Chapter 18 - Safety of Fermented Fruits and Vegetables

Abstract

Fermentation by lactic acid bacteria (LAB) has been used for years to preserve food and extend shelf life. LAB metabolism is characterized by the production of lactic acid from carbohydrates and the concomitant decrease of the pH. High acidity and low pH values enhance the microbiologic stability of fermented foods. Different studies have investigated the survival of foodborne pathogens in several fermented vegetable products, concluding that the acidic environment is not favorable to support their growth. Nevertheless, some outbreaks have been reported where fermented vegetables presented a risk for human health. For that reason, when a postpackaging pasteurization step is not applied, conditions able to achieve a 5-log reduction of pathogen populations have to be reached in acidified foods. Additions of preservatives or heat treatments stabilize the final products of many fermented vegetables and help attain good-quality and safe fermented vegetable foods.