Passion Fruit - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 314

with the stalks wrinkle and ferment later than those picked
without the stalk or those collected from the ground; (7)
delay between harvesting and refrigerated storage —the
shorter the time elapsed between collection and refrigera-
tion, the greater the storage life; and (8) exposition to air
currents —exposition of fruits to air currents in the packing-
house, refrigerated storage, and transport should be avoided
to retard the loss of water and onset of shriveling.
Refrigeration conditions should be well chosen because
passion fruits are very susceptible to chilling injury. The
principal symptoms of this physiological disturbance are
browning or darkening of the skin; appearance of small
depressions, as if the fruit had been pressed over grains
of sand; moist areas; the fruit does not ripen or ripens
irregularly; unpleasant flavor and odor; and acceleration of
infection by microorganisms (Sigrist, 2002).
Arjona et al. (1992) recommended storing yellow pas-
sion fruit at 7 ◦ -10 ◦ C, with 90-95% relative humidity;
these conditions give a storage life of about 2 weeks
(Arjona et al., 1992). Purple passion fruit, which is rela-
tively chilling injury tolerant, can be stored at 3 ◦ -5 ◦ Cfor
3-5 weeks. Pruthi (1963) reported that passion fruit stored
at

tect the fruits from mechanical damage during transport.
Corrugated cardboard boxes are increasingly employed,
with the advantages of being attractive and light in weight,
aside from protecting the fruits against bruising damage and
weight loss during transport. Plastic crates and polyethy-
lene sacks are also utilized.

CHEMICAL COMPOSITION AND
HEALTH BENEFITS
As with the other fruits, the chemical composition of pas-
sion fruit varies appreciably, being affected by factors such
as variety, soil composition, degree of ripeness, plant sta-
tus, date of picking, season, climate, locality or region, soil
composition, and cultural practices.
Purple passion fruits harvested in winter showed higher
weight, diameter, and peel thickness and lower juice yield
than those harvested in the summer (Saenz et al., 1998).
The juice from the summer harvest, however, had higher
contents of soluble solids, starch, pectin, and sugar, less
acidity, and better aroma in intensity and quality.

Proximate composition and micronutrients
Carbohydrates comprise the second largest constituent
of passion fruit, water being the principal component
(Table 17.1). The purple passion fruit is a fair source of
ascorbic acid and riboflavin, a good source of niacin, and
a fair source of minerals (Table 17.1). The yellow passion
fruit generally has less ascorbic acid, but higher carotenoid
content.

6.5 ◦ C suffered weight loss, greater loss of flavor, and
mold attack (towards the end of the storage life).
Although various researchers recommended storage of
passion fruit at temperatures of 7 ◦ to 10 ◦ C, studies at the
Brazilian Institute of Technology (Sigrist, 2002) showed
that fruits harvested at the recommended stage of matu-
rity (at least 30% yellow color) presented the symptoms of
chilling injury after 14 days at 7 ◦ C and 90% relative hu-
midity. Thus it was recommended that fruits at this maturity
should not be stored at temperatures lower than 10 ◦ C. At
this temperature, the passion fruits keep good quality for
4-5 weeks, although there is some wrinkling.
Fruits collected at more advanced stages, with skin
greater than 75% yellow, should be stored at lower tem-
peratures, that is, 7 ◦ C, though the storage life is restricted
to 7-10 days.
Shriveling remains a limiting factor for the conservation
of passion fruit for prolonged periods even under refrig-
eration and high humidity. Thus utilization of techniques
supplementary to refrigeration is recommended to main-
tain the quality for longer time. Among these techniques,
surface waxing appears to be the most efficient.
In Brazil, fresh passion fruits are commonly packed in
wooden or corrugated cardboard boxes of approximately
13 kg (Salomao et al., 2001; Garcia et al., 2002). Wooden
boxes are still used in spite of several disadvantages. When
these boxes are reused without adequate cleaning, serious
microbial contamination occurs. Moreover, they do not pro-

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Sugars and acids
Three sugars (glucose, fructose, and sucrose) make up 86%
of the total carbohydrates of passion fruit, the rest being
starch, mainly amylopectin. Yellow passion fruit was re-
ported to have 29% fructose, 38% glucose, and 32% su-
crose (Chan and Kwok, 1975). The purple passion fruit had
34% fructose, 37% glucose, and 29% sucrose.
Yellow passion fruit juice from Hawaii had acidity (ex-
pressed as citric acid) ranging from 3.0% to 5.0%, with an
average of 4.0% (Chan et al., 1972). The predominant acid
was citric acid (about 83% of the acids), followed by malic
acid (16%) and much lesser amounts of lactic, malonic, and
succinic acids. For the purple passion fruit juice, the total
acid content ranged from 2.4% to 4.8% with an average of
3.4%. The same organic acids were found as in the yellow
fruit, but the relative amounts are different (41% citric, 23%
lactic, 15% malonic, 12% malic, and 7.6% succinic acid).

Pigments
As early as 1958, Pruthi and Lal identified phytofluene,
β -carotene, and ζ -carotene (zeta-carotene) as the main