Comparison in the Reduction of Patulin Content under Different High Pressure Processing Conditions

Introduction: Patulin is a mycotoxin commonly encountered in juices and is produced by certain fungi within the genera of Penicillium, Aspergillus and Byssochlamys. The mycotoxin can cause a broad spectrum of toxicity (including carcinogenicity and teratogenicity) and hence the regulatory limit was set at 50 ppb.  Although patulin is reactive, it exhibits high stability under acidic pH and cannot be significantly inactivated by thermal or non-thermal processing. Therefore, more effective methods are required to degrade the mycotoxin when encountered in juices. 

Purpose: The purpose of this study was to evaluate if a combination of high hydrostatic pressure and hydrogen peroxide can be applied to degrade patulin encountered in juices. 

Methods: Patulin-spiked juices or simulated juice (including malic acid, sorbitol, sucrose, fructose, glucose and water, pH adjusted to 3.5) was treated with different HHP treatments (400 MPa to 600 MPa for 30 – 300 s) in the presence and absence of hydrogen peroxide (H₂O_2, 0 – 10% v/v). The patulin was extracted from treated juice samples and levels quantified using RP-HPLC at 276 nm. The data were calculated and statistical analysis performed using ANOVA. 

Results: There were statistically significant differences (P < 0.05) in the reduction of patulin in patulin-spiked juices after HHP-hydrogen peroxide combined treatment. For instance, after 600 MPa for 300 s, the remaining patulin contents were 61.43 ± 1.74 ppb for H₂O₂-added, 156.81 ± 2.65 ppb for H₂O₂-non added and 179.56 ± 0.78 ppb for the control. However, the levels of patulin in simulated juice were not significantly different between those with or without hydrogen peroxide or treated with high pressure. 

Significance: The results demonstrated that HHP can be applied in the presence of a suitable oxidant (e.g., hydrogen peroxide) to decrease patulin levels in juices. It is likely that the HHP degradation of patulin also involves other components within juices given that patulin reduction was negligible in simulated juice.