MSc

Passion fruit (Passiflora edulis Sims) belongs to the family Passifloraceae,
which have two distinct forms, the standard purple (Passiflora edulis Sims f. edulis)
and the yellow (Passiflora edulis f. flavicarpa). The fruits are valued for its
captivating flavour, nutritional benefits and medicinal properties. In the recent past
cultivation and consumption of passion fruit have increased and in this context, the
present investigation “Optimization of methods for juice extraction and value
addition of passion fruit (Passiflora edulis Sims)” was taken up. The objective of
the study was to select types with ideal processing attributes and to standardize
technology for juice extraction and value addition.
Yellow and purple accessions collected from different localities were
evaluated for their physico-chemical attributes along with the variety, Kaveri
(purple type) released by the Central Horticultural Experiment Station (CHES),
Chettali. The study revealed that the accessions differed significantly for different
physical and biochemical traits analysed. Among the yellow accessions, Acc.1
collected from orange and vegetable farm, Nelliyampathi, possessed the highest
mean fruit weight (98.27 g) and percentage juice recovery (35.38%), low rind
content (46.05%), highest TSS (19.430 Brix), high ascorbic acid (25.94 mg 100gˉ1)
and total carotenoid content (2.81 mg 100gˉ1). Among the purple accessions, Acc.7
recorded highest percentage juice recovery (36.79 %), low rind content (46.55%),
high TSS (19.200 Brix), total sugar (11.56 %) and ascorbic acid content (32.51 mg
100gˉ1). Hence Acc.1 in yellow and Acc.7 in purple types were selected for further
studies along with variety Kaveri.
Three methods of juice extraction (enzymatic, mechanical and conventional
methods) were compared to identify the most efficient method. Among the different
enzymatic treatments tried pectinase 5 ml per litre incubated at 50° C for 90 minutes
was found ideal. This treatment yielded more quantity of juice (74.91% in Acc.1,
74.20% in Acc.7 and 72.74% in Kaveri) with high TSS (19.560 Brix in Acc.1,
19.830 Brix in Acc.7 and 19.70 Brix in Kaveri), acidity (3.12% in Acc.1, 3.24% in
Acc.7 and 3.23% in Kaveri) and total sugars (9.51% in Acc.1, 11.61% in Acc.7
and 10.95% in Kaveri). The juice yield was comparatively less in mechanical and
conventional method of extraction. The result was same for all the accessions tried.
Sweetened juice, RTS beverage, carbonated drink and jam were prepared as
part of product development. Sweetened juice and RTS beverage prepared by
blending of passion fruit juice and cashew apple juice in 3:1 ratio was found more
acceptable than that prepared with passion fruit juice or cashew apple juice alone.
For preparation of carbonated drink blending of passion fruit juice and cashew
apple juice in 1:1 ratio was found better in the case of Acc.1 (yellow type) whereas
blending of passion fruit juice and cashew apple juice in 3:1 ratio was good for
Acc.7 (purple type) and Kaveri. Blending rind pulp with cashew apple pulp in 1:3
ratio in Acc.1 (yellow type), 3:1 ratio in Acc.7 (purple type) and 1:1 ratio in Kaveri
was found to produce the most acceptable jam.
The shelf life of RTS beverage and jam was studied by storing the products
and taking the observations on biochemical characters, sensory attributes and
microbial load at monthly intervals. In RTS beverage fungal population was present
beyond acceptable limit at four months after storage. In the case of jam the sensory
attributes recorded a drastic reduction at three months after storage. Further studies
are required to improve the shelf life and acceptability of RTS and jam.