Effect of pectinase treatment and concentration of litchi juice on quality characteristics of litchi juice

Litchi (Litchi chinensis L) juice concentrate
was prepared from pulp extracted from ripe fruits. Clarifi cation
of litchi pulp was optimized using pectinase at different
concentrations. Litchi pulp treated with pectinase enzyme
facilitated the removal of insoluble solids and extraction of
juice. Vacuum concentration of clarifi ed juice was carried
out in a pilot scale turbafi lm vacuum evaporator to obtain
litchi juice concentrate with total soluble solids of 60°Brix.
The litchi juice concentrate contained 49.9% total sugars,
47% reducing sugars, 32.7 mg/100 g ascorbic acid and its
titratable acidity was 0.73%. The litchi juice concentrate
was stored at –20°C for 6 months and analyzed at regular
intervals for changes in quality. No signifi cant changes in
the composition of juice concentrate was observed during
storage except tannin content and non-enzymatic browning
which increased during storage. Single strength litchi juice
reconstituted from juice concentrate was highly acceptable
sensorily during 6 months storage.