Lactic acid fermentation of smoothies and juices

Plant-based beverages produced by controlled fermentation of lactic acid bacteria are the new products meeting to the consumer’s demand for minimally processed foods characterized by high nutritional value, rich flavor and enhanced shelf-life. In these products high proportions of protective substances contained in the raw material are preserved. Moreover, during fermentation, lactic acid bacteria produce additional health-promoting components and allow a better preservation (Di Cagno et al. 2013). Lactic acid bacteria and, more in general, the lactic acid fermentation is considered as one of the most suitable tools to exploit the biogenic/functional potential of plant matrices and to enrich them with bioactive compounds (Gobbetti et al. 2010). Indeed, fermentation by select lactic acid bacteria was largely used to enhance the anti-microbial, antioxidant and immune-modulatory features of several vegetables and fruits as well as of medicinal plants, like Echinacea spp. (Rizzello et al. 2013) as a result of the ingestion of microbial metabolites (biogenic effect). Under optimal processing conditions, microbes contribute to plant functionality through their enzyme portfolio, which promotes the synthesis of various metabolites and/or the release of functional compounds that are cryptic in the raw matrix. Recently, lactic acid bacteria were used to synthesize ?-amino butyric acid (GABA) from grape juice (Di Cagno et al. 2010a). Besides, health benefits from fermentation of plant materials are usually direct, through interaction of ingested live microorganisms with the host (probiotic effect)