de Paiva, Medeiros, Fioravanti, Milani, Morgano, Pallone, Arisseto-Bragotto 2020 — Aluminium in infant foods: total content and bioaccessibility
This Journal of Food Composition and Analysis article from UNICAMP (Faculty of Food Engineering) and the Institute of Food Technology (ITAL) Campinas is the primary Brazilian-market Al occurrence survey for infant foods, covering 95 samples across 9 commercial brands in four product categories: salty purees, fruit purees, infant drinks, and petit-suisse. Two distinguishing features: it pairs total-Al measurement by ICP-OES with an optimized in vitro gastrointestinal-digestion protocol to estimate bioaccessibility, and it documents a dramatic 95-fold spread in bioaccessibility (0.5 to 48 percent) across sample compositions, demonstrating that total Al substantially overestimates actual gut absorption for many infant food matrices. The headline numbers: petit-suisse reached 4170 µg/kg, soy-based drink 2860 µg/kg, salty purees containing zucchini-lettuce-lentil-sweet-potato-egg 2760 µg/kg, salty puree containing zucchini-sweet-potato-lettuce-beans-egg-yolk 2310 µg/kg. Consumption of three portions per day of soy-based drink could reach the PTWI for Al.
Key numbers
Highest total Al concentrations by product category (µg/kg)
| Brand | Product | Classification | Total Al (µg/kg) |
|---|---|---|---|
| H | Petit-suisse | PS | 4170 |
| F | Soy-based drink | ID | 2860 |
| B | Zucchini, lettuce, lentil, sweet potato, egg | SP | 2760 |
| B | Apple and plum | FP | 2500 |
| G | Chocolate soy-based drink | ID | 2280 |
| B | Zucchini, sweet potato, lettuce, beans, egg yolk | SP | 2310 |
| D | Dark chocolate milk drink | ID | 2175 |
| C | Pear, grape, apple | FP | 1970 |
| C | Strawberry, raspberry, apple | FP | 1900 |
| E | Chocolate milk drink | ID | 1780 |
| A | Chopped meat | SP | 1170 |
| A | Fruits mix | FP | 925 |
Bioaccessibility (in vitro gastrointestinal digestion)
| Sample composition | Total Al (µg/kg) | Bioaccessible fraction | Bioaccessibility % |
|---|---|---|---|
| Cereal milk drink (brand D) | (158) | 258 µg/kg | 48.0 |
| Petit-suisse (brand I, whole-milk-based) | (208) | 77 µg/kg | 37.0 |
| Soy-based drink (brand G) | (635) | 24 µg/kg | 37.8 |
| Chocolate milk drink (brand E) | (440) | 53 µg/kg | 24.0 |
| Banana milk drink | (135) | 26 µg/kg | 19.3 |
| Strawberry milk drink | (522) | 95 µg/kg | 18.2 |
| Meat, vegetables, cassava (brand A SP) | (100) | 18.2 µg/kg | 18.2 |
| Chicken breast with vegetables (brand A SP) | (110) | 17.2 µg/kg | 15.6 |
| Soy-based drink (brand F) | (700) | 9.8 µg/kg | 1.4 |
| Apple and plum (brand B FP) | (600) | 3.0 µg/kg | 0.5 |
| Petit-suisse (brand H, skim-milk-based) | (1055) | 97 µg/kg | 9.2 |
Bioaccessibility spans 0.5 to 48 percent (96-fold range), driven by sample matrix composition: high-cellulose matrices (purees with fibrous vegetables) and high-protein dairy (skim-milk petit-suisse) reduce bioaccessibility through Al-cellulose and Al-protein binding; high-polyphenol or low-fiber matrices (cereal drink, whole-milk petit-suisse) increase it. Soy matrices show divergent results across brands (1.4 percent F vs 37.8 percent G), likely reflecting differential fat content and protein hydrolysis state.
Exposure assessment summary
Consumption of three portions per day of soy-based drink delivers Al at a substantial fraction of the EFSA TWI (1 mg/kg b.w./week) and could reach 100 percent of PTWI for infants. Petit-suisse and high-Al milk drinks similarly approach the TWI ceiling at typical consumption frequencies for Brazilian infants. Fruit purees from brand B (handmade-gourmet positioning) carry substantially higher Al than industrial-brand counterparts (brands A and C) at similar composition, suggesting handmade production involves more Al contamination through utensils, storage, and raw-material handling.
Methods (brief)
95 infant food samples obtained from retail in Campinas, SP, Brazil, across 9 commercial brands (industrial and handmade-gourmet). Brand B is handmade-gourmet; A, C, D-I industrial. Categories: 43 salty purees, 15 fruit purees, 28 infant drinks (including soy-based drinks), and 9 petit-suisse samples. Total Al by ICP-OES after oxidative microwave digestion in HNO3 + H2O2. LOD 49 µg/kg (purees) or 16 µg/kg (drinks); LOQ 92 µg/kg (purees) or 30 µg/kg (drinks). Accuracy validated on SRM 1548a Typical Diet and NRC EGGS Egg Power CRMs (87-97% recovery). Bioaccessibility by optimized in vitro gastrointestinal digestion (Minekus et al. 2014 protocol with INFOGEST-style salivary, gastric, and intestinal phases), n=3 per sample.
Implications
- Certification: HMTc Al-threshold development for infant food categories must distinguish total Al from bioaccessible Al. A high-total-Al but low-bioaccessibility product (apple-and-plum puree at 0.5 percent) presents different risk than a high-total-Al high-bioaccessibility product (cereal milk drink at 48 percent). The CC candidate framework should track both, particularly for infant drinks and petit-suisse subcategories. Handmade-positioning products (brand B) consistently higher than industrial counterparts is a market-segmentation signal worth flagging.
- Microbiome / clinical: Bioaccessibility variability indicates that Al-microbiome interactions are dose-modulated in unpredictable ways across infant diet items; high-cellulose plant-puree foods reduce gut Al exposure even when total Al is high.
- App: Per-product bioaccessibility correction factor is a strong app input. Default to 10-15 percent for milk-based mixed products, 1-5 percent for high-fiber plant purees, 30-48 percent for cereal-and-milk drinks.
- Courses: Standard reference for the “total Al vs bioaccessible Al” methodology question — a foundational distinction for infant exposure assessment that the regulatory framework does not capture.