2.3.2.3.1 Total phenolic compounds and DPPH radical scavenging capacity

Figure 2 illustrate that there was a gradual increase in the total phenolic acid content, and reaching a maximum value at day 5 and 10 (132.67 and 135.04 mg GAE/100 g F.W.) compared to the initial time. This concentration decreased in to 129.03 mg at day 15 due to thyme oil application (Figure 2). Keeping in view that the control treatment decreased to 73.84 GAE/100 g FW at day 5. On the 15th day, the old-sprout from storage, the control was reduced by 28.57% compared to thyme oil (1.98%). The control treatment of antioxidant capacity increased significantly until day 10 (29.43 mg/100 g F.W.), and finally decrease (28.46% mg 100/g F.W.) at day 15 increased from initial period (20.28%). While, application of thyme oil the change was not clear at the end of storage (1.98%) (Figure 3). During cold storage (Figure 3), the control was reduced DPPH by 28.57% compared to thyme oil at 15 day old-sprout (1.98%). Nath et al. [30] observed a constant decrease in the antioxidant capacity for 144 h of storage of broccoli inflorescences. This behavior in DPPH may be due to the steady changes in plant metabolism during storage period as a result of oxidative stress, which may include structural and chemical changes in synthesis or antioxidant content [31].

DPPH radical scavenging capacity as affected by thyme oil compared to control treatment at different storage period.

#### 2.3.2.3.2 Total flavonoids

Total flavonoids (Figure 4) were found in a higher concentration in 3-day-old sprouts of thyme treatment, with values of 115.95 mg/100 g F.W., after 5 and

10 days of storage slight decrease to 0.021 and 0.086%, respectively, when compared with the initial value, and finally reduced by 1.39%. The high loss of flavonoids reached to 10.59 and 47.89%, after 5 and 10 days, respectively, and at 15 days

Storage time had significant differences in glucosinolates content of the samples analyzed. Figure 5 illustrate that the thyme oil increased significantly glucosinolates content in 3-day-old sprouts, compared to control treatments. Moreover, thyme oil had a high value of total glucosinolates (27.02 μg/g F.W.) and slightly decreased up to 26.43 μg/g F.W. on day 15. At the end of storage, the decreasing changes percent

In sprout, the total glucosinolates level (27.02 μg/g F.W.) is higher than in florets or heads (7.37) (Figure 6). Glucoraphanin is the powerful of antioxidant and the most abundant aliphatic glucosinolates present in sprout. The glucoraphanin reached the highest 16.24 followed by glucoerucin 5.9 and glucoiberm 1.2 μg/g F.W.

the loss increased to 58.33% for control treatment (average two seasons).

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

was about 2.18%. In the control treatment, the highest decrease in total

On the other hand, the florets/heads contain the highest level of aromatic/ indolylglucosinolates, neoglucobrassicin (2.11) followed by glucobrassicin (1.67).

Horticulture Research Institute, Agriculture Research Center, Giza, Egypt

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: aml.elawady@yahoo.com

2.3.2.3.4 Glucosinolates content of mature head versus sprout broccoli

Our results are in agreement with those obtained by [32].

glucosinolates content was observed, where reached about 49.12% at the end of

2.3.2.3.3 Glucosinolates content

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

storage.

Author details

115

Aml Abo El-Fetouh El-Awady

provided the original work is properly cited.

#### Figure 4.

Total flavonoids content as affected by thyme oil compared to control treatment at different storage period.

#### Figure 5.

Total glucosinolates content as affected by thyme oil compared to control treatment at 0 time and 15 DAS.

Total and individual aliphatic, aromatic/indole glucosinolates levels in broccoli in 3-days-old sprout and mature at harvest.

10 days of storage slight decrease to 0.021 and 0.086%, respectively, when compared with the initial value, and finally reduced by 1.39%. The high loss of flavonoids reached to 10.59 and 47.89%, after 5 and 10 days, respectively, and at 15 days the loss increased to 58.33% for control treatment (average two seasons).
