Table 1.
Data from previous studies reported in the scientific literature on the occurrence of aflatoxin B1, ochratoxin A, and arsenic in rice.
| Country | Sample Type | Methodology | LOQ (LOD) (µg kg−1) |
N Samples | Frequency (%) |
Levels (µg kg−1) | Reference | ||
|---|---|---|---|---|---|---|---|---|---|
| Min. | Máx. | Average | |||||||
| Aflatoxins | |||||||||
| Austria | Rice | SPE(IAC)-LC-FD | 0.44 (0.1) | 81 | 29.6 | <LOQ | 9.86 | ns | [21] |
| Canada | Rice | LC-MS | 0.05 (0.002) | 200 | 49.5 | 1.44 | 7.14 | 0.18 | [22] |
| China | Rice | LLME-LC-FD | 0.03 (0.009) | 370 | 63.5 | 0.030 | 20.0 | 0.60 | [23] |
| China | Rice | ELISA/HPLC | (0.1) | 29 | 100 | 0.1 | 1.4 | 0.5 | [24] |
| China | Rice | SLE-LC-FD | (0.05) | 37 | 97.3 | 21 | 30 | 0.88 | [25] |
| Philippines | Rice | SPE(IAC)-LC-FD | (0.025) | 78 | 95 | ND | 8.33 | 1.48 | [26] |
| Iran | Rice | ELISA | ns | 40 | 100 | 0.29 | 2.92 | 2.09 | [27] |
| Iran | Rice | SPE(IAC)-LC-FD | (0.1) | 71 | 83 | ND | 10 | 1.89 | [28] |
| Malaysia | Rice products | ELISA | 0.35 (0.2) | 13 | 69.2 | 0.68 | 3.79 | 1.5 | [29] |
| Pakistan | Rice | SPE(IAC)-LC-FD | 0.20 (0.04) | 208 | 35 | ND | 21.30 | 8.31 | [30] |
| Pakistan | Brown rice | ELISA | (1.0) | 120 | 73.3 | 1.24 | 11.68 | 3.70 | [31] |
| Pakistan | Rice | SPE(IAC)-LC-FD | (0.5) | 20 | 25 | 1.5 a | 10.8 a | 4.6 a | [32] |
| Tunisia | Rice | SPE(IAC)-LC-FD | 0.1 (0.05) | 11 | 0 | ND | ND | ND | [33] |
| Turkey | Rice | ELISA | (1) | 100 | 58 | ND | 21.4 a | ns | [34] |
| Vietnam | Rice | SLE-LC-FD | 0.22 (0.07) | 100 | 51 | ND | 29.8 | 3.31 | [35] |
| Ochratoxin A | |||||||||
| Brazil | Rice | SPE(IAC)-LC-FD | (0.10) | 165 | 28 | ND | 30.24 | 1.78 | [36] |
| Canada | Rice | SPE(IAC)-LC-FD | 0.2 (0.05) | 100 99 |
43 1.01 |
ND | 0.49 | 0.11 0.49 |
[22] |
| Chile | Rice | SPE-LC-FD | 2.1 (0.6) | 31 | 42 | 0 | 12.5 | ns | [37] |
| China | Rice | SLE-LC-FD | 0.3 (0.08) | 370 | 4.9 | 0.3 | 3.2 | 0.85 | [23] |
| Iran | Rice | ELISA | 0.625 | 308 | 9.4 | 0.84 | 11.37 | 3.6 ± 2.66 | [38] |
| Côte d’Ivoire | Rice | SPE-LC-FD | 0.05 (0.01) | 10 | 100.0 | 9.0 | 92.0 | ns | [39] |
| Malaysia | Rice | 20 | 0 | NQ | NQ | NQ | [40] | ||
| Morocco | Rice | SPE(C8)-LC-FD | 0.021 | 20 | 90.0 | 0.02 ± 0.01 | 32.4 ± 2.10 | 4.15 ± 1.45 | [41] |
| Pakistan | White rice Brown rice |
SPE(IAC)-LC-FD | 0.18 (0.06) | 34 28 |
29.4 46.4 |
ns ns |
24.9 25.4 |
8.5 ± 0.6 7.84 ± 0.9 |
[30] |
| Portugal | Rice | SPE(IAC)-LC-FD | 0.05 | 42 | 14.2 | 0.09 | 3.52 | ns | [42] |
| Portugal and Spain | Organic rice Conventional rice |
SPE(C8)-LC-FD | 0.19 (0.05) | 9 4 |
44.4 0 |
2.10 NQ |
7.60 NQ |
2.57 ± 3.43 NQ |
[43] |
| Singapore | Rice | SLE-LC-MS-MS | 0.4 (0.2) | 190 | 0.5 | 46.5 | 46.5 | 46.5 | [44] |
| South Korea | Rice | SPE(C18)-LC-FD | (1) | 88 | 9.0 | 2.1 | 6.0 | 3.9 | [45] |
| Spain | Rice | ASE-LC-FD | 0.03 (0.01) | 64 | 7.8 | 4.3 | 27.3 | 0.74 | [46] |
| Tunisia | Rice | ELISA | (0.625) | 16 | 25.0 | 0.8 | 2.3 | 1.4 | [47] |
| Tunisia | Rice | SPE(IAC)-LC-FD | 0.15 (0.05) | 96 | 28 | 10 | 150 | 44 | [48] |
| Turkey | Rice | ELISA | (0.025) | 100 | 38.0 | 0.042 | 3.02 | 0.83 | [49] |
