A multivariate statistical approach to identify the factors influencing the grayanotoxin content of Italian Rhododendron honey

This work represents a step in the identification of hazards associated with the consumption of Italian Rhododendron honey, which could contain grayanotoxins, which can be found in plant belonging to genera of the Ericaceae family. An LC-MS/MS method was developed and validated to quantify Grayanotoxin I (GTX I) in 125 Italian Rhododendron honeys collected from 2017 to 2019. Sensitivity and linearity were demonstrated in the range 10-1000 mu g kg (-1), and a LOQ value of 10 mu g kg(-1) was obtained. Absolute recovery ranged from 88.2% to 99.3% and no matrix effect was measured. GTX I was found in the 30.4% of the samples, and the concentrations ranged from 12.3 to 103.5 mu g kg(-1). Multivariate statistical approaches were applied to investigate the relationship between the presence/absence of GTX I and different honey features (e.g. environmental factors, quality aspects). The main factors affecting the presence of GTX I resulted the environment, province, altitude and the purity of botanical origin. The mean GTX I level detected in the 'positive' Italian Rhododendron honeys was 119-668 times lower than GTX content found in mad honeys, which caused human intoxication, so the probability of an acute toxic syndrome, in this scenario, is remote.

Automated summary

This study identifies the hazards associated with Italian Rhododendron honey containing grayanotoxins. A method was developed to quantify Grayanotoxin I (GTX I) in Italian Rhododendron honeys, with 30.4% of the samples containing GTX I. Environmental factors, province, altitude, and botanical purity were found to affect the presence of GTX I. The levels of GTX I detected in the honey samples were much lower compared to honey causing human intoxication, indicating a remote probability of acute toxic syndrome.