Distribution of essential and non-essential elements in rice located in a Protected Natural Reserve “Marjal de Pego-Oliva”

Metal(loid) Analysis of Commercial Rice from Malaysia using ICP-MS: Potential Health Risk Evaluation

Rice is a predominant staple food in many countries. It is a great source of energy but can also accumulate toxic and trace metal(loid)s from the environment and pose serious health hazards to consumers if overdosed. This study aims to determine the concentration of toxic metal(loid)s [arsenic (As), cadmium (Cd), nickel (Ni)] and essential metal(loid)s [iron (Fe), selenium (Se), copper (Cu), chromium (Cr), cobalt (Co)] in various types of commercially available rice (basmati, glutinous, brown, local whites, and fragrant rice) in Malaysia, and to assess the potential human health risk. Rice samples were digested following the USEPA 3050B acid digestion method and the concentrations of metal(loid)s were analyzed using an inductively coupled plasma mass spectrometry (ICP-MS). Mean concentrations (mg/kg as dry weight) of metal(loid)s (n=45) across all rice types were found in the order of Fe (41.37)>Cu (6.51)>Cr (1.91)>Ni (0.38)>As (0.35)>Se (0.07)>Cd (0.03)>Co (0.02). Thirty-three percent and none of the rice samples surpassed, respectively, the FAO/WHO recommended limits of As and Cd. This study revealed that rice could be a primary exposure pathway to toxic metal(loid)s, leading to either noncarcinogenic or carcinogenic health problems. The non-carcinogenic health risk was mainly associated with As which contributed 63% to the hazard index followed by Cr (34%), Cd (2%), and Ni (1%). The carcinogenic risk to adults was high (>10-4) for As, Cr, Cd, and Ni. The cancer risk (CR) for each element was 5 to 8 times higher than the upper limit of cancer risk for an environmental carcinogen (<10-4). The findings from this study could provide the metal(loid)s pollution status of various types of rice which are beneficial to relevant authorities in addressing food safety and security-related issues.

Identifying the Food Sources of Selected Minerals for the Adult European Population among Rice and Rice Products

The problem of dietary deficiency of several essential elements among different stages of life is still observed. The consumption of whole grains (among others unprocessed rice) is recommended as a part of a healthy diet. This research aimed to determine the content of selected macro- and microelements in rice and rice products to verify whether the tested products could be regarded as a source of selected minerals in the diet of the adult European population.

METHODS

A total of 99 samples from 12 groups of rice products (basmati, black, brown, parboiled, red, wild, white rice and expanded rice, rice flakes, flour, pasta, and waffles) were obtained. The atomic absorption spectrometry method (AAS) was used to determine the content of Ca, Cu, Fe, Mg, Mn, Se and Zn in the study material.

RESULTS

The average measured contents of Ca, Cu, Fe, Mg, Mn, Se and Zn were as follows: 226.3 ± 160.6 mg/kg, 3.6 ± 2.8 mg/kg, 9.4 ± 7.0 mg/kg, 618.0 ± 498.4 mg/kg, 16.7 ± 10.0 mg/kg, 242.9 ± 140.4 µg/kg and 19.5 ± 15.0 mg/kg, respectively. Statistical analyses confirmed the differences in the levels of the studied elements between the subgroups of processed and unprocessed products. Considering the tolerable upper intake level of studied elements, the tested products could be regarded as safe to consume.

CONCLUSION

All tested products can be recommended as a source of Cu, Mn, and Se, while a majority of studied products can be considered a source of Mg and Zn in the diet of the adult European population.