Farid and Enani 2010 — Trace elements in commercial fruit juices, Jeddah, Saudi Arabia
This study measured Zn, Cu, Fe, Mn, Co, Cr, and Ni in 129 commercial fruit juice samples (apple, orange, mango) from 15 brands available in Jeddah, Saudi Arabia, using graphite furnace atomic absorption spectrometry (GFAAS). No Pb, Cd, As, Hg, or Sn were measured. All detected elements are classified as essential nutrients rather than toxic heavy metals by the authors. Reported concentrations for Cr and Ni are of interest because Cr is total chromium (not Cr-VI) and Ni is relevant to the HMT&C analyte panel. Daily intakes of all seven elements were well below recommended dietary allowance or tolerable limits.
Key numbers
Mean concentrations ± SD (ppb = µg/L), GFAAS, HNO3/V2O5 wet digestion:
| Element | Apple juice | Orange juice | Mango juice | Mean across juices |
|---|---|---|---|---|
| Zn | 524.00 ± 43.06 | 894.80 ± 45.21 | 486.57 ± 35.25 | 635.05 ± 23.90 |
| Fe | 325.36 ± 23.12 | 361.27 ± 24.11 | 463.50 ± 32.67 | 383.38 ± 15.57 |
| Cu | 317.79 ± 21.56 | 500.00 ± 38.88 | 461.07 ± 29.49 | 426.28 ± 17.78 |
| Mn | 23.48 ± 2.23 | 20.93 ± 2.36 | 21.85 ± 2.58 | 22.08 ± 1.38 |
| Co | 8.07 ± 0.95 | 7.93 ± 1.02 | 8.14 ± 1.28 | 8.05 ± 0.63 |
| Cr | 6.36 ± 0.94 | 5.93 ± 0.92 | 7.64 ± 1.02 | 6.63 ± 0.55 |
| Ni | 6.21 ± 0.90 | 5.73 ± 0.91 | 5.93 ± 0.96 | 5.95 ± 0.53 |
Note: these are total Cr values, not Cr-VI. No lead, cadmium, arsenic, mercury, tin, aluminum, or uranium measured. Recovery: Cr 94 ± 1%, Cu 96 ± 1%. Instrument: VARIAN Spectra AA 30P GFAAS.
Estimated daily intake (assuming 10 L/person/year = 27.4 mL/day): all values well below RDA/tolerance thresholds for all elements.
Methods (brief)
GFAAS (Varian Spectra AA 30P, deuterium background correction). Wet digestion with 65% HNO3 and V2O5 at 120°C for 90 min. Calibration R2 > 0.989 for all elements. Recovery against IAEA standard milk A-11 within 7% of certified values. Limitation: only 7 elements measured, all essential; no toxic heavy metals (Pb, Cd, As, Hg, Sn) were included in the analytical panel.
Implications
Certification: Limited direct relevance because Pb, Cd, iAs, and tHg were not measured. Cr and Ni concentrations (6.6 and 6.0 ppb mean across juices) provide baseline data for commercial fruit juices in a Middle Eastern market context. Total Cr values are not substitutable for Cr-VI.
Courses: Good illustration of essential-vs-toxic metal framing, and the difference in public health significance between nutrients (Zn, Cu, Fe) and contaminants in the same food matrix.
App: No usable Pb, Cd, iAs, or tHg data. Ni present at low levels (~6 ppb) across all three juice types.