Effect of vinegar on the viability of Giardia duodenalis cysts

• Autores: Adriana Oliveira Costa, Vanete Thomaz Soccol, Rosangela Clara Paulino, Edilene Alcântara de Castro
• Localización: International journal of food microbiology, ISSN 0168-1605, Vol. 128, Nº. 3, 2009, págs. 510-512
• Idioma: inglés
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• Resumen

  • The inactivation of Giardia duodenalis cysts by vinegar was investigated. Experiments were carried out in 100 ml volume of vinegar (acetic acid 4%), undiluted or diluted in distilled water in ratios of 1:1, 1:15.6, and 1:62.5 (vol/vol), which were inoculated with 5 × 105 cysts obtained from human feces. Experiments were performed at room temperature (21 ± 1 °C) and at 4 °C. After contact times of 1.5 min, 10, 30, and 60 min, the cysts were recovered from the treatment fluid and subjected to an in vitro excystation assay to determine their viability. The relative viability, which was calculated in relation to controls (maximum excystation percentage), was significantly affected (p < 0.1) by the vinegar concentration, contact time, and temperature. At 21 ± 1 °C, no cysts remained viable after being treated with undiluted vinegar for 60 min, while the treatment with 1:1, 1:15.6, and 1:62.5 vinegar–water mixtures decreased the relative viability to 1.8%, 19.4%, and 56.4%, respectively. The relative viability after corresponding treatments at 4 °C also decreased, but 23.6% to 48.8% remained viable after 60 min, and thus complete inactivation was not obtained with any treatment at that temperature.