Detection of protease activity is critical for assuring quality and safety of dairy products. Especially important is determination of plasmin activity. During the lactation period, typical plasmin concentrations fall in the 1–8 nM range. To prevent plasmin from cleaving β-casein, the main milk protein, causing the negative changes in milk, it is necessary to employ a proper heating technique, commonly ultra-high temperature (UHT) treatment, which can effectively inactivate plasmin. However, if the technique is not used properly, residual plasmin activity could remain and as the plasmin inhibitors are the least temperature-stable, and this activity will be enhanced by no regulated activation of plasmin. Traditional techniques of detection of residual plasmin activity are either not sensitive enough or too expensive to be employed for frequent use in dairy plasmin detection. Therefore one of important objective of FORMILK project is focused on development effective assay of plasmin detection in milk using novel technique based on high-resolution ultrasonic spectroscopy (HR-US) as well as on electrochemical and acoustics methods allowing detection of plasmin at surfaces. As a result of the effort of the project partners we were able to develop novel assay based on HR-US and thickness shear mode acoustic methods (TSM) for detection plasmin activity in milk. Both assays were validated in milk samples and detailed protocols applicable for dairy laboratories were prepared. For application of electrochemical methods of detection protease activity at surfaces we developed miniature potentiostat, software and electrode holder. The potentiostat was validated and its sensitivity compared with commercial instruments. It has been demonstrated to the potential end-users. Another important enzyme for milk industry is lactase that is responsible for cleaving of disaccharide lactose, into monosaccharides (glucose and galactose). Approximately 75% of the world population is affected by deficiency of enzyme lactase. Deficiency of lactase causes elevated concentration of lactose in the colon, where it suffers fermentation by resident bacteria. This can lead to medical disorders, termed lactose intolerance, after consumption of dairy products and therefore, requires milks and other dairy product with reduced level of lactose. The latter could be manufactured from the lactose free milk (obtained by hydrolysis of lactose). Another, low cost approach is an addition of lactase (β-galactosidase) in a form of liquid formulation (droplets) to milks (and other milk based products) prior their consumption, followed by incubation period. The composition of the formulation and the incubation time shall provide a reduction of the concentration of lactose in the milk to an acceptable level. It is, however necessary to find optimal conditions for incubation of lactase in a milk, which is another important objective of FORMILK. We were able to find these optimal conditions. Thus, the FORMILK project has substantial impact on the society in respect of improving food quality and safety. FORMILK is highly innovative project. It combines excellent science in nanotechnology and novel experimental techniques with transfer of technology to a milk industry. This also involved extensive collaboration between academic institutions and industrial partners. Involvement of young researchers from both sectors gives them possibility for better understanding what academy can bring into industry and what industry needs from academy. Innovative technologies that can academy bring into industry as well as better knowledge on the working conditions in academy and industry can affect also decision of young researchers on their further carrier.
