Mycotoxin Development in Cashew Apple-Wheat Flour Composite During Tropical Storage

Area of Science:

• Food Science
• Mycology
• Food Safety

Background:

• Ghana produces significant cashew but underutilizes cashew apples, contributing to food waste.
• Cashew apples are edible and rich in bioactive compounds, offering potential for food product development.

Purpose of the Study:

• To assess mycotoxin development in cashew apple-wheat composite flours during tropical storage.
• To evaluate the impact of varying cashew apple flour substitution levels (5%, 10%, 15%) on storage stability.

Main Methods:

• Composite flours were prepared with cashew apple flour substituting wheat flour at 5%, 10%, and 15% (w/w).
• Samples were stored under ambient tropical conditions (25°C ± 2°C, 65% ± 5% RH) for 14 days.
• Moisture content, fungal counts, and aflatoxin B1 levels were monitored using AOAC and ISO methods.

Main Results:

• Moisture content increased in all formulations, reaching 13.21% in the 5% cashew apple flour blend by day 14.
• Fungal populations grew exponentially (10^2-10^4 CFU/g) and correlated positively with moisture (r=0.87).
• Aflatoxin B1 levels reached 8.7 μg/kg in the 5% formulation, exceeding EU limits (2 μg/kg). Higher cashew content (15%) showed antimicrobial effects, reducing fungal counts and aflatoxin B1 levels (4.1 μg/kg).

Conclusions:

• Cashew apple flour incorporation into composite flours presents food safety risks due to mycotoxin development under uncontrolled tropical storage.
• Higher cashew apple flour substitution (15%) exhibits antimicrobial properties, potentially mitigating fungal growth and aflatoxin B1 contamination.
• Commercialization requires strict moisture control (≤13%) and temperature regulation to ensure food safety and meet international standards.