The major proteins of the seed of the fruit of the date palm (Phoenix dactylifera L.): Characterisation and emulsifying properties

•The proteome of the seed of the date palm has been characterised.•Date seed proteins are able to make stable oil-in-water emulsions.•Date seed proteins have potential a functional food ingredients.

Proteins were extracted from the seeds of the fruit of the date palm. Proteomic analysis and SDS–PAGE electrophoresis of the extracted proteome suggested it is composed predominantly of the storage proteins glycinin and β-conglycinin, although over 300 proteins were detected, 91 of which were identified with confidence. In terms of protein type, the largest numbers of proteins were associated, not unexpectedly, with metabolism and energy functions, which reflected the requirements of the germinating and growing embryonic plant. The emulsifying properties of the extracted proteins were determined. Date seed protein exhibited a lower emulsifying activity than either whey protein concentrate or soy protein isolate, at each of the pH values tested. However, the stability of the emulsions produced with all three proteins was very similar at the different pH values. This combination of large emulsion droplet size and high emulsion stability properties suggested that the date proteins may adsorb as large protein oligomers.