2.2.2.1 Sprouting, weight loss and dry matter content

All control tubers had significant values of sprouting and weight loss percentages at the end of storage period (Table 5). Geraniol and citral completely inhibited sprouting by 100%, decreased weight loss and increase tuber dry matter content in both seasons. Application of geranyl acetate inhibited sprouting by 95%. On the other hand, linalool and L-carvone had no significant effect on tuber sprouting. It has been reported that L-carvone and D-carvone displayed little or no inhibition of sprouting in potatoes [17]. Geraniol and citral have a high content in monoterpenes such as benzaldehyde, eugenol and thymol [23]. CIPC inhibited sprouting over 98.5%.

Under this study condition, the beneficial effect of the applied anti-sprouting agent (geraniol and citral) on controlling tubers sprouting and increasing dry matter content could be associated with their similar advantages effect in preservation of their tubers starch, carbohydrates, sugars and amino acid content (Table 6). Suppression of sprouting and weight loss logically associated with maintenance of dry matter. Furthermore, monoterpenes acts as antioxidant and had a protective role against oxidative stress under normal conditions of storage.

#### 2.2.2.2 Reducing sugars, amino acids and peroxidase POD activity

All storage treatments gave significant lower values on reducing sugars and amino acids content during two seasons of study as compared to the control (Table 6). In the ambient temperature, the lowest significant values of reducing


Means followed by the same letter(s) within each column do not significantly differ using Duncan's multiple range test at the level of 5%; where, (a) refer to the highest mean values, and (h) refer to the lowest mean values according to Duncan Multiple Range Test.

#### Table 5.

Sprouting behavior characters and dry matter of potato tubers as affected by anti-sprouting agent during 2012 and 2013 seasons (after 4 months of storage period).

antisprouting agent and stored at ambient temperature (average: 35/15°C day/night

Mean activities of peroxidase, polyphenoloxidase enzymes and phenol content (% 2SD) of JA tubers treated

The experiment included seven treatments, which were as follows: Cymbopogon

martini (rich in geraniol and geranyl acetate), C. flexuosus (rich in citral), C. winterianus (rich in rich in citronellal and citronellol), Ocimum sanctum (rich in rich in ketone and camphor), Carum carvi (rich in rich in carvone), Artemisia annua (rich in ketone camphor) and Lavendula officinalis (rich in linalool). The isolated terpenoids were purified by HPLC. Essential oils were purified by column chromatography and substantially pure compounds were used. Tubers dipped in emulsions

1 = storage JA tubers in polyethylene bags at 4°C and 2 = storage JA tubers in peat moss layer at 25°C. \*\*C = untreated control, P = infected tubers with pathogen, O = treated JA tubers with caraway essential oil and

O + P = infected tubers with pathogen and treated with caraway essential oil.

with caraway essential oil and infected with S. rolfsii using two storage methods.

and 70% RH) in Laboratory for 4 months.

\*\*\*NA = not applicable due to full decay.

Criterion Storage

Essential Oils - Oils of Nature

method\*

Treatment\*\* Storage period (day)

Peroxidase 1 C 0.40 0.02 0.30 0.0 0.28 0.05 NA

Polyphenoloxidase 1 C 0.39 0.01 0.36 0.01 0.35 0.02 NA

Total phenol 1 C 0.29 0.02 0.28 0.01 0.27 0.01 NA

30 60 90 120

P NA\*\*\* NA NA NA O 0.40 0.03 0.38 0.01 0.38 0.01 0.37 0.02 O + P 2.67 0.16 2.69 0.26 2.73 0.04 2.74 0.03

P 1.90 0.02 1.92 0.03 NA NA O 0.33 0.02 0.34 0.02 0.34 0.02 0.34 0.03 O + P 1.77 0.03 1.86 0.04 1.87 0.02 1.87 0.26

P NA NA NA NA O 0.47 0.03 0.47 0.02 0.45 0.03 0.42 0.06 O + P 1.46 0.02 1.57 0.05 1.47 0.02 1.57 0.03

P 1.49 0.03 1.50 0.04 NA NA O 0.46 0.02 0.43 0.01 0.41 0.06 0.40 0.01 O + P 1.46 0.02 1.57 0.02 1.57 0.03 1.67 0.02

P NA NA NA NA O 0.32 0.03 0.32 0.03 0.32 0.02 0.31 0.02 O + P 0.52 0.02 0.52 0.02 0.51 0.02 0.52 0.01

P 0.57 0.04 0.57 0.04 NA NA O 0.26 0.01 0.26 0.01 0.26 0.02 0.26 0.02 O + P 0.55 0.02 0.55 0.02 0.55 0.01 0.56 0.01

2 C 0.23 0.01 0.22 0.02 0.21 0.01 0.20 0.06

2 C 0.40 0.04 0.40 0.03 0.37 0.03 0.35 0.03

2 C 0.35 0.02 0.35 0.02 0.35 0.02 0.34 0.03

2.2.1.2 Treatments

\*

Table 4.

