A new study published in the Journal of Food Engineering demonstrated the risk of cross-contamination created by the dispersal of various allergenic food powders.

In an experiment, 50 grams of different allergenic food powders, including skim milk, infant formula, wheat flour, buckwheat flour, and soybean flour, were dropped from a height of 1.2 meters (m) and were allowed to settle for five minutes. Using immunochromatography and an enzyme-linked immunosorbent assay, the researchers measured the dispersal distance of each food powder from the initial dropping point.

Dispersal Distances and Patterns

The powders dispersed at distances ranging from 0.5 m to more than 5 m. Skim milk and buckwheat flour dispersed the farthest, followed by infant formula, wheat flour, and soybean flour. 

Visualization of dispersed food particles using laser irradiation and analysis of the powder properties provided insight into dispersal differences. The researchers found that skim milk, buckwheat flour, infant formula, and wheat flour rose into a cloud after falling until reaching a height near the starting position of the fall, subsequently becoming a cloud of particles on the experimental table that spread laterally into the surrounding area. On the other hand, soybean flour did not redisperse and no diffusion to the surrounding area could be confirmed.

Significance for Food Industry

Given that the dispersibility of a powder correlated with its dispersal distance, the researchers recommend that food producers add powders from as low a position as possible to control redispersion. Additionally, dispersibility may be a useful tool for simulating the dispersal distance and hygienic control of food powders, thereby helping to reduce the risk of cross-contamination of unintentionally dispersed food allergens.