1
Effectiveness of chitosan-clay coating as postharvest treatments on some chemical and
2
mechanical traits during cold storage of lemon
3
4
Ebrahim Taghinezhad*
5
Moghan College of Agriculture and Natural Resources, University of Mohaghegh Ardabili,
6
Ardabil, Iran
7
*Corresponding author: [email protected]
8
9
ABSTRACT
10
Lemon is one of the most important citrus fruits. It is cultivated in many countries including
11
of Iran. In this research, nano-composite composition of chitosan-clay was prepared and
12
characterization of nano-composite was investigated using X-ray diffraction (XRD)
13
instrument. According to XRD results, manufactured composition was nano-composite. Then,
14
the effect of nano-composite coating of chitosan-clay on some quality properties of lemon
15
was investigated during cold storage. After coating, the chemical properties (pH, total soluble
16
solid (TSS(%)), titratable acid (TA(%)) and mechanical properties (firmness, shear and punch
17
force) of lemon fruit were measured. Results showed that the amount of pH and TSS
18
increased significantly (p<0.05) during storage. Coated samples had the lowest value of TSS
19
(from 8.83 to 10.67%) and punch force (from 20.88 to 27.64 N) and the highest value of pH
20
(from 5.88 to 6.39), TA (from 2.5 to 2.97%), firmness (from 254.38 to 260.13 N) and peel
21
shear force (from 70.73 to 84.01 N) as compared to uncoated samples. Furthermore, coated
22
samples would be the lowest weight loss during storage. Therefore, quality properties of fruit
23
were maintained by using of nano-composite coating during storage.
24
Keywords: XRD, Lemon, quality properties, Chitosan-clay
25
1
26
INTRODUCTION
27
Citrus is the most important fruit tree crop on the world. Considering the annual production of
28
more than 2.7 million tones, it occupies first place among horticultural crops in Iran (FAO,
29
2013). Among the citrus, lemon is the third most important citrus species after orange and
30
Mandarin with about 0.6 million tones (FAO, 2013). It is a subtropical fruit of high
31
commercial value on the international fruit market. It has a split skin and very juicy which
32
easily can suffer damage by molds and environmental (Chien et al., 2007).
33
Similar to deciduous fruit, lemon fruits are not held in the cold storage and must be harvested
34
with delay from the tree. On the other hand, it is usually maintained on the tree until transfer
35
to market. However, under special circumstances such as low physical disorders, controlled
36
humidity and environment, application of coating material, disturb carbon dioxide and
37
employing ethylene in cold storage, the shelf life can be increased (Miller, 1946).
38
Nanotechnology has many applications in agriculture science including recycling of waste
39
from agricultural products and maintaining of product quality during storage (Moraru et al.,
40
2003; Chen et al., 2006; Chaudhry et al., 2008; Das et al., 2009; Moraru et al., 2009;
41
Dasgupta et al., 2015). Nano-coating and nano-composites are a way to increase of fruit
42
shelf life (De Azeredo, 2009). Some Iranian researchers used the nano-zeolite coating for
43
increasing of fruit shelf life during cold storage (Rezaei Kalaj et al., 2009). The main reason
44
for applying of coating's fruit is to control loss of fruit juice during storage. Juice loss usually
45
occurs at the vapor phase. Water vapor permeability describes the movement of water vapor
46
inside layer covered in different temperatures and moistures (McHugh and Krochta, 1994). In
47
recent years, many layers and edible coatings are commonly used for candies, fruit and fresh
48
vegetables and processed meats (Baldwin, 2007; Arnon et al., 2015). Natural wax was used
49
for coating of fruit and vegetables in America, England and Australia in 1930s. Furthermore,
50
the construction and development of edible coatings for using of meat were produced in the
2
51
late 1950 s at the first time (Baldwin, 2007; Kerch, 2015). Corn starch coating at different
52
concentration (1%, 2%, 3%, 4%, 5% and 6%) were used to study the storage life and post-
53
harvest quality of Assam lemon fruits (Ghosh et al., 2015). They suggested that coating with
54
4% corn starch was found very effective in fruit maintaining. Other researchers showed that
55
coating of citrus (Murcott tangor) by chitosan increased postharvest quality and shelf life of
56
fruit and had antifungal activity (Chien et al., 2007). Chitosan is a non-toxic, natural and
57
biodegradable polysaccharide (Sajomsang, 2010). It is derived from chitin and it is well
58
known as an anti-fungicide (Devlieghere et al., 2004). Chitosan film has been used as coating
59
of crops such as mandarin, strawberries and fresh fruit (Fornes et al., 2005; Ribeiro et al.,
60
2007; Kerch, 2015).
