Effect of natural and synthetic fruit coatings on the postharvest quality of kinnow mandarins

Abstract

Natural products are more preferred by consumers now-a-days over the synthetic ones. Therefore a natural fruit coating was developed from natural ingredients (shellac, rosin, gum arabic, water and ethanol from sugar industry) without ammonia or morphine as an alternative to the synthetic coatings. So this research was devised to compare the effects of this newly developed natural fruit coating (with 9% total solids) with those of synthetic one (polyethylene based ammonia containing wax with 21% total solids) on the postharvest quality of kinnow (Citrus reticulata Blanco) mandarins. The kinnow mandarins were either coated with natural or synthetic fruit coatings or were left uncoated and stored at 52°C with 85-90% relative humidity for 63 days with five replications for each treatment. The results showed that both fruit coatings significantly (p<0.05) delayed changes in physiological loss in weight, firmness, ascorbic acid and overall sensory quality during the storage period as compared to uncoated fruits, while non-significant (p>0.05) changes in total soluble solids and fruit acidity were recorded for all the treatments. Furthermore the difference between natural and synthetic fruit coatings was non-significant (p>0.05). Therefore, it could be suggested that the natural fruit coating is a good alternative of the synthetic fruit coating. © 2015, Int. Comm. of Agricultural and Biosystems Engineering. All rights reserved.

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March, 2015 AgricEngInt: CIGR Journal Open access at http://www.cigrjournal.org Vol. 17, No. 1 197
Effect of natural and synthetic fruit coatings on the postharvest
quality of kinnow mandarins
Muhammad A. Ali1, Adnan Zulfiqar1*, Atta M. Arif1, Abdul-Rahim Khan1,
Zafar Iqbal2and Muhammad A. Khan3
(1.Post Harvest Research Centre,Ayub Agricultural Research Institute, Faisalabad 38000, Pakistan
2. Oilseeds Research Institute, Ayub Agricultural Research Institute, Faisalabad 38000, Pakistan
3. Department of Food Engineering, Faculty of Agricultural Engineering & Technology, University of Agriculture, Faisalabad 38000,
Pakistan.）
Abstract:Natural products are more preferred by consumers now-a-days over the synthetic ones. Therefore a natural fruit
coating was developed from natural ingredients (shellac, rosin, gum arabic, water and ethanol from sugar industry) without
ammonia or morphine as an alternative to the synthetic coatings. So this research was devised to compare the effects of this
newly developed natural fruit coating (with 9% total solids) with those of synthetic one (polyethylene based ammonia
containing wax with 21% total solids) on the postharvest quality of kinnow (Citrus reticulata Blanco) mandarins. The kinnow
mandarins were either coated with natural or synthetic fruit coatings or were left uncoated and stored at 5 2°C with 85-90%
relative humidity for 63 days with five replications for each treatment. The results showed that both fruit coatings
significantly (p<0.05) delayed changes in physiological loss in weight, firmness, ascorbic acid and overall sensory quality
during the storage period as compared to uncoated fruits, while non-significant (p>0.05) changes in total soluble solids and
fruit acidity were recorded for all the treatments. Furthermore the difference between natural and synthetic fruit coatings was
non-significant (p>0.05). Therefore, it could be suggested that the natural fruit coating is a good alternative of the synthetic
fruit coating.
Keywords:Natural fruit coating, kinnow mandarins, synthetic fruit coating, morpholine, ammonia, ethanol
Citation: Ali, M. A., A. Zulfiqar, A. M. Arif, A. Khan, Z. Iqbal, and M. A. Khan. 2015. Effect of natural and synthetic
fruit coatings on the postharvest quality of kinnow mandarins. AgricEngInt: CIGR Journal, 17(1):197-206.
1 Introduction1
Pakistan is the largest producer of kinnow (Citrus
reticulata Blanco) mandarins (Razzaq et al., 2013) and
almost 90% of the kinnow mandarin produced in Pakistan
is exported (Mustafa and Ahmad, 2006). Harvested
kinnows are typically brought to a packinghouse to begin
the steps of preparing the fruit for market; washing,
coating, grading, packing, storage and transportation
(Naseer, 2010). During the washing process of fruit
preparation, most of the natural wax on fruit skin is
removed. It is essential that the natural waxes be replaced
Received date: 2014-05-06 Accepted date: 2015-02-07
*Corresponding author:Adnan Zulfiqar, Post Harvest Research
Centre; Ayub Agricultural Research Institute. Email:
adnanzulfiqar1036@gmail.com
by different coating materials. Various types of citrus
wax formulations are available (Boonyakiat et al., 2012).
