastric digestion, but were rapidly digested during subsequent simulated duodenal digestion. The results obtained with raw camel milk did not differ from those obtained with tunnel-frozen, home frozen and camel milk powder.
The characteristics of tunnel-frozen, home frozen camel milk and camel milk powder do not differ from those of fresh raw camel milk. The protein fraction of camel milk differs considerably from that of bovine milk. It contains several unidentified proteins. As in camel milk from other countries also camel milk does not contain the protein β-lactoglobulin, which is considered the main allergen in bovine milk.
Key words: Camel milk powder, camel, dromedary, health, home-frozen, tunnel-frozen, β-lactoglobulin
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