Essential Oils - Oils of Nature

encourages such amendment for its use in the preservation of JA tubers by increasing a relative humidity around the tubers and preventing heat transfer within the peat moss layer leading to the decrease of the water loss from fresh tubers depends on the difference between the water vapor pressure within the tubers and the water vapor pressure of the surrounding air, with moisture passing from the higher pressure to the lower even at 25°C. Cabezas et al. [18] reported that dry matter content in JA tubers decreased significantly depends on many factors, such as storage conditions, storage periods and keeping tubers for 30 days at 18°C, this leads to loosing water above 20%.

2.1.2.2.3 Biochemical constituents of JA tubers

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

mum level.

like carvone.

2.2.1 Methodology

105

2.2.1.1 Tuber material

antisprouting agent

Table 3 show the data of carbohydrates content, inulin and protein in JA tubers exposed to emulsion of caraway essential oil and then infected with fungal pathogenic S. rolfsii over the use of two storage methods. The application of caraway essential oil and uninfected JA tubers had significant effects on total carbohydrates, inulin and protein contents compared with the untreated-uninfected control in both storage methods. Along 4 months of storage, the treatment of infected JA tubers with pathogen and treated with caraway essential oil effectively decreased the carbohydrate, inulin and protein contents compared with the infected-untreated control JA tubers in both methods of storage. A fresh JA tuber contains 80% water, 15% carbohydrates, mainly in the form of inulin and about 2% protein in dry matter [19]. There are many changes in fresh JA tubers with long term storage, i.e., physical, biochemical, microbiological and enzymatic and which may lead to tuber decay. To inhibit these biochemical activities, natural or artificial drying products are widely used [20]. Davies [21] reported that the basic constituents of caraway oil (monoterpenes) tend to delay and the deterioration of carbohydrates and protein contents associated with the enzymatic system as well as respiration and energy metabolism enzyme keeping the internal biochemical enzymatic activities in mini-

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

2.1.2.2.4 Peroxidase, polyphenoloxidase enzymes and phenol content in JA tubers

with those obtained by [22] who reported an increasing in peroxidase and

polyhenoloxidase enzymes in potato fresh tubers when treated with caraway essential oil. Although regulatory mechanisms of plant enzyme complexes and the most enzymatic reactions are reduced at low temperature degree, JA tubers metabolism could continue at a slow rate even at minimum temperature (2°C) during cold storage. The enzymatic activation due to the exogenous application of caraway essential oil treatment could be directly related to its content of bioconstituents

2.2 Inhibition of sprout growth and increase storability of processing potato by

Fresh local potato cv. Fridor and uniformly size of 60–80 mm in diameter (weighing 180–250 g) were selected without any sprouting in eyes and no antisprouting treatment was used. Each treatment was treated with natural and safe

The mean activities data of peroxidase, polyphenoloxidase and phenol contents of JA fresh tubers treated with caraway essential oils and infected with pathogenic fungi over the use of two different two storage methods are presented on Table 4. Results revealed that infection with S. rolfsii had significant effects on total phenol and the activity of peroxidase and polyhenoloxidase enzymes in JA tubers than those of the uninfected JA tubers control in the two different storage methods. On the contrary, the application of caraway essential oil to infected/uninfected JA tubers increased peroxidase and polyphenoloxidase and phenol content compared with the untreated-uninfected JA tubers in both methods. These results are in a line


\* 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.

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

#### Table 3.

Mean contents of carbohydrates, inulin (mg/g 2SD) and protein (% 2SD) of JA tubers treated with caraway essential oil and infected with S. rolfsii using two storage methods.

