Detection of Adulteration in Commercial Fruit Juices

Abstract

Food safety and security remains an under investigated forensic problem. The US Department of Agriculture (USDA) and the Food and Drug Administration (FDA) examine close to 42 million imports per year, with a mere one percent being tested in a laboratory. These tests are often laborious, complicated, and time consuming with the consequence of economically motivated adulteration (EMA) products entering the consumer marketplace. EMA Is estimated by the Grocery Manufacturers Association to cost from $10-$15 billion per year, much of which is passed directly to the consumer. Fruit juice adulteration occurs when a more expensive product is diluted with a less expensive juice for an economic advantage. Acai juice is made from the berries of the acai palm, and is a major cash crop in the Amazon River region of South America. Due to the fragile nature of these berries, the expensive processing to create the juice, and the high importation costs, acai juice remains a target for adulteration by unscrupulous suppliers. The juice of these berries has a unique organic acid profile, which imparts the tartness of flavor and stability to the juice. This research uses high performance anion exchange chromatography followed by suppressed conductivity detection to profile the organic acids as a means to detect product authenticity. The linear range of this method spanned 0.2 μg/mL to 100 μg/mL for the nine investigated organic acids. The limit of detection for this assay was 0.1 μg/mL with a limit of quantitation of 0.2 μg/mL. Novel aspects of this research include the use of relative retention times to improve reproducibility, high throughput, and little to no sample preparation. This method allows for the establishment of the organic acid profile of a?ai juice as well as other juices. It also allows for the determination of the single strength, mixed juice, and adulterated juices. Importantly, this work can be expanded into other juices. The forensic utility of this method is highlighted by the successful determination of adulteration in a two juice blend.