| Vietnam | Rice | SLE-LC-FD | 0.25 (0.08) | 100 | 35.0 | 0.08 | 2.78 | 0.75 | [35] |
| Zearalenone | |||||||||
| R. Korea | Rice | SLE-LC-FD | 4 | 88 | 3.4 | 21.7 | 47.0 | 38.5 | [45] |
| Côte d’Ivoire | Rice | ELISA | ns | 10 | 100 | 50 | 200 | 95 | [50] |
| Côte d’Ivoire | Rice | QuEChERS-UHPLC-MS-MS | 5 (2.5) | 9 | 21.05 | <LOQ | 7.5 | 6.6 | [51] |
| Tunisia | Rice | ELISA | 0.025 | 16 | 0 | ND | ND | ND | [47] |
| Brazil | Rice | SPE (MycoSep)-LC-FD | (3.6) | 166 | 29 | ND | 4872 | 143 | [36] |
| Brazil | Rice | DSP-UHPLC-MS-MS | 58.6 (29.3) | 42 | 2.38 | ns | ns | 67 | [52] |
| Pakistan | Rice | SPE(C18)-LC-MS-MS | 13 (7) | 180 | 15 | ND | 114 | 8.48 | [15] |
| Vietnam | Rice | QuEChERS-LC-MS-MS | 1.5 (0.5) | 144 | 0 | ND | ND | ND | [53] |
| Algeria | Rice | QuEChERS-UHPLC-MS-MS | 8.4 (2.5) | 30 | 20 | 8.6 | 15.5 | 9.9 | [54] |
| Arsenic | |||||||||
| Belgium | White rice Brown rice Asian rice Wild/colored rice |
MWE-LC-ICP-MS | 2–4 | 30 | 100 | ns ns ns ns |
ns ns ns ns |
80–245 119–243 19–147 40–141 |
[55] |
| Brazil | Polished Brown Parboiled |
MWE-ICP-MS | 38.0 (11.0) b | 27 8 2 |
100 100 100 |
ns ns ns |
ns ns ns |
<38.0–245.0 101.0–660.0 61–80 |
[56] |
| Finland | Long grain rice | MWE-LC-ICP-MS | 10 (5) | ns | n = 8 | 90 | 280 | 160 | [57] |
| Portugal | White rice Brown rice |
SLE-LC-ICP-MS | 8 for As(III) 17 for As(V) |
22 17 |
100 100 |
ns ns |
ns ns |
62.9–121.2 119–190 |
[58] |
| Slovenia | Rice Polished Brown |
MWE-LC-HG-AFS | (1) for As(III) (2) for As(V) |
50 40 10 |
ns ns ns |
28.9 28.9 74.3 |
211 211 147.0 |
90.2 51.1–125 111.0 |
[59] |
| Spain | White rice Brown rice |
SLE-FI-HG-AAS | (130) | 39 | 100 | ns ns |
ns ns |
85 144 |
[60] |
| Spain | Rice | SLE-LC-ICP-MS | ns | 121 | ns | 47 | 190 | 101 | [61] |
| Switzerland | White rice Brown rice |
SLE-IC-ICP-MS | 10.3 (3.44) b | 27 4 |
100 100 |
5.6 117 |
188 172 |
94.0 152 |
[62] |
| Thailand | White rice Sticky rice |
SLE-ICP-MS | 100 | 96 63 |
ns ns |
<100 <100 |
254.9 262.0 |
134.0 124.5 |
[14] |
| Thailand | Rice | MWE-ICP-MS | 2.0 (0.98) | 55 | ns | 67 b | 402 b | 110–240 b | [63] |
| United Kingdom | Total rice | SLE-LC-ICP-MS | nsgg | 42 | 100 | 65 | 286 | 129 | [6] |
| United States | White rice | SLE-ESI-IT-MS | ns | 40 | 100 | 25 | 271 | 112 | [64] |
ND—not detected. NQ—not quantified. ns—not specified. SPE—Solid phase extraction. LC—Liquid chromatography. FD—Fluorescence detection. SLE—Solid-liquid extraction. ASE—Accelerated solvent extraction. LLME—Liquid–liquid microextraction. MWE—Microwave extraction. DSP—Dilute and shoot protocol. FI-HG-AAS—Flow injection–hydride generation–atomic absorption spectrometry. ESI-IT-MS—Ion-trap, electrospray, mass spectrometry. a—Total aflatoxin. b—Total arseniAs shown in Table 1, compared with previously published studies, the OTA incidence reported by other authors was higher, averaging between 0.11 μg kg−1 in Canada [22] and 44 μg kg−1 in Tunisia [48]. In Portugal, in 2005, 42 samples of Portuguese rice from different origins were analyzed, and none surpassed the maximum limit, with only 14% of the samples featuring detectable levels [42].