Effect of high pressure treatment on the antirotaviral activity of bovine and ovine dairy by-products and bioactive milk proteins

Whey and buttermilk have shown a certain degree of neutralizing activity against rotavirus, which are still a serious public health problem worldwide. High hydrostatic pressure (HHP) can be an alternative to thermal treatment for preservation of dairy products, providing acceptable safety and shelf life with minimal effects on their quality. The main objective of the present study was to evaluate the effect of HHP treatments of 400, 500 or 600 MPa for 5, 10 and 15 min, at 20 degrees C, on the antirotaviral activity of bovine and ovine whey and buttermilk, along with the effect of HHP and thermal treatments on the activity of some bioactive proteins, such as immunoglobulins and lactoferrin. The antirotaviral activity of dairy fractions was barely affected by treatments below 500 MPa for 15 min, with the greatest activity loss of 17%. High temperature-short time pasteurization was not significantly harmful to the antirotaviral activity of any of the milk proteins tested, which maintained 90-100% of their activity. By contrast, notable differences were observed among proteins regarding the loss of their activity upon low temperature-long time pasteurization and HHP treatments, with losses ranging 0-78% and 0-88%, respectively.