Pakistan imports all of the fruit coating to apply on
kinnow mandarins (PARB, 2013) which is all synthetic
(mainly polyethylene based which is a petroleum
by-product). But consumer trends are leaning towards
more natural products, and petroleum-based waxes, such
as polyethylene and paraffin, are becoming increasingly
unpopular and restricted in use (Hernandez E, 1994).
Edible coatings made from natural waxes, resins and
polysaccharides represent an environmentally ideal
package since they are biodegradable, can be consumed
with the packaged product and the main ingredients are
produced from renewable resources, in contrast to
paraffin, mineral oil, oxidized polyethylene, and plastics,
which are manufactured from a limited supply of fossil

198 March, 2015 Agric Eng Int: CIGR Journal Open access at http://www.cigrjournal.org Vol. 17, No. 1
fuels (Baldwin, 1994). Ammonia is also commonly used
in these synthetic coatings meant for fresh fruits, but it
has certain disadvantages. Ammonia-based
microemulsions are difficult to prepare because ammonia
is highly volatile and its vapors are unpleasant, toxic and
can cause false alarms in packinghouses that use its odor
as a warning that the ammonia based refrigeration system
is leaking (Hagenmaier, 2004). Considering the growing
interest in healthier, safer, more natural and
environment-friendly products, natural coatings have
been developed in recent years to avoid the use of
synthetic waxes (FreshPlaza, 2013). The consumer
acceptability of the coated product should have been the
focus of the studies on edible coatings (Olivas et al.,
2008). Reading the need of time, PostHarvest Research
Centre (PHRC), Faisalabad, developed a natural fruit
coating (NFC) from natural ingredients and without
ammonia as an alternative to the synthetic fruit coating
(based on oxidized polyethylene and containing
ammonia). Therefore, the objective of current research
was to compare the effects of the newly developed NFC
with those of synthetic one on the post-harvest quality of
kinnow (Citrus reticulata Blanco) mandarin stored at low
temperature.
2 Materials and methods
2.1 Preparation of NFC
The NFC was prepared by simple atmospheric method
with the following ingredients; shellac (2%), rosin (2%),
gum acacia (1%), sodium hydroxide (2%), castor oil
(1.5%), ethanol (26%), emulsifier Palsgaard® (0.5%)
and distilled water (65%). The total solids of the final
formulation were 9%. NFC was prepared in the following
way; Sodium hydroxide was added to distilled water to
make it alkaline. 70% of the total ethanol (26%) was also
added to this alkaline water. This alkaline water was then
divided into three equal parts. Shellac, rosin and gum
acacia were added separately to each part of this alkaline
water. After dissolving each ingredient separately, they
were combined to make an alkaline mixture. Castor oil
was heated to approximately 75°C and then emulsifier
Palsgaard® was added to it. The remaining 30% ethanol
of the formulation was added to the emulsified oil, which
was then added to the alkaline mixture. Gentle stirring
was done throughout the mixing process to ensure
uniformity of the mixture. The regulatory status of
different ingredients of the finalized formulation is shown
in Table 1.
2.2 Choice of commercial wax
For comparison, fruit coating waterwaxFomesa
(Fruitech, s.l., Valencia, Spain) was chosen amongst
commercial waxes because it is widely used by the citrus
industry of Pakistan and amongst its major ingredients is
oxidized polyethylene (a synthetic material). The
composition of Fomesa used in present study was:
oxidized polyethylene wax: 10%, glycerol ester of wood
rosin: 8% and ammonium hydroxide: 2% (as mentioned
on label).
Table 1Regulatory status of ingredients in the natural
fruit coating (NFC).
Name of Ingredient
Regulatory Status
FDA
EU
Castor oil
21CFR
172.876
E1503
Rosin
21CFR
172.210
E915a
Shellac
21CFR
175.300
E904
Gum acacia
21CFR
172.780
E414
Ethanol
21CFR
184.1239
E1510
Sodium Hydroxide
21CFR
184.1763
E524
Note: FDA: Food-and-Drug-Administration; EU: European Union; CFR:
Code-of-Federal-Regulation; aSANHA: South-African-National-Halal-Authority.
