Ingredients with human-trial evidence for vision and eye comfort: grades, doses, extract types and what the trials measured
Formulator’s summary: Carotene oil powder (palm-derived, Elaeis guineensis) and blueberry extract powder (Cyanococcus fruit) are food-colour ingredients. Carotene oil powder is soluble and disperses in water and suits colouring, beverages and bakery. Blueberry extract powder is water-soluble and suits beverages, dairy, desserts and confectionery. Neither product is one of the trial preparations reviewed below.
Company certifications/registrations
Quick facts for formulators
- Carotene oil powder: palm-derived (Elaeis guineensis); natural mixed carotenes 3.5%; arabic-gum emulsified, spray-dried; soluble in water; use level 0.5–5%; pack sizes 1 kg, 5 kg, 20 kg
- Blueberry extract powder: Cyanococcus fruit, 20:1 extract; total anthocyanins 750–760 mg/kg (AOAC 2005.02 pH-differential); water-soluble; use level 2–8%; pack sizes 1 kg, 5 kg, 20 kg
- Blueberry trial material standardisation: not described in the published record.
Evidence grades and what each trial measured
| Study and evidence grade | Population and design | Dose given | Outcomes measured and reported | Limits and comparison with the catalogue powder |
|---|---|---|---|---|
| Blueberry anthocyanins; Kalt et al., “Blueberry effects on dark vision and recovery after photobleaching: placebo-controlled crossover studies,” Journal of Agricultural and Food Chemistry, 2014. PMID 25335781. PubMed record. Evidence grade B. | Two placebo-controlled crossover studies. S2 (n=72): 3-week intervention, 3-week washout. L1 (n=59): 12-week intervention, 8-week washout. | S2: two anthocyanin doses, 271 and 7.11 mg cyanidin-3-glucoside (C3G) equivalents. L1: one dose, 346 mg C3G equivalents. | Measured: dark adaptation, functional night vision and visual recovery after retinal photobleaching. Dark adaptation and night vision did not improve in either trial. Anthocyanin intake hastened recovery of visual acuity after photobleaching in both trials (S2 P=0.014; L1 P=0.027 at 8 weeks and P=0.030 at 12 weeks). The authors state that it is not known whether this affects everyday vision. | Limit: the visual-acuity recovery is the only positive finding reported, and the authors caution on everyday relevance. Trial material standardisation: not described in the published record. Catalogue blueberry extract powder: 750–760 mg/kg total anthocyanins (AOAC 2005.02). The trial dose is in C3G equivalents and the catalogue figure is total anthocyanins, so the two are shown side by side and not converted. Neither trial used this catalogue powder. |
| 9-cis beta-carotene-rich alga preparation; Rotenstreich et al., “Treatment with 9-cis β-carotene-rich powder in patients with retinitis pigmentosa: a randomized crossover trial,” JAMA Ophthalmology, 2013. PMID 23700011. PubMed record. Evidence grade B. | Randomised, double-masked, placebo-controlled crossover trial in 34 patients with retinitis pigmentosa aged 18 or over; 29 completed. 90 days of treatment, 90-day washout, then 90 days on the alternate arm. | Daily 300 mg of 9-cis beta-carotene-rich alga Dunaliella bardawil (about 20 mg beta-carotene), or starch placebo. | Dark-adapted maximal b-wave amplitude: +8.4 µV versus −0.9 µV (P=.001). 10 of 29 (34.5%) rose by more than 10 µV in both eyes, versus 0 on placebo. Light-adapted b-wave: +17.8% versus 0.0% (P=.01). No significant difference in visual field or best-corrected visual acuity. No adverse effects observed. | Limits: one alga-derived preparation, one population of patients with retinitis pigmentosa, and a 29-participant completion set. Catalogue carotene oil powder: 3.5% natural mixed carotenes (bulk guide). The trial preparation is a 9-cis beta-carotene-rich alga material of about 20 mg beta-carotene per daily dose. The 3.5% mixed-carotene powder is not the 9-cis beta-carotene preparation the trial used. Neither trial used this catalogue powder. |
Limits stated by the studies
- The blueberry authors state that it is not known whether the visual-acuity recovery finding affects everyday vision.
- The blueberry trials are crossover studies of 72 and 59 participants. Dark adaptation and night vision did not improve in either.
- The 9-cis trial studied patients with retinitis pigmentosa aged 18 or over and tested one alga-derived preparation.
- Neither trial used these catalogue powders, so neither result is carried over to them.
