The preservation of acidic beverages is challenged by the resistance of Alicyclobacillus acidoterrestris spores to conventional treatments. The effects of four antimicrobials (nisin (NIS) at 20 and 50 mg/L, vanillic acid (VA) at 200 and 500 mg/L, coumaric acid (CA) at 100 and 200 mg/L, and sinapic acid (SA) at 100 and 200 mg/L) combined with pressure-assisted thermal processing (PATP), high-pressure processing (HPP) at room temperature (RT), and thermal processing (TP) on A. acidoterrestris spores' inactivation and guaiacol production in orange juice were investigated. Samples inoculated at 10 5 cfu/mL for total cells and spores were enriched with antimicrobials and subjected to: i) PATP (T500/70: 500 MPa at 70 °C and T600/65: 600 MPa at 65 °C), ii) HPP (T500/RT: 500 MPa at RT and T600/RT: 600 MPa at RT), and iii) TP (T0.1/70: 0.1 MPa at 70 °C and T0.1/65: 0.1 MPa at 65 °C) for 5 min. Juices were incubated at 45 °C for 12 days. PATP reduced total cells and spores below detection limit (300 ng/mL). Under HPP at RT, higher doses of NIS, CA, and SA reduced guaiacol production (5.7–8.3 ng/mL). NIS under T0.1/70 maintained populations at 4.5 log cfu/mL and guaiacol below quantification limit (< 4 ng/mL). Results confirm that PATP combined with NIS, CA, and SA is a promising strategy to control A. acidoterrestris spores and prevent guaiacol spoilage. • Pressure-assisted thermal processing (PATP) reduced AA spores by 4.2 log units. • Nisin, coumaric and sinapic acids under PATP reduced guaiacol below 10.0 ng/mL. • Vanillic acid inhibited AA growth but not guaiacol formation in orange juice. • Nisin combined with 70 °C kept guaiacol below quantification limit (4 ng/mL).
Neggazi et al. (Fri,) studied this question.