2.3 Treatment of fruit
The kinnow mandarins were grown in Chak No. 85SB,
District Sargodha (Punjab, Pakistan). These were
harvested with buttons in the morning, then transported in
a covered vehicle to processing factory where washing
was done firstly with tap water and then with the
fungicidal solution of thiabendazole (Textar® 60-T by
Tecnidex, Valencia, Spain) at the rate of 2000ppm in
separate washing tanks. Subsequent drying was carried

March, 2015 Effect of natural and synthetic fruit coatings on the postharvest quality of kinnow mandarins Vol. 17, No. 1 199
out in hot air tunnel at 50ºC for 1.50 minutes. NFC and
Fomesa were applied separately to kinnow mandarins by
a combination of spraying and brushing methods. The
rate of coating was maintained at the rate of 1L per Tonne
(1mL per Kg) of fruit because this amount of coating was
officially recommended by the manufacturer (Fruitech, s.
l., Valencia, Spain) and was typical of the amount of
coating widely practiced by the citrus industry of Pakistan.
Additional fungicide imazalil (DECCOZIL®50 by Decco
Italia, Italy) at the rate of 1L per 200 L of wax was added
to the Fomesa wax while no additional fungicide was
added to NFC at the time of application. After waxing,
kinnow mandarins were dried in a hot air tunnel at 55ºC
for 1.75 minutes. After manual packing in the corrugated
card boxes of 10 Kg capacity, the kinnow mandarins were
pre-cooled to internal temperature of 5ºC by the blast air
in a reefer container and then transported by the same (at
5±2ºC; 85-90% relative humidity) to cold chambers of
PHRC, Faisalabad and stored at 5±2ºC with 85%-90%
relative humidity for 63 days.
2.4 Physical analysis
Physiological loss in weight (PLW) was determined
by separately packing and tagging the samples in net bags.
Individual packs of kinnow mandarins were weighed by a
digital weighing balance (Sartorius GM 1501, Precision
Weighing Balances, Bradford, MA, US) at the beginning
of the study and thereafter weekly until the end of storage
period. The result was expressed as percentage of weight
loss relative to the initial weight (taken as 100%)
according to the Equation 1 given below:
%
=  

×100 (1)
The firmness of kinnow mandarins was determined by
using a digital penetrometer (model 53205, TR di Turoni,
Forli, Italy) and the results were expressed as N.
2.5 Bio-chemical analysis
Total soluble solids (TSS) of kinnow mandarins were
determined by using a digital refractometer (HI 96801,
Hanna Instruments, Inc., Romania). Fruit acidity was
determined by using digital fruit acidity meter
(GMK-835F Perfect, Germany). The ascorbic acid
contents of kinnow mandarins were determined according
to the method as described by AOAC (2000).
The ascorbic acid contents were computed according
to the Equation 2given below:
mg/100 
=1 × 1 × 
××1×100 (2)
Where, R = mL of dye used in titration against 1 mL
standard ascorbic acid solution (1 mg ascorbic acid /mL);
R1= mL of dye used in titration against V1 mL of aliquot;
V= Volume of aliquot made by 0.4% oxalic acid; W= mL
sample; V1= mL aliquot taken for titration.
Samples were injected through Gas Solid
Chromatography (GSC) to determine the ethanol contents
according to the method described by Perez et al., (2002)
described below:
Sample was prepared by extraction of kinnow
mandarin juice by citrus juice reamer (Philips) in
pre-sterilized 500 mL glass jars. Five mL juice was taken
and transferred to 10 mL glass vials with crimp top caps
and silicon septum seals for the removal of head space
from the glass vials. The vials were kept at 20°C for 1
hour, followed by 25 minutes at 30°C to attain the
equilibrium in the glass vials. Five mL head space vapors
were injected into the gas chromatograph (Perkin Elmer
3920) using pointed gases tight syringe (Hamilton, USA)
under following conditions:
Gas chromatograph: Perkin Elmer (3920), Perkin
Elmer Life and Analytical Sciences, Wellesley, USA
Recorder:Shimadzu (C-R4A), Shimadzu Corporation,
Kyoto, Japan
Column:Chromosorb glass column having 2 meters
(length) x 2 mm (internal Diameter) supplied by
Chromosorb, SKC, Inc., Pennsylvania, USA

200 March, 2015 Agric Eng Int: CIGR Journal Open access at http://www.cigrjournal.org Vol. 17, No. 1
Column temperature:150°C
Injector temperature: 160°C
Detector:Flame ionization detector (FID)
Detector Temperature: 250°C
The ethanol contents were determined in all samples
by the peak area comparison, retention time and peak
height of the ethanol standards (99.9% Merck). The
results were expressed as mg/kg.
2.6 Sensory analysis
A panel, consisting of five trained professional judges
(Five replicates) of the research and development staff,
from the PostHarvest Research Center, Ayub Agricultural
Research Institute, Faisalabad, Pakistan, conducted the
sensory analysis on weekly basis for gloss, color, flavor
and overall acceptability by using 9-point hedonic scale
according to the method as described by Lee et al., (2003).
