Incidence and health risk assessment of hydrogen cyanide and multi-mycotoxins in Nigerian garri

Abstract

Garri is a granular, starchy food prepared by the fermentation of mashed cassava. Hydrogen cyanide (HCN) and mycotoxins are contaminants in certain foods at different points along the food value chain. The incidence and contamination levels of HCN and multi-mycotoxins in garri from five agroecological zones of Nigeria were determined using a spectrophotometric method and ultra-high-performance liquid chromatography-tandem mass spectroscopy (UHPLC-MS/MS), respectively. The health risk associated with the consumption of contaminated garri was assessed. The health risk assessment model was used to calculate the dietary exposure of humans to the mycotoxins in garri. This was done by estimating the daily intake (EDI), the percentage tolerable daily intake (%TDI), the annual hepatocellular carcinoma (HCC) cases attributable to exposure to aflatoxins (AFs) in garri, as well as the HCC risk. The average intake of garri was estimated at 0.303 kg/day for a Nigerian adult. The incidence of HCN was 98.3% (0.056–2.463 mg/kg), and fermentation reduced the HCN level in garri more than other processing steps. The twenty-one mycotoxins identified and quantified were all within maximum levels, as applicable to those that are regulated by the EU. The %TDI for the other mycotoxins, with the exception of AFs, showed no alarming health risk with garri consumption. Annual HCC cases resulting from AF in garri were estimated at 10–60 cases for HBsAg + ve individuals and 4–23 cases for HBsAg − ve individuals based on 8.1% hepatitis B virus (HBV) incidence. Results further revealed no interdependence between HCN levels and mycotoxin content. This work suggests an unlikely chance of acute toxicity from HCN and major mycotoxins from a garri-based diet in Nigeria. Hence, it is recommended that concerned regulatory bodies maintain the existing permissible limits for HCN in Garri.

Keywords:

• Hydrogen cyanide
• multi-mycotoxins
• garri
• risk assessment
• Nigeria

Acknowledgments

We appreciate the technical assistance enjoyed from Department of Biotechnology and Food Technology, University of Johannesburg, Gauteng, South Africa, as well as that of Dr. Riaan Meyer and Mr. Darryl Harris from Shimadzu, South Africa.

Authors contributions

Conception and Design: Makun HA, Akanya HO, Njobeh PB; Data Collection: Olorunnado GB, Muhammad HK, Apeh OD, Salubuyi S; Analysis and Interpretation of Result: Muhammad HK, Olorunnado GB, Apeh OD, Gbashi S, Salibuyi S, Njobeh PB; Draft Manuscript Preparation: Olorunnado GB, Muhammad HK. Makun HA, Akanya HO, Gbashi S. Joseph Kumphanda; Result and Manuscript Review: (All the Authors) Makun HA, Akanya HO, Njobeh PB, Olorunnado GB, Muhammad HK, Apeh OD, Salubuyi S, Gbashi S, Joseph Kumphanda

Disclosure statement

No potential conflict of interest was reported by the author(s).