Data on Adulteration of Amla Fruit Extracts Sent to FDA and FTC

Extracts of the fruit of amla (Phyllanthus emblica, syn. Emblica officinalis, Phyllanthaceae) have a long-standing use in traditional systems of Indian medicine to reduce inflammatory conditions of the digestive system, to assist with constipation, and to strengthen the heart.¹ The fruit is also known for its vitamin C content, which ranges between 0.2 – 1.3%, depending on the fruit material (including where grown, etc.), processing method, and the analytical test.^2-5 However, some commercial amla products claim to be standardized to contain up to 50% vitamin C. Due to the relatively low amounts of vitamin C naturally occurring in the fruits, it would be considered cost-prohibitive to attempt to obtain this level of vitamin C naturally.

In a press release on November 30, 2020, Sabinsa, a New Jersey-based manufacturer, supplier, and marketer of herbal extracts, reported that it sent data to the FDA and FTC from investigations into the authenticity of a commercial amla bulk extract and one finished product standardized to contain high concentrations of vitamin C. After isolating the vitamin C, the ¹³C/¹²C carbon isotope ratio was obtained by mass spectrometry from two independent contract analytical laboratories. The vitamin C was shown to be derived from plants like corn (Zea mays, Poaceae) or sugar cane (Saccharum officinarum, Poaceae) rather than amla based on the higher ¹³C/¹²C ratio (often indicated as δ ¹³C value, which refers to the isotope ratio of the sample in relation to a certified external standard) than in vitamin C derived from amla. Sabinsa cautioned that dietary supplements containing high contents of allegedly “natural” vitamin C from amla are likely adulterated

Comment: The majority of vitamin C produced for the global vitamin market is made via a two-step fermentation process using sorbitol as a starting material. Sorbitol is commonly obtained by catalytic hydrogenation of glucose, which – in turn – is usually derived from corn, although several other sources such as rice (Oryza sativa, Poaceae), wheat (Triticum aestivum, Poaceae), or sugar cane, are also used. Many members of the grass family (Poaceae), including corn, sugar cane, and sorghum  are so-called C4 plants, which have a distinct way of fixing carbon. These plants are a little bit better at incorporating the heavier ¹³C isotope (which is more difficult to assimilate than ¹²C) than the C3 plants, which use the Calvin cycle to incorporate carbon and make up the majority of plants, including amla.⁶ Therefore, the ¹³C/¹²C ratio can be used to determine if an ingredient is made using a substance derived from a C4 plant.

Many consumers prefer vitamins to be derived from natural sources, which is why dietary supplement companies go to great lengths to source plant extracts that are enriched in certain vitamins. However, the enrichment of vitamins in plant extracts has its limits, and purification can go only so far to make it financially viable. Since pure vitamins from fermentation are available at much lower costs, fraudulent suppliers and manufacturers are reportedly fortifying plant extracts with vitamins obtained by fermentation which are advertised as “naturally occurring”.  Such practices are alleged for vitamin C derived from the fruits of, e.g., amla, acerola (Malpighia glabra or M. emarginata, Malpighiaceae), baobab (Adansonia digitata, Malvaceae), or camu camu (Myrciaria dubia, Myrtaceae). Direct evidence of the fraudulent sale of fermentation-derived vitamin C as originating from a plant extract using analytical tests have been lacking in the past, so this report to our knowledge represents the first instance where such practices have been confirmed with state-of-the-art mass spectrometric data. To be clear, if such practice were fully disclosed on ingredient certificates of analysis and finished product labels, it would not be considered adulteration and thus would not be fraudulent.  

References

1. Upton R, Mukherjee PK (Eds.). American Herbal Pharmacopoeia and Therapeutic Compendium: Triphala: Three Fruits: Amla (Phyllanthus emblica), Vibhitaka (Terminalia bellirica), Haritaki (Terminalia chebula). Scotts Valley, CA: American Herbal Pharmacopoeia. 2020.
2. Scartezzini P, Antognoni F, Raggi MA, Poli F, Sabbioni C. Vitamin C content and antioxidant activity of the fruit and of the Ayurvedic preparation of Emblica officinalis Gaertn. J Ethnopharmacol. 2006;104(1-2):113-118.
   
3. Anbarasu S, Sundar R, Joseph J, Kumar V. A comparative study between the moist heat versus microwave method for the determination of vitamin C content in amla. Der Pharma Chemica. 2014;7(8):46-49.
   
4. Bajgai TR, Hashinaga F, Isobe S, Raghavan GSV, Ngadi MO. Application of high electric field (HEF) on the shelf-life extension of emblic fruit (Phyllanthus emblica L.). J Food Engineer. 2006;74(3):308-313.
   
5. Kulkarni KV, Ghurghure SM. Indian gooseberry (Emblica officinalis): Complete pharmacognosy review. Int J Chem Stud. 2018:2(2):5-11.
   
6. O’Leary MH. Carbon isotopes in photosynthesis. BioScience. 1988;38(5):328-336.