Deodorisation of off-odour during sweet potato juice production by employing physical and chemical deodorants

The mechanism and efficiency of three types of deodorants, namely activated carbon (AC), maltosyl cyclodextrin (MCD) and apple polyphenol (AP), in reducing the “boiled heavy odour” of saccharified sweet potato juice was investigated. The highest deodorising efficiency of AC, followed by MCD and AP, was confirmed by using the electronic nose and sensory analysis. Furthermore, flavour compounds in the sweet potato juice were identified by GC–MS analysis. While AC decreased the peak intensities of all the compounds to below the minimum detection limit, MCD, which eliminated the odour components by the formation of enclosure compounds, did not reduce the peak intensities to a similar extent. The mechanisms of adsorption with AC and envelopment with MCD for the identified odour components of sweet potato juice was also clarified.