Zhang et al. 2020 — Rice cadmium bioaccessibility under dietary-supplement additions

Zhang et al. measured selenium, zinc, and cadmium in steamed rice from Guangxi Province and tested how common dietary supplement additions changed in vitro gastrointestinal bioaccessibility. The source contributes rice occurrence and bioaccessibility context for cadmium, while the supplement additions are mitigation/intervention conditions rather than measurements of supplement contamination.

Key numbers

• Rice total concentrations: Se 287.11 +/- 6.84 ug/kg, Zn 8.11 +/- 0.94 mg/kg, Cd 63.30 +/- 15.12 ug/kg.
• Control gastric-phase bioaccessibility: Cd 52.07%, Zn 36.63%, Se 10.19%.
• Control intestinal-phase bioaccessibility: Zn 26.82%, Cd 18.72%, Se 14.70%.
• Reported Cd bioaccessibility ranges: 47.05-55.09% during the gastric phase and 15.09-20.58% during the intestinal phase.
• Reported Zn bioaccessibility ranges: 35.74-39.51% during the gastric phase and 22.35-33.27% during the intestinal phase.
• Food mass and digestion setup: 1.5 g steamed rice was incubated in 25 mL gastric solution at pH 1.5, 37 C, 100 rpm for 1 h; intestinal digestion added bile extract and pancreatin, adjusted to pH 7, and incubated for 4 h.
• Replication: five replicates per treatment.
• Supplement additions to 1.5 g rice: 7.5 ug vitamin B6, 500 ug vitamin C, 75 ug vitamin E, 2 ug folvite/vitamin B9, 60 ug niacin/vitamin B3, 60 ug copper, 150 ug coenzyme Q10, 3.75 mg methionine, or 4 mg procyanidins.
• Intervention finding: vitamin C significantly increased selenium bioaccessibility, increased zinc bioaccessibility, and reduced cadmium bioaccessibility to some extent; vitamin E, vitamin B6, and vitamin B9 also significantly increased selenium bioaccessibility. Procyanidins, methionine, and coenzyme Q10 significantly reduced selenium bioaccessibility.

Methods (brief)

The study used steamed rice and an in vitro digestion model based on gastric and intestinal simulation fluids. Se, Zn, and Cd were measured by ICP-MS; limits of detection were 0.1-1 ng/g for Se and Zn and less than 0.1 ng/g for Cd. Method accuracy was checked with rice powder certified reference material GBW 10043.

Limitation: this is a preliminary in vitro bioaccessibility experiment, not a dietary intervention trial and not a market survey. The rice concentration value is useful occurrence context for Guangxi rice, while the supplement effects should be treated as bioaccessibility/mitigation evidence.

Implications

Certification: The total Cd value of 63.30 +/- 15.12 ug/kg is routeable rice occurrence evidence, but the bioaccessibility percentages should not be substituted for total-Cd occurrence thresholds. Bioaccessibility values can inform exposure modeling and sensitivity checks.

Courses: Useful teaching case for why the same total cadmium concentration may produce different bioaccessible fractions depending on digestion phase and co-consumed supplements.

App: Supports future app logic that distinguishes total concentration from bioaccessible fraction; no immediate consumer-facing supplement recommendation should be inferred from this in vitro experiment alone.

Microbiome: Not a microbiome study.

Wiki pages this source may touch

• rice
• rice-bulk-grain
• cadmium
• formulation

Verification notes

• DOI, title, authors, journal, year, license, concentration values, digestion conditions, supplement doses, and analytical method were transcribed from the PDF.
• The same nu12061769 thyroid-gut review appeared as a separate auto-fetch hit in both probiotic and vitamin-mineral queues and was skipped separately; this page is the distinct IJERPH rice bioaccessibility paper with DOI 10.3390/ijerph17144978.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.