## 4 Discussion  
In the preliminary phase, sample preparation was optimized for the subsequent extraction phase according to the methods indicated in the kits. Regarding the determination of ochratoxin A, the results obtained on the 'blanks' in the preliminary tests did not reveal interferences in antigen-antibody recognition for both kits used; the absorbance levels obtained were well below the limit of quantification of the methods (Veratov(r): LOQ = 2 ug/kg;  
Figure 3: Analysis performed with ELISA method: (**A1**) aflatoxin concentrations in Bella di Cerignola cultivar for both years; (**A2**) aflat concentrations in Nocellara del Belice cultivar for both years; (**B1**) ochratoxin A concentrations in Bella di Cerignola cultivar for both years; (**B2**) ochratoxin A concentrations in Nocellara del Belice cultivar for both years. Figure 2: Analysis performed with ELISA method: (**A1**) aflatoxin concentration per year present in the 4 shipments; (**A2**) detail of aflatoxin concentrations in the two cultivars Bella di Cerignola and Nocellara del Belice; (**B1**) ochratoxin A concentration per year present in the 4 shipments; (**B2**) detail of ochratoxin A concentration in the two cultivars Bella di Cerignola and Nocellara del Belice. AgraQuant(r): LOQ = 2 \(\upmu\)g/kg). To confirm the lack of interference for the specific antibody, fortification tests performed revealed unsatisfactory results. In fact, on the fortified extracts, the values obtained gave a recovery of \(\leq\)40% for both kits. Therefore, the revised method applied with dichloromethane on both the extraction procedures and the replacement of the organic solvent mixture proved more compatible. In this regard, different specificity characteristics of the antibodies were described in the method kits; in particular, concerning the Veratov(r) kit, the reaction specificity was greater for aflat B1 and B2, while AgraQuant(r) showed percentages of specificity towards the four aflat equal to 100% for AFB1, 65% for AFB2, 70% for AFG1, and 42% for AFG2 (Veratov(r): LOQ = 5 \(\upmu\)g/kg; AgraQuant(r): LOQ = 4 \(\upmu\)g/kg). Previously, recovery tests on fortified green olive paste samples carried out according to the methods indicated in the two kits and including known quantities of total aflat (20 \(\upmu\)g/kg) demonstrated sufficient efficacy in the extraction of mycotoxins in the solvent mixture (methyl alcohol at 70% \(v/v\) in water), resulting in values close to 55% for total aflat (no. three samples) and 76% for aflatoxin B1 (no. one sample). On the other hand, with the new method, for aflatoxin B1 concentrations between 6 and 10 \(\upmu\)g/kg, the results showed that AgraQuant(r) improved the recovery of AFB1 to over 90% with the new extraction conditions (no. six samples). A good recovery was also observed with Veratov(r) on the same samples and for the same concentration range (approx. 70%). This confirms the extraction validity of the modified method applied (dichloromethane). Concerning the results obtained on OTA fortified samples, results showed about 55% recovery for Veratov(r) (n. 17 samples), while for AgraQuant(r), the recovery was almost 80% (n. 15 samples). Another aspect to be highlighted is that sample preparation methods (laboratory homogenizer mixer vs. coffee grinder) did not affect the final results, with us finding non-significant differences in final mycotoxin recovery (\(p<0.05\)) at a mycotoxin concentration range between 20 and 100 \(\upmu\)g/kg (n = 4). In general, the use of the ELISA kits gave interesting results, especially for aflatoxin detection, where the match of findings with the official method (LC-MS/MS) was very high (only 3% false positives in one kit). The literature describes that the applicability of ELISA in the detection of mycotoxins is studied by scientists in different foods and feeds [39; 40]. Interestingly, [PERSON] et al.