Yellow spherical particles (～10 μm) were identified as a slime mold species by IR analysis and culture testing, likely transferred from wooden pallets during transport.

The foreign matter, an orange-tinted transparent film, was identified as crustacean shell by microscopy, color reactions, and IR analysis. Contamination likely originated from raw materials or processing, as the food was a marine product.

The solid, composed of white and black substances, was identified as a mixture of precipitated high-molecular-weight palm oil and soot. Precipitation likely resulted from insufficient heating, with external soot possibly incorporated during solidification.

A brown substance from fuel oil was captured in the filter. After oil removal, IR and X-ray analyses identified it as paint film fragments and iron rust. Tank deterioration was suspected, with the paint film and rust likely contaminating the fuel oil.

The cake crumb turned green. Staining tests and verification experiments revealed that the berry pigment (anthocyanin) had turned green due to alkaline conditions. The discoloration was likely caused by contact with alkaline substances present in the cake.

Identification and comparison of red paint adhered to fishing nets and buoys were conducted against the ship’s paint. IR and X-ray analyses of resin and pigment components showed that the paint on the buoy matched the ship’s paint.