limate change is one of the major factors affecting the ecology of mycotoxin producing fungi. In the next years mycotoxin contamination is expected to dramatically increase. In this scenario, prevention strategies hardly counteract the evolving mycotoxin contamination pattern and alternative methods for mycotoxin control are needed to ensure food safety within the whole supply chain. Aflatoxin M1 (AFM1) is a common contaminant of milk and dairy products as carry over of aflatoxin B1. It represents a great health concern worldwide since it is classified in group 2B by the International Agency on Research on Cancer, thus possible carcinogenic to humans. In this study the application of a laccase mediator system (LMS) was studied for AFM1 degradation in vitro and in skim UHT milk. Laccase alone as well as with five different natural and artificial mediators was tested. An in vitro screening was performed in acetate buffer 1mM pH 6.5 for 72h at 25°C. Time course degradation was then evaluated in vitro and in skim UHT milk. Laccase alone was not able to degrade AFM1, while the addition of any of the tested mediator lead to a significant reduction (68%) or complete removal (100% degradation) of the toxin within 72h. In buffer solution AFM1 was halved within 1h of incubation and reduced by 90% after 24h with a logarithmic fit. The same trend was registered in milk, though the rate of degradation was slower in the first hours of assay. LMS crosslinking activity on milk proteins was also investigated. Preliminary data showed that caseins and lactoglobulins are involved in oligomer formation, with important potential implication in the rheology and allergenicity of milk based products. The application of laccase enzymes in combination with natural redox mediators is a promising strategy to reduce AFM1 contamination. The green feature of LMS and the effectiveness in real food matrix open new perspectives for AFM1 control and to ensure the safety of milk and dairy products.
Biotechnological potential of a laccase mediator system for aflatoxin M1 degradation
Loi M;Fanelli F;Quintieri L;Liuzzi VC;Logrieco AF;
2017
Abstract
limate change is one of the major factors affecting the ecology of mycotoxin producing fungi. In the next years mycotoxin contamination is expected to dramatically increase. In this scenario, prevention strategies hardly counteract the evolving mycotoxin contamination pattern and alternative methods for mycotoxin control are needed to ensure food safety within the whole supply chain. Aflatoxin M1 (AFM1) is a common contaminant of milk and dairy products as carry over of aflatoxin B1. It represents a great health concern worldwide since it is classified in group 2B by the International Agency on Research on Cancer, thus possible carcinogenic to humans. In this study the application of a laccase mediator system (LMS) was studied for AFM1 degradation in vitro and in skim UHT milk. Laccase alone as well as with five different natural and artificial mediators was tested. An in vitro screening was performed in acetate buffer 1mM pH 6.5 for 72h at 25°C. Time course degradation was then evaluated in vitro and in skim UHT milk. Laccase alone was not able to degrade AFM1, while the addition of any of the tested mediator lead to a significant reduction (68%) or complete removal (100% degradation) of the toxin within 72h. In buffer solution AFM1 was halved within 1h of incubation and reduced by 90% after 24h with a logarithmic fit. The same trend was registered in milk, though the rate of degradation was slower in the first hours of assay. LMS crosslinking activity on milk proteins was also investigated. Preliminary data showed that caseins and lactoglobulins are involved in oligomer formation, with important potential implication in the rheology and allergenicity of milk based products. The application of laccase enzymes in combination with natural redox mediators is a promising strategy to reduce AFM1 contamination. The green feature of LMS and the effectiveness in real food matrix open new perspectives for AFM1 control and to ensure the safety of milk and dairy products.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
