Aflatoxin itself does not glow under black light. What glows under 365 nm UV light is a trace left by the aflatoxin-producing mould: on dried figs and in-shell pistachios it shows up as a bright greenish-yellow glow.

Dried figs

A suspect fig that may contain aflatoxin stands out in a dark setting as if it had been marked with a highlighter. The colour is greenish-yellow and part of the fruit seems to radiate light. Sound figs do not show this glow.

The glow can be on the skin or inside the fig’s cavity, so a fig that looks clean outside but raises doubt should be checked inside too.

In-shell pistachios

The sign is again a greenish-yellow glow, seen on the shell. In a study in Iran, removing the glowing nuts clearly reduced the aflatoxin level of the lot.

Maize (corn)

Look for a bright greenish-yellow spot in the germ or starchy part of broken or damaged kernels. A pale yellow glow at the tip of the kernel should not be confused with this sign.

Almonds

Almonds are different. Almond kernels that may contain aflatoxin glow violet-blue. A bright yellow glow on almonds is not taken as an aflatoxin sign.

Why the exact colour matters

Many things glow under UV light: dust, some stains, packaging fibres. The fruit you remove should glow in the colour you are looking for and appear to radiate light. Dull or differently coloured glows are usually false alarms.

Wavelength matters too. Aflatoxin pre-sorting uses long-wave UV of around 360 to 365 nm.

What does a glowing kernel mean?

A glowing kernel is suspect fruit that may contain aflatoxin. UV light helps you sort it out. Whether the lot is really clean is shown by laboratory analysis. The right order is: first remove suspect fruit under UV light, then take a sample from the lot and send it to the laboratory.

See the AFLALED models with 365 nm ± 5 nm LEDs.

Ask us which colour to look for in your product and we will check it with you.
Phone / WhatsApp: +90 532 233 42 81 · E-mail: satis@altayshop.com

Related questions: How can you tell if dried figs contain aflatoxin? · How is a UV lamp used on a dried fig sorting belt?