Vol.4, No.9, 477-482 (2013) Agricultural Sciences
http://dx.doi.org/10.4236/as.2013.49064
Influence of cutting size and packaging materials on
the quality of fresh-cut winter squash (var. Ajijimang)
Alexander Joel G. Gibe1, Ji Gang Kim2*
1Philippine Center for Postharvest Development and Mechanization, Munoz, Philippines
2National Institute of Horticultural and Herbal Science, Rural Development Administration, Suwon, Korea;
*Corresponding Author:
Received 9 June 2013; revised 10 July 2013; accepted 15 August 2013
Copyright © 2013 Alexander Joel G. Gibe, Ji Gang Kim. This is an open access article distributed under the Creative Commons At-
tribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is prop-
erly cited.
ABSTRACT
Winter squash (var. Ajijimang) washed in 100
mg·L−1 chlorine water and cut into 4 and 8 parts
was packed in different packaging materials, 35
µm micro-perforated P-Plus (MPP), 50 µm poly-
ethylene (PE), 80 µm nylon/PE (Ny/PE), and 90
µm PE films separately. Fresh-cut samples were
then stored at 10˚C for up to 17 days. The 35 µm
MPP having a high oxygen transmission rate
(OTR) has the most stable gas exchange ratio
while the 80 µm Ny/PE was the most unstable.
Firmness of the mesocarp remained acceptable
until the end of storage regardless of the cutting
size. Soluble solids content (SSC) remained
stable and even slightly increased to a certain
extent within 6 days. An increase in pH after
10-day storage suggested the activity of micro-
organisms within the packaging films. Strong
off-odor was detected in samples packaged in
80 µm Ny/PE film after 13 days of storage. Mold
was observed in all 1/4 cut samples on day 13
except the sample packaged with 80 µm Ny/PE
film. However, no mold was found in all 1/8 cut
samples except 35 µm MPP film on day 13. Se-
vere mold invasion was apparent on the onset of
the 17-day storage in 35 µm MPP film and 50 µm
PE film. Samples cut into 8 parts and packed in
80 µm Ny/PE and 90 µm PE films had less mold
incidence compared with other two packaging
films. Fresh-cut winter squash packaged in 90
µm PE film maintained quality with shelf-life of
10 days at 10˚C. Winter squash as fresh-cut
commodity, with the right packaging material
has the potential for longer period of storage in
retail stores.
Keywords: Fresh-Cut; Packaging Films; Shelf-Life;
Storage; Winter Squash
1. INTRODUCTION
Fresh-cut commodities are gaining popularity in Korea
for the last decade in response to an increased consumer
demand for convenient food. However, fresh-cut produce
has limited shelf-life due to rapid quality deterioration.
Quality of fresh-cut produce depends mainly on the qual-
ity of the intact product and its maintenance between
harvest and preparation of the fresh-cut products, proc-
essing method, and subsequent handling conditions [1].
Korean fresh-cut processors recognize the importance of
postharvest handling of raw materials. Processors are
aware that raw materials affect shelf-life of fresh-cut
produce [2].
In winter squash (Cucurbita maxima D.), it is vital to
wash newly harvested fruits with 200 ppm of NaOCl to
control growth of spoilage fungi before storage or proc-
essing [3]. The atmosphere surrounding fresh-cut proc-
essed vegetables likewise is extremely important to ex-
tend shelf-life. One of the most influential factors on its
composition is the permeability of the film used for
packaging [4] and the interaction between film oxygen
transmission rates (OTR) and initial headspace O2 [5].
Polyethylene (PE) is one of the most commonly used
materials in packaging. Polypropylene (PP) either un-
perforated or micro-perforated is likewise gaining popu-
larity. These films in different thickness possess a range
of gas transmission rates. Fresh-cut products that nor-
mally have elevated respiration rate require films with
high gas transmission capabilities. Even within the
package, fresh-cut vegetables are bound to deteriorate.
