Abstract:
Fruits are an excellent source of Vitamin C. Citrus madurensis
(NasNaaran) and Spondias dulcis (Ambarella) are two tropical trees that
bear fruits with high levels of Vitamin C, flavor and aroma compounds.
Both fruits are currently under-utilized and therefore, this study was carried
out to identify suitable method to concentrate their fruit juices while
retaining the original qualities of the juices. The fruits were obtained from
Maharagama in the Western province and juices were extracted by peeling
and blending. The juices were concentrated by using Progressive Freeze
Concentration (PFC), a novel non-thermal liquid food concentration
method and evaporative concentration (Rotary Evaporation) method. The
vitamin C content in the original juice and the concentrated juices were
determined by spectrophotometerically at 521 nm. C.madurensis was
concentrated up to brix 7.9o from brix 5.4o. S. dulcis was concentrated up to
brix 9o from 6.9o using PFC and C. madurensis juice was concentrated up to
brix 10.6o from 7.5o. S. dulcis was concentrated up to 10o brix from 7o from
evaporative concentration. The initial vitamin C content in NasNaaran and
Ambarella were 19.87 and 26.73 ppm respectively. Vitamin C loss for PFC
method for C. madurensis and S. dulcis was 18.94% and 3.47%
respectively. Vitamin C loss for evaporative concentration method for C.
madurensis and S.dulcis was 73.67% and 29.24% respectively. Therefore,
PFC is a suitable method to concentrate liquid fruit juice compare to
conventional evaporative concentration.
