Photocatalytic disinfection of patulin using titania in apple juice

Abstract

The food industry is facing many challenges to provide safe food free from microbial contamination and especially free from mycotoxins, which seems to bypass the pasteurisation treatment frequently used for microbial deactivation in industry. Mycotoxins are secondary metabolites produced by numerous microorganisms. Among mycotoxins, patulin is well known to affect apples and is therefore found in apple juice and apple cider. Patulin is in fact a mycotoxin produced by Penicillium expansum. It is toxic; hence, there is a need to remediate the toxin from juices. After the ingestion of patulin, gastrointestinal symptoms such as diarrhoea, vomiting, nausea and may ensue leading to death. In this study, different method of patulin treatment was elaborated on but the emphasis was on photocatalysis. The purpose of this thesis was to treat patulin in apple juice by the means of photocatalysis. Photocatalysis requires nanoparticles and light. The choice of nanoparticles was (TiO2) which were synthesized from titanium chloride (TiCl4) in different solubilising matrices using a wet chemical method. The quantification of patulin from apple juice was measured using the LC/MS instrument. As a result, the best TiO2 nanoparticles derived from TiCl4 dissolved in water. Photocatalysis experiment was done in 2 different conditions under different Ultraviolet (UV) light intensity of 15V and 30 V. The results shown that UV 30 provided the greater percentage degradation as compared to UV 15 demonstrating that, the efficiency of photocatalysis depends on the light intensity. Overall, the patulin level, were reduced to below 10 ng/L within 180 min of treatment, with the juice adhering to the internal quality standard of patulin in apple juices. In conclusion, photocatalysis was determined as an efficient treatment for patulin degradation in apple juice. This is therefore, a cheap and easy method of patulin treatment for small-scale juice producers.