SYSTEMATIC BENZOATE PRESERVATIVE ANALYSIS IN POPULAR BEVERAGES

Abstract

Introduction Benzoic acid derivatives (such as sodium benzoate and potassium benzoate) are frequently added to commercial beverages as a preservative. FDA regulations prohibit benzoate levels from exceeding 1000 mg/L (0.1% w/v) of a beverage, and empirical evidence demonstrates manufacturers seem to follow this mandate. However, there is concern that even at a legal level, consumers may exceed the FAO/WHO Acceptable Daily Intake (ADI) benzoate guideline of 5 mg benzoate/kg of body weight/day. Several lines of evidence indicate that such exposure may promote weight gain and maintenance.

Methods A high performance liquid chromatography (HPLC) method was developed, allowing for accurate and precise detection and quantitation of benzoate in beverages. This HPLC method consists of a 6-minute isocratic analysis utilizing a 0.2% formic acid/15% acetonitrile mobile phase and a 100x3.0 mm, 3.5 µm Agilent Zorbax Eclipse Plus Phenyl-Hexyl column. Beverages were systematically quantitated using this HPLC method to examine trends in benzoate concentration.

Data Benzoate concentration data was systematically obtained for a variety of drinks categorized using industry/WHO standards. Over 375 beverage samples have been analyzed by this group, including 164 for this Senior Honors Project targeting citrus and orange sodas, reduced-calorie colas, pre-packaged teas, and sparkling waters. Subcategories based on packaging, name, and brand were also created based on survey results from our patient population. Trends in benzoate concentration were examined across several variables, including stability in solution, trends across types of beverages and manufacturers, as well as consistency across different production batches and packaging sizes.

Discussion/Future Work Data from this study demonstrates several important findings regarding benzoate concentration. Most notably, benzoate levels can be found at widely varying amounts in beverages, from 0.192 mg/L in Diet Coke to 0.519 mg/L in Crush Orange. However, benzoate is stable in solution over time, and benzoate concentration is consistent across different container sizes and bottling/canning materials for a given type. Future work will utilize benzoate concentration data described in this report to create an application which allows patient benzoate exposure to be accurately determined clinically. Results obtained through this application will provide more data to assess the relationship between benzoate consumption and body weight changes.