61
The effects of chitosan and clay concentrations on the barrier, mechanical, optical and thermal
62
properties of chitosan films containing clay micro/nanoparticles in view of their possible use
63
in the food and medical industries was investigated by researchers (Casariego et al., 2009;
64
Giannakas et al., 2014; Giannakas et al., 2016). Also, Khoshtaghaza and Taghinezhad (2016)
65
studied the effect of particle Nano coating on quality properties of Thomson orange during
66
storage (KhoshTaghaza and Taghinezhad, 2016). According their results, nano coating
67
increased orange resistance to fungal diseases and retained peel color and texture inner
68
strength of fruit during storage. Advantages of chitosan-clay components are the delay in the
69
loss of moisture; reduce in evaporation and breathing rate and changes in material tissue
70
properties (Muzzarelli et al., 1990; Sajomsang, 2010). Nowadays studies are focused on the
71
expansion of technology to improve food quality and its durability. To our knowledge, no
72
researchers have studied the effect of chitosan-clay coating on Lemon quality. Therefore the
73
aim of this study was to investigate the effect of nano-composite coating of chitosan-clay on
74
lemon quality attributes during cold storage.
75
3
76
MATERIAL AND METHODS
77
Raw material
78
Sweet Lemon's fruits (20 kg) were purchased randomly from a citrus orchard in Sari, Iran
79
(January, 2016). The samples immediately brought into the laboratory of at the department of
80
food science and technology for storage after necessary treatments.
81
82
Chitosan- clay coating
83
Chitosan and clay were bought from Sigma Aldrich Company with low molecular weight
84
(43KD) and from Sefid Sang Aligoodarz Company in Iran, respectively. Chitosan- clay
85
solution was prepared by dissolving 20 g chitosan and 10 g clay in 50 ml of glacial acetic
86
acid, 900 ml distilled water, 1 g tween 80 and 0.1 M NaoH to pH 5 until was produced 1 L
87
chitosan solution (Casariego et al., 2009). Fruit were washed with tap water and then dried in
88
the shade for a few minutes. The fruit were dipped in chitosan-clay composition by hand. The
89
surface coating on fruit was dried at environment temperature (12oC) along 12 h then fruit
90
were stored at about 8oC and 75-80% relative humidity for 63 d. Experiments were carried out
91
at four storage time, 0, 21, 42 and 63 d, with coated and uncoated samples. The chemical and
92
mechanical properties of lemon fruit were measured at zero times of storage (beginning) and
93
an interval of 21 d in triplicate.
94
95
X-ray diffraction (XRD) characterization
96
The structure of chitosan-clay nano-composite was evaluated by XRD measurement. X-ray
97
diffraction (XRD) instrument (Siemens, D500, Germany) was applied using Ni-filtered Cu-
98
kαradiation with diffraction angle (2θ) from 2 to 20 degree, scan rate of 1.2°/min and step size
99
of 0.02.
100
4
101
Chemical properties
102
After peeling and removal of seed, juice was extracted from the pulp through a mechanical
103
juice extractor and strained. The chemical parameters of fruit juice such as total soluble solid
104
(TSS) (%), titratable acid (TA) (%) and pH of lemon juice were measured. TSS was
105
determined by digital refractometer (model Atago- ATC- 20 E, made in Japan) in the range 0
106
- 20% (Sánchez-Moreno, 2002).
107
TA was estimated by the method described by Sánchez-Moreno (2002). The pH of the
108
solution was measured by pH meter (Model Inolab pH 720, made in Germany).
