The Utah-based mangosteen juice company distributes the product worldwide through direct marketing. The peer-reviewed, single lab validated high performance liquid chromatography (HPLC) analysis of selected xanthones in mangosteen was published in June's issue of the Journal of Separation Science. Promoting ingredients or products along the line of validation methods may become more prevalent as manufacturers and labs alike increasingly highlight the disparities between nutritional content claims and how these can be affected by the exact sourcing of compounds. This study "ensures a more consistent and reliable marketing of mangosteen products to consumers relative to claims of xanthone content," said lead researcher Edward Walker, from Weber State University. Dubbed the 'Queen of Fruits', the mangosteen grows from a tropical evergreen tree found in southeast Asia. Its healthy reputation stems from the 40-odd xanthones - polyphenolic compounds that have been researched for their role in immune, joint and intestinal health - which are concentrated in the rind. Xango claims its juice maintains the structure of xanthone compounds, thereby delivering optimum nutritional benefits to the consumer. The company, which manufactures the final product in Utah, uses only puree for its juice, and no extracts. It uses this fact to bolster the claim its juice is superior as a source of mangosteen nutrition. "There are many other phytochemicals found in the fruit that have beneficial effects which are lost in extraction or jeopardized when the natural balance of the fruit is manipulated," said Mike Pugh, manager of research and development at Xango. As well as a source of xanthones, the mangosteen is a source of flavonoids, and Xango claims the EGCG catechins found in green tea are slightly more abundant in whole mangosteen. The company said the superfruit lends well to the juice format due to challenges of maintaining freshness. In addition to enhancing the profile of its product through claims the whole fruit goes into the bottle, the company is now promoting the new analytical method for distinguishing xanthone content. "A xanthone measurement standard is in place," said Walker. "Now claims concerning xanthone quantity and efficacy can be evaluated through credible research." An 80:20 acetone/water mixture was used to extract xanthones from dried, ground whole mangosteen fruit rind. The company said six specific xanthones were identified. Research lab ChromaDex developed the standards in accordance with AOAC International protocol. According to Walker, the researchers are still in the process of identifying additional xanthones. Various groups and associations have been calling for the development of industry-wide analytical methods in order to prevent manufacturers making false claims surrounding the nutritional content of their products. One idea presented repeatedly has been the formation of analytical laboratory collectives for the purpose of sharing methods, and maintaining consistency between them, in the interest of heightening the credibility of the industry as a whole.