Insect Fragments in Food : Part 2

by Food and Drug Administration (FDA)

(Page 2 of 3)

"Finding an insect fragment in food will not tell you how the fragment got there. You start with the insect," Olsen explains, "but you also have to look at the process. We extrapolate back to find out where the fragment came from.

"Was it in the raw material, or did it come after the raw materials were first ground, or much later, after they were extruded through the noodle machine? We have to understand the process and factor it in. We have to know when the product was cooked, ground and formed."

Olsen explains that entomologists on his staff are educated in the many stages of food processing during their early FDA days, when they accompany inspectors on their rounds. "The scientist helps track down the root of the problem while learning food processing. We're a team."

Extracting Fragments

According to Olsen, Trauba is one of FDA's masters at the extraction of insect fragments. Trauba's initial scientific expertise and college training was in chemistry, and extracting insect fragments from food is reminiscent of a college chemistry experiment.

Before explaining the process, Trauba emphasizes the importance of following the extraction procedures exactly as published by the Association of Official Analytical Chemists (AOAC).

He explains that the AOAC book of methods includes directions for separating the filth elements from many food products. "Some of the categories include dairy products, nuts, grains, baked goods, spices, pasta, cereal, egg products, seafood, jams, and jellies — there's even a methodology for determining if there's mouse or rat urine on the bagging."

Sticking strictly to these methods permits foreign businesses to know exactly how their products will be tested, and the likely results once they come under FDA's jurisdiction. It's much the same for domestic businesses — everyone is playing with the same deck.

But the trump card for FDA and the consumer in using the AOAC methods, according to Trauba, is that "all of the federal courts accept them as official. There's never any question. That's why it's so important to use the methodology in the book."

Since he developed the methods adopted by the AOAC for extracting fragments of insects burrowed into wheat and oat kernels, Trauba speaks from first-hand experience.

AOAC methods have been around since the 1920s. One reason the courts accept the AOAC standards as authoritative is that they have been "collaborated" or verified by other labs, Trauba points out.

In the collaboration process, a product is "spiked" with a known amount of insect fragments, then sent to 10 or 12 labs throughout the FDA and industry, which conduct identical tests to verify the method. The results are statistically validated, and, if acceptable, the new method is accepted by the AOAC.

Using a packaged macaroni product to demonstrate the extraction process, Trauba makes it seem simple. First, the macaroni needs to be "digested," as Trauba puts it — that is, broken down enough to free the baked-in fragments, allowing them to be removed.

The macaroni is added to a solution of water and dilute hydrochloric acid and then heated, under pressure, in an autoclave for 30 minutes. The heating eliminates the starches, leaving soluble sugars and carbohydrates.

Pouring hot water over the material in a very fine sieve washes away soluble matter and some, but not all, of what Trauba at this point refers to as "plant material."

At this stage, the insect fragments are freed but not separated from the plant material. More hot water, mineral oil, and hydrochloric acid are added next. The mixture is placed in a "percolator," a glass vessel with a drain in the bottom. The mineral oil selectively coats the insect fragments and other animal material, such as hairs and feathers. These float to the surface with the oil.

"When the aqueous phase drains, we wash the 'percolator' out with alcohol and drain the contents into a beaker and filter it through paper," Trauba explains.

The fragments on the filter paper are then ready for identification using a microscope. The viewer compares the fragment with slides or pictures of known insects. Identification of the type of insect from which the fragment came often necessitates the higher magnification of a compound microscope.

Testing some food products calls for additional steps. Although it's much the same, Trauba warns that as the number of steps in a method increases, so does the risk of losing some of the insect fragments. "The more mechanical things are involved, the more chance there is of losing tiny fragments. The less manipulation the better."

Fragment examination is particularly important with imported foods. "We have no inspection authority to go overseas to see what an industry looks like," says Brickey. "When we get an import in, we have no idea whether the manufacturing process was good or what — that's why we have to rely on the fragment count."

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.