109
110
Mechanical properties
111
Mechanical properties are comprised the compression, punch and peel shear test. The
112
mechanical properties of samples were measured using Instron machine (Hounsfield Co.,
113
England, and Model 4400). The mechanical test was conducted at a cross-head speed of 60
114
mm/min. Furthermore, six replications were performed for each treatment and the average of
115
the measured forces was calculated (Singh and Reddy, 2006).
116
Compression test: The samples were placed on a flat plate and pressed with a movable plate
117
and a 500 N load cell fixed parallel to the base. The movable plate was shifted 35 mm from
118
the contact point (Churchill et al., 1980; Singh and Reddy, 2006). Passable axis from fruit
119
stem was vertical in the movement direction (Churchill et al., 1980). The force at rupture
120
(first breaking) was recorded as the firmness force for each run.
121
122
Punch test
123
The samples were placed on a flat plate and punched with a steel rod 4.8 mm in diameter
124
connected to the load cell of Instron. Steel rod was penetrated 10 mm in fruit (Singh and
125
Reddy, 2006).
5
126
Shear test
127
The shear test was conducted on 12 peel pieces with 6 cm2 surface areas. Peel piece was
128
placed between two aluminum plates. Each plate had a 2.6 cm diameter hole in the central.
129
Steel pins held the plates in place. A cylindrical knife-edges cutter 2.54 cm in diameter
130
attached to the load cell of Instron was used to shear the peel pieces (Fidelibus et al., 2002).
131
132
Weight losses (%)
133
Fruit were weighted periodically by digital scale with an accuracy of 0.001 gr (Model
134
GE2102). Weight losses percentage is calculated according relation (1):
135
Weight losses percentage=
(fruit wei ght before test - fruit weig ht after test )
 100 (1)
fruit weig ht before test
136
137
Statistical analysis
138
A full-factorial design was used for experimental analysis. The obtained data were analyzed
139
by SPSS software (Version 15; SPSS Inc., Chicago, IL, USA) and Excel (2011, USA).
140
Duncan’s multiple range tests were used to determine the differences between treatments’
141
mean values at a confidence level of 95%. All experiments were performed in triplicate and
142
mean values are reported with standard deviations.
143
144
RESULTS AND DISCUSSION
145
XRD analysis of chitosan-clay nanocomposites
146
The determination of a nano-composite has been based on XRD results (Reddy, 2011). Due to
147
ease of usage and availability, XRD is mostly used for nano-composites structure
148
characterization. Fig. 1, showed a sharp peak at 2θ=7° (i.e., d-spacing of 15.85 Å). This
149
conclusion is in agreement with the results of other investigators (Darder et al., 2003). They
150
the interlayer spacing of clay particles and clay particles at chitosan-clay nanocomposite (2%
6
151
chitosan, 1% caly) reported 12 and 20 Å, respectively. So, the insertion of clay into the
152
chitosan increases the d-spacing of clay particles for this research.
153
154
Chemical properties
155
pH
156
Fig. (2) shows pH of fruit juice for coated and uncoated samples during storage. pH increased
157
(from 3.21 to 3.63) for all of treatments during storage. These findings are in agreement with
158
the reported observations by Martín-Diana et al. (2009). The pH value only was significant
159
(p<0.05) at the first three weeks of storage, but it turned to not significant at the remained
160
storage period for two treatments. The results showed that the pH of coated samples had been
161
higher than the uncoated samples. It shows that coated samples induced increasing in the pH
162
of lemon juice. Furthermore, pH of juices has been associated to microbial spoilage (Del Caro
163
et al., 2004; Cortés et al., 2008). The pH value of juice was raised by using of chitosan- clay
164
coating. Pervious researchers had used different concentrations of chitosan for the fortifying
165
orange juice (Martín-Diana et al., 2009). They indicated that pH values of samples increased
166
during storage time. Therefore, Chitosan–clay coating could increase the pH of fruit juice and
167
prevents the fruit quality reduction.