The main spoilage mechanisms influencing processed
products include oxidation, water loss and the activity of

A. J. G. Gibe, J. G. Kim / Agricultural Sciences 4 (2013) 477-482
478
microorganisms. Reducing the respiration rate and inhib-
iting agents of spoilage with the right packaging films
having appropriate gas transmission rates and right tem-
perature at storage would result in longer shelf-life of
packed commodity.
Green rind winter squashes commonly known as but-
tercup is a popular variety that has an appealing yellow
orange flesh with high soluble solids content (SSC) of 13
to 17% [6,7]. Cultivar Ajijimang is another green rind
winter squash more appealing for its higher SSC of 17 to
19% [8]. Ajijimang is a potential variety as fresh-cut
winter squash that may be used for ready-to-cook com-
modity. Oftentimes, the fruit is cut in halves or in quarter
covered with a 15 μm polyvinyl chloride (PVC) wrap
and displayed at 15˚C to 20˚C shelves in supermarkets in
Korea. The cut squash fruits often last for 2 to 3 days.
Optimum modified atmosphere (MA) packaging is effec-
tive in prolonging the shelf-life of fresh-cut produce by
matching film permeability for O2 and CO2 to the respi-
ration rate of the packaged commodity. The respiration
rate of fresh-cut produce is influenced by storage tem-
perature, cut size, etc. Little information exists on opti-
mum packaging film for different sized fresh-cut winter
squash. To date, vacuum packaging with Ny/PE film and
PVC wrap are utilized for covering cut winter squash. In
the present experiment, different films were assessed as
packaging material for fresh-cut winter squash (var. Aji-
jimang) prepared in different cuts.
2. MATERIALS AND METHODS
2.1. Materials, Fresh-Cut Processing, and
Packaging
Winter squash (Cucurbita maxima D., cv. Ajijimang)
grown in a plastic house in Suwon was harvested 45 days
after flowering. The fruits were conditioned for a month
for further maturation at room temperature (25˚C ± 2˚C).
The squash material was subjected to further storage of
three months at 12˚C. The average weight of intact win-
ter squash was 1.8 kg.
Three months stored Ajijimang were washed with 100
ppm of sodium hypochlorite (NaOCl) prior to cutting.
The squash was cut into quarter (1/4) and eight parts (1/8)
with seeds removed and washed with cold sterile water
to remove cellular exudates released during cutting of
winter squash. Samples were air dried for a few minutes
to remove surface water. After surface drying, fresh-cut
squash were packaged in 35 μm micro-perforated P-Plus
(MPP), 80 µm Nylon/PE (Ny/PE), 50 µm PE, or 90 µm
PE films. Fresh-cut squash samples in packages (20  25
cm) were then stored at 10˚C for up to 17 days.
Oxygen transmission rates (OTR) of 50 and 90 µm PE
films (Samkyoung Chemistry Ltd., Korea) were 1850
mL· m−2·d−1 and <1300 mL·m−2·d−1 at 10˚C [9], respec-
tively. 35 µm MPP film (Amcor, UK) with an OTR of
11,648 mL·m−2·d−1 at 10˚C and 80 µm NY/PE film (Da-
san Polybag, Korea) with an OTR of about <100
mL· m−2·d−1 at 25˚C [10] were also used to pack different
cutting sizes of winter squash.
2.2. Gas Composition Analyses
Oxygen (O2) level and accumulation of carbon dioxide
(CO2) within the package of different films containing
fresh-cut winter squash were monitored in every sam-
pling occasion. Gases were measured using a gas moni-
toring devise (PBI-Dansensor CheckMate II, Denmark)
by placing the needle directly into the packages.
2.3. Texture Measurements
In every period of analysis, samples of each cut in
triplicate representing a treatment were sliced twice
horizontally making a 5 cm-thick cut in the middle. The
top slice represented the stalk side while the bottom slice
represented the underside of the fruit where the calyx is
located. The middle slices were analyzed for firmness
while top and bottom parts were analyzed for soluble
solids content and change in pH. In each sampling occa-
sion, cut samples from the middle section of the fruit were
analyzed for firmness by using a texture analyzer (Model
TA-XT2-5, Stable Microsystems, UK). Two spots per
replicate on flat surface of sliced samples were pricked
with a cylindrical probe of 3 mm in diameter mounted on
a drill stand at 3 mm per second speed and deformation
distance of 8 mm.
