Agriculture Reference
In-Depth Information
activities, such as hypoglycemic, anticancer, antibacterial,
and antiviral properties of lychee fruit, have been found
(Wang et al., 2006a; Zhao et al., 2007; Nimmanpipug et al.,
2009; Ogasawara et al., 2009). However, side effects (such
as skin erythema and throat swelling) on some consumers
occur when they consume fresh lychee fruit, possibly due
to the presence of allergens (Hoppe et al., 2006a; Costa
et al., 2007; Garrido et al., 2007). Thermal processing can
eliminate the allergenic potency in lychee fruit (Hoppe
et al., 2006b; Paschke, 2009), which can help to meet the
increasing demands of consumers.
Lychee fruit is a nutritionally significant source of vi-
tamin C (ascorbic acid), along with thiamine, riboflavin,
and niacin (Jiang et al., 2006b; Sivakumar et al., 2008).
The arils of lychee fruit contain about 0.3-0.7 mg/g vitamin
C (fresh-weight basis), depending on cultivar. The fruit is
also a significant source of minerals, especially potassium
(Zeng et al., 2008).
while epicatechin and procyanidin B2 had lower cytotoxic-
ities toward MCF-7 and HELF than paclitaxel (Fig. 13.6). It
was suggested that epicatechin and procyanidin B2 can be
employed as components of breast cancer-treating drugs.
INNOVATIVE PROCESSING TECHNOLOGIES
The emerging processing technologies that essentially rely
on nonthermal to inactivate micro-organisms has been
driven by the need to provide new methods for preserving
foods while optimizing biological and sensory properties.
Research and development in this field of microbial inacti-
vation has embraced the use of high-pressure, high-power
ultrasonics; pulsed ultraviolet light; pulsed electric fields;
and more recently, low-temperature plasma of gases. Of
these technologies, the use of pressures in ranges up to about
a maximum of 300-700 MPa has been adopted for selec-
tive commercial applications by the food industry. Huang
et al. (2007) reported that application of ultra high pressure
(100
−
500 M Pa for 30 min at 10
◦
C) showed significant
bactericidal effect and retention of nutritional ingredients
of lychee juice. The use of other emerging processing tech-
nologies, including high-power ultrasonics, pulsed ultravi-
olet light, and pulsed electric fields, needs to be explored
for the lychee processed products.
Health-beneficial compounds
Lychee fruit contains significant amount of phenolic com-
pounds (Fig. 13.5). Previous work has identified five ma-
jor phenolic compounds: gallic acid, (
−
)-gallocatechin,
procyanidin B2, (
)-epicatechin-3-
gallate (Prasad et al., 2009). Phenolic compounds have
attracted great attention due to their beneficial effects on
human health. Wang et al. (2006a, 2006b) reported that
lychee fruit pericarp (LFP) extract exhibited potential in
vitro and in vivo anticancer activity against hepatocellular
carcinoma. The anticancer activity of the flavanols present
in LFP is similar to that of the anthocyanins. The anticancer
activities of epicatechin, procyanidin B2, procyanidin B4,
and the ethyl acetate fraction from LFP were examined by
Zhao et al. (2007). Procyanidin B4 and ethyl acetate fraction
showed a stronger inhibitory effect on HELF than MCF-7,
−
)-epicatechin, and (
−
SUMMARY
Considering the importance of lychee fruit crop in the
tropical and subtropical region, efforts should be made to
provide technological support through research and pro-
moting production, preharvest management, postharvest
handling, and marketing through development programs.
Currently lychee fruit sales make a significant contribu-
tion to economic development in these countries, espe-
cially those in Southeast Asia. Most lychee fruits produced
mV
Detector A:280nm
200
%
13.8
19.7
150
75.0
22.9
16.4
100
50.0
18.3
24.3
5.7
50
25.0
0
0.0
0
10
20
30
40
min
Figure 13.5.
HPLC profile of ethanolic extract from lychee seed. Five phenolic compounds were identified
from this chromatogram. Retention time: 5.7 min, gallic acid; 16.4 min, (−)-gallocatechin; 18.3 min,
procyanidin B2; 19.7 min, (
−
)-epicatechin; and 24.3 min, (
−
)-epicatechin-3-gallate.
Search WWH ::
Custom Search