## 3 Effect of Food Processing and Culinary Preparations on PAs, TAs and OAs
### Infusion  
Most of the food alerts that have noted high concentrations of these alkaloids (e.g., PAs and TAs) have been reported in teas and herbal teas [6,7,9]. However, in many cases, the high levels of these alkaloids have been referred to the dry products instead of the hot drink obtained via the infusion process [88]. In this sense, many of the published works directly analyzed the dry samples instead of the infusions [88,89]. This is a relevant issue, as for the risk assessment of these contaminants it is also important to consider the transfer rate of these alkaloids in culinary preparations, such as infusions, so that a more reliable scenario of the real intake of these contaminants by consumers can be determined. Accordingly, besides thermal degradation, the investigation of the transfer rate of these alkaloids during the preparation of tea and herbal tea infusions with boiling water has also been one of the most studied processes, especially in the case of PAs (Figure 3). Table 3 collects the works available in the literature that have addressed this issue to date. Currently, according to the EFSA, the concentration of PAs and PANOs in infusions is estimated by applying a dilution factor to the data obtained in the dry products considering a 100% transfer rate [89, 90, 91, 92]. Nonetheless, current data in the literature concerning the transfer rate of PAs in infusion samples also show discrepancies. For instance, [PERSON] (2007) evaluated the content of retorsine in both dried and boiled herbal tea samples, observing no differences between both samples [71]. [PERSON] et al. (2014) also indicated the complete migration of PAs from the dry plant to the herbal infusion. The results obtained showed that the PA levels determined in hot tea drinks prepared with boiled water were similar to the PA concentrations quantified in the dry raw herbs after extraction under acidic conditions [93]. However, other authors have stated that the transfer rate of PAs from the dry product to the infusion was not always 100% [72,90,93, 94, 95, 96, 97]. Thus, some works have determined high transfer rates of PAs to infusions in the range of 80-100% [94, 95, 96]. For instance, [PERSON] et al. (1980) indicated a transfer rate of 80% for senkirkine from colotsfoot [94], [PERSON] et al. (2018) reported about an 85% transfer rate for 28 PAs in 38 tea samples [95], and [PERSON] (2014) a range between 84 and 103% for nine PAs in peppermin infusions [96]. However, conversely, [PERSON] et al. (2018) observed low transfer rates of PAs during the brewing process (16-28%, except monocotaline with 45%) [90]. Similarly, [PERSON] et al. (2015) also found that the total PA content in infusion samples was relatively smaller than that of their respective dry herbal product, with concentration levels ranging between 13 and 1080 and 1127 and 5137 \(\upmu\)g/kg, respectively [97]. Additionally, a high prevalence of PANOs was detected in aqueous infusion samples [97]. Likewise, this same trend was observed in the work of [PERSON] et al. (2022), in which the greater transfer rate of PANOs was attributed to their higher polarity [72]. However, in this case, higher transfer rates for PAs (\(\leq\)57%) and PANOs (\(\geq\)76%) were reported [72]. In the work of [PERSON] and [PERSON] (2021), PANOs also showed higher transfer rates than PAs using different brewing processes [98]. In this sense, in samples prepared with the ISO brewing procedure [99], the transfer rates of PAs and PANOs were between 52 and 89% (median 73%) and 87 and 100% (median 91%), respectively [98]. Conversely, transfer rates of PAs and PANOs were higher in samples prepared according to the vendor's instructions, ranging between 63 and 95% (median 84%) and 95 and 100% (median 99%), respectively [98]. Therefore, PAs were extracted less efficiently with the ISO procedure than with the vendor's instructions.