Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice.
Ultraviolet (UV) treatment has been proven effective for killing a variety of microorganisms in liquid foods and on the surfaces of solid foods. However, there is a growing concern of inadequate decontamination in coloured and turbid fluids containing UV-absorbing compounds. Thus, the main objective...
| Main Authors: | , , , |
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| Format: | Conference or Workshop Item |
| Language: | English English |
| Published: |
2012
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| Online Access: | http://psasir.upm.edu.my/id/eprint/27291/ http://psasir.upm.edu.my/id/eprint/27291/1/ID%2027291.pdf |
| _version_ | 1848845805477167104 |
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| author | Sew, Chang Chew Mohd Ghazali, Hasanah Olga, Martin-Belloso Mohd Adzahan, Noranizan |
| author_facet | Sew, Chang Chew Mohd Ghazali, Hasanah Olga, Martin-Belloso Mohd Adzahan, Noranizan |
| author_sort | Sew, Chang Chew |
| building | UPM Institutional Repository |
| collection | Online Access |
| description | Ultraviolet (UV) treatment has been proven effective for killing a variety of microorganisms in liquid foods and on the surfaces of solid foods. However, there is a growing concern of inadequate decontamination in coloured and turbid fluids containing UV-absorbing compounds. Thus, the main objective of this work was to examine the microbiocidal effect of mid-thermal and UV treatments on L. innocuo reduction in pineapple juice. Pineapples were peeled and cubed prior to juice extraction. The extracted juice was clarified using pectinase Ultra SP-l and filtered before inoculation with surrogate L. Innoeuo. The inoculated juice was given 4 separate treatments: (i) mid-thermal heating at 55 ·C for 10 minutes, (iI) UV treatments at different dosages (1.7 - 11.1 mJ/cm'), (iii) mid-thermal heating followed by UV treatments at different dosage, and (iv) heat pasteurisation at 95 ·C for 1 minute. The control sample was untreated pineapple juice. Exposure to mid-thermal heating caused a 4.62 ±0.40 log reduction of L. Innocuo, while the highest decontamination level achieved within the various UV doses applied (without mid-thermal treatment) was 2.16 ± 0.10 log reduction at 11.06 mJ/cm'. Results showed that the mid-thermal treatment
increased the absorption coefficient of pineapple juice from 16.7 cm-' to 27.8 cm-', which increases the lethality of UV treatment. When mid-thermal treated juices were further treated with UV, an inactivation of N7 log reduction was observed indicating a synergistic effect. Similar level of inactivation was observed for conventionally pasteurised juices. Thus, the combined treatments could be a possible solution for pasteurising juices in cases when UV treatment alone is not sufficient. |
| first_indexed | 2025-11-15T08:52:39Z |
| format | Conference or Workshop Item |
| id | upm-27291 |
| institution | Universiti Putra Malaysia |
| institution_category | Local University |
| language | English English |
| last_indexed | 2025-11-15T08:52:39Z |
| publishDate | 2012 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | upm-272912014-04-11T08:42:58Z http://psasir.upm.edu.my/id/eprint/27291/ Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. Sew, Chang Chew Mohd Ghazali, Hasanah Olga, Martin-Belloso Mohd Adzahan, Noranizan Ultraviolet (UV) treatment has been proven effective for killing a variety of microorganisms in liquid foods and on the surfaces of solid foods. However, there is a growing concern of inadequate decontamination in coloured and turbid fluids containing UV-absorbing compounds. Thus, the main objective of this work was to examine the microbiocidal effect of mid-thermal and UV treatments on L. innocuo reduction in pineapple juice. Pineapples were peeled and cubed prior to juice extraction. The extracted juice was clarified using pectinase Ultra SP-l and filtered before inoculation with surrogate L. Innoeuo. The inoculated juice was given 4 separate treatments: (i) mid-thermal heating at 55 ·C for 10 minutes, (iI) UV treatments at different dosages (1.7 - 11.1 mJ/cm'), (iii) mid-thermal heating followed by UV treatments at different dosage, and (iv) heat pasteurisation at 95 ·C for 1 minute. The control sample was untreated pineapple juice. Exposure to mid-thermal heating caused a 4.62 ±0.40 log reduction of L. Innocuo, while the highest decontamination level achieved within the various UV doses applied (without mid-thermal treatment) was 2.16 ± 0.10 log reduction at 11.06 mJ/cm'. Results showed that the mid-thermal treatment increased the absorption coefficient of pineapple juice from 16.7 cm-' to 27.8 cm-', which increases the lethality of UV treatment. When mid-thermal treated juices were further treated with UV, an inactivation of N7 log reduction was observed indicating a synergistic effect. Similar level of inactivation was observed for conventionally pasteurised juices. Thus, the combined treatments could be a possible solution for pasteurising juices in cases when UV treatment alone is not sufficient. 2012 Conference or Workshop Item NonPeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/27291/1/ID%2027291.pdf Sew, Chang Chew and Mohd Ghazali, Hasanah and Olga, Martin-Belloso and Mohd Adzahan, Noranizan (2012) Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. In: International Nonthermal Food Processing Workshop – FIESTA 2012, 16-17 Oct. 2012, Melbourne, Australia. . (Submitted) English |
| spellingShingle | Sew, Chang Chew Mohd Ghazali, Hasanah Olga, Martin-Belloso Mohd Adzahan, Noranizan Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
| title | Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
| title_full | Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
| title_fullStr | Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
| title_full_unstemmed | Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
| title_short | Effects of mid-thermal and ultraviolet treatments on Listeria innocua inactivation in pineapple juice. |
| title_sort | effects of mid-thermal and ultraviolet treatments on listeria innocua inactivation in pineapple juice. |
| url | http://psasir.upm.edu.my/id/eprint/27291/ http://psasir.upm.edu.my/id/eprint/27291/1/ID%2027291.pdf |