Toxic and micronutrient elements in organic, brown and polished rice in Brazil

Organic Rice Production Practices: Effects on Grain End-Use Quality, Healthfulness, and Safety

Demand for rice labeled as organic is growing globally. Consumers state that foods labeled as organic are nutritionally superior and safer than their conventionally produced equivalent. The research question for this systematic review is as follows: is there a difference between the effects of sustainable agriculture and conventional farming methods on rice grain end-use quality, healthfulness, and safety? The studies (n = 23) examined for this review suggest that organic production practices don't influence most end-use quality (e.g., chalk, milling yield, pasting properties) and healthfulness (e.g., gamma-oryzanol fraction and tocols) traits studied, or if it does, it will be to a small degree. If differences in end-use quality traits are found, they will be associated with grain protein content, which varies along with the dose of nitrogen applied during rice growth. We conclude that the studies evaluated in this review found that organically produced rice grain was less likely to contain residues of the pesticides (e.g., organochlorine) examined in the study than the rice is grown using conventional methods. There was some evidence that organically grown rice is more likely to be contaminated with mycotoxin-producing fungi and some mycotoxins. Common shortcomings of the studies were that they were poorly designed, with limited to no details of the cultural management practices used to grow the rice studied, the length of time fields was under organic management not stated, cultivars were not named, and the data wasn't analyzed statistically.

Arsenic speciation in rice bran: Agronomic practices, postharvest fermentation, and human health risk assessment across the lifespan

Arsenic (As) exposure is a global public health concern affecting millions worldwide and stems from drinking water and foods containing As. Here, we assessed how agronomic practices and postharvest fermentation techniques influence As concentrations in rice bran, and calculated health risks from consumption. A global suite of 53 rice brans were tested for total As and speciation. Targeted quantification of inorganic As (iAs) concentrations in rice bran were used to calculate Target Hazard Quotient (THQ) and Lifetime Cancer Risk (LCR) across the lifespan. Mean iAs was highest in Thailand rice bran samples (0.619 mg kg^-1) and lowest in Guatemala (0.017 mg kg^-1) rice bran samples. When comparing monosodium-methanearsonate (MSMA) treated and the Native-soil counterpart under the irrigation technique Alternate Wetting and Drying (AWD) management, the MSMA treatment had significantly higher total As (p = 0.022), and iAs (p = 0.016). No significant differences in As concentrations were found between conventional and organic production, nor between fermented and non-fermented rice bran. Health risk assessment calculations for the highest iAs-rice bran dosage scenario for adults, children and infants exceeded THQ and LCR thresholds, and LCR was above threshold for median iAs-rice bran. This environmental exposure investigation into rice bran provides novel information with food safety guidance for an emerging global ingredient.

Arsenic and cadmium contents in Brazilian rice from different origins can vary more than two orders of magnitude

Brazil is a major producer of rice, but there is not enough information about As and Cd in rice grown under different conditions in this country. Here, As and Cd were determined by ICP-MS and species of As by HPLC-ICP-MS in Brazilian husked rice, covering diverse cultivars and regions, as well as upland and flooded production systems. Significant differences were observed for contents of both elements according to the origin of rice. All samples were below the maximum limit for Cd (400 µg/kg) set by national legislation, while nine samples presented total As above the legislation limit (300 µg/kg). From 24 samples analyzed for As species, 42% showed iAs above the European limit for production of food to infants (100 µg/kg). The total As content in samples from Mato Grosso state presented a maximum value of 6 µg/kg, which combined with low Cd content make interesting further studies.

Arsenic speciation in Brazilian rice grains organically and traditionally cultivated: Is there any difference in arsenic content?

Inorganic arsenic contamination in rice is a global public concern due to the risks associated. In spite of being an important issue, few studies concerning differences between inorganic arsenic in rice grains under organic and conventional methods of cultivation are available in Brazil, which is an important producer and consumer. In the present work, samples of polished and husked rice (organic and conventional) and gastronomic rice (Arborio, Carnaroli and red/black rice) were analyzed and the results compared to FAO/Codex maximum limits. The total determination and speciation analysis of arsenic were carried out by ICP-MS and HPLC-ICP-MS, respectively. The results showed no significant statistical differences in total As concentration in organic rice (157.7±56.1ngg^-1) vs. conventional rice (137.4±46.6ngg^-1) and also in organic husked rice (227.7±95.5ngg^-1) vs. conventional husked (217.7±60.9ngg^-1). However, inorganic As was 45% higher in organic polished rice than in conventional polished rice and 41% higher in organic husked rice than in conventional husked rice. Gastronomic rice presented total arsenic ranging from 65.4 to 348ngg^-1 for black and Arborio rice, respectively. Regarding the maximum levels adopted by Codex for i-As (200ngg^-1), no violation was found.

