Intact fruits from the frozen berries were thawed. The thawed bilberries then immediately heated to 95 °C for 2 min, and then cooled to 38 °C. Subsequently, the thawed berries were squeezed in a hydraulic juice press.
To improve juice recovery, berries can be treated with elevated temperatures. Heating or blanching the berries before pressing is a common step used in juicing fruits. Cold press extracted juice has a light blue color and delicate flavor, although hot press enzyme treated juice has a deep purple-blue color and stronger flavor.
Juices were pooled and diluted with ultra-pure water at the ratio of 1:1 (v/v). The juices were then cooled down to room temperature in a cold-water bath. The pH and °Brix were subsequently adjusted to 3.5 and 14.0 using sodium hydroxide and sucrose, respectively.
Bilberry juice processing
