## 3 Results and Discussion
### Biogenic Amine Content in Wheat Wholemal Samples  
The biogenic amine (BA) content in WW samples is shown in Table 2. Tryptamine (TRY) and spermine (SPRM) were not found in WW; however, all the other BAs identified in the WW samples were significantly influenced by the wheat variety, the type of LAB used for fermentation, and the wheat variety * LAB type interaction (Supplementary File S3 Table S5). Also, between the sample pH and phenylethylamine (PHE), a positive weak correlation was found (r = 0.389, \(p\) = 0.006). Also, between the LAB count in the samples and the spermidine (SPRMD) concentration, a positive moderate correlation was established (r = 0.422, \(p\) = 0.003) (Supplementary File S3 Table S6). PHE was the predominant BA in the WW samples, and the lowest PHE concentration was found in the DS8526-2 purple WW samples fermented with the LUHS245 strain (26.4 mg/kg). In the other samples, the PHE concentration was from 2.8 to 1.8 times higher (in nontreated 'Ada' WW and in LUHS245 fermented 'Santa' samples, respectively). Putrescine (PUT) was established in all (nontreated and fermented) 'Ada' and 'Santa' samples. When comparing the PUT concentration in the 'Ada' samples, the lowest PUT content was found in the LUHS29 fermented 'Ada' WW (20.3 mg/kg). However, in nontreated and in LUHS245 fermented 'Ada' samples, on average, a 40.9% higher PUT concentration was established, and the highest PUT content was formed in the LUHS122 fermented samples (98.1 mg/kg). PUT was not found in DS8472-5 blue WW, and when comparing DS8526-2 purple WW, PUT was formed in just one sample (fermented with the LUHS245 strain) (26.8 mg/kg). Cadaverine (CAD) was not found in waxy wheat 'Santa' WW and in other wheat varieties WW fermented with the LUHS29 strain. Also, CAD was not established in DS8472-5 blue WW fermented with the LUHS245 strain; however, in DS8526-2 purple WW fermented with the LUHS245 strain, the CAD concentration was, on average, 84.0 mg/kg. In both blue and purple WW fermented with the LUHS122 strain, on average, a CAD concentration of 94.0 mg/kg was found. Histamine (HIS) was found in just two samples (in 'Ada' and 'Santa' WW fermented with the LUHS122 strain), and tyramine (TYR) was found in one sample (DSS526-2 purple WW fermented with the LUHS122 strain). The spermidine (SPRMD) concentration in WW samples ranged from, on average, 28.0 mg/kg (in nonfermented and LUHS245 fermented 'Ada', in LUHS245 fermented 'Santa', in LUHS29 and LUHS122 fermented blue WW, and in all purple WW samples) to, on average, 36.3 mg/kg (in LUHS29 fermented 'Ada' WW and in LUHS245 fermented blue WW). HIS, TYR, PUT, CAD, TYR, agmatine, SPRM, and SPRMD are the main BAs in food and beverages [50; 51]. Despite the fact that the LAB has a GRAS (Generally Recognized as Safe) status, these very popular industrial microorganisms are the main BA producers in fermented foods [52]. In addition, it was reported that the pH between 4.0 and 5.5 is optimal for enzymes, forming BAs, activities [50]. Other factors that influence the formation of BAs are bacterial activity, humidity, the concentration of free amino acids, etc. ; however, the number of bacterial cells in the substrate does not always correlate with the amount of BAs [53]. Consumption of food containing a high concentration of BAs is implicated in various pharmacological reactions [54], which lead to different types of foodborne diseases [27]. HIS can be formed from histidine, TYR from tyrosine, CAD from lysine, PUT from arginine, and SPRMD and SPRM from arginine and methionine, and their toxicity depends on synergistic effects, e.g., HIS toxicity is enhanced by the presence of CAD, PUT, and TYR [55]. Despite the fact that HIS and TYR are the most toxic BAs [56; 57; 58; 59], PUT and CAD, although not toxic themselves, aggravate the adverse effects of HIS and TYR [60].