Santos Joana, Oliveira Constança, Teixeira Filipe, Venâncio Armando, Silva Carla
Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
Centre of Chemistry, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal.
Foods. 2025 Jan 25;14(3):397. doi: 10.3390/foods14030397.
Ochratoxin A (OTA) is a toxic mycotoxin, making its removal from food essential for public health. This study examines OTA degradation by porcine pancreatic lipase (PPL) in ultra-pure water versus buffer systems through in vitro assays and molecular modeling. The results show that PPL fully degrades OTA in ultra-pure water within 7 h at 44 °C, whereas only partial degradation occurs in phosphate buffer. After 4 h, PPL in water degrades 91% of OTA, compared to only 12% in buffer. The enzyme's half-life is longer in water (4 h 4 min) than in phosphate buffer (2 h 30 min), suggesting better stability in water. Other buffers, including acetate, citrate, and borate, confirmed higher degradation efficiency in low-conductivity, acidic environments similar to ultra-pure water. Additionally, using the model compound -nitrophenyl octanoate (-NPO), it was found that -NPO degrades faster in buffer, likely due to a salting-out effect. Molecular modeling and circular dichroism analysis indicate that PPL's secondary structure in water promotes an ideal conformation for OTA binding. This study suggests ultra-pure water as a greener, sustainable option for reducing mycotoxins in food, with broad industrial applications.
赭曲霉毒素A（OTA）是一种有毒的霉菌毒素，因此从食品中去除该毒素对公众健康至关重要。本研究通过体外试验和分子建模，研究了猪胰脂肪酶（PPL）在超纯水和缓冲体系中对OTA的降解作用。结果表明，在44℃下，PPL在7小时内可使超纯水中的OTA完全降解，而在磷酸盐缓冲液中只能发生部分降解。4小时后，水中的PPL可降解91%的OTA，而缓冲液中仅为12%。该酶在水中的半衰期（约4小时4分钟）比在磷酸盐缓冲液中（约2小时30分钟）更长，表明其在水中具有更好的稳定性。包括醋酸盐、柠檬酸盐和硼酸盐在内的其他缓冲液证实，在类似于超纯水的低电导率、酸性环境中具有更高的降解效率。此外，使用模型化合物辛酰-对硝基苯酯（-NPO）发现，-NPO在缓冲液中降解更快，这可能是由于盐析效应。分子建模和圆二色性分析表明，PPL在水中的二级结构促进了OTA结合的理想构象。本研究表明，超纯水是减少食品中霉菌毒素的更绿色、可持续的选择，具有广泛的工业应用前景。
