Acrylamide increases and furanoic compounds decrease in plant-based meat alternatives during pan-frying.

Plant-based meat alternatives are gaining popularity as protein sources. However, pan-frying may lead to the formation of potentially harmful food contaminants. We investigated the formation of acrylamide and furanoic compounds in four different plant-based meat alternatives and two meat burger patties during pan-frying at 160 and 200 °C. The highest acrylamide contents (72. ± 7.7 and 69.2 ± 9.5 µg/kg, respectively) were found in soy flour- and sunflower-protein based patties fried at 200 °C. Unprepared pea and soy protein-based burger patties contained the highest furfural amounts (2832.8 ± 576.2 and 2683.0 ± 868.5 µg/kg, respectively). Furfuryl alcohol content was highest in soy flour-based patties and increased temperature-dependently up to 1120.9 ± 383.4 µg/kg. Based on the tolerable intake calculated by the EFSA Scientific Panel on Contaminants in the Food Chain, these amounts do not pose a health risk. Nevertheless, since plant-based novel food are being increasingly consumed, further investigations into the formation of food contaminants in novel processed foods are warranted.

Metabolism of Daidzein and Genistein by Gut Bacteria of the Class Coriobacteriia.

The intake of isoflavones is presumed to be associated with health benefits in humans, but also potential adverse effects of isoflavones are controversially discussed. Isoflavones can be metabolized by gut bacteria leading to modulation of the bioactivity, such as estrogenic effects. Especially bacterial strains of the Eggerthellaceae, a well-known bacterial family of the human gut microbiota, are able to convert the isoflavone daidzein into equol. In addition, metabolization of genistein is also described for strains of the Eggerthellaceae. The aim of this study was to identify and investigate gut bacterial strains of the family Eggerthellaceae as well as the narrowly related family Coriobacteriaceae which are able to metabolize daidzein and genistein. This study provides a comprehensive, polyphasic approach comprising in silico analysis of the equol gene cluster, detection of genes associated with the daidzein, and genistein metabolism via PCR and fermentation of these isoflavones. The in silico search for protein sequences that are associated with daidzein metabolism identified sequences with high similarity values in already well-known equol-producing strains. Furthermore, protein sequences that are presumed to be associated with daidzein and genistein metabolism were detected in the two type strains 'Hugonella massiliensis' and Senegalimassilia faecalis which were not yet described to metabolize these isoflavones. An alignment of these protein sequences showed that the equol gene cluster is highly conserved. In addition, PCR amplification supported the presence of genes associated with daidzein and genistein metabolism. Furthermore, the metabolism of daidzein and genistein was investigated in fermentations of pure bacterial cultures under strictly anaerobic conditions and proofed the metabolism of daidzein and genistein by the strains 'Hugonella massiliensis' DSM 101782T and Senegalimassilia faecalis KGMB04484T.