168
169
Total soluble solid (TSS)
170
Fig. (3) shows the amount of TSS of lemon fruit juice for coated and uncoated samples during
171
storage. TSS of coated samples significantly (p<0.05) increased, but no significant difference
172
in TSS were detected for uncoated samples during storage. These findings are in agreement
173
with the reported observations by Ghosh et al., (2015). The effect of maintenance various
174
conditions, including of cold and local storage was investigated (Zareei et al., 2005). They
175
resulted that the TSS values of fruit juice for cold storage were lower than local storage
7
176
because fruit peel moisture was protected in cold storage. The loss of soluble solids during the
177
storage period is as natural as sugars which are the primary constituent of the soluble solids
178
content of a product, consumed by respiration and used for the metabolic activities of the
179
fruits (Özden and Bayindirli, 2002).
180
TSS values were about 8.83 to 11.07% in the uncoated fruit. It was higher than the
181
coated samples (from 8.83 to 10.67%). The effect of coating on value of orange TSS was
182
studied by Baldwin et al., (1995). The results showed that coated fruit had slightly lower TSS
183
than uncoated fruit. They had resulted that the permeability of uncoated fruit were higher than
184
coated fruit. So lemon fruit with chitosan- clay coating may have the lowest respiration and
185
moisture loss. Therefore, coated treatment by using of chitosan- clay protected the fruit
186
quality.
187
188
Total acidity (TA)
189
The TA values of the lemon juice for coated and uncoated samples are shown in Fig. 4. The
190
TA of coated and uncoated samples decreased during storage between 2.97 to 2.5% and
191
between 2.97 to 2.33%, respectively. According to Fig. 4, the TA values for coated samples
192
were higher than uncoated samples. The low level of TA in uncoated samples as compared to
193
coated samples suggests that the chitosan-clay coating delayed ripening by providing a
194
transparent coating around the fruit. It is also considered that coatings reduce the rate of
195
respiration and may therefore delay the utilization of organic acids (Yaman and Bayoιndιrlι,
196
2002). Furthermore, decreasing of the TA values during storage is in agreement with the
197
reported observations by El-Zeftawi (1976) which he showed that the TA and TSS of fruit
198
juice decreased and increased, respectively during storage (El-Zeftawi, 1976). So the coated
199
samples had lower TA than uncoated samples due to high TSS.
200
8
201
Mechanical properties
202
Cells and tissues of fruit are arranged relative to the fruit axis. Therefore, orientation of the
203
fruit relative to the applied force can affect its mechanical behavior (Harker et al., 2010). By
204
placing the fruit axis perpendicular to the orientation of the plate movement, the mechanical
205
properties such as firmness, punch and cutting force were measured.
206
207
Compression test
208
The firmness force amount of Lemon's fruits for coated and uncoated samples is shown in
209
Fig. 5. The firmness force decreased during storage for coated and uncoated samples. These
210
findings were in agreement with the data reported by Singh and Reddy (2006) for oranges.
211
Equations 1 and 2 show the relationship between the fruit firmness (F (N)) and storage
212
time (t (s)) for coated samples (equation (1)) and uncoated samples (equation (2)) by a linear
213
equation.
214
F = -0.1115t+ 260.76
R2 = 0.93
(1)
215
F = -1.5756t + 252.07
R2 = 0.91
(2)
216
The firmness force for the coated lemons (260.13 to 252.98 N) was generally measured higher
217
than uncoated samples (260.13 to 165.18 N) during storage, but there was no significant
218
difference in the firmness of all samples. This might be because of a metabolic delay.
219
Consequently, fruit softening was also delayed, at the coated fruit (Singh and Reddy, 2006).
220
Thus, when storage was prolonged, coatings were more effective in maintaining of lemon
221
firmness.
222
223
Punch test
224
Punch force of lemon fruit is revealed in Fig. 6, for coated and uncoated samples. The values
225
of punch force decreased from 27.64 to 25.34 N and 27.64 to 20.88 N for uncoated and coated
9
226
samples, respectively. No significant changes (p>0.05) were observed in punch force for
227
uncoated fruit, but it changed significantly (p<0.05) at the first three weeks of storage for
228
coated samples. The punch force of coated samples was lower than uncoated samples. The
229
similar results were also explained by Singh and Reddy (2006).
230
231
Shear test
232
Peel shear force of lemon fruit during storage is depicted in Fig. 7. It decreased significantly
233
(p<0.05) for coated samples, but there was found no significant difference in peel shear force
234
of uncoated samples. The values of peel shear force for uncoated sample was significantly
235
(p<0.05) less than coated samples.
