## 4 Discussion
A significant correlation between arginine and putrescine (r = 0.80, \(p<0.05\)) was also noticed, which may also indicate the relevance of this AA. As agmatine was not one of the studied BA, it is not possible to draw conclusions about the relevance of this pathway in putrescine formation. In addition, spermine and spermidine are interconvertible with each other and the latter into putrescine. Thus, the presence of these two endogenous amines may also contribute for the formation of putrescine in dry-fermented sausages. In his work, [PERSON] et al. [34] found that the production of putrescine in response to spermine and spermidine addition was dependent on the involved microorganism. Our results showed a progressive spermine decrease over time, as opposed to an increase in spermidine, accompanied by an increase in putrescine concentration. This observation is statistically supported by the correlation found between spermine and spermidine (r = \(-0.40,p<0.05\)) and the latter with putrescine (r = 0.90, \(p<0.05\)). In global terms, the levels of amines from bacterial origin found in our study are comparable to the results that have been reported by several authors, in the most varied traditional meat products, whether produced in Portugal or other countries [3, 15, 35, 36, 37, 38, 39]. From the point of view of consumer safety, there is currently no legislation that determines maximum levels of BA applicable to dry-fermented sausages. Therefore, the levels at which toxicological effects are observed are often considered as a reference, i.e., 100 mg/kg WW for histamine as well as for tyramine, 30 mg/kg WW for \(\beta\)-phenylethylamine and 200 mg/kg WW for vasoactive amines [40]. With the exception of \"Control_3M\" dry-fermented sausages from Batch A, the presence of vasoactive amines was exclusively due to tyramine and never surpassed the content of 100 mg/kg WW recommended for this BA. A different scenario was observed for Batch B products, where this level was attained already in \"FP\" or after \"1M\" of storage (\"Control\" and \"LSF\", respectively). Concerning the sum of vasoactive amines, the content of 200 mg/kg was only exceeded in \"Control_3M\" samples from Batch B. As endogenous polyamines, spermine and spermidine, are involved in several physiological processes, they occur naturally in meat. Hence, these are usually the most predominant in early processing stages, similarly to what was found in this research. Spermine is more abundant in foods of animal origin, a fact that justifies the observed prevalence over spermidine. Overall, the found levels for spermine and spermidine were slightly higher than those reported by [PERSON] et al. [3], [PERSON] [41], [PERSON] et al. [42] and [PERSON] et al. [43] but still slightly lower than those found by [PERSON] et al. [39]. When compared to their initial levels found in \"RM\" samples, during the processing stage, spermine levels decreased, while spermidine levels increased. In the opinion of several authors, the levels of these polyamines are not usually affected by processing [41, 44, 45]. In turn, [PERSON] et al. [46] also state that spermine content may slightly decrease during processing. However, the levels of these polyamines depend on several factors that are not yet fully explained, namely their use as a source of nitrogen by some microorganisms, but also the conversion of spermine into spermidine [9, 47].