Effect of nitrogen and sulfur fertilization on glucosinolates in the leaves and roots of broccoli sprouts (Brassica oleracea var. italica)

Abstract

Broccoli (Brassica oleracea L. var. italica cv. Marathon) sprouts are a rich source of glucosinolates, particularly 4-methylsulfinylbutyl glucosinolate (glucoraphanin), the precursor of the chemoprotective isothiocyanate, sulforaphane. Sulfur and nitrogen fertilization have been shown to influence the pattern and levels of glucosinolates in mature broccoli, but little information is available on the fertilization of sprouts, a transient stage of broccoli growth, which have been recommended for salads. Therefore, an experiment was set up to evaluate the effect of N and S fertilization on the glucosinolate content of the aerial part and roots of broccoli sprouts. Nitrogen was tested at 0, 45.5, 91.0 mg L −1 and sulfur at 0, 14.6 and 29.2 mg L −1 . The results showed that total glucosinolates in the aerial part were significantly higher (P < 0.001) than in the roots. The major glucosinolates in the aerial part were 4-methylsulfinylbutyl and 3-methylsulfinylpropyl whereas in the roots they were 2-phenylethyl and 4-methylthiobutyl. Fertilization of broccoli sprouts had a significant (P < 0.001) detrimental effect on the levels of aliphatic glucosinolates whereas the opposite was noted for indole and aromatic glucosinolates, for some of the fertilization combinations tested. Overall, the results indicate that broccoli sprouts do not benefit from fertilization.

Effect of NaCl treatments on glucosinolate metabolism in broccoli sprouts

“…In the research by Aires et al (2006), the glucosinolates in broccoli include 3-methyl-sulfinylpropyl glucosinolate and 2-phenyl-ethyl glucosinolate, which were not found in the present study. However, two indole glucosinolates, 4-methoxy glucobrassicin (4-IM) and neoglucobrassicin (1-IM), were detected in our research.…”

Assessment of the nitrogen fertilization effect on bioactive compounds of frozen fresh and dried samples of Stevia rebaudiana Bertoni

“…However, there is a lack of information about the real effects of fertilization on the chemical and bioactive properties of stevia plants. In fact, N, phosphorous (P) and potassium (K) fertilization, as well as plant status, display an important role in defining the final concentration of secondary metabolites and, therefore, biological potential (Aires, Rosa, & Carvalho, 2006). Among them, N is considered as being one of the most important essential elements in plant science, being used by plants to synthesize many organic compounds, such as amino acids, proteins, enzymes and nucleic acids (Koeduka et al, 2006).…”

On farm and fresh produce management

“…Given the high content of glucoraphanin found in broccoli sprouted seed some authors have investigated the effect of N and S application during growth of broccoli and other Brassica sprouts [3,78]. In the study of (K2SO4) from 6 days after sowing.…”

“…However, in this study fertilization was found to have a significant detrimental effect on accumulation of aliphatic glucosinolates including glucoraphanin. This may have been due to salt stress at the concentrations used [3]. In the study of Kestwal et al (2010) broccoli, radish and cabbage seeds were sprouted in soil supplemented with S as sodium thiosulphate (Na2S2O3) at S concentrations equivalent to 20 to 60 kg/ha.…”