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 (50C, 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 ' Cacanska 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.
Original language | English |
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Pages (from-to) | 83-94 |
Journal | Journal of Horticultural Research |
Volume | 23 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2015 |
MoE publication type | A1 Journal article-refereed |
Keywords
- degradation of anthocyanins
- enzyme activity
- juice processing
- plum
- PPO activity