Modelling the Radial Growth of <i>Geotrichum candidum</i>: Effects of Temperature and Water Activity
Modelling the growth of microorganisms in relation to environmental factors provides quantitative knowledge that can be used to predict their behaviour in foods. For this reason, the effects of temperature and water activity (<i>a<sub>w</sub></i>) adjusted with NaCl on the su...
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| Format: | Article |
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MDPI AG
2021-03-01
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| Series: | Microorganisms |
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| Online Access: | https://www.mdpi.com/2076-2607/9/3/532 |
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| author | Martina Koňuchová Ľubomír Valík |
| author_facet | Martina Koňuchová Ľubomír Valík |
| author_sort | Martina Koňuchová |
| collection | DOAJ |
| description | Modelling the growth of microorganisms in relation to environmental factors provides quantitative knowledge that can be used to predict their behaviour in foods. For this reason, the effects of temperature and water activity (<i>a<sub>w</sub></i>) adjusted with NaCl on the surface growth of two isolates and one culture strain of <i>Geotrichum candidum</i> were studied. A dataset of growth parameters obtained from almost 600 growth curves was employed for secondary modelling with cardinal models (CMs). The theoretical minimal temperature resulting from the modelling of the mycelium proliferation rate ranged from −5.2 to −0.4 °C. Optimal and maximal temperatures were calculated and found to have narrow ranges of 25.4 to 28.0 °C and 34.2 to 37.6 °C, respectively. Cardinal <i>a<sub>w</sub></i> values associated with radial growth (<i>a<sub>w</sub></i><sub>min</sub> from 0.948–0.960 and <i>a<sub>w</sub></i><sub>opt</sub> from 0.992–0.993) confirmed the salt sensitivity of the species. Model goodness-of-fit was evaluated by the coefficient of determination <i>R</i><sup>2</sup>, which ranged from 0.954 to 0.985, and <i>RMSE</i>, which ranged from 0.28 to 0.42. Substantially higher variability accompanied the lag time for growth modelling than the radial growth rate modelling despite the square root transformation of the reciprocal lag phase data (<i>R</i><sup>2</sup> = 0.685 to 0.808). Nevertheless, the findings demonstrate that the outputs of growth modelling can be applied to the quantitative evaluation of the roles of <i>G. candidum</i> in fresh cheese spoilage as well as the ripening of Camembert-type cheeses or various artisanal cheeses. Along with validation, the interactions with lactic acid bacteria can be included to improve the predictions of <i>G. candidum</i> in the future. |
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| issn | 2076-2607 |
| language | English |
| last_indexed | 2024-03-09T05:24:37Z |
| publishDate | 2021-03-01 |
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| series | Microorganisms |
| spelling | doaj.art-ba3b24a7f3ce40ff970764b2673ae8712023-12-03T12:37:45ZengMDPI AGMicroorganisms2076-26072021-03-019353210.3390/microorganisms9030532Modelling the Radial Growth of <i>Geotrichum candidum</i>: Effects of Temperature and Water ActivityMartina Koňuchová0Ľubomír Valík1Department of Nutrition and Food Quality Assessment, Institute of Food Science and Nutrition, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinskeho 9, SK-812 37 Bratislava, SlovakiaDepartment of Nutrition and Food Quality Assessment, Institute of Food Science and Nutrition, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinskeho 9, SK-812 37 Bratislava, SlovakiaModelling the growth of microorganisms in relation to environmental factors provides quantitative knowledge that can be used to predict their behaviour in foods. For this reason, the effects of temperature and water activity (<i>a<sub>w</sub></i>) adjusted with NaCl on the surface growth of two isolates and one culture strain of <i>Geotrichum candidum</i> were studied. A dataset of growth parameters obtained from almost 600 growth curves was employed for secondary modelling with cardinal models (CMs). The theoretical minimal temperature resulting from the modelling of the mycelium proliferation rate ranged from −5.2 to −0.4 °C. Optimal and maximal temperatures were calculated and found to have narrow ranges of 25.4 to 28.0 °C and 34.2 to 37.6 °C, respectively. Cardinal <i>a<sub>w</sub></i> values associated with radial growth (<i>a<sub>w</sub></i><sub>min</sub> from 0.948–0.960 and <i>a<sub>w</sub></i><sub>opt</sub> from 0.992–0.993) confirmed the salt sensitivity of the species. Model goodness-of-fit was evaluated by the coefficient of determination <i>R</i><sup>2</sup>, which ranged from 0.954 to 0.985, and <i>RMSE</i>, which ranged from 0.28 to 0.42. Substantially higher variability accompanied the lag time for growth modelling than the radial growth rate modelling despite the square root transformation of the reciprocal lag phase data (<i>R</i><sup>2</sup> = 0.685 to 0.808). Nevertheless, the findings demonstrate that the outputs of growth modelling can be applied to the quantitative evaluation of the roles of <i>G. candidum</i> in fresh cheese spoilage as well as the ripening of Camembert-type cheeses or various artisanal cheeses. Along with validation, the interactions with lactic acid bacteria can be included to improve the predictions of <i>G. candidum</i> in the future.https://www.mdpi.com/2076-2607/9/3/532<i>Geotrichum candidum</i>surface growth modellingcardinal modelspoilage |
| spellingShingle | Martina Koňuchová Ľubomír Valík Modelling the Radial Growth of <i>Geotrichum candidum</i>: Effects of Temperature and Water Activity Microorganisms <i>Geotrichum candidum</i> surface growth modelling cardinal model spoilage |
| title | Modelling the Radial Growth of <i>Geotrichum candidum</i>: Effects of Temperature and Water Activity |
| title_full | Modelling the Radial Growth of <i>Geotrichum candidum</i>: Effects of Temperature and Water Activity |
| title_fullStr | Modelling the Radial Growth of <i>Geotrichum candidum</i>: Effects of Temperature and Water Activity |
| title_full_unstemmed | Modelling the Radial Growth of <i>Geotrichum candidum</i>: Effects of Temperature and Water Activity |
| title_short | Modelling the Radial Growth of <i>Geotrichum candidum</i>: Effects of Temperature and Water Activity |
| title_sort | modelling the radial growth of i geotrichum candidum i effects of temperature and water activity |
| topic | <i>Geotrichum candidum</i> surface growth modelling cardinal model spoilage |
| url | https://www.mdpi.com/2076-2607/9/3/532 |
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