2.4. Soluble Solids Content and pH
Juice samples used for soluble solids content (SSC)
and pH measurements were obtained by grating of
peeled samples and squeezing of the squash samples
from each replicate with a hand juicer. Samples were
then filtered through two layers of cotton gauze. Soluble
solids content and pH of the juice were measured at
room temperature with a digital refractometer (Model
PAL-1, Atago Co., Japan) and a pH meter (Model Titro-
Line Easy, Schott, UK), respectively.
2.5. Mold Infection and Off-Odor
Development
Incidence of mold infection was monitored throughout
the storage period. The incidence rate was calculated by
the weight of all mold infected pieces in each package,
divided by the total fresh weight of the sample and mul-
tiplied by 100 to obtain percentage. Off-odor was evalu-
ated immediately after opening the packages and scored
on a five-point scale where 0 = none; 1 = slight; 2 =
moderate; 3 = strong; and 4 = severe [5]; a score of 3 or

A. J. G. Gibe, J. G. Kim / Agricultural Sciences 4 (2013) 477-482 479
above was considered unacceptable.
3. RESULTS AND DISCUSSION
3.1. Gas Composition
Any vegetables when processed or cut will have in-
creased metabolic activity as a result of an increased sur-
face area exposed to the atmosphere. The respiration rate
increases as the cutting allows oxygen to diffuse into the
interior cells more rapidly [11]. Winter squash in two
different cuts were packaged in four different films with
different OTRs. Levels of O2 and CO2 within the pack-
age as the squash were stored at 10˚C are presented in
Figure 1. Fresh-cut winter squash packaged in 35 µm
MPP film has the most stable gas concentrations/ex-
change within the package for the entire storage period
of 17 days. This type of film has a high OTR of 11,648
mL· m−2·d−1 at 10˚C [9] and therefore allows higher gas
exchange. On the other hand, O2 concentration in pack-
age prepared with 80 µm Ny/PE film decreased rapidly
to zero from 18% while CO2 increased tremendously
within three days. This film has a very low OTR of about
<100 mL·m−2·d−1 at 25˚C [10] and level of CO2 keeps on
accumulating as storage progressed which resulted in
ballooning of the package. CO2 levels within the package
even reached 60 % in 10 days. Both 50 and 90 µm PE
films exhibited better gas exchange in the presence of
fresh-cut winter squash. Although O2 levels in those
films reached anaerobic conditions from 3 days until the
end of the storage period, ballooning was not observed
Figure 1. Levels of O
2 and CO2 concentration in fresh-cut
winter squash packaged in different films (µm) and stored at
10˚C for 17 days. Each symbol is the mean of three replicate
measurements; vertical lines represent SE. (●) 50 µm PE, (○)
90 µm PE, (▲) 35 µm MPP, (∆) 80 µm Ny/PE.
neither in the two PE films tested. However, the level of
CO2 in 50 µm PE film was lower than 90 µm PE film
because CO2 diffusion in 50 µm PE film was faster due
to a higher OTR compared to 90 µm PE film [9].
3.2. Firmness
Mesocarp of fresh-cut Ajijimang was highly firm ini-
tially at 36.9 N when preconditioned one month after
harvest. Firmness of fresh-cut winter squash was gener-
ally maintained for 10 days regardless of the cut and
packaging film (Figure 2). Slicing plant tissues generally
results in loss of firmness causing direct water loss due
to cell leakage [12]. As minimally processed vegetables
are stored, loss in turgor pressure and textural breakdown
due to enzymatic hydrolysis of cell compounds becomes
apparent [13]. The mechanism of physical spoilage in
fresh-cut winter squash is unique. The breakdown of
tissues may have been very slow due to its high starch
content. The result only suggests that firmness is not go-
ing to be a problem in winter squash as a fresh-cut com-
modity. More so, with the right packaging film and stor-
age temperature, other quality attributes will likewise be
preserved.
