THE PROBLEM:

A food company received a complaint of insect parts observed in their chocolate chip granola bar. A portion of the suspicious bar was sent to MVA Scientific Consultants with a request that we determine if insect parts were indeed present in the bar.

THE ANALYSIS:

The partial granola bar was examined using a combination of brightfield reflected light microscopy (Figures 1 & 2) and transmitted polarized light microscopy (PLM) (Figures 3 & 4).

Figure 1. Brightfield reflected light image of suspicious particle.

Figure 2. Brightfield reflected light image of second suspicious particle.

Figure 3. Transmitted light image of suspicious particle.

Figure 4. Same image as in Figure 3 with crossed polarizers.

THE OUTCOME:

Examination of the granola bar revealed two areas at the open end of the wrapper that appeared to have dark, elongated structures resembling a non-food product.

PLM analysis of sections from those areas revealed that each was composed of cellulose (plant material) with a structure consistent with cereal grain husk. No insects or insect parts were observed on the granola bar.