236
Intercellular spaces result in less cell wall material per volume of tissue and less
237
contact area between cells. Both factors could cause the tissue to be less resistant to shear
238
stress (Harker et al., 2010). Therefore, uncoated samples had the lowest stiffness because of
239
less contact area between cells.
240
241
Weight loss
242
A comparison of the weight loss of all treated fruit (Fig. 8) exhibited the weight loss in all
243
samples significantly increased (p<0.05). After 63 days of storage, the coated samples had
244
5.28% weight loss, as compared to 12.17% weight loss in uncoated samples. Weight loss is
245
caused by evaporation of water from the fruit (Amarante et al., 2001). According to
246
investigation of chemical properties in this paper, low weight loss in common coated fruit
247
may be occurred very low respiration of fruit. Thus this coating not could protect fruit quality.
248
Clearly, relatively lower weight loss in coated samples as compared to uncoated samples,
249
contributed to maintaining better quality of fruit during storage.
250
10
251
CONCLUSION
252
Investigation of lemon quality properties showed that coated samples had the higher pH and
253
TA and lower TSS than uncoated samples. Thus coated samples have the lowest weight loss.
254
Furthermore, studying of mechanical properties showed that coated samples had the highest
255
firmness and peel shear force and the lowest punch force. The coated samples have more
256
resistance than uncoated samples. Finally, this study suggests that coating of chitosan-clay
257
extends the shelf life and preserves the quality during storage.
258
259
260
261
ACKNOWLEDGEMENTS
The author would like to thank to thank University of Mohaghegh Ardabili for financial
supports.
262
263
REFRENCES
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
Amarante, C., Banks, N. H. and Ganesh, S. 2001. Relationship between character of skin cover of coated pears
and permeance to water vapour and gases. Postharvest Biology and Technology. 21(3): 291-301.
Arnon, H., Granit, R., Porat, R. and Poverenov, E. 2015. Development of polysaccharides-based edible coatings
for citrus fruits: A layer-by-layer approach. Food Chemistry. 166: 465-472.
Baldwin, E. A. 2007. Surface treatments and edible coatings in food preservation. Handbook of Food
Preservation. 21: 478-508.
Casariego, A., Souza, B., Cerqueira, M., Teixeira, J., Cruz, L., Díaz, R. and Vicente, A. 2009. Chitosan/clay
films' properties as affected by biopolymer and clay micro/nanoparticles' concentrations. Food
Hydrocolloids. 23(7): 1895-1902.
Chaudhry, Q., Scotter, M., Blackburn, J., Ross, B., Boxall, A., Castle, L., Aitken, R. and Watkins, R. 2008.
Applications and implications of nanotechnologies for the food sector. Food Additives and
Contaminants. 25(3): 241-258.
Chen, H., Weiss, J. and Shahidi, F. 2006. Nanotechnology in nutraceuticals and functional foods. Food
Technology. 60(3): 30-36.
Chien, P.-J., Sheu, F. and Lin, H.-R. 2007. Coating citrus (Murcott tangor) fruit with low molecular weight
chitosan increases postharvest quality and shelf life. Food Chemistry. 100(3): 1160-1164.
Churchill, D., Sumner, H. and Whitney, J. 1980. Peel strength properties of three orange varieties. Transactions
of American Society of Agriculture Engineering. 23: 173-176.
Cortés, C., Esteve, M. J. and Frígola, A. 2008. Color of orange juice treated by high intensity pulsed electric
fields during refrigerated storage and comparison with pasteurized juice. Food Control. 19(2): 151-158.
Darder, M., Colilla, M. and Ruiz-Hitzky, E. 2003. Biopolymer−Clay Nanocomposites Based on Chitosan
Intercalated in Montmorillonite. Chemistry of Materials. 15(20): 3774-3780.
Das, M., Saxena, N. and Dwivedi, P. D. 2009. Emerging trends of nanoparticles application in food technology:
Safety paradigms. Nanotoxicology. 3(1): 10-18.
Dasgupta, N., Ranjan, S., Mundekkad, D., Ramalingam, C., Shanker, R. and Kumar, A. 2015. Nanotechnology
in agro-food: From field to plate. Food Research International. 69: 381-400.
