<abstract xmlns="http://www.w3.org/1999/xhtml">The quality of cloudy juices produced from two plum cultivars varied in chemical characteristics and native polyphenol oxidase (PPO) activity, and was studied in relation to specific pectinolytic activity of enzyme preparations used for fresh fruit maceration before pressing. Process effectiveness expressed as juice yield, turbidity and the rate of transfer of anthocyanins and polyphenols were determined for five different enzyme preparations, whose activity was also analysed. Juice yields obtained after 1 hour mash maceration (50 ºC, 100 g·t−1) were between 86.6 and 95.4%. The anthocyanins content of the obtained juices strongly depended on the cultivar and ranged from 26 to 50 mg·L−1 for ‘Promis’, and from 269 to 289 mg·L−1 for ‘Čačanska Najbolja’, which could be related to the differences in the measured PPO activity (175.4 and 79.8 nkat·g−1, respectively). The type of enzyme preparation strongly affected the degradation rate of anthocyanins during juice processing. Peonidin-3-rutinoside proved to be the most stable during plum juice production in contrast to cyanidin-3-glucoside. Irrespectively of the cultivar, the juice prepared with the mixture of Rohapect PTE + Rohament PL (2 : 1) showed the highest turbidity among the investigated combinations. The results suggest that for the production of cloudy plum juice use of a preparation with low pectin methyl esterase and polygalacturonase activities and high pectin lyase activity could be recommended.</abstract>

The quality of cloudy juices produced from two plum cultivars varied in chemical characteristics and native polyphenol oxidase (PPO) activity, and was studied in relation to specific pectinolytic activity of enzyme preparations used for fresh fruit maceration before pressing. Process effectiveness expressed as juice yield, turbidity and the rate of transfer of anthocyanins and polyphenols were determined for five different enzyme preparations, whose activity was also analysed. Juice yields obtained after 1 hour mash maceration (50 ºC, 100 g·t−1) were between 86.6 and 95.4%. The anthocyanins content of the obtained juices strongly depended on the cultivar and ranged from 26 to 50 mg·L−1 for ‘Promis’, and from 269 to 289 mg·L−1 for ‘Čačanska Najbolja’, which could be related to the differences in the measured PPO activity (175.4 and 79.8 nkat·g−1, respectively). The type of enzyme preparation strongly affected the degradation rate of anthocyanins during juice processing. Peonidin-3-rutinoside proved to be the most stable during plum juice production in contrast to cyanidin-3-glucoside. Irrespectively of the cultivar, the juice prepared with the mixture of Rohapect PTE + Rohament PL (2 : 1) showed the highest turbidity among the investigated combinations. The results suggest that for the production of cloudy plum juice use of a preparation with low pectin methyl esterase and polygalacturonase activities and high pectin lyase activity could be recommended.

Quality Of Cloudy Plum Juice Produced From Fresh Fruit Of <italic>Prunus Domestica</italic> L. – The Effect Of Cultivar And Enzyme Treatment

Research Institute of Horticulture, 96-100 Skierniewice, Poland

VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Finland

Journal of Horticultural Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Quality Of Cloudy Plum Juice Produced From Fresh Fruit Of  L. – The Effect Of Cultivar And Enzyme Treatment

The quality of cloudy juices produced from two plum cultivars varied in chemical characteristics and native polyphenol oxidase (PPO) activity, and was studied...

Quality Of Cloudy Plum Juice Produced From Fresh Fruit Of Prunus Domestica L. – The Effect Of Cultivar And Enzyme Treatment

Published Online: Dec 30, 2015

Page range: 83 - 94

Received: Jun 01, 2015

Accepted: Oct 01, 2015

DOI: https://doi.org/10.2478/johr-2015-0018

Keywords
enzyme activity, plum, juice processing, degradation of anthocyanins, PPO activity

© 2015 Monika Zbrzeźniak et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Quality Of Cloudy Plum Juice Produced From Fresh Fruit Of Prunus Domestica L. – The Effect Of Cultivar And Enzyme Treatment

Published Online: Dec 30, 2015

Page range: 83 - 94

Received: Jun 01, 2015

Accepted: Oct 01, 2015

DOI: https://doi.org/10.2478/johr-2015-0018

Keywordsenzyme activity, plum, juice processing, degradation of anthocyanins, PPO activity

© 2015 Monika Zbrzeźniak et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
enzyme activity, plum, juice processing, degradation of anthocyanins, PPO activity