Influence of sulphur dioxide, controlled atmospheres and water availability on in vitro germination, growth and ochratoxin A production by strains of Aspergillus carbonarius isolated from grapes
Marianthi Pateraki, Alexandra Dekanea, D. Mitchell, D. Lydakis and N. Magan
Postharvest Biology and Technology, Volume 44, Issue 2, May 2007, Pages 141-149
2007
บทคัดย่อ
The potential for control of germination, growth and ochratoxin A (OTA) production by five strains of Aspergillus carbonarius isolated from grapes (Vitis vinifera) using sodium metabisulphite (NaMBS, mg L−1) or controlled atmospheres (25 and 50% CO2) at different water activity levels (0.985, 0.965 and 0.93aw) on grape juice-based media at 25 °C was determined. The efficacy of NaMBS against the five strains was relatively similar. Generally, germination was inhibited by >500 mg L−1 of NaMBS. However, mycelial growth was stimulated by low NaMBS concentrations (100 and 250 mg L−1). Up to 1000 mg L−1 was required for complete inhibition of growth. The production of OTA was inhibited by up to 750 mg L−1 NaBMS. However, at lowered aw (0.93) OTA production was inhibited by 500 mg L−1. The ED50 and ED90 ranges were determined for both growth and OTA production. The efficacy of controlled atmospheres × aw showed that there was very little effect on spore germination, even by 50% CO2, regardless of aw treatment. However, 50% CO2 inhibited growth after 5 days exposure, although after 10 days growth was not as effectively controlled. OTA production by A. carbonarius strains was influenced predominantly by the aw treatment and less so by the controlled atmospheres used.