De Azeredo, H. M. 2009. Nanocomposites for food packaging applications. Food Research International. 42(9):
1240-1253.
11
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
Del Caro, A., Piga, A., Vacca, V. and Agabbio, M. 2004. Changes of flavonoids, vitamin C and antioxidant
capacity in minimally processed citrus segments and juices during storage. Food Chemistry. 84(1): 99105.
Devlieghere, F., Vermeulen, A. and Debevere, J. 2004. Chitosan: antimicrobial activity, interactions with food
components and applicability as a coating on fruit and vegetables. Food Microbiology. 21(6): 703-714.
El-Zeftawi, B. 1976. Cool storage to improve the quality of Valencia oranges [Australia]. Journal of
Horticultural Science (UK). 51(3): 411-418.
FAO. 2013. Citrus fruit, Production quantity, Annual Statistics. . Commodities and Trade Division, FAO of the
UN, Rome. Retrieved on August 2, 2016 from FAO Website: http://faostat3.fao.org/download/Q/QC/E.
Fidelibus, M., Teixeira, A. and Davies, F. 2002. Mechanical properties of orange peel and fruit treated preharvest with gibberellic acid. Transactions of American Society of Agriculture Engineering. 45(4):
1057-1062.
Fornes, F., Almela, V., Abad, M. and Agustí, M. 2005. Low concentrations of chitosan coating reduce water spot
incidence and delay peel pigmentation of Clementine mandarin fruit. Journal of the Science of Food
and Agriculture. 85(7): 1105-1112.
Ghosh, A., Dey, K. and Bhowmick, N. 2015. Effect of corn starch coating on storage life and quality of Assam
lemon (Citrus limon Burn.). Journal Crop and Weed. 11(1): 101-107.
Giannakas, A., Grigoriadi, K., Leontiou, A., Barkoula, N.-M. and Ladavos, A. 2014. Preparation,
characterization, mechanical and barrier properties investigation of chitosan–clay nanocomposites.
Carbohydrate Polymers. 108: 103-111.
Giannakas, A., Vlacha, M., Salmas, C., Leontiou, A., Katapodis, P., Stamatis, H., Barkoula, N.-M. and Ladavos,
A. 2016. Preparation, characterization, mechanical, barrier and antimicrobial properties of
chitosan/PVOH/clay nanocomposites. Carbohydrate Polymers. 140: 408-415.
Harker, F. R., Redgwell, R. J., Hallett, I. C., Murray, S. H. and Carter, G. 2010. Texture of fresh fruit.
Horticultural Reviews, Volume 20. 20: 121-224.
Kerch, G. 2015. Chitosan films and coatings prevent losses of fresh fruit nutritional quality: A review. Trends in
Food Science & Technology. 46(2, Part A): 159-166.
KhoshTaghaza, M. H. and Taghinezhad, E. 2016. Investigation effect of particle Nano coating on storage quality
properties of Thomson orange. Food Science & Technology. 13(61): 133-121.
Martín-Diana, A. B., Rico, D., Barat, J. and Barry-Ryan, C. 2009. Orange juices enriched with chitosan:
Optimisation for extending the shelf-life. Innovative Food Science & Emerging Technologies. 10(4):
590-600.
McHugh, T. H. and Krochta, J. M. 1994. Milk-protein-based edible films and coatings. Food Technology. 48(1):
97-103.
Miller, E. V. 1946. Physiology of citrus fruits in storage. The Botanical Review. 12(7): 393-423.
Moraru, C. I., Huang, Q., Takhistov, P., Dogan, H. and Kokini, J. L. 2009. Food nanotechnology: current
developments and future prospects. Global Issues in Food Science and Technology. 21: 369-399.
Moraru, C. I., Panchapakesan, C. P., Huang, Q., Takhistov, P., LIU, S. and Kokini, J. L. 2003. Nanotechnology:
a new frontier in food science. Food Technology. 57(12): 24-29.
Muzzarelli, R., Tarsi, R., Filippini, O., Giovanetti, E., Biagini, G. and Varaldo, P. 1990. Antimicrobial properties
of N-carboxybutyl chitosan. Antimicrobial Agents and Chemotherapy. 34(10): 2019-2023.
