Food Research Bulletin 2025

Risk assessment of Aflatoxin B1 from the consumption of different foods in South East Asia region (A case study based on Bangladesh food consumption data)

- Dr. Kshitij Shrestha, SFRO, DFTQC

Risk Assessment of Aflatoxins from JECFA

The report of sixty-eighth meeting of the Joint FAO/WHO Expert Committee on Food Additives (JECFA) on Aflatoxins is given below. It discusses about the impact of different hypothetical limits for almonds, brazil nuts, hazelnuts, pistachios and dried figs.

EFSA Risk Assessment of Aflatoxins in food

EFSA (European Food Safety Authority) has recently published the report on "Risk Assessment of Aflatoxins in Food". The abstract and summary of the report is given below: 

Abstract

EFSA was asked to deliver a scientific opinion on the risks to public health related to the presence of aflatoxins in food. The risk assessment was confined to aflatoxin B1 (AFB 1), AFB 2, AFG 1, AFG 2 and AFM 1. More than 200,000 analytical results on the occurrence of aflatoxins were used in the evaluation. Grains and grain‐based products made the largest contribution to the mean chronic dietary exposure to AFB 1 in all age classes, while ‘liquid milk’ and ‘fermented milk products’ were the main contributors to the AFM 1 mean exposure. Aflatoxins are genotoxic and AFB 1 can cause hepatocellular carcinomas (HCC s) in humans. The CONTAM Panel selected a benchmark dose lower confidence limit (BMDL ) for a benchmark response of 10% of 0.4 μg/kg body weight (bw) per day for the incidence of HCC in male rats following AFB 1 exposure to be used in a margin of exposure (MOE ) approach. The calculation of a BMDL from the human data was not appropriate; instead, the cancer potencies estimated by the Joint FAO /WHO Expert Committee on Food Additives in 2016 were used. For AFM 1, a potency factor of 0.1 relative to AFB 1 was used. For AFG 1, AFB 2 and AFG 2, the in vivo data are not sufficient to derive potency factors and equal potency to AFB 1 was assumed as in previous assessments. MOE values for AFB 1 exposure ranged from 5,000 to 29 and for AFM 1 from 100,000 to 508. The calculated MOE s are below 10,000 for AFB 1 and also for AFM 1 where some surveys, particularly for the younger age groups, have an MOE below 10,000. This raises a health concern. The estimated cancer risks in humans following exposure to AFB 1 and AFM 1 are in‐line with the conclusion drawn from the MOE s. The conclusions also apply to the combined exposure to all five aflatoxins.

Comparison of Aflatoxin B1 contamination in different categories of food products

Aflatoxin B1 (AFB1) is a toxin produced by mold (Aspergillus flavus and A. parasiticus) in the food products. It is one of the most potent carcinogen. Based on WHO/FAO data, the distribution of Aflatoxin B1 in different category of food products is shown in the figure below. 

The major categories of food products likely to have AFB1 contamination are: (1) Nuts and Oilseeds; (2) Herbs, spices and condiments; and (3) Cereals and cereal-based products.

1. Nuts and Oilseeds: AFB1 is generally found to be contaminated in hazelnut, pistachio nut, almond and peanut. The probability distribution of concentration of  AFB1  (mcg/kg) in these nuts are shown in the figure below. 

Rapid Risk Analysis for Contaminants having No Regulatory Limit

With the advancement of analytical capabilities, new chemical contaminants having no regulatory limits are being detected in the foods. Under such scenarios, risk managers of the competent authority might not have enough time to wait for the full risk assessment. Nevertheless, they must take appropriate measures to protect the public health based on the rapid risk assessment. Codex has recently formulated a guideline CXG 92-2019 to address such scenarios.

This guideline should only be applied in the conditions: (a) the contaminant is new in the food and was not previously reported; (b) it has no regulatory limit; (c) there are no specific codex guidelines or standards related to that contaminants in the foods.

Decision tree for rapid risk analysis

The codex guideline CXG 92-2019 provides the decision tree for the rapid risk analysis and is shown in the figure below:

Microbial Risk Assessment: Salmonella in Chicken

This is a reconstruction of paper from Oscar 2004. He used @Risk software to carry out the risk assessment. I am reconstructing his paper using R- software taking the same model input values. So for details, please refer to the paper of Oscar 2004. The following are the important model parameters described in that paper.

Model design

The following 5 nodes were considered during model development.

Node 1- Retail

"The incidence of Salmonella contamination of whole chickens ranged from 0% to 100% with a median value of 30%. The MPN of Salmonella on contaminated whole chickens is low, often below 10 MPN, whereas the maximum MPN per chicken ranges from >300 to >1100. A minimum value of 1 MPN (by definition, the minimum level of contamination that is possible), a median value of 10 MPN, and a maximum value of 450 MPN per chicken were used to define the input settings for the PERT distribution for the extent of Salmonella contamination of ready-to-cook whole chickens at retail."

Microbial Risk Assessment: Salmonella in Peanut butter: graphs

Have you already read the first part titled:

Microbial Risk Assessment: A case study of salmonella in peanut butter

If you have not read that part, first you should read that part before looking at these graphs. This is graphical output of that microbial risk assessment using Monte Carlo simulation.

Microbial Risk Assessment: Salmonella in Peanut butter

Do you know the case of salmonella outbreak from peanut butter in America?

Background:

In 2008/2009, 9 people died and at least 714 people (half of them children) fell ill, all from food poisoning after eating products containing salmonella contaminated peanuts. It triggered the most extensive food recall in US involving 46 states, more than 360 companies, and more than 3,900 different products manufactured using Peanut Corporation of America (PCA) ingredients. In September 2015, Stewart Parnell was sentenced to 28 years in prison for his role in the nationwide outbreak.( for details check Wikipedia)

Microbial Risk Assessment

Let’s carry out microbial risk assessment of salmonella from peanut butter. The assumption of this case study is taken from the paper of Chen 2013.

The salmonella is not very common in peanut. Based on the historical data, the initial prevalence of salmonella in peanut during manufacturing is estimated to be 5.5 x 10^-6 (i.e. 55 units out of 10⁷ units could be contaminated with salmonella).