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One
of the problems consistently raised by pili farmers, traders
and processors is the need to prolong the shelf life of pili
nuts.
The problem
is hindering the further growth of the pili industry and possible
penetration of export markets. This compelled Dr. Marissa
C. Nate-Estrella, of Bicol University to study some packaging
techniques for pili nuts.
Estrella
evaluated the use of vacuum packaging, benzoic acid and edible
coatings during her dissertation, which was financially assisted
by the Department of Agriculture-Bureau of Agriculture Resources
(DA-BAR) and National Research Council of the Philippines
(NRCP).
During
the study, pili nut kernels were packed in 5 mils thick transparent
polyethylene bags (PEB) and stored under ordinary room condition.
Each package contained 400 grams of dried pili nuts. Samples
were taken every four months and quality changes were determined
through microbiological, physical, chemical (rancidity) tests
and sensory evaluation.
Results
showed that vacuum packed pili nuts and those treated with
benzoic acid (0.1%) were protected from fungi and were not
rancid even after 11 months of storage under ordinary room
conditions. The combination of benzoic acid and vacuum packaging
significantly reduced fungal occurrence by almost 20-30% in
stored pili kernels.
Edible
coatings (chitosan and carboxymethylcellulose) for pili nuts
were also tried. Recently, edible films and coatings have
been receiving interest in the food industry because of their
possible advantages over non-edible packaging. They can replace
polysterene items or plastic-plus-foil packages and can be
cost effective.
Chitosan
has been reported for its anti-microbial properties while
carboxymethylcellulose (CMC) has been reported to effectively
maintain the shelf life of pecan nuts.
In this
study, chitosan was found to be ineffective while kernels
treated with carboxymethylcellulose at 1% were not rancid
and moldy after 4 months of storage.
With
these findings, pili nut traders and processors can have a
number of technological options in extending the keeping quality
of pili nuts. (Marissa C. Nate-Estrella, BCARRD RACO Coordinator).
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