Alexander J. W. Elferink

Growing insects for food consumption contributes to sustainability as insects can grow efficiently on a wide variety of organic residual streams. These residual streams however contain a variety of proteins and – depending on their origin – can contain allergenic ingredients potentially triggering a response in patients. This study aimed to investigate the possible transfer of milk and wheat from residual streams to black soldier fly larvae (BSFL) and yellow meal worm (YMW). Using ELISA based test kits, transfer of wheat to BSFL but not to YMW larvae was shown. Concentrations of wheat in BSFL were not linear to concentrations in the different wheat based substrates, suggesting transfer is matrix depended. Four days of fasting BSFL showed to be sufficient to reduce the amount of wheat present in the larvae to concentrations below the detection limit of the assay. For milk, no transfer of the investigated substrates to BSFL was observed. For YMW the matrix reduced the signal of the test kit, hampering drawing conclusions about the milk transfer. In conclusion, only low transfer for wheat to BSFL was detected in amounts below the action levels set for allergic responses, indicating no allergic responses are expected in case of consumption.

Processed milk and milk products produced from bovine milk, commonly contain β-casein A1 (βCA1) and β-casein A2 (βCA2). Since the presence of βCA1 is linked to milk intolerance and digestion problems, A2A2 milk, which only contains βCA2, is proposed as a healthier alternative. To support this health claim, the purity of A2A2-milk has to be guaranteed. In the presented study, a multiplex immunoassay, able to distinguish between βCA2 and βCA1, was developed and real-life applicability was shown on raw milk samples from genotyped A1A1, A1A2 and A2A2 cows. Because of its ability to discriminate between βCA2 and βCA1, this newly developed method was able to detect the addition of common bovine A1A2 milk to A2A2 milk, as low as 1%. Besides the detection of A2A2 milk purity, the developed assay can also be implemented as a rapid phenotyping method at dairy farms to replace the more invasive DNA-based screening. Additionally, the developed method was capable of detecting the addition of common bovine milk up to 1% in sheep, goat, buffalo, horse and donkey milk, which conforms to EU recommendations. In conclusion, a newly developed multiplex method capable of reliably detecting the dilution of A2A2 milk of multiple species, with common bovine milk up to 1%, is presented.