A study on toxic and essential elements in rice from the Republic of Kazakhstan: comparing the level of contamination in rice from the European Community

Selected toxic elements (total As, Cd, Cr, Hg, Pb, Sr, U and V) and essential elements (Co, Cu, Fe, Mn and Zn) were analyzed using an inductively coupled plasma mass spectrometry (ICP-MS) in unpolished and milled rice collected from Kazakhstan and milled rice from Spain and Portugal to evaluate the potential health risk to the population. Arsenic species (arsenite, arsenate, arsenobetaine, dimethylarsinate and monomethilarsonate) were analyzed using HPLC-IC-MS. From 146 samples analyzed, none of them exceeded the maximum limit set by the European Legislation for Cd or Pb or values recommended by the Codex Alimentarius. Concentrations of Sr, U and V were below LOD and those of Hg, Pb, Co and Cr between <LOD and 0.54 mg/kg (highest concentration of Cr) in milled rice. Portuguese rice samples contained the highest mean concentration of As, Hg, Pb, Co, Cr, Cu, Mn and Zn. The highest mean of arsenobetaine (0.001 mg/kg), dimethylarsinate (0.27 mg/kg) and monomethilarsonate (0.02 mg/kg) was found in Spanish rice and that of arsenite (0.30 mg/kg) in Kazakh rice. Inorganic As in samples from Kazakhstan was above the ML (0.2 mg/kg) proposed by FAO/WHO, but in seven samples from Spain and in four from Portugal were above the limit. The estimated weekly intake of total or inorganic As(III, V), Cd, Hg and Pb for rice consumption by Kazakh, Spanish and Portuguese adults and children was lower than the provisional tolerable weekly intake established by Joint FAO/WHO Expert Committee on Food Additives and the European Food Safety Authority.

Total Arsenic, Cadmium, and Lead Determination in Brazilian Rice Samples Using ICP-MS

This study is aimed at investigating a suitable method for rice sample preparation as well as validating and applying the method for monitoring the concentration of total arsenic, cadmium, and lead in rice by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Various rice sample preparation procedures were evaluated. The analytical method was validated by measuring several parameters including limit of detection (LOD), limit of quantification (LOQ), linearity, relative bias, and repeatability. Regarding the sample preparation, recoveries of spiked samples were within the acceptable range from 89.3 to 98.2% for muffle furnace, 94.2 to 103.3% for heating block, 81.0 to 115.0% for hot plate, and 92.8 to 108.2% for microwave. Validation parameters showed that the method fits for its purpose, being the total arsenic, cadmium, and lead within the Brazilian Legislation limits. The method was applied for analyzing 37 rice samples (including polished, brown, and parboiled), consumed by the Brazilian population. The total arsenic, cadmium, and lead contents were lower than the established legislative values, except for total arsenic in one brown rice sample. This study indicated the need to establish monitoring programs for emphasizing the study on this type of cereal, aiming at promoting the Public Health.

Toxic and essential elements in Nigerian rice and estimation of dietary intake through rice consumption

In this study, levels and estimated daily intake (EDI) of two toxic elements, Cd and Pb, and eight essential elements: Ca, P, Zn, Mn, Co, Cu, Se and Mo, were determined in Nigerian rice samples. The mean levels of Cd, Pb and Co were 5.43±0.88, 38.66±5.42, 25.8±3.18 ng/g. The mean levels of Ca, P, Zn, Mn, Cu, Se and Mo were 71.5±7.31, 951±52.0, 10.2±0.63, 8.5±0.47, 3.07±0.18, 40.1±9.2 and 0.39±0.05 µg/g, respectively. The percentage contribution to the reference values for each element was 0.54, 7.71, 0.38, 9.51, 8.97, 31.3, 30.7, 5.1 and 60.7% for Cd, Pb, Ca, P, Zn, Mn, Cu, Se and Mo, respectively. The elemental nutrient levels in Nigerian rice samples are comparable to those obtained from other regions and their consumption does not pose any serious health risk to consumers.