Quantification and partial characterization of the residual protein in fully and partially refined commercial soybean oils

Neil M. Rigby, Ana I. Sancho, Louise J. Salt, Rob Foxall, Steve Taylor, Ana Raczynski, Stella A. Cochrane, Rene W.R. Crevel, E. N.Clare Mills

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

A method has been developed to determine residual protein in refined oils, a potential trigger of allergic reactions. High-pH bicarbonate or borate buffers were found to be the most effective extractants, residual oil protein comprising a mixture of proteins of Mr 6000-100000. Extracted protein could be quantified with superior precision using 3-(4-carboxybenzoyl) quinolone-2-carboxaldehyde (CBQCA). Residual protein content determined in a set of oils using the borate extraction-CBQCA assay was positively correlated with contents determined using a bicarbonate-total amino acid analysis method. Oil refining substantially reduced the oil protein content determined by the borate-CBQCA assay with neutralized/refined, bleached, and deodorized (fully refined) oils containing 62-265 ng/g oil, whereas crude un-degummed oils contained 86000-87900 ng/g of protein. These analyses and published data on cumulative threshold doses for soybean suggest that even the most sensitive individuals would need to consume at least 50 g of highly refined oil to experience subjective symptoms.

Original languageEnglish (US)
Pages (from-to)1752-1759
Number of pages8
JournalJournal of Agricultural and Food Chemistry
Volume59
Issue number5
DOIs
StatePublished - Mar 9 2011

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Keywords

  • determination
  • food allergy
  • protein
  • refining
  • soybean oil

ASJC Scopus subject areas

  • Chemistry(all)
  • Agricultural and Biological Sciences(all)

Cite this

Rigby, N. M., Sancho, A. I., Salt, L. J., Foxall, R., Taylor, S., Raczynski, A., Cochrane, S. A., Crevel, R. W. R., & Mills, E. N. C. (2011). Quantification and partial characterization of the residual protein in fully and partially refined commercial soybean oils. Journal of Agricultural and Food Chemistry, 59(5), 1752-1759. https://doi.org/10.1021/jf103560h