Factors affecting Alicyclobacillus acidoterrestris growth and guaiacol production and controlling apple juice spoilage by lauric arginate and ϵ-polylysine

Abstract

Growth of Alicyclobacillus acidoterrestris in fruit juices has been associated with the release of off-odor compounds, such as guaiacol. Guaiacol release was quantified using Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) and method's minimum detection level was 3.6 ppb. The amount of guaiacol released was dependent on the amount of vanillin added to the medium. Sucrose-supplemented yeast starch glucose broth (SS-YSG broth; pH 3.7) and apple juice were spiked with vanillin (10 mg/L), inoculated with A. acidoterrestris and incubated at different temperatures (20°C–45 °C) for up to 528 h. At the temperatures that permitted growth, the bacterium grew slower in apple juice than in SS-YSG broth. Bacterial growth and guaiacol production were prevented in apple juice and inhibited in SS-YSG, when the inoculated products were incubated at 20 °C and 25 °C. When Alicyclobacillus was inoculated in SS-YSG adjusted to pH 2.7–6.7 and incubated at 37 °C, growth of the bacterium and guaiacol production were suppressed at pH 6.7 for up to 354 h and delayed at pH 2.7. Lauric arginate and ϵ-polylysine inactivated Alicyclobacillus cells with no guaiacol production in both SS-YSG and apple juice. However, ϵ-polylysine was more effective than lauric arginate when the SS-YSG (pH 3.7) was inoculated with Alicyclobacillus spores.