A rapid method to assess authenticity of "100% pure" pomegranate juices by UV-visible spectroscopy and multivariate analysis

Scientific research employing in vitro, animal, and human models has found that pomegranate juice (PJ) consumption promotes cardiovascular health and inhibits the proliferation of many types of cancer. These activities have been largely attributed to the phenolic fraction of PJ. Indeed it contains a significantly high level of powerful antioxidant ellagitannins, such as ellagic acid, punicalagin and punicalin, as well as anthocyanins (delphinidin, cyanidin and pelargonidin 3-glucosides and 3,5-diglucosides). Several studies have even shown that PJ contains much more antioxidant compounds than other common fruit juices and beverages. Thus consumer demand for pomegranate juice has considerably grown, during the last years, for its health benefits. Since it is an expensive functional food, cheaper fruit juices addition (i.e. grape and apple juices) or its simple dilution are deceptively used. At present, the quality control of this product is often based on modern and sophisticated instruments that are time-consuming and/or involve high costs and/or require well-trained analysts [5]. The purpose of this study was to propose a high-speed and easy-to-use shortcut. Based on UV–Visible spectroscopy and chemometrics, a screening method is proposed to quickly detect the dilution or the adulteration of pomegranate juice that decrease the antiradical scavenging capacity of pure products. The analytical method was applied to representative experimental mixtures at different levels of water and filler juices. The outcomes were evaluated by means of multivariate exploratory analysis. The results indicate that the proposed strategy can be a useful screening tool to assess authenticity of "100% pure" pomegranate juices