## 3 Effect of Food Processing and Culinary Preparations on PAs, TAs and OAs
### Thermal Treatment
On the other hand, it is also important to determine if the degradation reported is real and the compounds are being completely eliminated or if they are being transformed in other ones. As has been indicated, some authors observed the interconversion of PANOs to PAs, but it is also important to determine if they can be transformed into other different degradation products. Accordingly, if this is the case, it will be important to study the toxicity of these new compounds formed as a result of the thermal process, since they might exert even higher toxicities. Thus, the regulation of these degradation compounds should be considered and included in the corresponding legislation. On the other hand, the thermal stability of TAs has also been evaluated in some works (Table 1). In this context, the first study addressing the effect of temperature on samples contaminated with TAs was carried out by [PERSON] and [PERSON] in 1989 [78]. This research was focused on the analysis of bread prepared with \(D\). _stramonium_ seeds. The bread was separated into crumb and bark, and each part was analyzed separately. The results showed an atropine degradation of 25% in the crumb and 18% in the bark, while scopolamine degradation was of 13% in the crumb and 28% in the bark [78]. The results obtained in this study showed a slight degradation of the TAs analyzed, suggesting they may resist the baking procedure. In contrast, [PERSON] et al. (2019) evaluated the effect of baking (190 \({}^{\circ}\)C) on different TAs in vial trials (standard solutions under simulated bread-making conditions) and bread prepared with buckwheat and millet contaminated with _Datura stramonium_ and _Brugmansia arbora_. In the vial trials, the results showed almost complete degradation of TAs (between 94 and 100% degradation). However, in the contaminated bread samples lower degradation of TAs was reported (between 11 and 100% degradation for \(D\). _stramonium_ and 30 and 100% for \(B\). _arbora_), suggesting the food matrix may act as a protection against the degradation of TAs [79]. For this reason, it would be suitable to compare different matrices and evaluate how temperature affects these alkaloids in them. Furthermore, it was observed that the most complex TAs (e.g., atropine, scopolamine, homatropine) degraded to low molecular weight TAs, such asropine and tropinone. Accordingly, these compounds could be used as potential markers of TAs in heat-treated foods. Nonetheless, how the concentration of some compounds, like aposcopolamine or apoatropine, increased during the baking procedure was also observed, possibly due to the degradation of the most complex TAs into these molecules. In this sense, the partial conversion of the main TAs (atropine and scopolamine) to other degradation products, such as aposcopolamine and apoatropine, and from aposcopolamine to apoatropine, compounds even more toxic than the initial atropine and scopolamine TAs,was also confirmed [79]. Thermal degradation of TAs was also evaluated in breadsticks samples prepared with corn flour contaminated with _D. strmonium_ seeds [80]. In this case, it was observed that the baking process produced the degradation of TAs by up to 65%. Baking at 180 \({}^{\circ}\)C for 20 min led to the degradation of atropine between 7 and 65%, depending on the preparation conditions used, whereas under these baking conditions the degradation of scopolamine and anisodamine was between 35 and 49% [80]. Overall, the data obtained in these works seem to indicate that baking can contribute to reducing the content of TAs that generally appear in high concentrations, such as atropine and scopolamine. Nonetheless, the wide variation in the results observed among the different works may be due to the inadequate control of critical parameters in the baking process. Thus, more work evaluating the different parameters (e.g., temperature, baking time, type of food, presence of additives, etc.) should be carried out to draw reliable conclusions.