Preface - kmutt

KMUTT Annual Research Abstracts 2005
However, this common feeding selection of ripe
fruit may leave gibbon and hornbill species as
major food competitors. This role will appear of
higher importance during the reproduction
period, when their consequent high energy
requirements overlap.
Parallel detailed ecological studies on
the feeding habits and reproductive strategies of
white-handed gibbon and hornbill populations
have been conducted at Khao Yai National Park
in Thailand. Concerning gibbons, the study
combined long-term demographic data from
over a decade with detailed forest ecological
quality variation measurements for each
inhabited home range. Forest quality was
measured in terms of potential food productivity
by combining a food abundance index (F.A.I.).
The F.A.I investigated the spatio-temporal
distribution of important gibbon food resources,
with a biomass coefficient quantifying fruit
production on a kg per ha basis. Spatial
distribution of resources was defined for 20% of
each home range, while the temporal
reproductive status of trees was defined for
species comprising 80% of the monthly gibbon
diet. Our results show a marked seasonal
variation in forest food productivity,
significantly corresponding with reproductive
events; gibbon conception follows months of
higher food productivity (from January to April,
peaking in March). Synchronizing conception
with periods of high food productivity is a direct
consequence of the higher energetic
requirements of females to achieve regular
ovulation.
Our combined work on female gibbon
and hornbill reproductive performances revealed
a high dependence on good quality resources
during the conception period and nesting period
for both species. These appear to strongly
overlap in time: from February to April for
gibbons, and from January to early June for
hornbills. During this period, hornbills also rely
on high quality resources to feed their
developing chicks, while female gibbons need
high quality items to guarantee a regular
ovulatory cycle.
In this presentation, we have assessed
the importance of some plant species used by
both animals (e.g. Polyalthia viridis). In order to
assess the degree of feeding competition, we
examined which plants reflect a higher cost for
the different breeding animals, as well as their
nutritional composition.
IC-244 EFFECT OF CONTROLLED
ATMOSPHERES ON BROWNING OF
LONGKONG (Aglaia dookkoo GRIFF)
Intira Lichanporn, Sirichai Kanlayanarat
APEC Symposium on Assuring Quality and
Safety of Fresh Produce, August 1-3, 2005,
Radisson Hotel, Bangkok, Thailand
161
Longkong (Aglaia dookkoo Griff) is a
famous tropical fruit of Southeast Asia. The
fruits, a non-climacteric type, are usually
harvested ripe and consequently, postharvest life
is very short due to rapid peel browning.
Controlled atmospheres (CA) of 2-6% O 2 and 3-
6% CO 2 or their combination remarkably
inhibited peel browning during 12 day storage at
13°C, 90-95%RH. The fruits showed browning
symptoms only after 6 days of storage whereas
fruits stored in air, as early as after 3 days of
storage. At the end of the 12 days storage period,
all CA-stored fruits had browning scores of
about 4 (40% browning) while those stored in
air, 10 (100% browning). Weight loss,
phenylalanine ammonia lyase (PAL) activity and
ethylene production rate correlated well with
browning development while no direct
correlation was obtained for total phenolics
content, respiration rate and polyphenol oxidase
(PPO) activity. Weight loss of all CA-stored
fruits appreciably decreased and was maintained
at about lower than 4% throughout the storage
period while fruits stored in air lost more lower
than 2% of its after only 3 days of storage
increasing to about 16% after 12 days. CAstored
fruits had also consistently lower PAL
activity during the first 9 days of storage, CA
likewise suppressed the dramatic rise in ethylene
production after 6 days of storage observed in
fruits stored in air. However 2% O 2 in
combination with 3-6% CO 2 caused much
higher ethylene production than the other CA
treatments. PPO activity was generally higher in
CA-stored fruits than that of fruits stored in air.
Among CA treatments, 6% CO 2 in combination
with 2-6% O 2 appeared most effective in
inhibiting browning but among these two
treatments, the use of 2% O 2 resulted to offflavor
development.
IC-245 QUALITY AND SHELF LIFE OF THAI
SWEET BASIL (Ocimum basilicum L.) SHOOTS
PACKED IN DIFFERENT PACKAGING
MATERIALS
Pathompong Penchaiya, Sirichai Kanlayanarat
International Conference