The impact of high power ultrasound for controlling spoilage by Alicyclobacillus acidoterrestris: A population and a single spore assessment

摘要: Abstract Consumer demand for healthier, microbiologically safe and stable, higher quality minimally processed foods has increased in the last decades, promoting application of non-thermal process technologies. Ultrasound processing is gaining attention because its potential improving safety while retaining product flavor, texture, color nutrient composition. Recently, Alicyclobacillus acidoterrestris been recognized by manufacturers processors fruit industry as a new type thermoacidophilic, endospore-forming spoilage bacterium commercialized juices that can withstand high temperatures applied pasteurization spoil them producing taint compounds. Based on above, present study was undertaken to investigate separate combined effect ultrasound treatment operating at 26 kHz, 90 μm, 200 W 5, 10, 15 min heat stress (at 80 °C 10 min) recovery A. spores K broth adjusted pH = 4.5 with 25% (w/v) citric acid between 35 45 °C population individual spore level. At level, statistically significant differences average lag time from different treatments have found. After 100% Amplitude shock 10 min), 35 °C (7.24 ± 0.34 h) (6.38 ± 0.18 h) shown be longer compared control (5.68 ± 0.36 h) (2.87 ± 0.19 h), this combination, maximum specific growth rate not significantly samples. Additionally, findings λ among greatly variable when they were treated and/or thermal 10 min). The resulted more pronounced median phase duration (25.74 h) than (11.63 h) affected both position spread distributions spores. This work would help better assess optimize proposed treatments, since could synergistic way delaying tested bacterial