American Journal of Food Science and Nutrition Research
2015; 2(2): 67-69
Published online March 20, 2015 (http://www.openscienceonline.com/journal/fsnr)
Effect of Plastic Cling Film on the Shelf Life of
Carrot
Raees-ul Haq*, Kamlesh Prasad
Department of Food Engineering and Technology, Sant Longowal Institute of Engineering & Technology, Sangrur, India
Email address
raeeswani@gmail.com (Raees-ul H.)
To cite this article
Raees-ul Haq, Kamlesh Prasad. Effect of Plastic Cling Film on the Shelf Life of Carrot. American Journal of Food Science and Nutrition
Research. Vol. 2, No. 2, 2015, pp. 67-69.
Abstract
Carrot is an important crop with a wide range of colored roots with high post harvest losses due to perishable nature of the
roots. The perishable nature of the roots is enhanced by bruising, microbes and water loss. The continuous water loss affects
the cell structure rendering it a flaccid that results in the production of the unacceptable root types. The shelf life increase with
the use of simple low cost packaging cling films has been studied in the present work under the refrigeration conditions. The
results yielded a positive response towards the use of cling films over the roots in order decrease the losses incurred due to
escaping tendency of moisture.
Keywords
Carrot, Package, Cling Film, Shelf Life, Weight Loss
1. Introduction
Fruits and vegetables are highly perishable plant
commodities due to the presence of high amounts of moisture.
The moisture content is directly related to perish-ability of
the products as the higher water activity favors the growth of
micro-organisms. The moisture content of fruits and
vegetables is amongst the high moisture food products
present in this universe with a water content ranging to about
95%. The main causes of the fruit and vegetable spoilage in
addition to mechanical injuries are bacteria and fungi
requiring a water activity (αw) >0.7 for their normal
metabolism. Fruits and vegetables are ideal substrates for
these microbes to flourish as they are high in moisture and
contain the basic nutrients necessary for their growth.
Carrot is an important root crop that grows well in the cool
regions and is cultivated throughout the world. These conical
root crops belong to family Umbelliferea with diverse
colored varieties found throughout the globe and the orange
colored dominate the production worldwide. Carrots are
regarded as veg-fruit commodities containing appreciable
amounts of sugars, vitamins, minerals and various bioactive
components ([1], [3], [4], [8], [9] and [10]).
The
consumption of carrots is popular due to the economic
sources of pro vitamin A. the deficiency of vitamin A is the
main reason of child deaths in developing countries. The
juice extraction from carrots upon hydraulic pressing resulted
in the formation of juice with low suspended solids [5]. Dried
carrots have also been used for production of functional
fractions [6].
The carrot roots are among the diverse colored crops
ranging from black to red [7]. The orange colored carrots are
found almost all round the year and considering the
importance of these roots in health and nutrition their postharvest losses are needed to slow down in the interest of the
consumer and producer. The moisture loss in addition to
microbial contamination is the main parameter affecting the
quality of the root crop. The continuous daily moisture loss
renders the basic crunchy structure as flaccid and like a
semidried product whose quality isn’t acceptable among the
consumers and this directly or indirectly affects the producer
of the crop. The bringing down the post harvest losses is
important to avoid loss of the food to spoilage that directly
benefits both producer as well as consumer. The present
study was conducted to study the effect of moisture loss in
the quality of the orange carrot roots.
2. Materials and Methods
The fresh carrots were sorted, washed and divided into two
groups one of them wrapped tightly with LDPE films (Fig.1)
and kept under refrigeration storage along with the another
68
Raees-ul Haq and Kamlesh Prasad: Effect of Plastic Cling Film on the Shelf Life of Carrot
carrot group without any packaging. Ten different carrots
were wrapped with the package film and the same numbered
were stored without any packaging. The carrots were kept
under the refrigeration conditions for a period of one week (7
days) and were daily recorded for the moisture loss, if any. A
balance of 0.001 precision from Ishida MB-150 was
employed in determining the weights of the different samples.
