Comparison of Spectrophotometry and HPLC methods in measurement of potassium sorbate in industrial fruit juices

Abstract

Today, assessing the presence of preservatives in food are important measures to ensure food safety. Potassium sorbate is one of the most usual preservatives that acceptable in some of food for suppressing mold spoilage. In this research sorbate was measured in several industrial fruit juices to make a comparison between spectrophotometry and HPLC assays and consequently to examine the reliability of spectrophotometry data. Although the methods were optimized by maximum speed, attention, reduction of solvent consumption. A total of 28 samples of industrial fruit juices was collected and analyzed. The results showed that all of the fruit juices contained potassium sorbate. Highest level of sorbate was determined in pomegranate juice which was estimated at 7.22, 1.23 ppm by spectrophotometer and HPLC, respectively. The high level of sorbate in spectrophotometry method is related to interference of some material due to their absorbance ability of UV-visible ray. The comparison of spectrophotometry and HPLC data showed that in spite of simplicity and low cost of spectrophotometry, it did not have efficiency to determine the exact amount of sorbate. Moreover, due to the presence of sorbate in industrial fruit juices, it is necessary to strictly monitor sorbate concentration in foods.

Keywords

• ssium sorbet
• Fruit juice
• Spectrophotometry
• HPLC