Sterilization of liquid foods by pulsed electric fields – an innovative ultra-high temperature process
dc.bibliographicCitation.journalTitle | Frontiers in Microbiology | eng |
dc.bibliographicCitation.volume | 6 | |
dc.contributor.author | Reineke, Kai | |
dc.contributor.author | Schottroff, Felix | |
dc.contributor.author | Meneses, Nicolas | |
dc.contributor.author | Knorr, Dietrich | |
dc.date.accessioned | 2017-06-30T23:57:16Z | |
dc.date.available | 2019-06-28T13:38:21Z | |
dc.date.issued | 2015 | |
dc.description.abstract | The intention of this study was to investigate the inactivation of endospores by a combined thermal and pulsed electric field (PEF) treatment. Therefore, self-cultivated spores of Bacillus subtilis and commercial Geobacillus stearothermophilus spores with certified heat resistance were utilized. Spores of both strains were suspended in saline water (5.3 mS cm−1), skim milk (0.3% fat; 5.3 mS cm−1) and fresh prepared carrot juice (7.73 mS cm−1). The combination of moderate preheating (70–90°C) and an insulated PEF-chamber, combined with a holding tube (65 cm) and a heat exchanger for cooling, enabled a rapid heat up to 105–140°C (measured above the PEF chamber) within 92.2–368.9 μs. To compare the PEF process with a pure thermal inactivation, each spore suspension was heat treated in thin glass capillaries and D-values from 90 to 130°C and its corresponding z-values were calculated. For a comparison of the inactivation data, F-values for the temperature fields of both processes were calculated by using computational fluid dynamics (CFD). A preheating of saline water to 70°C with a flow rate of 5 l h−1, a frequency of 150 Hz and an energy input of 226.5 kJ kg−1, resulted in a measured outlet temperature of 117°C and a 4.67 log10 inactivation of B. subtilis. The thermal process with identical F-value caused only a 3.71 log10 inactivation. This synergism of moderate preheating and PEF was even more pronounced for G. stearothermophilus spores in saline water. A preheating to 95°C and an energy input of 144 kJ kg−1 resulted in an outlet temperature of 126°C and a 3.28 log10 inactivation, whereas nearly no inactivation (0.2 log10) was achieved during the thermal treatment. Hence, the PEF technology was evaluated as an alternative ultra-high temperature process. However, for an industrial scale application of this process for sterilization, optimization of the treatment chamber design is needed to reduce the occurring inhomogeneous temperature fields. | eng |
dc.description.version | publishedVersion | eng |
dc.format | application/pdf | |
dc.identifier.uri | https://doi.org/10.34657/396 | |
dc.identifier.uri | https://oa.tib.eu/renate/handle/123456789/4542 | |
dc.language.iso | eng | eng |
dc.publisher | Lausanne : Frontiers Media | eng |
dc.relation.doi | https://doi.org/10.3389/fmicb.2015.00400 | |
dc.rights.license | CC BY 4.0 Unported | eng |
dc.rights.uri | https://creativecommons.org/licenses/by/4.0/ | eng |
dc.subject.ddc | 630 | eng |
dc.subject.other | Pulsed electric fields | eng |
dc.subject.other | sterilization | eng |
dc.subject.other | endospore-forming bacteria | eng |
dc.subject.other | milk | eng |
dc.subject.other | inactivation mechanisms | eng |
dc.title | Sterilization of liquid foods by pulsed electric fields – an innovative ultra-high temperature process | eng |
dc.type | Article | eng |
dc.type | Text | eng |
tib.accessRights | openAccess | eng |
wgl.contributor | ATB | eng |
wgl.subject | Landwirtschaft | eng |
wgl.type | Zeitschriftenartikel | eng |
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