The use of light microscopy in a study of extraneous matter and authenticity of guava, strawberry and grape jams

Samples of guava, strawberry and grape jams were analyzed to determine the presence of filth and mold filaments, and to test their authenticity. Eighty percent of the samples (36/45) presented at least one extraneous material. According to the type of fruit, in 100.0% (15/15), 73.3% (11/15) and 66.7% (10/15) of the samples of guava, strawberry and grape jams, respectively, at least one extraneous material was found. The extraneous materials found were mold filaments, insect fragments, mites, non-edible plant parts (leaves and stems), maggots, a whole insect, a nylon thread, a piece of plastic material, and a metallic particle. No foreign plant tissue was found in any sample when compared to authentic fruit tissues