Even at the lowest examined peptidase activity (0.03 pkat mL−1) a shelf-life of UHT milk of 4 months at 20 °C cannot be guaranteed. To produce UHT milk with shelf-lives of approximately one year destined for export, it is therefore advisable to only use raw milk free from proteolytic activity produced by Pseudomonas spp. Prolonged raw milk storage, however, will most probably lead to non-shelf-stable products. Storage of UHT milk at temperatures lower than 20 °C can increase its shelf-life ( Gebre-Egziabher et al., 1980).