Changes in Heterogeneity of Aflatoxin Distribution During Processing Coconut Oil from Copra

Abstract

Background and Objective: Aflatoxin distribution in nuts and seeds is highly uneven, which makes test results unreliable and can cause errors of up to 90%. This variability depends on kernel size and surface area. Copra (smoked coconut kernels) provides a large surface for fungal growth and its oil is an important dietary source in coconut-growing countries. The study aimed to determine the most suitable point of sampling for accurate aflatoxin quantification.

Materials and Methods: Aflatoxin B1 levels were measured by quantified in contaminated copra kernels, steam-cooked copra pieces, expelled coconut oil and copra cake collected from 44 oil mills in Sri Lanka over one year. A total of 414 samples were analyzed.

Results: The coefficient of variation (CV) for aflatoxin B1 decreased progressively across the processing stages: 2.6 in moldy copra kernels, 1.4 in copra pieces, 1.0 in oil and 1.1 in copra cake. This shows that size reduction and mixing improve sampling accuracy. Some visibly moldy kernels tested negative for aflatoxins.

Conclusion: Accurate aflatoxin detection depends on when, where and how samples are collected. Sampling coconut oil provides a more reliable measure of aflatoxin hazards compared to testing raw copra kernels.