106


Means followed by the same letter(s) within each column do not significantly differ using Duncan's multiple range test at the level of 5%; where, (a) refer to the highest mean values, and (g) refer to the lowest mean values according to Duncan Multiple Range Test.

#### Table 6.

Reducing sugars, amino acids and peroxidase enzyme of potato tubers as affected by anti-sprouting agent during 2012 and 2013 seasons (after 4 months of storage period).

sugars and amino acids content were found in tubers exposed to emulsion of geraniol and citral, without significant difference between the two treatments.

The monoterpenes rich in compounds had a potential role in preservation and maintenance of the stored tubers reserves, keeping the enzymatic activities in a minimal level and in more stable case thereby prolonged their dormancy period. Also, application of these treatments were highly effective in tuber protection against the degradable effects of oxidative stressful during high temperature storage conditions and accordance to the findings of [20] who indicated that monoterpenes and antioxidants tended to slow down the activity of carbohydrates, breakdown of protein and enzymatic activity as well as reduce respiration rate and metabolism enzyme. The role of POD in sprouting of potatoes was widely reported, particularly its degrading activity of IAA, and cytokinin which is considered an effective promote oxidative stress is of great importance and depending on the activation degree of peroxidase as affected by storage treatments.

#### 2.2.2.3 Processing quality of potato fries and chips

All storage treatments and CIPC treatment at ambient temperature had significant differences on quality characters of potato chips and French fries, i.e., color, crispiness and taste in comparison with the control treatment (Table 7).

The same treatments prevented and blocked the accumulation of total sugars, and kept the reducing sugars and amino acids in optimize levels in the stored tubers at ambient temperature. This is true in the end of storage (4 months). Thus, we noticed the worst processing quality (dark potato chips and crispness with bad taste) of storage treatments due to the appearance of Millard reaction during frying process and the accumulation of reducing sugars and amino acids [23]. The same processing quality parameters were correlated with dry matter content (Table 8) and with amino acids content (Table 9) in both seasons. These results are in harmony with those previously obtained by [24]. Meanwhile, we also noticed that

Treatments

109

Chips Taste

Crispness

Color

Taste

Crispness

Color

2012

3.00e 3.33de

3.33c 4.67ab

5.00a

4.67a

5.00a

5.00a

4.67ab

4.67ab

5.00a

4.67ab

5.00a

4.33 abc

4.33a–c

4.33ab

4.33a–c

4.67ab

3.67 cde

3.33 cd

4.00a–c

4.33a–c

4.67ab

4.67 ab

3.33c

3.00d

3.33bc

4.33a–c

4.33a–c

3.33 de

3.00 d

3.33cd

4.00b–d

4.67ab

4.67 ab

> 1. Control

2. CIPC

3. Geranyl acetate

4. Geraniol 5. Camphor

6. Citral

7. Linalool

8. 9. 10. 11. Means followed by the same letter(s) within each column do not significantly

mean values according to Duncan Multiple Range Test.

Table 7. Quality processing of potato tubers as affected by

anti-sprouting

 agent during 2012 and 2013 seasons (after 4 months of storage period).

L-Citronellol

 4.33a–c

D-Citronellol

 4.00b–d

D-Carvone

5.00a

5.00a 4.67ab 4.67ab

4.67ab

4.67a

 differ using Duncan's multiple range test at the level of 5%; where, (a) refer to the highest mean values, and (d) refer to the lowest

4.67ab

4.67a

4.00b–d

4.33a–c

3.67b–d

4.33a–c

4.67ab

4.67ab

4.67ab

4.67a

4.67ab

4.67a

4.00b–d

4.00a–c

4.33a–c

4.33a–c

4.67ab

5.00a

5.00a

4.67a

5.00a

5.00a

5.00a

5.00a

4.67ab

5.00a

5.00a

5.00a

L-Carvone

4.67ab

4.67ab

4.67ab

4.67a

5.00a

5.00a

4.67ab

4.67ab

5.00a

5.00a

5.00a

5.00a

 4.67ab 5.00a 4.67ab 5.00a 4.67ab

4.67 ab

 4.64ab

4.67a

5.00a

5.00a

4.67ab

4.67ab

4.67ab

4.67ab

5.00a

5.00a

5.00a

5.00a

4.67a

5.00a

5.00a

5.00a

5.00a

4.67ab

5.00a

5.00a

5.00a

4.67ab

5.00a

4.67a

5.00a

5.00a

4.67ab

4.67ab

4.67 ab

4.67ab

5.00a

5.00a

5.00a

5.00a

4.67a

5.00a

5.00a

4.67ab

4.67ab

5.00a

4.67ab

5.00a

4.33 a–c

Effect of Essential Oils on Storability and Preservation of Some Vegetable Crops

 2013

 2012

 2013

 2012

 2013

 2012

 2013

 2012

 2013

 2012

 2013

DOI: http://dx.doi.org/10.5772/intechopen.87213

French fries


Table 7. Quality processing of potato tubers as affected by

anti-sprouting

 agent during 2012 and 2013 seasons (after 4 months of storage period).

