Enzyme-Based Patulin Removal from Apple Juice: Evaluating the Potential of URA5 with LC-MS

A study conducted by the Department of Biotechnology and Food Technology at the University of Johannesburg (Gauteng, South Africa) explored the possibility of orotate phosphoribosyl transferase (URA5) used in the detoxification of the mycotoxin patulin in apple juice under controlled condition, with liquid chromatography-mass spectrometry (LC-MS) used to monitor the degradation process. A paper based on their research was published in BMC Biotechnology (1).

Hazardous secondary metabolites produced by various toxic fungi widely distributed in nature, mycotoxins are regularly found in food and present critical health risks to both humans and animals. To date, more than 400 mycotoxins have been identified, with their contamination levels increasing in agricultural products both during and after harvest, and especially during storage (2,3). Among the most significant mycotoxins is patulin (PAT), which is often found in fruits, especially apples, which are among the most widely cultivated fruits globally, with a yearly production of approximately 86 million tons (4,5).

Produced mainly through Penicillium expansum, the pathogen responsible for blue mold in apples, PAT was first identified alongside Penicillium griseofulvum following the discovery of penicillin by Alexander Fleming in 1928. (6,7). This carcinogenic mycotoxin poses significant economic and public health risks to the food and beverage industry, with consumers, particularly children, especially vulnerable to being exposed to it through contaminated fruit juices (8-10). Apples undergo various processing methods in the juicing process, which makes PAT contamination a major food safety concern (11).

PAT degradation was assessed by the researchers at initial concentrations of 100 µg/L and 250 µg/L, with enzymatic treatment using 0.2 mg/mL URA5, which is a gene which may influence cellular repair mechanisms and oxidative stress responses, potentially mitigating the toxic effects of compounds like PAT. Samples were incubated for up to 24 h, and PAT degradation was monitored at time intervals of 3, 6, 9, 12, 18, and 24 h using LC-MS. The results demonstrated a time-dependent PAT degradation, with significant reductions observed as incubation time increased. After 6 h, PAT concentrations decreased to 57.30 µg/L and 112.69 µg/L for the 100 µg/L and 250 µg/L samples, respectively. At 12 h, PAT levels in the 100 µg/L sample fell just below the permissible limit (50 µg/kg), while substantial degradation was observed in the 250 µg/L sample. By 18 h, PAT concentrations dropped further to 47.22 µg/L and 40.10 µg/L, reaching safe consumption levels. After 24 h, degradation rates reached 96.36% and 98.25%, reducing PAT levels to 30.22 µg/L and 31.48 µg/L, confirming the efficacy of URA5 in detoxifying PAT-contaminated apple juice (1)

The results emphasize URA5’s potential ability to act as a biocatalyst for PAT detoxification in the fruit juice industry. Compared to existing detoxification methods, enzyme-based degradation presents a promising alternative that is environmentally friendly, cost-effective, and non-toxic. In addition, they recommend that future studies should concentrate on the feasibility of using the technique in large-scale processing as well as its interaction with other contaminants in commercial apple juice production (1).

References

1. Mapheto, K.; Akinmoladun, O. F.; Maphaisa, T. C. et al. Biodegradation of Patulin in Apple juice by Phosphoribosyl Transferase (URA5): Implications for Food Safety. BMC Biotechnol. 2025, 25 (1), 100.DOI: 10.1186/s12896-025-00992-4
2. Adebo, O. A. Degradation of Aflatoxin B₁ AFB₁ by Lysates of Bacterial Obtained from a Gold Mine Aquifer. Pro Quest Dissertation & Thesis 2016, 3–58. https://ujcontent.uj.ac.za/esploro/outputs/graduate/Degradation-of-Aflatoxin-B1-AFB1-by/9911466707691 (accessed 2024-03-24)
3. Rocha, C.; Durau, J. F.; Barrilli, L. N. E, et al The Effect of Raw and Roasted Soybeans on Intestinal Health, Diet Digestibility and Pancreas Weight of Broilers. J. Appl. Poult. Res. 2014, 23, 71–79. DOI: 10.3382/japr.2013-00829
4. Areo, O. M. Natural Occurrence of Fungi and mMcotoxin in Some Selected South African Medicinal Plants with Some Antifungal Properties. Pro Quest Dissertation & Thesis 2017, 25–51.
5. Food and Agriculture Data. Food and Agriculture Organization of the United Nation website.https://www.fao.org/faostat. 2021.
6. Sanzani, S. M.; Schena, L.; de Cicco, V. et al. Early Detection of Botrytis cinerea Latent Infections as a Tool to Improve Postharvest Quality of Table Grapes. Postharvest Biol. Technol. 2012, 68, 64–71. DOI: 10.1016/j.postharvbio.2012.02.003
7. Serrano, C. Z. Development and Secondary Metabolism in Penicillium expansum: Implication of Global Transcription Factors VeA and BrlA. Doctoral dissertation, Institut National Polytechnique de Toulouse-INPT. 2020.
8. Beretta, B.; Gaiaschi, A.; Galli, C. L. et al. Patulin in Apple-Based Foods: Occurrence and Safety Evaluation. Food Addit. Contam. 2000, 17 (5), 399-406. DOI: 10.1080/026520300404815
9. Moake, M. M.; Padilla-Zakour, O. I.; Worobo, R. W. Comprehensive Review of Patulin Control Methods in Foods. Compr. Rev. Food Sci. F. 2010, 4, 8–21. DOI: 10.1111/j.1541-4337.2005.tb00068.x
10. Castoria, R.; Mannina, L.; Durán-Patrón, R. et al. Conversion of the Mycotoxin Patulin to the Less Toxic Desoxypatulinic Acid by the Biocontrol Yeast Rhodosporidium kratochvilovae strain LS11. J. Agric. Food Chem. 2011, 59 (21), 11571-8. DOI: 10.1021/jf203098v
11. Bacha, S. A. S.; Li, Y.; Nie, J. et al. Comprehensive Review on Patulin and Alternaria Toxins in Fruit and Derived Products. Front. Plant Sci. 2023, 14, 1–8. DOI: 10.3389/fpls.2023.1139757