Agriculture Reference
In-Depth Information
The health benefits associated with their consumption in-
clude fulfillment of vitamin C requirements. The bioac-
tive molecules present in such fruits are limonoids, poly-
methoxy flavones (PMF), and flavones glycosylates (FGs).
These components hold several health-promoting perspec-
tives (Areias et al., 2001). Some basic effects include
antioxidant activity, while complex responses are anti-
inflammatory, anticancer, and antiatherogenic. It has al-
ready been described that citrus peel is a valuable source of
dietary fiber (Marti et al., 2011), especially pectin, which
has strong influence in modulating various metabolic/ di-
gestive pathways and is thus helpful in reducing the ex-
tent of hyperglycemia and hypercholesterolemia (Joshipura
et al., 1999). The antioxidant activity of these fruits is de-
pendent on the concentration of bioactive molecules. The
presence of functional ingredients can strengthen the an-
tioxidant potential of citrus cultivars (Choi et al., 2000).
The tangerine peel owing to higher amounts of extractable
polyphenols (4.3-7.6 g/100 g) showed radical-scavenging
activity, as reported by Chafer et al. (2001) and Rincon et al.
(2005).
The total antioxidant activity can be correlated with con-
centrations of hesperidin and narirutin (Miller and Rice-
Evans, 1997; Gorinstein et al., 2006). The components
of interest include tangeretin and nobiletin. Tangeretin
holds the ability to cause cell-cycle arrest in human HL-60
leukemia (Takamatsu et al., 2003), JCS cells, and myeloide
leukemia through induction of apoptosis (Middleton and
Kandaswami, 1994). Additionally, it can modify the expres-
sion of some cytochrome P450 isoforms, modulate inter-
cellular communication, and induce an upregulation of E-
cadherinicatenin invasion-suppressor complex (Canivenc-
Lavier et al., 1996). Diets containing citrus fiber have been
reported to reduce the risk of intestinal cancer (Marti et al.,
2011).
Limonene and its derivatives are present in their high-
est amount in some mandarin species (92-95%) and have
established chemopreventive and chemotherapeutic activ-
ity against mammary, skin, lung, pancreas, and colon tu-
mors in rodent modeling (Stark et al., 1995). The limonene
is a major fraction present in the essential oil of tan-
gerine ranging from 92% to 95%, showing effectiveness
against mammary and colon cancer (Crowell and Gould,
1994).
the shelf life. Preservation by means of wax coating is a
known treatment of the postharvest arena. Citrus cultivars
can be canned, refrigerated, frozen, and pulped. Further-
more, they may be processed into value-added products
like jams, jellies, and marmalades. Numerous studies have
been conducted to evaluate the nutritional losses during
processing such as loss in color, acidity, pH, and other fac-
tors. It has been observed that freezing and chilling for a
prolonged period results in loss of overall acceptability. It
was shown by Beltran-Gonzalez et al. (2009) that ascorbic
contents decrease progressively during storage, followed
by darkening in juice color. Moreover, heat treatment of
juice leads to the development of off flavors (Kwak et al.,
1990).
Obenland et al. (2011) reported that mandarins are very
prone to losing flavor quality during storage and, as a re-
sult, often have a short shelf life. To better understand the
basis of this flavor loss, two mandarin varieties ('W. Mur-
cott' and 'Owari') were stored for 0, 3, and 6 weeks at
either 0
◦
,4
◦
,or8
◦
C plus 1 week at 20
◦
C and then eval-
uated for sensory attributes as well as quality parameters
and aroma volatile profile. Large increases in alcohols and
esters occurred during storage in both varieties, a number
of which were present in concentrations in excess of their
odor threshold values and are likely contributing to the loss
in flavor quality (Table 22.8). Thirteen aroma volatiles, con-
sisting mainly of terpenes and aldehydes, declined during
storage by up to 73% in 'Owari,' while only one of those
significantly changed in 'W. Murcott.' Aroma volatiles did
not play a role in the temperature effect on flavor as there
were no significant differences in volatile concentrations
among the three temperatures.
A research experiment was conducted by Perez-Lopez
et al. (2006) involving four volatile compounds, d-
limonene, linalool, alpha-terpineol, and terpinen-4-ol in
mandarin originated from Spanish varieties. They deduced
that both pasteurization and storage affected the concen-
tration of aromatic compounds significantly. They also
observed development of off-flavor compounds (alpha-
terpineol and terpinen-4-ol) along with simultaneous de-
composition of d-limonene and linalool.
Vitamin C (ascorbic acid) is considered as one of the
major indicators of nutritional losses. Storage at higher
temperatures may cause excessive vitamin C loss com-
pared to low-temperature storage. Tangerine and mandarin
grown in the tropical zone contain less ascorbic acid than
those grown in a subtropical region. Moreover, 26% of vi-
tamin C is present in the juice, while the rest is in peel and
rind portions at 53% and 21%, respectively. The mode of
Nutritional losses during storage or processing
Tangerine, like other citrus species, can be processed and
preserved by adopting the appropriate technique to extend
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