Abstract
South Tyrol is the largest European producers of apples, where fruit processing generates a consistent volume of apple by-products that needs to be disposed. The huge volume of the low-cost apple by-products offers economical perspectives due to the presence of potentially biogenic valuable components. Chemical industries are now involving microbial fermentation to mediate the chemical conversion to produce industrially important compounds.
This study aims to develop tailored bioprocessing technologies, which include the combination of selected microbes to metabolize cholorogenic acid, one of the most abundant phenolics of apples. It can be trasformed to quinic acid and subsequently to shikimic acid, an industrially important compound that is used as key ingredient for the formulation of the drug Oseltamivir phosphate, emplied to treat swine/avian flu.
Chemical and microbiological composition of apple by-products, as well as the selection of appropriate pre-treatments, and the most promising microbes were investigated. According to the main target, the most suitable processing conditions was set-up. The analyses of the profiles of phenolics and organic acids establish the main modifications occurring during bioprocessing. Extraction and purification of biogenic compounds was performed through a multi-technology approach, and their exploitation was carried out through in vitro assay on human line cells.
Pre-treatments of apple by-products might be suitable to optimize the microbial fermentation. Microbes suitable to allow the quinic acid reduction pathway and favor the production of shikimic acid were selected. Sustainable shikimate extraction and purification procedures might favor economic and green process, and be a source of potential human functionality.