Influence of calcium chloride in the high temperature acetification by strain Acetobacter aceti WK for vinegar.
OBJECTIVE
To improve the thermotolerant properties (TTP) of acetic acid bacteria (AAB) cells for high temperature acetification.


RESULTS
At high temperature (36 ± 1°C), the acetification rate (ETA) is usually lower than at 30 ± 1°C. The addition of 0·15% calcium chloride (CaCl2 ) may decrease the negative effect of the increase of temperature from 30 ± 1°C to 36 ± 1°C on the ETA. The effect of CaCl2 on the thermotolerant properties of acetic acid bacteria cells was investigated. The CaCl2 increased the content of phospholipids (phosphotidylcholine and phosphatidylglycerol), fatty acids (cis-vaccenic acid, palmitic acid and myristic acid) and the activities of membrane-bound enzymes involved in acetification, alcohol dehydrogenase and aldehyde dehydrogenase. Transmission electron microscope images revealed a more compact cell wall with CaCl2. Process consistency at 36 ± 1°C was tested in nine sequential acetification cycles using 0·15% (w/v) CaCl2. High ETAs (9·33 ± 0·6; 8·67 ± 0·8 and 9·67 ± 0·7 g l(-1) day(-1)) were obtained during the last three cycles.


CONCLUSIONS
The results confirm that changes of the content of lipid, activities of membrane-bound enzymes and cell-wall thickness occurred with added CaCl2.


CONCLUSIONS
High temperature acetification (HTA) with additions of CaCl2 was investigated. Significant reductions in the overall production costs result from lower cooling costs associated with HTA.
Fermentation Technology Division, Faculty of Agro-Industry, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand.
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Krusong
Food Science and Technology Division, Faculty of Agro-Industry, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand.
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Kerdpiboon
Fermentation Technology Division, Faculty of Agro-Industry, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand.
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Jindaprasert
Fermentation Technology Division, Faculty of Agro-Industry, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand.
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Yaiyen
Fermentation Technology Division, Faculty of Agro-Industry, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand.
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Pornpukdeewatana
Department of Food Technology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
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Tantratian
D019342:Acetic Acid / Q000378:metabolism*; D000091:Acetobacter / Q000201:enzymology / Q000378:metabolism*; D000426:Alcohol Dehydrogenase / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D002122:Calcium Chloride / Q000378:metabolism*; D005285:Fermentation; D006358:Hot Temperature; D009829:Oleic Acids / Q000378:metabolism
D001426:Bacterial Proteins; D009829:Oleic Acids; C065593:cis-vaccenic acid; D000426:Alcohol Dehydrogenase; D002122:Calcium Chloride; D019342:Acetic Acid
calcium chloride; cell-wall thickness; cis-vaccenic acid; high temperature acetification; improved production economics; membrane-bound enzyme