ABSTRACT
The blackberry belongs to the genus Rubus and has a complex genetic background, growth characteristics, and a number of species. It is a specic fruit that consists of aggregates of drupelets [1]. Blackberries contain a high content of bioactive compounds, especially anthocyanins and ellagitannins, possessing high antioxidant activity [2-4]. Blackberry juice can be extracted either from fresh or frozen fruits. Frozen fruit may be cold pressed. The benets of this method are a higher yield and that the plant may operate outside the harvest season. The nal product has a better color than that of fresh cold press juice and nearly as good as that from heated fresh berries and seems to have a fresh fruit avor not present in the heated juice. In hot processing method, clean, ripe, and wholesome fruit is heated and agitated in a steam-jacketed kettle between 60°C and 82°C. When this temperature range is reached, the crushed berries can be pressed in a hydraulic rack and cloth press. Usually, with thermal treatment, pretreatment of fruit with pectolytic enzymes is used causing the release of more juice due to cell wall breakdown. The resultant juice contains high amounts of pectin making the juice viscous and an enzymatic depectinization is necessary in the production of clear juices and concentrates. The addition of pectinase improves juice and color of the extract while retaining the organoleptic properties of the fruit [5]. Detailed blackberry juice production can be found elsewhere [6-8].
