Table 4.
Detection of mat K target in several commercial food products by real-time PCR. Mean Ct and standard deviation is shown. Measurements of the same sample were performed at least twice in two different DNA extractions. N.D. means that non-signal after 40 cycles of amplification. All samples were first assayed for amplification inhibitor presence using eukaryotic universal primers.
| Food | Food Allergen Declaration | Ct ± SD | Peanut mg/kg * |
|---|---|---|---|
| Cereal Bar I | Peanut (35%), Hazelnut (24%) | 17.97 ± 0.26 | >105 |
| Cereal Muesli | Tree nut and peanut traces | 38.73 ± 0.76 | <LOQ |
| Cereal Bar II | Almond and tree nuts | 32.40 ± 0.29 | 2.5 |
| Cereal Bar III | Hazelnut (10%), Almond and Peanut traces | 33.74 ± 0.29 | <1 |
| Cereal Bar IV | May content tree nut traces | 35.90 ± 0.94 | <LOQ |
| Chocolate with pistachio | Pistachio (5%), Almond, Hazelnut, tree nut traces | 36.80 ± 0.43 | <LOQ |
| Vegetal Burger | May content tree nut traces | 39.17 ± 0.96 | <LOQ |
| Sausage with walnut | Walnuts | N.D. | N.D. |
| Chocolate | Almond and Hazelnut traces | 37.99 ± 0.33 | <LOQ |
| Chocolate Bar I | Tree nut traces | 32.42 ± 0.16 | 2.5 |
| Chocolate Bar II | Not declared | 31.32 ± 0.21 | 5.7 |
| Cookies with fiber | Not declared | 31.02 ± 0.30 | 7.1 |
| Cookies with chocolate | Not declared | 32.25 ± 0.46 | 5.7 |
* Estimated quantity of peanut by substitution of the obtained mean Ct in the standard curve from mixtures spiked with untreated peanut.