Non-protein amino acids in Australian acacia seed: implications for food security and recommended processing methods to reduce djenkolic acid

Berin A Boughton; Priyanka Reddy; Martin P Boland; Ute Roessner; Peter Yates

doi:10.1016/j.foodchem.2015.01.072

Non-protein amino acids in Australian acacia seed: implications for food security and recommended processing methods to reduce djenkolic acid

Food Chem. 2015 Jul 15:179:109-15. doi: 10.1016/j.foodchem.2015.01.072. Epub 2015 Jan 20.

Authors

Berin A Boughton¹, Priyanka Reddy¹, Martin P Boland², Ute Roessner³, Peter Yates⁴

Affiliations

¹ Metabolomics Australia, School of Botany, The University of Melbourne, Parkville, VIC 3010, Australia.
² Metabolomics Australia, School of Botany, The University of Melbourne, Parkville, VIC 3010, Australia; School of Psychological and Clinical Sciences, Charles Darwin University, Casuarina, NT 0909, Australia.
³ Metabolomics Australia, School of Botany, The University of Melbourne, Parkville, VIC 3010, Australia; Australian Centre for Plant Functional Genomics, The School of Biosciences, University of Melbourne, Parkville, VIC 3010, Australia.
⁴ World Vision Australia, Burwood East, VIC 3151, Australia; Research Institute for Environment and Livelihoods, Charles Darwin University, Casuarina, NT 0909, Australia. Electronic address: [email protected].

PMID: 25722145
DOI: 10.1016/j.foodchem.2015.01.072

Abstract

Seed of Australian acacia species, Acacia colei, Acacia elecantha, Acacia torulosa, Acacia turmida and Acacia saligna, were analysed for the presence of toxic non-protein amino acids and the levels of essential amino acids. Amines were derivatised with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate before analysis using liquid chromatography electrospray ionisation triple quadrupole mass spectrometry (LC-ESI-QQQ-MS). Multiple reaction monitoring (MRM) with optimised transitions and collision energies for each analyte were employed. The known nephrotoxic compound djenkolic acid was found to be present at elevated levels in all species tested. The lowest levels were in A. colei (0.49% w/w) and the highest in A. saligna (1.85% w/w). Observed levels of djenkolic acid are comparable to measured and reported levels found in the djenkol bean. Subsequent testing of seed processing methods showed djenkolic acid levels can be significantly reduced by over 90% by dry roasting at 180 °C rendering the seed safe for human consumption.

Keywords: (S)-carboxymethyl cysteine (PubChem CID: 193653); Acacia; Acacia colei; Acacia elacantha; Acacia saligna; Acacia torulosa; Acacia tumida; Canavanine (PubChem CID: 439202); Collision induced dissociation; Derivatisation; Djenkolic acid; Djenkolic acid (PubChem CID: 68134); Essential amino acid; Famine food; Food security; Lanthionine (PubChem CID: 98504); Mass spectrometry; Mimosine (PubChem CID: 440473); Multiple reaction monitor; Non-protein amino acid.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acacia / chemistry*
Amino Acids / analysis*
Australia
Chromatography, Liquid
Cysteine / analogs & derivatives*
Cysteine / analysis
Food Handling / methods*
Food Supply*
Humans
Mass Spectrometry / methods
Seeds / chemistry

Substances

Amino Acids
djenkolic acid
Cysteine