Abstract
Patulin (PAT) is a secondary metabolite (toxin) primarily produced by Penicillium expansum. PAT is the most dangerous mycotoxin that causes a broad range of negative health and financial consequences with the most being reported as a common contaminant of apple fruits. This mycotoxin continues to exist along the food chain despite numerous physical, chemical and biological methods intended to lessen or inactivate it. This has made it necessary to find effective methods of lowering or, at most, getting rid of them from diets and feeds. Enzymatic degradation of PAT offers a practical, economical and efficient method of doing so. Therefore, this study investigated PAT degradation by Recombinant Cryptococcus neoformans var. neoformans serotype D Orotate phosphoribosyl transferase (URA5) using LC-MS and physicochemical analysis of treated apple juice. PAT was incubated with two enzyme concentrations at 100 and 250 μg/L for 3, 6, 9, 12,18 and 24 hrs. At 12 hrs of incubation, over 50% of PAT was degraded in final products whereas after 18hrs, both treated apple products had concentrations of PAT that were below South African permissible limit of 50 μg/L which were regarded safe for human consumption. After 24 hrs of incubation, the highest degradation percentage acquired for PAT at 250 μg/L was 87.41 with the lowest at 15.61% for 100μg/L concentration. The final concentrations were 30.22 and 31.49 μg/L with 96.36 and 98.25% degradation rate and 69.78 and 87.14% PAT recovered for 100 and 250 μg/L. Hence, there is a significant effect (p<0.05) of this enzyme on PAT. The study's findings indicated that this enzyme degraded PAT intensively, as evidenced by the noticeable drop in PAT on LC-MS chromatographs. Nutritionally, the treated apple juice after degradation process showed acceptable results with a slight increase in acidity, amino acids and decrease in ascorbic acid by 15.84%. This enzyme's ability to effectively break down PAT is a crucial biocontrol method for preserving the quality of agricultural products with enormous potential for industrial use.
Keywords: Patulin, degradation, enzyme, LC-MS, apple juice, total soluble solids.