It is important for suppliers and manufacturers to understand what heavy metals are, the breadth of their impact on human health and global water quality, and why heavy metal controls must be present in microalgae cultivation and astaxanthin production. The term ‘heavy metal’ is ubiquitously associated with toxicity, although numerous dense metals—which is the formal classification of a heavy metals—such as iron, cobalt and zinc, are nutritionally essential. However, there is a general consensus certain heavy metals pose a threat to human health, namely; arsenic, cadmium, lead, and mercury. Their intake should be minimised, and all dietary supplements should therefore be routinely screened for these metals, and their associated compounds. Arsenic is included—although formally a metalloid—due to its similar link to potential toxicity or eco-toxicity. These elements are also listed by the World Health Organization (WHO) as part of the Ten Chemicals of Major Public Concern.
Microalgae cultivation and astaxanthin production are particularly vulnerable to heavy metal contamination through water. Therefore, these metals must be strictly and routinely monitored for during the production process. Although guidelines are in place to limit exposure to consumers, the goal for astaxanthin producers should be to surpass the guidelines and eliminate the presence of heavy metals entirely. As the primary input for microalgae cultivation, the importance of water purity and heavy metal controls cannot be overstated. Microalgae have high biosorption capabilities of heavy metals, so any trace amount of heavy metals present in water will accumulate and magnify in microalgae cultures. Therefore, continual elemental analysis of water should be carried out to ensure minimal (if any) heavy metal contamination is present, as is standard procedure by Algalif® in Iceland.
In many parts of the world, the heavy metal concentrations found in the water supply exceed maximum permitted levels. Iceland, on the other hand, has one of the most pristine environments on earth and is committed to preserving it. Iceland ranked second in the latest Yale Environmental Performance Index—a biennial, data-intensive ranking evaluating how 180 countries protect ecosystems and human health. Iceland also has some of the cleanest, contaminant-free air in the world, ranking fourth on air quality among all OECD-countries. Glaciers, rivers and lakes cover 13 percent of Iceland’s area, resulting in abundant freshwater supplies. Naturally filtered through layers of volcanic rock, Icelandic water is extremely clean, low in minerals and unchlorinated.
Additional controls may be implemented to reduce heavy metal contamination risk in microalgae cultivation. In addition to using exclusively high-end nutrient—food grade, or preferably pharmaceutical grade—the exclusion of external pollution risks can be achieved by cultivating microalgae in completely enclosed photobioreactor systems (PBRs). An additional benefit of indoor enclosed PBRs, is perfect control of all cultivation parameters, such as lighting and temperature, which dramatically increases the efficiency, and subsequently the sustainability of the microalgae cultivation.
Without an abundance of pure water, the cultivation of pure microalgae and production of Astaxanthin is not an easy task. However, simply having pure water, the highest grade of nutrients, and full contamination control is not entirely sufficient. Due to the severity of heavy metal poisoning, continual determination of heavy metal content of any high-end product must be carried out. The analysis should ideally use internationally approved methods and accredited laboratories. This is why Algalíf regularly sends samples of its Astalíf™ ingredient to an external accredited laboratory to evaluate the heavy metal content.
The United States Pharmacopoeia suggests using either inductively coupled plasma-atomic (optical) emission spectroscopy (ICP-AES / ICP-OES) or inductively coupled plasma-mass spectrometry (ICP-MS) to evaluate the heavy metal content of astaxanthin oleoresin. It also states, however, that any validated procedure that gives equivalent or better results can be used. In addition to these methods, Algalif’s Astalíf oleoresins have been analysed by graphite furnace atomic absorption spectrometry (GF-AAS), hydride generation atomic absorption spectrometry (HG-AAS), and cold-vapour atomic absorption spectrometry (CV-AAS), always giving the same result. To date, no Astalíf product has ever had a quantifiable amount of the heavy metals listed.
Questions to Ask Astaxanthin Suppliers
- What heavy metal specifications are in place?
- What are the actual heavy metal values measured?
- What methods are used to test for heavy metals?
- How frequently is the material tested for heavy metals?
- What is the quality of the water supply regarding heavy metals?
Dr Tryggvi Stefánsson will be speaking at Vitafoods Europe 2018 about heavy metal contamination in astaxanthin production. Register to attend Vitafoods Europe 2018 here.