Multianalytical Detection of Pig-Derived Ingredients in Bread

Most of the bread on the market contains several additional ingredients compared to those used for traditional baking (flour, water, yeast, and salt). Modern bread is often baked using enzymatic dough improvers, which, as technological aids, can be omitted on the label. Baking mixes also can contain varying percentages of hard fat or their derivatives. The possible animal origin of enzymes or fats in bread might remain unknown, raising ethical concerns for some categories of consumers. Herein, an array of analytical methodologies recently exploited to disclose the origin of enzymes in dough improvers has been extended to the detection of pig-derived ingredients in bread. PCR amplification of a mitochondrial cytochrome b (mt-Cytb) gene region enabled the detection of even trace amounts of porcine DNA in bread. Porcine pancreatic alpha-amylase was detected in bread spiked with porcine pancreatic enzymes using both Western blot and HPLC-tandem mass spectrometry-based targeted or untargeted proteomics. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) enabled quick discrimination between lard-containing (1%, w/w) and conventional bread. However, gas chromatographic analysis of fatty acids produced characteristic patterns for bread baked with lard or other oils.