2.7 Statistics
The experiment was laid out under the scheme of
two-factorial completely randomized design (CRD). Five
replicates were made for each treatment with five fruits
per treatment. The data were subjected to analysis of
variance (ANOVA) using Statistix 8.1 software and
treatment means were compared using Least Significance
Difference (LSD) Test at 5% level of significance
(p≤0.05) (Steel et al., 1997).
3 Results and discussion
3.1Physical analysis
The control of weight loss is important in that most
fresh produce is sold by weight (Khout et al., 2007).
Physiological loss in weight (PLW) of uncoated kinnows
and the kinnows coated with the NFC and Fomesa was
recorded at 9.71%, 6.15% and 6.12% respectively after
63 days of storage (Figure 1). The coated kinnows were
significantly different (p<0.05) from the uncoated
kinnows while those coated with the NFC and Fomesa
were at statistical parity concerning the PLW. The loss of
fruit weight is mainly caused by fruit transpiration in
which water moves out and results in wilted rind and a
shriveled appearance (Wills et al., 2007).
Water transfer is restricted by coatings that act as
barriers and protect fruit skin, thus delaying dehydration
(Hernandez-Munoz et al., 2008). Both coatings reduced
weight loss percentage almost equally as reported earlier
by Mahajan et al., (2013) who stated that wax coating
successfully reduced weight loss percentage in kinnow
fruits during cold storage.
Firmness of kinnows decreased gradually (Figure 2)
as the storage period progressed, but the kinnows coated
with the NFC retained maximum fruit firmness (Start:
17.95 N→ End: 9.91 N) followed by the kinnows coated
with Fomesa (Start: 17.85 N→ End: 9.51 N) while the
least firmness (Start: 17.85 N→ End: 4.80 N) was
recorded for the kinnows which were uncoated.
Figure 1 Mean values with SE for the effect of NFC and Fomesa on the physiological loss in weight (PLW) of
kinnow mandarins stored at 5±2°C, (p< 0.05)
-2
0
2
4
6
8
10
12
0
7
14
21
28
35
42
49
56
63
PLW /%
Storage Time /Days
Uncoated
NFC
Fomesa

March, 2015 Effect of natural and synthetic fruit coatings on the postharvest quality of kinnow mandarins Vol. 17, No. 1 201
Fruit firmness diminishes as the degree of ripening
increases due to the action of pectolytic enzymes
(Muramatsu et al., 1996). Coatings sustain fruit firmness
by mechanisms similar to the controlled atmosphere and
modified atmosphere packaging i.e., by decreasing
respiration and transpiration, slowing ripening and
senescence, and delaying degradation of cell wall (Bai et
al., 2009; Baldwin, 1994). Similar observations were
made in an earlier study on wax treated kinnow fruits by
Mahajan et al., (2013).
3.2Bio-chemical analysis
There was a non-significant increase in the TSS of all
the treatments as the storage period progressed (Figure 3).
The highest increase was observed for the uncoated
kinnow mandarins (from 9.81% to 10.51%) followed by
the kinnow mandarins coated with the NFC (from 9.82%
to 10.41%) and Fomesa (from 9.83% to 10.42%).
Figure 2 Mean values with SE for the effect of NFC and Fomesa on the firmness of kinnow mandarins stored
at 5±2°C, (p< 0.05)
0
5
10
15
20
25
0
7
14
21
28
35
42
49
56
63
Firmness /N
Storage Time /Days
Uncoated
NFC
Fomesa
Figure 3 Mean values with SE for the effect of NFC and Fomesa on the TSS of kinnow mandarins stored at
5±2°C, (p< 0.05)
0
2
4
6
8
10
12
0
7
14
21
28
35
42
49
56
63
Total Soluble Solids /%
Storage Time /Days
Uncoated
SCM
Teycer

202 March, 2015 Agric Eng Int: CIGR Journal Open access at http://www.cigrjournal.org Vol. 17, No. 1
The results showed that wax coating has no significant
effect on the TSS of kinnow mandarins. The slight
increase in TSS of all the treatments might be due to the
conversion of organic acids to sugars through
gluconeogenesis (Echeverria & Ismail, 1987), and the
solubilization of cell wall constituents by galactosidases
and glucosidases present in citrus fruit (Burns, 1990).
Similar non-significant effect of different coatings on
TSS was observed in Sai Nam Pheung tangerines by
Seehanam et al., (2010).
