Photocatalytic Treatment Technology for Reducing Chemical Contaminants in Fruit Processing

Abstract

Chemical contamination in fruit processing presents challenges involving pesticide residues, contaminated washing water and mycotoxins in processed products. Photocatalytic treatment offers a potential approach through light-driven reactions that transform susceptible contaminants. However, performance depends on the pollutant, treatment matrix, catalyst and irradiation conditions. This paper evaluates photocatalytic technology through a focused narrative review of twelve verified publications addressing semiconductor mechanisms, water-treatment engineering, pesticide removal and fruit-related applications. Published numerical findings were extracted without combining incompatible experiments. A study of nitrogen-doped chitosan–titanium dioxide reported complete degradation of patulin initially present at 500 μg/kg in apple juice within 35 minutes. Supported titanium dioxide research investigated citrus-processing pesticides at 100 μg/L each and demonstrated substantial matrix-dependent behavior. Fresh-produce research reported pesticide-removal ranges of 72–94% for combined ultraviolet treatments, compared with 53–73% for bubble-water washing; nevertheless, adding titanium dioxide did not significantly improve pesticide removal relative to combined ultraviolet treatment alone. These findings indicate that contaminant disappearance, mineralization, detoxification and product acceptability must be assessed separately. Photocatalysis appears promising for selected processing-water and juice applications, but its contribution must be demonstrated against appropriate controls. Commercial development requires verified analytical methods, transformation-product assessment, catalyst containment, energy evaluation and validation under realistic processing conditions.