Ochratoxin A in cocoa and chocolate sampled in Canada

Figures & data

Figure 1. Chromatogram of baking chocolate (0.35 ng OTA g⁻¹) extracted with 40% methanol and analysed with mobile phase conditions from Method I (upper curve) and Method II (lower curve).

Table 1. Validation data for cocoa (Method I).

	Alkalized cocoa (n = 3)			Natural cocoa (n = 3)
	No spike (ng g^−1)	0.5 ng g^−1 spike, recovery (%)	5 ng g^−1 spike, recovery (%)	No spike (ng g^−1)	0.5 ng g^−1 spike, recovery (%)	5 ng g^−1 spike, recovery (%)
Mean ± standard deviation (SD)	0.57 ± 0.02	61 ± 5	56.8 ± 0.7	0.26 ± 0.03	58 ± 13	46 ± 2
Note: The limit of detection (LOD) is based on 3 × S/N = 0.02 ng g^−1; and the limit of quantification (LOQ) is based on 10 × S/N = 0.07 ng g^−1.

Table 2. Validation data for natural cocoa and chocolate (Method II).

	Natural cocoa (n = 3)			Baking chocolate (n = 3)
	No spike (ng g^−1)	0.5 ng g^−1 spike, recovery (%)	5 ng g^−1 spike, recovery (%)	No spike (ng g^−1)	0.5 ng g^−1 spike, recovery (%)	5 ng g^−1 spike, recovery (%)
Mean ± standard deviation (SD)	0.345 ± 0.003	81 ± 4	79 ± 1	0.35 ± 0.01	93 ± 1	94 ± 1
Note: The limit of detection (LOD) is based on 3 × S/N = 0.02 ng g^−1 for cocoa and chocolate; and the limit of quantification (LOQ) is based on 10 × S/N = 0.07 ng g^−1 for cocoa and 0.08 ng g^−1 for chocolate.

Figure 2. Chromatogram of OTA methyl ester for baking chocolate sample (1.4 ng g⁻¹).

Figure 3. OTA in cocoa. The dotted line is the previously considered European Commission limit.

Figure 4. OTA in chocolate. The dotted line is the previously considered European Commission limit.

Table 3. Results for OTA in cocoa and chocolate.

Sample type	Number of samples analysed	Samples above the LOQ^a	Concentration range (ng g^−1)	Mean (ng g^−1)	Samples above the previously considered European Commission limits^b
Alkalized cocoa	16	16	0.57–7.8	2.0	5
Natural cocoa	16	16	0.25–2.6	0.89	1
Baking chocolate	7	7	0.12–1.4	0.63	1
Dark chocolate	14	14	0.17–0.88	0.38	0
Milk chocolate	7	5	<LOQ–0.19	0.11	0
Notes: ^aThe limits of quantification (LOQs) are 0.07 ng g^−1 for cocoa (analysed by Method I) and 0.08 ng g^−1 for chocolate (analysed by Method II).
^bPreviously considered European Commission limits are 2 ng g^−1 for cocoa and 1 ng g^−1 for chocolate.