The fruit acidity continuously decreased with the
increasing storage period for all the treatments (Figure 4)
but the decrease in acidity was slightly less for the coated
kinnow mandarins (from 1.01% to 0.81% for NFC and
from 1.03% to 0.82% for Fomesa) as compared to the
uncoated ones (from 1.02% to 0.79%). The decreasing
trend in the fruit acidity with the increasing storage
period might be due to the oxidation of organic acid and
its further utilization in metabolic processes (Obenland et
al., 2011). The results of present study coincide with
those of Seehanam at al., (2010) and Boonyakiat et al.,
(2012), who also found a non-significant decrease in the
fruit acidity of waxed and unwaxed “Sai Nam Peung”
tangerine fruit during storage.
A gradual decline in the ascorbic acid contents of the
kinnow mandarin was observed for all the treatments
(Figure 5), but the decline was significantly less in the
coated (both natural and synthetic) kinnow mandarins as
compared to the uncoated ones. The maximum value was
recorded for the kinnow mandarins coated with Fomesa
(26.06%) followed by those coated with NFC (26.05%)
while the least value was recorded for the uncoated
kinnow mandarins (24.77%). Ascorbic acid is highly
sensitive to oxygen and is readily oxidized when exposed
to it (Hussain et al., 2006). Coatings create a modified
atmosphere and limit the exchange of gases thus reducing
the amount of oxygen reaching to the interior of fruit that
prevents the oxidation of ascorbic acid (Baldwin et al.,
1994). These results are at par with the previous findings
of studies which found that the ascorbic acid contents of
waxed and unwaxed tangerines (Arekemase and Oyeyiola,
2011) and kinnow fruits (Mahajan et al., 2013) decreased
during storage at low temperature and that the coated
fruits had higher ascorbic acid contents than the uncoated
ones (Mahajan et al., 2005).
Figure 4 Mean values with SE for the effect of NFC and Fomesa on the acidity of kinnow mandarins stored at
5±2°C, (p< 0.05)
0
0.2
0.4
0.6
0.8
1
1.2
0
7
14
21
28
35
42
49
56
63
Acidity /%
Storage TIme /Days
Uncoated
NFC
Fomesa

March, 2015 Effect of natural and synthetic fruit coatings on the postharvest quality of kinnow mandarins Vol. 17, No. 1 203
Ethanol contents exhibit great variations in citrus
during storage owing to their volatile nature (Baldwin et
al., 1995). The ethanol contents in kinnow mandarins
increased linearly as a function of storage (Figure 6).The
ethanol contents of coated and uncoated kinnow
mandarins were significantly different, with higher values
recorded for both of the coated kinnow mandarins as
compared to the uncoated ones.
At start of the study, the mean values were not
significantly different and ranged from 126 to 129 mg/kg
for all the treatments but at the end of the study, these
values were significantly different with 175 mg/kg for
uncoated kinnow mandarins while 207 and 204 mg/kg for
the NFC and Fomesa coated kinnow mandarins
respectively. The level of ethanol contents observed in
both of the coated kinnow mandarins did not have an
adverse impact on the taste/flavor of the mandarins as
observed earlier by Curtis (1988) probably due to the fact
that oxidized polyethylene is relatively permeable to
gases (Bai and Plotto, 2011) and the permeability of
Figure 5 Mean values with SE for the effect of NFC and Fomesa on ascorbic acid contents of kinnow mandarins
stored at 5±2°C, (p< 0.05)
Figure 6 Mean values with SE for the effect of NFC and Fomesa on ethanol contents of kinnow mandarins
stored at 5±2°C, (p< 0.05)
23
23.5
24
24.5
25
25.5
26
26.5
27
27.5
0
7
14
21
28
35
42
49
56
63
Ascorbic Acid /(mg/100 mL)
Storage Time /Days
Uncoated
NFC
Fomesa
0
50
100
150
200
250
0
7
14
21
28
35
42
49
56
63
Ethanol Contents/ (mg/Kg)
Storage Time /Days
Uncoated
NFC
Fomesa

204 March, 2015 Agric Eng Int: CIGR Journal Open access at http://www.cigrjournal.org Vol. 17, No. 1
shellac-type coatings increases at high humidity levels
that are used for commercial citrus storage (Hagenmaier
and Shaw, 1992). Furthermore, the ethanol contents of
the NFC coated kinnow mandarins were not significantly
different from the synthetic Fomesa coated kinnow
mandarins. The higher ethanol contents for the coated
kinnow mandarins might be due to the creation of a
modified atmosphere created by fruit coatings that
significantly affects the ethanol levels (Baldwin et al.,
1995). The same increasing trend in ethanol contents was
also observed by Hagenmaier (2002) for coated Valencia
oranges and citrus fruits by Curtis (1988) during storage.
