Distribution of elements and their correlation in bran, polished rice, and whole grain

Abstract

The relationship of toxic elements (As, Cd, Cr) and trace elements (Cu, Se, Ni, Zn, Mn) in rice bran and corresponding polished rice is not well known. A total of 446 rice grains were collected from paddy fields distributed across China, and the concentrations of 8 elements in rice bran and their corresponding polished rice were measured. The levels of As, Cd, Cr, and Se have a good linear relationship between rice bran and polished rice (R2: .79, .97, .82, .99, respectively; all p < .001). Polishing rice could effectively remove the average contents of 44.4% As, 19.8% Cd, and 15.4% Cr in the whole grain, but caused the substantial losses of more than half of Mn and Ni (57.7% and 56.9%), and nearly one‐third (30.9%, 31.5%, and 29.1%) of Cu, Se, and Zn in brown rice although only about 10% of rice bran was milled. The "L" type correlation exists not only between As and Cd, but also between the nutrients Se, Mn, Ni, and the toxic elements As, Cd. These results indicated that As accumulation in rice could reduce the levels of essential mineral nutrients Mn, Ni, and Se. On the contrary, improving nutrient elements by fertilization could decrease the accumulation of some toxic elements. This provides a practical new idea for the prevention and control of rice As or Cd, and concomitantly improves the deficiency of nutrient elements in rice.

Chemical Speciation and Distribution of Cadmium in Rice Grain and Implications for Bioavailability to Humans

“…Our findings indicate that milling decreased grain Cd concentrations by an average of 23.5% (median of 27.5%), with the decreasing magnitude being similar to that for Zn and Cu, but considerably less than the reduction for As, Fe, Ca, Mn, K, P, and Mg (Figures , S5 and Table S2). Previous studies show that milling reduced grain Cd concentrations by an average of 3% ( n = 6), 12% ( n = 35), and 20% ( n = 446) . Although the average reduction in grain Cd concentrations observed in the present study (mean 23.5%; median 27.5%) was relatively small, there was a large variation from −20.2 to 64.7% among rice grain samples (Figure e and Table S2).…”

“…Previous studies show that milling reduced grain Cd concentrations by on average 3% (n = 6), 44 12% (n = 35), 22 and 20% (n = 446). 45 Although the average reduction in grain Cd concentration observed in the present study (mean 23.5%; median 27.5%) was relatively small, there was a large variation from -20.2% to 64.7% among rice grain samples (Figure 4e and Table S2). Furthermore, this variation was related with the total Cd concentration of the bran (Figure 4c), but not related to the total Cd concentration of the brown rice and nor was it related to the cultivar (Figure 4d,f).…”

NILs of Cold Tolerant Japonica Cultivar Exhibited New QTLs for Mineral Elements in Rice

“…Understanding the correlation between mineral elements in brown rice has an auxiliary effect on the selection of high-mineral rice varieties of brown rice. The analysis showed high significant correlation up to 16 elements, while the least is only seven as reporter before ( Zeng Y. W. et al, 2009 ; Huang et al, 2015 ; Yao et al, 2020 ). The antagonism or promotion of mineral elements in absorption has been confirmed in rice, such as Fe inhibits Cu and Mn absorption while it promotes Zn absorption, and Zn inhibits Cr absorption ( Sasaki et al, 2016 ).…”

Genetic studies for grain quality traits and correlation analysis of mineral element contents on Al-Ahsa rice and some different varieties (Oryza Sativa L.)

“…In contrast, the distribution of elements and correlation in rice bran were tested using 446 rice grains obtained from paddy fields in China, with 8 elements in rice bran, and the results revealed a good linear association between rice bran and polished rice ( Tattibayeva et al, 2016 , Yao et al, 2020 ). Grain quality characteristics, such as grain length, grain breadth, grain shape, hulling percent, milling percent, head rice percent, elongation, gelatinization temperature (GT), and amylose content percent (AC), are significant to progeny heredity.…”