The daily moisture loss was calculated by subtracting the
weight of the sample with the previous recorded (a day
before) sample weight. The daily moisture loss was
represented as % daily moisture loss calculated for the day 2
with the following equation
100
%Daily moisture loss (DM) =
(1)
Where, W1 is the previous recorded weight (a day before)
W2 denotes the current sample weight (weight recorded at
observed day)
The total moisture is almost similar to the daily moisture
loss except for the fact that the former calculates the moisture
loss from all the previously passed days. More ever the total
moisture loss at each calculated step is corresponded with the
loss of initial (first wt. of carrot) sample weight and the
equation for calculating the % total moisture loss is
%
100
In comparison to unwrapped roots the wrapped ones under
the same conditions had a very low comparative average
daily weight loss (1.18%) than the roots without packing.
The percent daily moisture loss and percent total moisture
loss are given in Table 1as calculated from equation 1 and 2.
The average daily moisture loss is highest at the 9th day of
storage period where as its minimum value is shown by day
3rd of storage period in case of the wrapped carrots. The case
for the unwrapped roots is a different scenario with the
storage period resulting in the decrease of the daily moisture
content. The values are highest at the starting periods that
slow down with the storage period under refrigeration. The
lowest and highest value in case of unwrapped roots is shown
respectively by 12th and 2nd day of refrigeration storage
period. The percent total moisture loss increases in both the
cases with the increase more prominent in unwrapped ones
than the wrapped ones. The weight loss is almost linear in
case of wrapped carrots where as the loss is exponential up to
5th day of storage and thereafter almost behaves as linear in
unwrapped roots (Fig. 2).
(2)
Where, “(TM)n” is the % moisture loss at the nth storage
day
“Xi” is the initial sample weight
“Xn” is weight at the nth storage day
“n” is storage period (1 to 13 days)
Moisture Content: The moisture content of the carrot was
determined as per the standard method of AOAC 1995 [2].
Ten grams of the fresh grated sample was placed in a hot air
oven maintained at 105 oC until the sample comes to a
constant weight or the successive weights of the dried sample
didn’t show significant difference in weight loss. The
moisture content was calculated as % water loss (wet basis)
and the experiments were completed in triplicates.
1
2
1
100
M1 and M2 are the respective weights of fresh sample and
dry samples.
3. Results and Discussion
The total moisture content as determined by the standard
AOAC procedure is 91%. The gradual moisture loss from the
un-wrapped carrot root is significantly higher than the water
loss through the wrapped carrots. The daily weight loss of the
roots was described as the moisture loss and is calculated
daily after a gap of 24 hours.
The shelf life of carrots without wrapped films is
comparatively very low and every day under refrigeration
storage contributed to a weight loss of approximately 11.4%.
Fig. 1. Packaged and Unpackaged carrots at different days of storage
Figure 2 is the graphical depiction of moisture loss /
weight loss of the orange roots (packaged and unpackaged)
with storage period. The depiction shows the slope in case of
the unpackaged roots is much more prominent than the
packaged roots. The quality deterioration of the roots (packed
and unpacked) due to the moisture loss within refrigeration
American Journal of Food Science and Nutrition Research 2015; 2(2): 67-69
storage is presented in figure 1. The gradual decrease in the
quality of unpacked roots is very much evident from the
figure and also the contribution of the packaging film
certainly increased the shelf life of carrots. The cling package
acts as a potent barrier for the extra moisture loss that will
otherwise reduce the quality of the roots. The package
maintains the moisture loss that does not significantly affect
the quality. The use of the simple packaging films on the
carrots must be encouraged in order to extend the shelf life of
the fresh roots both in retail and household practices. The
weight loss under the packaged films is also evident by
observing the package that was initially tightly wrapped and
now loosely depicting the decrease in the size owing to
moisture loss. The loose film is most prominent at the tip of
the conical root (Fig 1).
