Determination of benzoic and sorbic acids in some foodstuffs in Tabriz

Abstract

Abstract Background and purpose: Benzoate and sorbate are used to prevent the growth of microorganisms and to increase the shelf life of food in many food products. The purpose of this study was to detect benzoate and sorbate in some food product using high performance liquid chromatography as well as to determine benzoate and sorbate contents in foods which using them as additives are allowed or forbidden. Material and methods: Eight types of food samples including soft drinks (n=15), Ultra High Temperature (UHT) milk (n=15), ketchup sauce (n=15), Doogh (n=15), fruit juice (n=15), tomato paste (n=15), cake (n=15) and bread (n=9) were analyzed based on Dispersive Liquid Liquid Microextraction method. Optimum conditions were determined as follows: sample volume, 5ml; extraction solvent (chloroform) volume, 250µl; disperser solvent (acetone) volume, 1.2ml; NaCl amount, ‎0.75 g/5 ml at pH 4. Results: Of total 114 food samples analyzed, benzoic acid was detected in 107 (93.8%) of the samples ranged from > 0.1 to 1520 µg/mL and sorbic acid in 60 (52.6%) samples ranged from < 0.08 and 2305 µg/mL. Among all food samples, soft drinks showed the highest concentrations for benzoate (1520 µg/mL) and sorbate (2305 µg/mL). Benzoate and sorbate contents above the permitted level based on national standards were found in 74/1% and 24.9% of food samples, respectively. Among all samples, soft drinks and Dooghs were found to have the most adulteration. Conclusion: In general, sorbate and benzoate contents of soft drink, Doogh, fruit juice, milk UHT, tomato paste and ketchup sauce were above the national standard, while the contents were lower than national standard in industrial breads and cakes.