Phenolic compounds as functional ingredients and nutraceuticals: the case of Juice PLUS+

Abstract

The protective effects of diets rich in fruits and vegetables are not only due to fibre, vitamins and minerals, but also to a diversity of plant secondary metabolites, in particular phenolic compounds and flavonoids. These compounds are now widely used as food ingredients and supplements, with the final aim of making the health benefits associated with their intake more widely and easily available. The bioavailability of these compounds after dietary intake has been a topic of increasing research in recent years, and could be one of the crucial issues when trying to develop commercial products containing polyphenols. Moreover, it is now well recognised that following ingestion, phenolic compounds undergo extensive metabolism during their passage through the gastrointestinal tract and, with very few exceptions, only metabolites and catabolites of the parent compounds enter the circulatory system. Metabolism occurs initially in the lumen of the small intestine with cleavage of sugar moieties after which the released aglycone undergoes glucuronidation, sulfation and/or methylation [1]. After entry of these metabolites into the circulatory system, phase II metabolism may also occur in the liver and other organs [1]. However, a large proportion of ingested polyphenols are not absorbed in the small intestine [1] and so pass to the large intestine, where substantial structural modifications are mediated by the local colonic microbiota [1]. The resultant low‐molecular‐weight compounds, may be absorbed and circulate in the body prior to excretion in urine in amounts that greatly exceed those of metabolites absorbed in the small intestine, whose concentration in plasma rarely exceeds the nmol/l levels [1]. Here we evaluated the composition and the absorption kinetics of a set commercially available encapsulated nutraceuticals, namely Juice PLUS+ Vineyard (a berry blend, JBB), Juice PLUS+ Fruit Blend (JFB) and Juice PLUS+ Vegetable Blend (JVB), kindly supplied by Juice PLUS+ company. The analysis of the three supplements by uHPLC–MSn allowed to tentatively identify 119 (poly)phenolic compounds. The main microbial/human metabolites were then tracked in a short pharmacokinetic study involving 20 healthy volunteers, demonstrating that a diversity of compounds circulate in vivo after Juice PLUS+ capsules intake, becoming potentially responsible of the health related effects which have been previously reported in a plethora of intervention studies [examples 2–4].Support or Funding InformationPart of this work has been supported by “Green Beat – Institute of Nutrient Research and Sport Nutrition”