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

#### 2.1.2.2.3 Biochemical constituents of JA tubers

encourages such amendment for its use in the preservation of JA tubers by increasing a relative humidity around the tubers and preventing heat transfer within the peat moss layer leading to the decrease of the water loss from fresh tubers depends on the difference between the water vapor pressure within the tubers and the water vapor pressure of the surrounding air, with moisture passing from the higher pressure to the lower even at 25°C. Cabezas et al. [18] reported that dry matter content in JA tubers decreased significantly depends on many factors, such as storage conditions, storage periods and keeping tubers for 30 days at 18°C, this leads to

Criterion Storage method\* Treatment\*\* Storage period (day)

Carbohydrates 1 C 42.5 1.4 41.7 1.5 38.4 4.3 NA

Inulin 1 C 14.2 0.6 13.6 0.7 12.8 1.2 NA

Protein 1 C 12.2 0.4 12.0 0.2 11.9 0.4 NA

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

Mean contents of carbohydrates, inulin (mg/g 2SD) and protein (% 2SD) of JA tubers treated with

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

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

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

30 60 90 120

P NA\*\*\* NA NA NA O 44.6 1.3 44.2 1.3 43.3 1.3 43.0 1.0 O + P 42.7 1.7 42.0 0.7 41.6 1.1 41.3 0.3

P 36.7 1.4 36.0 0.3 NA NA O 46.0 0.3 46.9 0.5 47.0 0.8 47.7 0.9 O + P 42.0 0.8 41.9 0.7 41.5 1.2 41.0 1.4

P NA NA NA NA O 15.6 0.8 15.0 0.3 16.7 0.6 15.0 0.2 O + P 14.9 0.6 14.0 0.1 14.0 0.0 13.9 0.4

P 13.0 0.4 12.0 0.3 NA NA O 18.9 0.5 18.0 0.4 17.9 0.2 17.6 0.6 O + P 17.9 0.5 17.6 0.8 17.0 0.2 17.0 0.0

P NA NA NA NA O 12.8 0.3 12.7 0.3 12.7 0.4 12.6 0.4 O + P 12.6 0.5 12.6 0.2 12.4 0.1 12.0 0.1

P 9.9 0.2 9.0 0.4 NA NA O 13.0 0.3 13.0 0.6 12.7 0.5 12.7 0.2 O + P 12.6 0.5 12.4 0.5 12.3 0.4 12.0 0.4

2 C 42.0 0.3 40.2 1.4 37.7 1.0 36.0 0.5

2 C 14.3 0.5 14.0 0.4 13.8 0.6 13.0 0.2

2 C 12.5 0.3 12.3 0.4 12.0 0.4 11.9 0.2

loosing water above 20%.

Essential Oils - Oils of Nature

\*

Table 3.

104

Table 3 show the data of carbohydrates content, inulin and protein in JA tubers exposed to emulsion of caraway essential oil and then infected with fungal pathogenic S. rolfsii over the use of two storage methods. The application of caraway essential oil and uninfected JA tubers had significant effects on total carbohydrates, inulin and protein contents compared with the untreated-uninfected control in both storage methods. Along 4 months of storage, the treatment of infected JA tubers with pathogen and treated with caraway essential oil effectively decreased the carbohydrate, inulin and protein contents compared with the infected-untreated control JA tubers in both methods of storage. A fresh JA tuber contains 80% water, 15% carbohydrates, mainly in the form of inulin and about 2% protein in dry matter [19]. There are many changes in fresh JA tubers with long term storage, i.e., physical, biochemical, microbiological and enzymatic and which may lead to tuber decay. To inhibit these biochemical activities, natural or artificial drying products are widely used [20]. Davies [21] reported that the basic constituents of caraway oil (monoterpenes) tend to delay and the deterioration of carbohydrates and protein contents associated with the enzymatic system as well as respiration and energy metabolism enzyme keeping the internal biochemical enzymatic activities in minimum level.

#### 2.1.2.2.4 Peroxidase, polyphenoloxidase enzymes and phenol content in JA tubers

The mean activities data of peroxidase, polyphenoloxidase and phenol contents of JA fresh tubers treated with caraway essential oils and infected with pathogenic fungi over the use of two different two storage methods are presented on Table 4. Results revealed that infection with S. rolfsii had significant effects on total phenol and the activity of peroxidase and polyhenoloxidase enzymes in JA tubers than those of the uninfected JA tubers control in the two different storage methods. On the contrary, the application of caraway essential oil to infected/uninfected JA tubers increased peroxidase and polyphenoloxidase and phenol content compared with the untreated-uninfected JA tubers in both methods. These results are in a line with those obtained by [22] who reported an increasing in peroxidase and polyhenoloxidase enzymes in potato fresh tubers when treated with caraway essential oil. Although regulatory mechanisms of plant enzyme complexes and the most enzymatic reactions are reduced at low temperature degree, JA tubers metabolism could continue at a slow rate even at minimum temperature (2°C) during cold storage. The enzymatic activation due to the exogenous application of caraway essential oil treatment could be directly related to its content of bioconstituents like carvone.