Özden, Ç. and Bayindirli, L. 2002. Effects of combinational use of controlled atmosphere, cold storage and
edible coating applications on shelf life and quality attributes of green peppers. European Food
Research and Technology. 214(4): 320-326.
Reddy, B. S. R. 2011. Advances in diverse industrial applications of nanocomposites (Vol. DOI: 10.5772/1931.).
India: InTech.
Rezaei Kalaj, Y., Ghareyazie, B., Emadpour, M. and Omrani, A. 2009. Effect of the removal of ethylen hormone
by potassium permangenate coated zeolite nanoparticles on the increased quality and quantity of
Storage of iceberg lettuce (Lactuca sativa L.) and chinese cabbage (Brassica pekinensis) J. Journal of
Agricultural Science and Natural Resources. 15(6): 1-11.
Ribeiro, C., Vicente, A. A., Teixeira, J. A. and Miranda, C. 2007. Optimization of edible coating composition to
retard strawberry fruit senescence. Postharvest Biology and Technology. 44(1): 63-70.
Sajomsang, W. 2010. Synthetic methods and applications of chitosan containing pyridylmethyl moiety and its
quaternized derivatives: A review. Carbohydrate Polymers. 80(3): 631-647.
Sánchez-Moreno, C. 2002. Review: Methods used to evaluate the free radical scavenging activity in foods and
biological systems. Food Science and Technology International. 8(3): 121-137.
Singh, K. K. and Reddy, B. S. 2006. Post-harvest physico-mechanical properties of orange peel and fruit. Journal
of Food Engineering. 73(2): 112-120.
Yaman, Ö. and Bayoιndιrlι, L. 2002. Effects of an Edible Coating and Cold Storage on Shelf-life and Quality of
Cherries. LWT - Food Science and Technology. 35(2): 146-150.
12
352
353
354
Zareei, H., Sharifani, M., Razavi, S. E. and Maghsoudlou, Y. 2005. Evaluation of chemical and physical
tretments on storage life of Tompson orange fruit. Journal of Agricultural and Natural Resources. .
12(1): 37-45.
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
13
371
372
Fig 1. Chitosan- clay nan composites XRD spectra
373
374
375
376
377
378
379
380
381
382
Fig 2. The pH value of juice fruit for coated and uncoated samples during storage.
383
384
385
* The same letter over column shows that the mean amount had no significant difference
(p<0.05) for every treatment during storage, the error bars represent ± one standard error of
the mean.
14
386
387
388
389
390
391
392
Fig 3. The Total Soluble Solid (TSS) amount of juice fruit for coated and uncoated samples
during storage.
* The same letter over column shows that the mean amount had no significant difference
(p<0.05) for every treatment during storage, the error bars represent ± one standard error of
the mean.
393
394
395
Fig 4. The Total Acidity (TA) amount of juice fruit for coated and uncoated samples during
storage.
396
397
398
399
* The same letter over column shows that the mean amount had no significant difference
(p<0.05) for every treatment during storage, the error bars represent ± one standard error of
the mean.
400
401
15
402
403
404
Fig 5. The firmness force amount of Lemon fruits for coated and uncoated samples during
storage.
405
406
407
* The same letter over column shows that the mean amount had no significant difference
(p<0.05) for every treatment during storage, the error bars represent ± one standard error of
the mean.
408
409
410
Fig 6. The amount of puncture force of Lemon fruits for coated and uncoated samples during
storage.
411
412
413
* The same letter over column shows that the mean amount had no significant difference
(p<0.05) for every treatment during storage, the error bars represent ± one standard error of
the mean.
16
414
415
416
417
418
419
420
Fig 7. The shear force amount of Lemon fruits for coated and uncoated samples during
storage
* The same letter over column shows that the mean amount had no significant difference
(p<0.05) for every treatment during storage, the error bars represent ± one standard error of
the mean.
421
422
423
424
425
426
Fig 8. The weight loss amount of Lemon fruits for coated and uncoated samples during
storage
* The same letter over column shows that the mean amount had no significant difference
(p<0.05) for every treatment during storage, the error bars represent ± one standard error of
the mean.
17