3.3Sensory analysis
The primary reason coatings are applied to citrus
fruits is to improve appearance by imparting gloss and in
that way improve marketability. Appearance can be
affected by surface dehydration resulting in whitening,
waxiness, and discoloration Selective coating materials
can reduce moisture loss, control surface dehydration and
discoloration, delay the surface whitening, and enhance
the glossiness of fruit surfaces (Lin and Zhao, 2007). The
kinnow mandarins coated with NFC and Fomesa showed
good initial gloss as compared to the uncoated ones
(Table 2) as previously reported for „Mor‟ mandarins
(Porat et al., 2005). The gloss provided by NFC (shellac
and rosin) was slightly higher than that provided by
Fomesa (polyethylene based) though it was
non-significant as reported earlier by Hagenmaier and
Baker (1994) that the shellac and rosin based coatings
provide more gloss than coatings made from waxes such
as polyethylene or carnauba wax.
The gloss decreased as the storage period progressed
(Table 2) as previously observed for coated grapefruits by
Arif et al., (2013). Similar pattern was observed for other
sensory parameters viz. color, flavor and overall
acceptability (Table 2). Hagenmaier (2002) has reported
that higher rates of weight loss decrease the color scores.
Both of the coatings reduced the rate of weight loss in the
present study thus minimizing the negative changes on
the sensory qualities. The present results are supported by
the earlier findings of Seehanam et al., (2010) which said
that the coated Tangerine fruits showed higher gloss and
better visual appearance results as compared with the
non-coated fruit. The flavor of the coated kinnow
mandarins was recorded better than the uncoated ones as
reported earlier by Curtis (1988), who applied a
polysaccharide based fruit coating (Semperfresh) in
combination with shellac to citrus fruits and recorded
higher firmness, good flavor and increased ethanol levels
as compared to uncoated ones.
Table 2 Means of scores for the sensory attributes for comparison of NFC and Fomesa on kinnow mandarins
stored at 5±2ºC.
Attribute
Treatment
Storage Time ,days
0
7
14
21
28
35
42
49
56
63
Gloss
Uncoated
7.90a
7.75b
7.50c
7.25d
7.00e
6.75f
6.50g
6.10i
5.75j
5.25l
NFC
8.05a
8.05a
8.00a
8.00a
8.00a
8.00a
7.75b
7.65b
7.50c
7.25d
Fomesa
8.00a
8.00a
8.00a
8.00a
8.00a
7.95a
7.75b
7.60b
7.50c
7.25d
Color
Uncoated
7.90a
7.75b
7.60b
7.50c
7.25d
7.00e
6.50g
6.10i
5.50k
5.25l
NFC
8.00a
8.00a
8.00a
8.00a
8.00a
7.75b
7.70b
7.60b
7.50c
7.25d
Fomesa
8.00a
8.00a
8.00a
8.00a
8.00a
7.75b
7.70b
7.60b
7.50c
7.25d
Flavor
Uncoated
8.00a
7.90a
7.80a
7.75b
7.50c
7.25d
7.00e
6.50g
6.25h
5.50k
NFC
8.00a
8.00a
8.00a
8.00a
7.90a
7.80a
7.75b
7.50c
7.25d
7.00e
Fomesa
8.00a
8.00a
8.00a
8.00a
7.90a
7.80a
7.75b
7.55b
7.25d
7.00e
Overall Acceptability
Uncoated
7.90a
7.80a
7.65b
7.50c
7.25d
7.00e
6.65g
6.25h
5.85j
5.35k
NFC
8.00a
8.00a
8.00a
8.00a
7.95a
7.85a
7.75b
7.60b
7.40c
7.15d
Fomesa
8.00a
8.00a
8.00a
8.00a
8.95a
7.85a
7.75b
7.60b
7.40c
7.15d
NFC: Natural-Fruit-Coating.
(Means in a column with different superscripts are not the same, p < 0.05, LSD)

March, 2015 Effect of natural and synthetic fruit coatings on the postharvest quality of kinnow mandarins Vol. 17, No. 1 205
4Conclusion
The newly developed NFC prepared by the PHRC,
Ayub Agricultural Research Institute, Faisalabad proved
up to the mark in efficiency. This NFC came up with
non-significant differences against Fomesa in all the
tested physical, bio-chemical and sensory parameters. It
has an additional benefit of being the natural one and
ammonia free over Fomesa which is synthetic and
contains ammonia. It can safely be a good alternative of
Fomesa for postharvest application on kinnow mandarins.