#### Effect of Essential Oils on Storability and Preservation of Some Vegetable Crops DOI: http://dx.doi.org/10.5772/intechopen.87213

sugars and amino acids content were found in tubers exposed to emulsion of geraniol and citral, without significant difference between the two treatments. The monoterpenes rich in compounds had a potential role in preservation and maintenance of the stored tubers reserves, keeping the enzymatic activities in a minimal level and in more stable case thereby prolonged their dormancy period. Also, application of these treatments were highly effective in tuber protection against the degradable effects of oxidative stressful during high temperature storage conditions and accordance to the findings of [20] who indicated that monoterpenes and antioxidants tended to slow down the activity of carbohydrates, breakdown of protein and enzymatic activity as well as reduce respiration rate and metabolism enzyme. The role of POD in sprouting of potatoes was widely reported, particularly its degrading activity of IAA, and cytokinin which is considered an effective promote oxidative stress is of great importance and depending on the activation degree

Reducing sugars, amino acids and peroxidase enzyme of potato tubers as affected by anti-sprouting agent

Treatments Reducing sugars (%) Total free amino acids (%) Peroxidase activity POD (%)

1. Control 4.29a 4.52<sup>a</sup> 0.352<sup>a</sup> 0.348<sup>a</sup> 56.77g 55.51<sup>g</sup> 2. CIPC 2.05<sup>c</sup> 3.18<sup>d</sup> 0.307ab 0.301ab 95.81<sup>b</sup> 94.63<sup>b</sup> 3. Geranyl acetate 1.39cd 3.93<sup>b</sup> 0.084bc 0.047<sup>c</sup> 79.75<sup>e</sup> 79.33<sup>e</sup> 4. Geraniol 1.24<sup>d</sup> 1.51<sup>f</sup> 0.030<sup>c</sup> 0.028c 97.33<sup>a</sup> 96.29a 5. Camphor 3.41<sup>b</sup> 3.48c 0.152a–<sup>c</sup> 0.153a–<sup>c</sup> 80.68<sup>e</sup> 80.26<sup>e</sup> 6. Citral 1.25<sup>d</sup> 1.52<sup>f</sup> 0.045<sup>c</sup> 0.045<sup>c</sup> 97.68<sup>a</sup> 96.46<sup>a</sup> 7. Linalool 4.07ab 4.13<sup>b</sup> 0.106bc 0.108bc 80.67<sup>e</sup> 79.06<sup>c</sup> 8. L-Carvone 3.81ab 1.83<sup>e</sup> 0.084bc 0.151a–<sup>c</sup> 81.67e 80.50<sup>e</sup> 9. D-Carvone 1.45 cd 1.68ef 0.146a–<sup>c</sup> 0.157a–<sup>c</sup> 77.55<sup>f</sup> 76.77<sup>f</sup> 10. D-Citronellol 1.76cd 1.54<sup>f</sup> 0.186a–<sup>c</sup> 0.187a–<sup>c</sup> 84.50<sup>d</sup> 83.62<sup>d</sup> 11. L-Citronellol 1.29d 1.58f 0.147a–<sup>c</sup> 0.059<sup>c</sup> 87.67c 86.65<sup>c</sup> Means followed by the same letter(s) within each column do not significantly differ using Duncan's multiple range test at the level of 5%; where, (a) refer to the highest mean values, and (g) refer to the lowest mean values according to Duncan Multiple Range

2012 2013 2012 2013 2012 2013

All storage treatments and CIPC treatment at ambient temperature had significant differences on quality characters of potato chips and French fries, i.e., color,

The same treatments prevented and blocked the accumulation of total sugars, and kept the reducing sugars and amino acids in optimize levels in the stored tubers at ambient temperature. This is true in the end of storage (4 months). Thus, we noticed the worst processing quality (dark potato chips and crispness with bad taste) of storage treatments due to the appearance of Millard reaction during frying process and the accumulation of reducing sugars and amino acids [23]. The same processing quality parameters were correlated with dry matter content (Table 8) and with amino acids content (Table 9) in both seasons. These results are in harmony with those previously obtained by [24]. Meanwhile, we also noticed that

crispiness and taste in comparison with the control treatment (Table 7).

of peroxidase as affected by storage treatments.

during 2012 and 2013 seasons (after 4 months of storage period).

Test.

108

Table 6.

Essential Oils - Oils of Nature

2.2.2.3 Processing quality of potato fries and chips


Means followed by the same letter(s) within each column do not significantly differ using Duncan's multiple range test at the level of 5%; where, (a) refer to the highest mean values, and (e) refer to the lowest mean values according to Duncan Multiple Range Test.

#### Table 8.

Vegetative characters of treated broccoli seeds with different essential oils before cold storage.

the best processing quality of basic constituents of essential oils produced chips, the optimization of reducing sugars and amino acids of their tubers thereby, the prevention of Millard reaction occurrence during frying processes and thus it turn reflects on best color, crispiness and taste.