69
of the color and body-form by the packed roots as compared
to unpacked ones whose color is dull and lost while the bodyform is like a dried product. The above effects on the
unpacked roots have deteriorated the quality parameters to
unacceptability levels and there is no way that these roots can
be utilized for the human kitchen purposes. The need of the
packing carrots needs to be supported to deliver the
provitamin A form roots to a wide consumer range with
elevated shelf life periods.
References
[1]
Algarra, M., Fernandes, A., Mateus, N., de Freitas, V., da Silva,
J.C. and Casado, J. (2014). Anthocyanin profile and
antioxidant capacity of black carrots (Daucus carota L. ssp.
sativus var. atrorubens Alef.) from Cuevas Bajas, Spain.
Journal of Food Composition and Analysis, 33: 71–76.
[2]
AOAC international. (1995). Official methods of analysis of
AOAC International. AOAC International.
[3]
Assous, M.T.M., Abdel-Hady, M.M. and Medany, G.M.
(2014). Evaluation of red pigment extracted from purple
carrots and its utilization as antioxidant and natural food
colorants. Annals of Agricultural Science, 59, 1–7.
[4]
Chun, J., Lee, J., Yea, L., Exler, J. and Eitenmiller, R.R.
(2006). Tocopherol and tocotrienol contents of raw and
processed fruits and vegetables in the United States diet.
Journal of Food Composition and Analysis, 19: 196–204.
[5]
Haq, Raees-ul., Singh, Y., Kumar, P. and Prasad, K. (2013a).
Quality of dehydrated carrot shreds as affected by partial juice
extraction through hydraulic press. International Journal of
Agriculture and Food Science Technology, 4(4): 331-336.
[6]
Haq, Raees-ul., Singh, Y., Kumar, P. and Prasad, K. (2013b).
Development of dehydrated carrot powder fractions as
functional ingredient, Proceedings of 6th International
Conference on Fermented foods, health status and social wellbeing, organized by Swedish South Asian Network on
Fermented Foods and in collaboration with Hildur on
December 6-7, 2013 at Anand Agricultural University, Anand
p 94-95.
[7]
Haq, Raees-ul. and Prasad, K. (2014). Carrot-one of the most
nutritious root crops. Ingredients South Asia, 1-15th October, p.
94-95.
[8]
Kotecha, P.M., B.B. Desai and D.L. Madhavi. (1998). Carrot.
In: Salunke, D.K. and Kadam, S.S. (eds.). Handbook of
Vegetable Science and Technology: Production, Composition,
Storage and Processing. Marcel Dekker, New York, pp.119140.
4. Conclusion
[9]
The evidence of the packaging films in extending the shelf
life of carrots brings out the possibilities of its use on
commercial scale. The roots whether packed individually or
in groups certainly increases the shelf life from days to weeks.
The use of packaging is further supported due to the retaining
Thomas, S.C.L. (2008). Vegetables and Fruits: Nutritional
and Therapeutic Values. Taylor and Francis Group, CRC Press.
[10] USDA. (2012). Agriculture Handbook: Composition of Foods:
Vegetables and Vegetables Products, Raw, Processed,
Prepared. U.S. Government Printing Office, Washington, DC.
Fig. 2. Graphical representation of weight loss with storage period.
Table 1. % Daily and Total moisture loss of carrot roots wrapped and
unwrapped under refrigeration storage.
Day
1
2
3
4
5
6
7
8
9
1
11
12
13
Packaged (moisture loss)
Total (%)
Daily (%)
0
0
1.103
1.103
2.156
1.065
3.188
1.054
4.214
1.060
5.322
1.157
6.435
1.175
7.533
1.174
8.673
1.233
9.857
1.297
11.025
1.295
12.165
1.281
13.288
1.278
Unpackaged (moisture loss)
Total (%)
Daily (%)
0
0
19.248
19.248
36.446
21.297
45.547
14.320
53.735
15.038
59.057
11.502
63.561
11.002
67.242
10.101
70.254
9.196
72.662
8.095
74.716
7.514
76.109
5.510
77.075
4.040