ABSTRACT
Lactic acid fermentation has been carried out for thousands of years to preserve surplus and perishable foodstuff as well as to enhance them organoleptically. A wide range of fruits and vegetables have been traditionally used to serve as a substrate for lactic acid fermentation, resulting in a wealth of final products, some of which are characteristic of certain geographical areas. Dominance of lactic acid bacteria in the developing microecosystem is of principal importance for a desirable outcome of the process. Rapid acidification that results from lactic acid bacteria metabolism suppresses growth of antagonistic microbiota. Salting is a processing step that assists in development of lactic acid bacteria during the beginning of fermentation; proper temperature as well as the quality of raw material also play a decisive role. Failure of acidity to develop quickly, due to the unsuccessful control of the aforementioned parameters, may lead to the dominance of antagonistic biota, mainly Enterobacteriaceae, the development of which is perceived as spoilage. Another effective way to control the fermentation process is to develop starter cultures that have been the epicenter of intensive study, especially regarding the products that hold worldwide commercial significance, i.e. fermented olives, cucumbers, sauerkraut and kimchi. Several bacteriocinogenic strains, that enhance the safety as well as potential probiotic strains that improve the nutritional quality of the final products, have been examined and reported. At the same time, the microecosystem
development of several other spontaneously-fermented fruits and vegetables is helping to improve our understanding of lactic acid bacteria in general and of specific products in particular. The following paragraphs present an overview of lactic acid fermentation in fruits and vegetables. An historical overview, based on ancient Greek and Roman literature, the main attributes of the production procedure, the safety concerns and the nutritional properties, are also presented.