3.3. Soluble Solid Content and pH
Winter squashes are not only known for its excellent
nutritive value and eating quality, its seeds and flesh
likewise contain high level of Vitamin E and carotenoids,
respectively as anti-oxidants [14,15]. In the same way,
winter squash which has high sugar content is attractive.
It is therefore important that give attention to SSC as a
quality attribute of fresh-cut winter squash. Levels of
SSC in fresh-cut Ajijimang increased slightly from
17.2% to 18.6% and were maintained within 10 days of
storage (Figure 3(a)). The same trend was true with 80
µm Ny/PE film (data is not shown). Fresh-cut winter
(a) (b)
Figure 2. Firmness of fresh-cut winter squash packaged in
different films (µm) and stored at 10˚C for 17 days. Each sym-
bol is the mean of three replicate measurements; vertical lines
represent SE. (●) 50 µm PE, (○) 90 µm PE, (▲) 35 µm MPP,
(∆) 80 µm Ny/PE.

A. J. G. Gibe, J. G. Kim / Agricultural Sciences 4 (2013) 477-482
480
(a) (b)
Figure 3. Levels of soluble solid content (SSC) and pH in
fresh-cut winter squash packaged in two different films (µm)
and stored at 10˚C for 17 days. Each symbol is the mean of
three replicate measurements; vertical lines represent SE. (●)
1/4 Cut + 50 µm PE, (○) 1/4 Cut + 90 µm PE, (▲) 1/8 Cut + 50
µm PE, (∆)1/8 Cut + 80 µm PE.
squash from Ajijimang, in this case, continued to ripen
within the specified period of time. The same findings
were observed by Roura et al. [16] in diced squash (C.
moschata) packed and covered with 15 µm PE wrap
where SSC and sugar/titratable acidity ratios increased
during storage at 10˚C ± 2˚C. Soluble solids content in
fresh-cut winter squashes although initially very high
were at a plateau and started to decline after 10 days.
These findings suggest the importance of selecting pro-
per maturity and preconditioning details of squash varie-
ties as fresh-cut vegetable. It appears that packaging
films used facilitated maintenance in quality in terms of
increasing or maintaining SSC in storage. However, sur-
face drying was noticeable early in storage even within 6
days in 35 µm MPP film package. The RH during stor-
age period ranged from 45% to 60%. Increasing the RH
would improve dryness of fresh-cut surface.
It is worth interesting to note that pH of fresh-cut win-
ter squash increased slowly during storage. Increase in
pH became prominent after 10 days of storage (Figure
3(b)) signifying higher microbial activity which is con-
sistent with the visible growth of fungi on day 13 for
winter squash packed in 50 µm PE film (Figure 5) and
possible bacterial accumulation or other fermenting or-
ganisms in squash packed in 90 µm PE film.
3.4. Spoilage and Off-Odor
The main causes of deterioration mechanisms influ-
encing processed products include oxidation, water loss
and the activity of microorganisms. All three mecha-
nisms were observed in fresh-cut winter squash depend-
ing on the films used. 35 µm MPP film is capable of ex-
changing more balanced gases however surface of
fresh-cut winter squash dries up within the package. Ap-
pearance of mold spots in fresh-cut squash packaged in
35 µm MPP film was apparent on day 10 (data is not
(a) (b)
Figure 4. Decay incidence of fresh-cut winter squash packaged
in different films stored at 10˚C for 13 and 17 days. Each sym-
bol is the mean of three replicate measurements; vertical lines
represent SE. (□) 50 µm PE, (■) 90 µm PE, (■) 35 µm MPP, (■)
80 µm Ny/PE.