Specification: standardised and crude powders
A standardised extract is specified by a named marker, its assay method and an acceptance range, verified on each lot COA. Carotene oil powder is standardised to natural mixed carotenes at 3.5%. Blueberry extract powder is standardised to its natural anthocyanins at 750–760 mg/kg total anthocyanins by AOAC 2005.02 pH-differential, with the pigment profile resolved by HPLC. A crude powder is specified by the milled material and its processing, without a marker assay range. This is a difference in specification and quality-control documentation, not a claim about physiological effect.
Colour, sensory contribution and stability
Carotene oil powder is a free-flowing light-yellow to orange powder with a characteristic odour. Its carotenoids give crude palm oil an orange-red colour, according to the product record. Blueberry extract powder is a purple-red fine powder with a characteristic odour and a natural berry note. Its anthocyanins give a purple-red to blue colour that shifts with pH, so the colour should be checked in the finished product at its target pH. Colour, taste and texture may vary from batch to batch for both products. Keep both sealed, in a cool, dry place, away from sunlight; the shelf life is 24 months sealed.
Catalogue comparison
Carotene. The 9-cis trial preparation provided about 20 mg beta-carotene per daily 300 mg dose. The catalogue carotene oil powder is specified at 3.5% natural mixed carotenes. These are different materials measured in different ways, shown side by side here, and no equivalence is claimed.
Blueberry. The trial doses were 271 and 7.11 mg C3G equivalents (S2) and 346 mg C3G equivalents (L1). The catalogue blueberry extract powder is specified at 750–760 mg/kg total anthocyanins. The trial material standardisation is not described in the published record. These figures are shown side by side and not converted.
What a formulator should require before using a trial in product rationale
Obtain the full study record and document the ingredient form, botanical identity, marker or assay, dose, route, duration, participant population and measured endpoint. Compare those details with the current supplier specification and lot COA before any use in rationale. A shared ingredient name does not establish a match, and no trial result is transferred to a supplier’s product or a finished blend.
Supplying carotene oil powder and blueberry extract powder in bulk
The catalogue lists Carotene Oil Powder and Blueberry (Cyanococcus) Extract Powder as distinct ingredient pages. The bulk guides are the Carotene Oil Powder bulk buyer guide and the Blueberry Extract Powder bulk buyer guide. Both list pack sizes of 1 kg, 5 kg and 20 kg.
Three related catalogue ingredients, each a distinct product:
- Mixed Berries Standardized Extract Powder, a berry powder with its own specification.
- Carrot Standardized Extract Powder, a carrot powder for colour and beverage use.
- Jackfruit (Artocarpus heterophyllus) Standardized Extract Powder, a sweet fruit powder for beverage and bakery use.
Bulk supply, a certificate of analysis per lot, supporting documentation and packing options are arranged through the quotation for each item.
Reference structure
The structure below is beta-carotene, the reference carotenoid of the carotene class. It is not the 9-cis isomer used in the trial and is not the standardised marker of either catalogue powder.
Frequently asked questions
What did the blueberry trial measure? Dark adaptation, functional night vision and visual recovery after retinal photobleaching. Dark adaptation and night vision did not improve in either trial. Recovery of visual acuity after photobleaching was faster with anthocyanin intake in both trials. The authors state that it is not known whether this affects everyday vision.
Does the blueberry result apply to the catalogue blueberry extract powder? No. The trial material standardisation is not described in the published record. The catalogue powder is specified at 750–760 mg/kg total anthocyanins by AOAC 2005.02, and the trial doses are in C3G equivalents, so the figures are shown side by side and not converted. No result is transferred to the catalogue powder.
Who was studied in the 9-cis beta-carotene trial, and at what dose? Thirty-four patients with retinitis pigmentosa aged 18 or over were enrolled, and 29 completed. Each received daily 300 mg of 9-cis beta-carotene-rich alga Dunaliella bardawil (about 20 mg beta-carotene) or starch placebo, in crossover periods of 90 days.
Does the 9-cis beta-carotene trial establish a result for carotene oil powder? No. The trial used a 9-cis beta-carotene-rich alga preparation in patients with retinitis pigmentosa. Carotene oil powder is specified at 3.5% natural mixed carotenes and is a separate product.
What documents are needed for a study-to-specification comparison? Obtain the full study record and the current product specification and lot COA. Compare identity, preparation, marker and assay, dose and measured endpoint.
Request the specification sheet and the lot certificate of analysis for Carotene Oil Powder and Blueberry (Cyanococcus) Extract Powder.
