The ABC-AHP-NCNPR Botanical Adulterants Prevention Program (BAPP) has released a Laboratory Guidance Document (LGD) on pomegranate (Punica granatum) juice and extracts.

Pomegranate is a popular food and dietary supplement ingredient. As a food, the fleshy seeds are used raw or pressed into juice. For dietary supplements, the whole fruit, rind (or husk), seed, or seed oil is processed into various forms (e.g., powders, extracts, etc.).

The predominant adulteration issue reported for pomegranate juice is dilution with lower-cost fruit juices, but undeclared colorants also have been reported. In the dietary supplement category, the main problem seems to be the addition of ellagic acid from extraneous (i.e., non-pomegranate) sources. Ellagic acid is a naturally occurring polyphenolic compound found in pomegranate and many other plants. It can be obtained in highly purified form from a number of lower-cost botanical sources, including various tree barks, and it can be made via chemical synthesis. Some commercial “pomegranate” extracts contain up to 90% ellagic acid; these extracts are adulterated presumably to enhance the perceived value of the product.

The new pomegranate LGD was written by John H. Cardellina II, PhD, a noted expert in natural products chemistry and analysis and chief technical consultant for BAPP. The guidance document details the chemical composition of pomegranate fruit and includes summaries of published analytical methods for juice and extract identity testing. The main advantages and disadvantages of each analytical method are listed, and the usefulness of these methods to detect adulteration of pomegranate juice and extract products are summarized. The LGD has been peer reviewed by 20 experts from academia and industry.

“As is too often the case with relatively high-cost ingredients like pomegranate, unethical producers have found ways to sell diluted or counterfeit ‘pomegranate’ ingredients that contain lower-cost materials,” said Mark Blumenthal, founder and executive director of the American Botanical Council (ABC) and founder and director of BAPP. “Our new Lab Guidance Document on pomegranate provides industry quality-control personnel with the tools they need to use only laboratory methods that can successfully authenticate true, unadulterated pomegranate ingredients and determine if any adulterants are present.”

Dr. Cardellina added: “While the nature of adulteration may be different for juice or other food forms of botanical materials relative to supplements, the motivation for the fraudulent behavior is the same: higher profits. The analytical targets and laboratory methods may be different in the two product categories, but the challenge is the same: identifying effective methods and tools to ensure that products in the marketplace are properly composed and convey the expected nutrients and benefits. This might be a great opportunity for the food and supplement sectors to recognize common ground and work toward resolving this challenging issue.”

Stefan Gafner, PhD, chief science officer of ABC and technical director of BAPP, commented: “The concentrations of ellagic acid in pomegranate supplements have become a marketing tool, with product labels prominently featuring the percent of ellagic acid, which may suggest to the consumer that higher levels represent more potent and thus more efficacious extracts. But high concentrations of ellagic acid may actually be an indicator of adulteration, since these materials may be from plants other than pomegranate. As explained in this LGD, there are no simple analytical methods to distinguish ellagic acid derived from pomegranate or other botanical sources. However, the absence of characteristic polyphenols, such as the punicalagins, in ingredients labeled as pomegranate extracts, should raise a red flag.”

The pomegranate LGD is the 40th peer-reviewed publication published by the program and the fifth in the series of LGDs. As with all publications in the program, the LGDs are freely accessible to all ABC members, registered users of the ABC website, and all members of the public on the Program’s website (registration required).

BAPP Laboratory Guidance Documents identify the most suitable analytical methods for detection of certain adulterants and authentication of specific botanical materials in various forms (whole, cut, powdered raw materials, extracts, juices, and/or essential oils). Assessments of analytical methods are based on a thorough review of available methods from official compendia, relevant methods in the published peer-reviewed literature, and sometimes those provided by botanical ingredient suppliers, manufacturing companies, and independent third-party analytical laboratories. The LGDs are intended to help quality-control personnel in the herbal medicine, botanical ingredient, dietary supplement, and conventional food industry sectors to identify the appropriate techniques and methods for their specific analytical needs.