shown) while the activity of molds in fresh-cut squash
packaged in other three films occurred later. No mold
activity was recorded in fresh-cut winter squash packed
with 80 µm Ny/PE film on day 13 in both 1/4 and 1/8 cut
samples (Figure 4). High CO2 levels in both 90 µm PE
and 80 µm Ny/PE film suppressed fungal growth for at
least or over 10 days. Suppression of fungi in MPP film,
on the other hand, was less than 10 days. A decrease in
temperature has a tremendous effect on lowering respire-
tion rates, thereby lowering microbial activity. Moreover,
its affects on permeability of gases through the package-
ing films also slow microbial growth [17]. Occurrence of
mold growth was evident in either 90 µm PE or 80 µm
Ny/PE film.
Off-odor development was not detected in fresh-cut
squash packed in 35 µm MPP film until 6 days (Figure
5). On the other hand, the absence of O2 inside the pack-
age for other three films encouraged fermentative me-
tabolism resulting in the development of off-odor within
3 days in squash packaged in 80 Ny/PE film (Figure 5).
Sour smell was produced and became stronger in 6 days
as the package is opened. However, the sour smell dis-
appears once the fresh-cut winter squash are aerated for a
few minutes. It also worth noting that off-odor develop-
ment was much intense in fresh-cut winter squash cut
into 8 parts than 4 parts in 50 µm PE, 90 µm PE, and 35
µm MPP film. Higher number of cuts probably increased
respiration which can cause more off-odor development
of samples packaged in only 80 µm Ny/PE film. Both 80
µm Ny/PE and 90 µm PE films was best in suppressing
respiration by reducing O2 levels to almost zero and
similarly increasing CO2 levels within three days (Figure
1). This condition suppressed sensitivity of fresh-cut
winter squash of further ripening and the growth of mi-
croorganisms [11]. The CO2 levels on day 3 were 12 to
14% in 90 µm PE film and 30 to 40% in 80 µm Ny/PE
film that was more than enough to cause such suppres-
sion. In these conditions, off-odor development in winter

A. J. G. Gibe, J. G. Kim / Agricultural Sciences 4 (2013) 477-482 481
Figure 5. Off-odor development in fresh-cut winter squash
packaged in four different films (µm) and stored at 10˚C for 17
days. Off-odor was scored using a 0 to 4 hedonic scale where 0
= no off odor; 1 = slight; 2 = moderate; 3 = strong and 4 = se-
vere. Each symbol is the mean of three replicate measurements.
(●) 50 µm PE, (○) 90 µm PE, (▲) 35 µm MPP, (∆) 80 µm
Ny/PE.
squash in the early days of storage may not be a product
of microbial action since no signs of physical deteriora-
tion are apparent.
The shelf-life of fresh-cut winter squash packaged in
35 µm MPP was 6 days at 10˚C regardless of cutting size.
However, both 1/4 and 1/8 cut samples packaged with 90
µm PE films had longer than 10 days of shelf-life though
off-odor development was detected in the samples. The
samples had less mold incidence and the off-odor was
acceptable until 10 to 13 days in 1/4 and 1/8 cut treat-
ments, respectively.
4. CONCLUSION
Packaging film affected package atmosphere, mold in-
cidence, and off-odor development of fresh-cut winter
squash during the 10˚C storage. Firmness, SSC, and PH
of fresh-cut winter squash remained acceptable for at
least 10 days regardless of the cutting size. Mold was
detected in all packaging films after 17 days of storage.
However, less mold incidence was found in samples cut
into 8 parts and packed with 80 µm Ny/PE and 90 µm PE
films compared with 35 µm MPP film and 50 µm PE
film. Strong off-odor was detected in samples packaged
in 80 µm Ny/PE film after 13 days of storage. Therefore,
fresh-cut winter squash packaged with 90 µm PE film
maintained better quality with 10 to 13 days of shelf-life
in 1/4 and 1/8 cut, respectively at 10˚C.
5. ACKNOWLEDGEMENTS
The authors would like to acknowledge Rural Development Admini-
stration, Republic of Korea for supporting this project financially.
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