Jujube and Loquat - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 581

improve shelf life by delaying fruit decay, reducing respira-
tion rate and superoxide dismutase activity and minimizing
the loss of vitamin C (Wang et al., 2006). Effects of chitosan
and cinnamon oil coating on blue mold disease and quality
attributes of jujube fruits was studied by Xing et al. (2011);
chitosan-oil treatments reduced fungal decay caused by P.
citrinum markedly.
Li et al. (2009) studied the effect of a novel nanopack-
ing material with higher barrier and mechanical properties
for preservation of Chinese jujube shelf life during room
temperature storage. The nanopacking material with lower
relative humidity, O 2 transmission rate, and high longitudi-
nal strength (2.05 g/m 2 /24 hr, 12.56 cm 3 /m 2 /24hr,0.1MPa
and 40.16 MPa, respectively) was synthesized by blending
polyethylene with nanopowder (nano-Ag, kaolin, anatase
TiO 2 , rutile TiO 2 ). The results showed that the nanopack-
ing material had quite beneficial effects on physicochemical
and physiological quality compared with normal packaging
material.

results of this study indicated that it is possible to describe
moisture content, drying rate, and effective diffusivity, with
the models used including the effect of drying air tempera-
ture on the model constants and coefficients.
Low-sugar jam with 40% soluble solid was produced
from Chinese jujube by Wang (2004); the jam exhibited
acceptable sensory quality attributes. Production of spray-
dried jujube powder (using 70% malodextrin as a carrier)
has been reported by Wang et al. (2007).
Lee et al. (2011) developed edible films from Chinese
jujube using depolymerization with ultrasound and high-
pressure homogenization. A 4.6% (w/w) jujube hydrocol-
loid was treated by ultrasound (600 W, 20 min) or ho-
mogenized at high pressure (172 MPa, 6 sec) and mixed
with whey protein isolate, glycerol, xanthan, and sucrose
esters of fatty acids to produce film-forming solutions from
which films were formed by drying. The high pressure
treatment produced more homogeneous films without par-
ticles than those prepared without depolymerization or with
the ultrasound treatment. These films possessed the highest
tensile strength (4.7 MPa), the lowest water vapor perme-
ability (2.9 g/mm/kPa/h/m 2 ), and had a heat seal strength
of 44.4 N/m.

Jujube processing and products
Jujube fruit is processed on a very limited scale. Some of
the products made on a small scale include dried jujube,
jujube butter, pickled jujubes, honey, or sugar jujubes (pre-
serves). For processing, jujube fruit should be harvested at
the yellow-green stage, which is the optimum maturity, for
example, for drying this fruit. Dried jujube fruit maintains
its quality for over a year if stored in moisture-barrier pack-
aging. Some of the studies that have reported on attempts
to prepare processed products from jujube are described
below.
Zhang et al. (2003) studied extraction of Chinese jujube
juice by using hot water, ultrasonic wave, or a combination
method. Their results showed that the optimal parameters
for juice extraction by hot water were 40 min extraction
time at 70 ◦ -80 ◦ C with a 1:7 to 1:8 ratio of fruit flesh to
added water. The optimal parameters for juice extraction
by ultrasonic wave were 20 min at a power level of 75 W
(0.9 A). The best combination method for extracting jujube
juice was by using the pectinase treatment followed by hot
water extraction or by ultrasonic wave.
A jujube-carrot juice blend was developed by Liu (2009),
with best quality combination as 40% jujube and 45% carrot
juice, and the rest as water. To improve flavor, 8% sugar and
0.1% citric acid were added; this juice blend exhibited good
sensory taste and aroma qualities. The mixed beverage had
the red color, sweet and sour taste, and overall flavor of
strong jujube and carrot.
Fang et al. (2009) reported drying Chinese jujube fruits
at 50 ◦ ,60 ◦ , and 70 ◦ C in an electric heat blast dryer. The

Composition and health benefits
Composition and nutritional profile of raw and dried jujube
fruit is shown in Table 31.2. The jujube fruit has high sugar
content and high levels of vitamin A, C, and B complexes;
phosphorus; and calcium. The composition of fruit varies
depending on the cultivar, as is shown in Fig. 31.2 for vi-
tamin C content in selected Indian jujube cultivars. Jujube
fruits, leaves, seeds, roots, and bark of jujube have been
commonly used as a source of simple medicines in tradi-
tional medicine (Belford, 1994; Abdel-Zaher et al., 2005; Li
et al., 2005). Flowers of Chinese jujube have high-quality
nectar, and the leaves are consumed as tea (Shii et al.,
2011). Alkaloids, flavonoids, sterols, tannins, saponin, and
fatty acids have been detected in the different species of the
genus Ziziphus (Abdel-Zaher et al., 2005; San and Yildirim,
2010).
Jujube fruit contains some phenolics, such as chlorogenic
acid, caffeic acid, catechin, epicatechin, and rutin (Table
31.3). Phenolic compounds have been reported to play a
major physiological role in fruit, especially in resistance
to various stress factors, and in fruit quality. In addition,
phenolic compounds have significant levels of antioxidant
activity and are free radical scavengers (Li et al., 2005).
Bi et al. (2011) investigated volatile compounds in fresh
and dried jujubes using solid-phase microextraction and
GC-MS. Predominant compounds in fresh jujubes included