Degradation of Preservatives with the Formation of Off-Odor Volatile Compounds—The Case of Strawberry-Flavored Bottled Water

Abstract

Foods preserved with sorbic acid or its salts can undergo spoilage with the formation of chemicals characterized by odors of plastic, hydrocarbons, or kerosene. 1,3-pentadiene, which is formed through the decarboxylation of sorbic acid or its salts, is one such compound. Numerous species of molds and yeasts have been reported as capable of degrading sorbic acid. This work is aimed to identify the off-odor compounds in samples of strawberry-flavored water preserved with potassium sorbate and sodium benzoate. In addition, the mold isolated from this drink was evaluated for the ability to form undesirable compounds, and the results revealed the presence of 1,4-pentadiene and benzaldehyde in the tested samples. The mold isolated from the samples was identified as Penicillium corylophilum. During its 5-day incubation at 25 °C in a liquid medium, potassium sorbate added at a final concentration of 200 and 400 mg/L was completely assimilated by the growing mycelium and converted into 1,4-pentadiene. The concentration of the latter was determined as 46.5 and 92.6 mg/L, respectively. The decrease in the concentration of sodium benzoate exceeded 53% in the broth spiked at 200 mg/L and 23% at 400 mg/L, resulting in the formation of benzaldehyde.