CLOUDY FRUIT JUICES AND METHODS FOR MAKING SAME

摘要

It was surprisingly found that a cloudy apple juice is obtained when a method is used comprising the step of treating apple material with a mixture of enzymes comprising a homogalacturonan depolymerising activity, such as pectin lyase (EC 4.2.2.10), and an enzyme with endoglucanase activity (EC 3.-2.1.4), in the absence of enzymes which reduce the cloud volume by more than 25 %, as determined by a method which comprises: (a) suspending 5 mg of a cloud material obtainable by homogenising 1 g of apple pieces of Malus malus L. cv. Jonagold, after removal of the peel and core, using a Braun Kitchen machine (MX32, Frankfurt, Germany; 5 mm blade), incubating at 40 °C under continuous head-over-tail mixing at 150 rpm in 3 mL of a 200 mM NaOAc buffer (pH4) containing 0.01% (w/v) NaN3, 1 % ascorbic acid, 50 mU pectin lyase and an amount of endoglucanase with an equivalent of 25 mU of xyloglucanase activity, in 3 ml of a 25 mM NaOAc buffer (pH 5), containing about 0.01 % (w/v) NaN3, (b) incubating the cloud suspension so obtained for 16 h at about 40 °C, in the presence of the said enzyme, during which the cloud suspension and enzyme is mixed head-over-tail, (c) allowing the cloud to settle at about 4 °C for 24 hours, and (d) determining the effect of the enzyme on cloud stability by calculating the difference between the cloud volume of the cloud suspension obtained by following the above steps in the absence of the said enzyme and subtracting the volume obtained of the cloud suspension obtained by following the above steps in the presence of the enzyme.