Nutritional and Volatile Characterisation of Milk Inoculated With Thermo-Tolerant Lactobacillus bulgaricus Through Adaptive Laboratory Evolution

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aut.relation.endpage2944
aut.relation.issue12en_NZ
aut.relation.journalFoodsen_NZ
aut.relation.startpage2944
aut.relation.volume10en_NZ
aut.researcherYoo, Ji Yeon
dc.contributor.authorLiang, Jen_NZ
dc.contributor.authorYoo, MJYen_NZ
dc.contributor.authorSeale, Ben_NZ
dc.contributor.authorGrazioli, Gen_NZ
dc.date.accessioned2021-12-02T01:14:12Z
dc.date.available2021-12-02T01:14:12Z
dc.description.abstractIn this study, thermo-tolerant strain of Lactobacillus bulgaricus (L. bulgaricus) was developed using gradual increase in temperature to induce Adaptive Laboratory Evolution (ALE). Viable colony count of 1.87 ± 0.98 log cfu/mL was achieved at 52 °C, using MRS agar supplemented with 2% lactose. Changes in bacteria morphology were discovered, from rod (control) to filament (52 °C) to cocci after frozen storage (−80 °C). When milk was inoculated with thermo-tolerant L. bulgaricus, lactic acid production was absent, leaving pH at 6.84 ± 0.13. This has caused weakening of the protein network, resulting in high whey separation and lower water-holding capacity (37.1 ± 0.35%) compared to the control (98.10 ± 0.60%). Significantly higher proteolytic activity was observed through free amino acids analysis by LC-MS. Arginine and methionine (237.24 ± 5.94 and 98.83 ± 1.78 µg/100 g, respectively) were found to be 115- and 275-fold higher than the control, contributing to changing the aroma similar to cheese. Further volatile analysis through SPME-GC-MS has confirmed significant increase in cheese-aroma volatiles compared to the control, with increase in diacetyl formation. Further work on DNA profiling, metabolomics and peptidomics will help to answer mechanisms behind the observed changes made in the study.en_NZ
dc.identifier.citationFoods 2021, 10, 2944. https://doi.org/10.3390/foods10122944
dc.identifier.doi10.3390/foods10122944en_NZ
dc.identifier.issn2304-8158en_NZ
dc.identifier.urihttps://hdl.handle.net/10292/14765
dc.languageenen_NZ
dc.publisherMDPI AGen_NZ
dc.relation.urihttps://www.mdpi.com/2304-8158/10/12/2944
dc.rights© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/ 4.0/).
dc.rights.accessrightsOpenAccessen_NZ
dc.subjectLactobacillus bulgaricus; Adaptive laboratory evolution; Volatiles; Amino acids
dc.titleNutritional and Volatile Characterisation of Milk Inoculated With Thermo-Tolerant Lactobacillus bulgaricus Through Adaptive Laboratory Evolutionen_NZ
dc.typeJournal Article
pubs.elements-id445010
pubs.organisational-data/AUT
pubs.organisational-data/AUT/Faculty of Health & Environmental Science
pubs.organisational-data/AUT/Faculty of Health & Environmental Science/School of Science
pubs.organisational-data/AUT/Faculty of Health & Environmental Science/School of Science/Food Science & Microbiology Department
pubs.organisational-data/AUT/PBRF
pubs.organisational-data/AUT/PBRF/PBRF Health and Environmental Sciences
pubs.organisational-data/AUT/PBRF/PBRF Health and Environmental Sciences/HA Science 2018 PBRF
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