Acknowledgment
This study was funded by the Punjab Agricultural
Research Board (PARB) under PARB project number
152.
References
Arekemase, M. O., and G. P. Oyeyiola.2011. Effects of skin
coating materials, storage conditions on pH, titratable
acidity and vitamin c contents of citrus fruits stored at room
and refrigerated temperatures. Journal of Asian Scientific
Research, 1 (8): 376-389.
Arif, A. M., A. Zulfiqar, M. A. Ali, S. Parveen, A. R. Khan, and Z.
Iqbal. 2013. Effect of oil-based edible skin-coating material
on the post-harvest quality of grapefruits (Citrus paradisi)
stored at low temperature. Research and Reviews: Journal
of Food Science and Technology, 2 (1): 16-23.
AOAC.2000. Official methods of analysis of Association of
Official Analytical Chemists (16th ed). Arlington:
Association of Official Analytical Chemists.
Bai, J., and A.Plotto.2011. Coatings for fresh fruits and vegetables.
In Edible coatings and films to improve food quality, 2nd
edition, ch. 7, 185-242.eds. E. A. Baldwin, R. Hagenmaier
and J. Bai. New York: CRC Press.
Bai, J., R. K. Prange, and P. A. Toivonen.2009. Pome fruits. In
Modified and controlled atmospheres for the storage,
transportation, and packaging of horticultural
commodities.ed. E. Yahia. E. ch. 12, 267–285. Boca
Raton, Florida: CRC Press.
Baldwin, E. A. 1994. Edible coatings for fresh fruits and vegetables:
past, present, and future. In Edible coatings and films to
improve food quality.eds. J. M. Krochta, E. A. Baldwin and
M. O. Nisperos-Carriedo. ch. 2, 25-64. Lancaster Basel:
Technomic Publishing Company, Inc.
Baldwin, E. A., M. Nisperos-Carriedo, P. E. Shaw, and J. K.
Burns.1995. Effect of coatings and prolonged storage
conditions on fresh orange flavor volatiles, degrees brix and
ascorbic acid levels. Journal of Agricultural and Food
Chemistry, 43(5): 1321-1331.
Boonyakiat, D., P. Seehanam, and M. Rattanapanone.2012. Effect
of fruit size and coating material on quality of tangerine
fruit cv. Sai Nam Phueng.CMU Journal of Natural
Sciences, 11(2): 213-230.
Burns, J. K. 1990.α- and β-Galactosidase activities in juice vesicles
of stored Valencia oranges. Phytochemistry, 29(8):
2425-2429.
Curtis, G. J. 1988. Some experiments with edible coatings on the
long-term storage of citrus fruits. Proceedings of 6th
International Citrus Congress, 3: 1514–1520.
Echeverria, E. and Ismail, M. 1987. Changes in sugars and acids of
citrus fruits during storage. Proceedings of the Florida
State Horticultural Society. 100: 50-52.
FreshPlaza.2013. Spain: Naturcover, the new natural coating for
stone fruit. Available at:
http://www.freshplaza.com/news_detail.asp?id=106695
(accessed 12 March 2013).
Hagenmaier, R. D. 2002. The flavor of mandarin hybrids with
different coatings. Postharvest Biology and Technology, 24
(1): 79-87.
Hagenmaier, R. D. 2004. Fruit coatings containing ammonia
instead of morpholine. Proceedings of Florida State
Horticultural Society, 117:396-402.
Hagenmaier, R. D., and P. E. Shaw.1992. Gas permeability of fruit
coating waxes. Journal of American Society of
Horticultural Sciences, 117(1):105–109.
Hagenmaier, R. D., and R. A. Baker.1994. Internal gases, ethanol
content and gloss of citrus fruit coated with polyethylene
wax, carnauba wax, shellac or resin at different application
levels. Proceedings of Florida State Horticultural Society.
107:261–265.
Hernandez, E.1994. Edible coatings from lipids and resins. In
Edible coatings and films to improve food quality.ed. J. M.
Krochta, E. A. Baldwin and M. O. Nisperos-Carriedo.
279-303. Lancaster Basel: Technomic Publishing Company,
Inc.
Hernandez-Munoz, P., E. Almenar, V. Valle, D. Velez, and R.
Gavara.2008. Effect of chitosan coating combined with
postharvest calcium treatment on strawberry
(Fragaria×ananassa) quality during refrigerated storage.
