Identifying four proteins that trigger macadamia nut allergy in people
What it found
Four proteins in macadamia nuts were identified as allergens using blood samples from allergic children.
These proteins were mainly recognized by people with macadamia nut allergy, not by those who tolerate the nut.
What they found
Studies in people
Allergic children's blood reactions
Blood from all 5 children with macadamia nut allergy reacted to the whole nut extract and to a protein called Mac i 2. Four out of 5 reacted to Mac i 1, and 3 out of 5 reacted to MiAMP2a.
Tolerant children's blood reactions
Children who could eat macadamia nuts without symptoms showed much weaker reactions to the individual proteins. Only 2 out of 8 sensitized but tolerant children reacted weakly to Mac i 1 and MiAMP2a.
Other nut allergy comparisons
Among 14 children allergic to peanuts or other tree nuts but able to eat macadamia nuts, only 3 showed very weak reactions to the individual macadamia proteins.
Studies in people and animals
Proteins purified from nuts
The team isolated three proteins directly from 120 g of roasted macadamia nuts. They also made a fourth protein, nsLTP, in yeast cells because there was too little of it naturally in the nut.
What the authors conclude
- They suggest the four newly identified proteins can serve as markers for diagnosing macadamia nut allergy more precisely.
- Their results indicate that one protein, MiAMP2a, is especially useful for telling apart people who are truly allergic from those who merely test positive but can eat the nut safely.
- The authors note that larger studies across different populations are needed to confirm these findings.
How it was done
Macadamia nuts are eaten more often now, but scientists know little about which specific proteins cause allergic reactions to them. Better knowledge of these proteins could improve allergy testing.
Researchers used blood serum from 5 children with confirmed macadamia nut allergy, 8 children sensitized but tolerant to it, and 14 children allergic to other nuts but tolerant to macadamia. They purified four proteins from roasted macadamia nuts bought at a supermarket and tested how the blood samples reacted to each one.
What it can’t tell you
- This study tested blood samples in a lab rather than giving people macadamia nuts to eat. It shows immune recognition but cannot measure actual allergic symptoms or their severity.
- Only 5 children with confirmed macadamia nut allergy provided blood samples. Such a small group means the exact reaction rates might differ in the wider population.
Who paid
- Funding
- Funded by Austrian Science Fund FWF (from the PubMed record).
- Conflicts
- Declaration of Competing Interest . The authors have no conflicts of interest to declare.
- Authors work at
- Medical University of Vienna, Austria; James Cook University, Australia; The University of Melbourne, Australia
The paper
- Title
- Identification of vicilin, legumin and antimicrobial peptide 2a as macadamia nut allergens
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Kabasser S, Pratap K, Kamath S, et al (2022). Identification of vicilin, legumin and antimicrobial peptide 2a as macadamia nut allergens. Food chemistry. doi:10.1016/j.foodchem.2021.131028Free full textPubMed 34525424DOI
Summary written 1 Oct 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error