#### 2.2 Inhibition of sprout growth and increase storability of processing potato by antisprouting agent

#### 2.2.1 Methodology

#### 2.2.1.1 Tuber material

Fresh local potato cv. Fridor and uniformly size of 60–80 mm in diameter (weighing 180–250 g) were selected without any sprouting in eyes and no antisprouting treatment was used. Each treatment was treated with natural and safe


of 8 mm concentration of each compound in distilled water and Tween 20 (6%) for 30 min after 1 month of harvest or at such time that the tubers begin to sprout.

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

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

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

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

Treatments Sprouting (%) Weight loss (%) Dry matter (%)

1. Control 100.0<sup>a</sup> 96.00<sup>a</sup> 25.12<sup>a</sup> 26.18<sup>a</sup> 21.65<sup>f</sup> 22.80<sup>e</sup> 2. CIPC 2.49<sup>e</sup> 1.20c 4.33e 2.80ef 23.60a–<sup>d</sup> 23.66<sup>d</sup> 3. Geranyl acetate 4.68<sup>d</sup> 4.33<sup>c</sup> 3.41<sup>f</sup> 4.65<sup>d</sup> 22.50ef 24.55ab 4. Geraniol 0.00<sup>f</sup> 0.00c 2.19<sup>h</sup> 1.45<sup>g</sup> 24.56<sup>a</sup> 25.30<sup>a</sup> 5. Camphor 6.92<sup>c</sup> 5.98c 2.88<sup>g</sup> 2.95ef 23.33b–<sup>e</sup> 24.38bc 6. Citral 0.00<sup>f</sup> 0.00c 1.51<sup>i</sup> 1.26<sup>g</sup> 24.00ab 24.95ab 7. Linalool 100.00<sup>a</sup> 72.00<sup>b</sup> 9.50b 8.00<sup>b</sup> 22.66de 23.60d 8. L-Carvone 70.58<sup>b</sup> 62.00<sup>b</sup> 9.50b 6.25c 22.80c–<sup>e</sup> 23.70cd 9. D-Carvone 72.00<sup>b</sup> 76.98<sup>b</sup> 8.03<sup>c</sup> 3.45<sup>e</sup> 22.90c–<sup>e</sup> 24.89 ab 10. D-Citronellol 2.89<sup>e</sup> 2.00c 6.75<sup>d</sup> 5.73<sup>c</sup> 23.60a<sup>d</sup> 24.68ab 11. L-Citronellol 0.00<sup>f</sup> 0.00c 2.25gh 2.10fg 23.80a–<sup>c</sup> 24.55ab 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

Sprouting behavior characters and dry matter of potato tubers as affected by anti-sprouting agent during 2012

2012 2013 2012 2013 2012 2013

role against oxidative stress under normal conditions of storage.

2.2.2.2 Reducing sugars, amino acids and peroxidase POD activity

2.2.2 Results and discussion

98.5%.

Range Test.

Table 5.

107

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

2.2.2.1 Sprouting, weight loss and dry matter content

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

\* 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.

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

#### Table 4.

Mean activities of peroxidase, polyphenoloxidase enzymes and phenol content (% 2SD) of JA tubers treated with caraway essential oil and infected with S. rolfsii using two storage methods.

antisprouting agent and stored at ambient temperature (average: 35/15°C day/night and 70% RH) in Laboratory for 4 months.

### 2.2.1.2 Treatments

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

of 8 mm concentration of each compound in distilled water and Tween 20 (6%) for 30 min after 1 month of harvest or at such time that the tubers begin to sprout.