Food Chemistry, 110 (2): 428-435
Hussain, I., M. Ishaq, I. Rehman, I. Ahmad, and M.
Shakirullah.2006. Comparative studies of vitamin C
contents in different processed and unprocessed milk

206 March, 2015 Agric Eng Int: CIGR Journal Open access at http://www.cigrjournal.org Vol. 17, No. 1
samples. Journal of Chemists Society of Pakistan, 28(3):
236-240.
Khout, M. P., M. A. Ritenour, and J. J. Salvatoe.2007. BASF
Freshseal® CHC helps keep packed tomatoes firmer and
fresher longer. Proceedings of Florida State Horticultural
Society, 120:217–221.
Lee, J. Y., H. J. Park, C. Y. Lee, and W. Y. Choi.2003. Extending
shelf-life of minimally processed apples with edible
coatings and antibrowning
agents.Lebensmittel-Wissenschaft and Technology,
36(3):323-329.
Lin, D., and Y. Zhao.2007. Innovation in development and
application of edible coatings for fresh and minimally
processed fruits and vegetables. Comprehensive Reviews in
Food Science and Food Safety, 6(3): 60–75.
Mahajan, B. V. C., A. S. Dhatt, and K. S. Sandhu.2005. Effect of
different post harvest treatments on the storage life of
Kinnow. Journal of Food Science and Technology, 42(4):
269-299.
Mahajan, B. V. C., W. S. Dhillon and M. Kumar. 2013. Effect of
surface coatings on the shelf life and quality of kinnow
fruits during storage.Journal of Postharvest Technology,
1(1): 008-015.
Muramatsu, N., T. Takahara, K. Kojima, and T. Ogata.1996.
Relationship between texture and cell wall polysaccharides
of fruit flesh in various species of citrus. HortScience. 31(1):
114–116.
Mustafa, K. and B. Ahmad.2006.An econometric model for
forecasting export of kinnow from Pakistan. International
Journal of Agriculture and Biology, 8(4):459-462.
Naseer, M. 2010. Report on export of kinnow. Trade Development
Authority of Pakistan. Government of Pakistan.Available at:
http://www.tdap.gov.pk/doc_reports/TDAP_REPORT_ON
_EXPORT_%20OF_KINNOW.pdf (accessed 10 March
2013).
Obenland, D., S. Collin, B. Mackey, J. Sievert, and M. L.
Arpaia.2011. Storage temperature and time influences
sensory quality of mandarins by altering soluble solids,
acidity and aroma volatile composition. Postharvest
Biology and Technology, 59(2): 187-193.
Olivas, G. I., J. E. Davila-Avina, N. A. Salas-Salazar, and F. J.
Molina.2008. Use of edible coatings to preserve the quality
of fruits and vegetables during storage.Stewart Postharvest
Review, 4 (3): 1–10.
Perez, M. B., C. Rojas, and M. A. Del-Rio. 2002. Effect of lipid
type and amount of edible hydroxyl propyl methylcellulose
lipid composite coatings used to protect postharvest quality
of Mandarins cv Fortune.Journal of Food Science,
67(8):2903-2910.
Porat, R., B. Weiss, L. Cohen, A. Daus, and A. Biton.2005. Effects
of polyethylene wax content and composition on taste,
quality, and emission of off-flavor volatiles in „Mor‟
mandarins. Postharvest Biology and Technology, 38 (3):
262–268.
PARB. 2013. Available at:
http://www.parb.gop.pk/Commercialization/Brochure-Proje
ct152.pdf (accessed 10 March 2013).
Razzaq, K., A. S. Khan, A. U. Malik, M. Shahid, and Sanaullah.
2013. Foliar application of zinc influences the leaf mineral
status, vegetative and reproductive growth, yield and fruit
quality of „kinnow‟ mandarin.Journal of Plant Nutrition,
36 (10):1479-1495.
Seehanam, P., D. Boonyakiat and N. Rattanapanone. 2010.
Physiological and physicochemical responses of „Sai Nam
Phueng‟ tangerine to commercial coatings. Hortscience,
45(4): 605–609.
R. G. D. Steel, J. H., Torrie, and D. A. Dickey.1997.Principles and
Procedures of Statistics: A Biological Approach (3rded).
New York: McGraw Hill Book Inc.
Wills, R., B. McGlasson, D. Graham, and D. Joyce. 2007.
Postharvest: An Introduction to the Physiology and
Handling of Fruit, Vegetables and Ornamentals. (5thed).
Oxfordshire: CABI, pp. 227.