Potential bioactive compounds in health promotion from broccoli cultivars grown in Spain

Glucosinolates, phenolic compounds and vitamin C were evaluated in two commercial and 12 experimental cultivars of broccoli (Brassica oleracea L var italica) grown under uniform cultural conditions. The predominant glucosinolates in all broccoli cultivars were 4‐methylsulphinylbutyl glucosinolate (glucoraphanin) and 3‐indolylmethyl glucosinolate (glucobrassicin). Other glucosinolates such as 4‐OH‐glucobrassicin and N‐methoxyglucobrassicin were detected in lower amounts. The total glucosinolate concentration ranged from 3.0 µmol g^?1 dw (dry weight) in Pentathlon (experimental cultivar) to 28.3 µmol g^?1 dw in I‐9905 (experimental cultivar). Flavonoids, caffeic acid derivatives and sinapic acid derivatives were quantified in methanol extracts. The largest content of flavonoids was found in the commercial cultivars Marathon and Lord, around 60 mg kg^?1 fw (fresh weight). The vitamin C content of broccoli ranged from 43.1 mg per 100 g fw in Lord (commercial cultivar) to 146.3 mg per 100 g fw in SG‐4515 (experimental cultivar). © 2002 Society of Chemical Industry     

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

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. Copyright © 2006 Society of Chemical Industry     

菜籽加工对硫代葡萄糖甙的影响

本文分析比较了水剂法、有机溶剂浸出法、机榨法三种工艺过程中硫代葡萄糖甙(硫甙)的变化,阐明了菜籽加工过程中硫甙分解的主要原因。     

The effects of dry extrusion of rapeseed with other feedstuffs upon its nutritional value and anti-thyroid activity

The effects of dry extrusion of mixtures of high-glucosinolate rapeseed (cv. Jet Neuf) with barley, sunflower meal and rapeseed meal and a mixture of low-glucosinolate rapeseed (Canola) and sunflower meal upon dry matter intake, utilisation of protein, liveweight gain and anti-thyroid activity in rats, measured in terms of plasma thyroxine and tri-iodothyronine, were studied in comparison with equivalent milled mixtures. Extrusion of the Jet Neuf mixtures increased dry matter intake, liveweight gain and biological value of the protein but only for the Jet Neuf/barley and Jet Neuf/sunflower mixtures did extrusion reduce the anti-thyroid activity. Extrusion of the Canola mixture had no effect on the biological value or anti-thyroid activity; in both respects it was superior to the Jet Neuf mixt–res.     

Comparison of glucosinolate levels in commercial broccoli and red cabbage from conventional and ecological farming

Broccoli heads and red cabbage of both conventional and ecological origin were purchased from the market at monthly intervals over a 1-year period. After freeze-drying of the samples the glucosinolates were extracted, enzymatically desulphated and analyzed by HPLC-UV. Glucoraphanin, glucobrassicin and neo-glucobrassicin turned out to be the predominant glucosinolates in broccoli. Red cabbage contained similar amounts of glucoraphanin and glucobrassicin but, in addition, appreciable amounts of glucoiberin, progoitrin, sinigrin, gluconapin and glucoerucin, while neo-glucobrassicin occurred at trace levels only. No significance was found comparing the contents of glucoraphanin in the two cultivation groups for either broccoli or red cabbage. Organic broccoli and red cabbage both contained significantly higher amounts of glucobrassicin than their conventionally grown counterparts. Conventional crops of red cabbage yielded significantly higher quantities of gluconapin than ecological crops. Broccoli imported from Spain and Italy during the winter months yielded levels of glucosinolates similar to those of the home-grown products available in summer and autumn.

MgSO4处理对西兰花芽苗菜生理活性物质和抗氧化能力的影响

本实验研究了外源喷施0、25、50、75 mmol/L的MgSO4对西兰花芽苗菜生长状况、生理活性物质含量和抗 氧化能力的影响。结果表明：MgSO4处理对西兰花芽苗菜造成了生长胁迫效应;叶绿素和总酚含量随着MgSO4浓度 的增大而增加,抗坏血酸含量却随着MgSO4浓度的增加而降低。发芽5 d的西兰花芽苗菜中总硫代葡萄糖苷（简称 硫苷）和萝卜硫素含量显著高于发芽8 d的,但发芽8 d的黑芥子酶活力高于发芽5 d的;MgSO4处理后,总硫苷和萝 卜硫素含量及黑芥子酶活力显著提高,但50 mmol/L和75 mmol/L MgSO4处理组之间差异不显著。MgSO4处理显著提 高了西兰花芽苗菜的抗氧化能力,但1,1-二苯基-2-三硝基苯肼自由基清除率在50 mmol/L和75 mmol/L处理组之间无 显著差异,H2O2清除率随MgSO4浓度的增加逐渐增强。因此,综合考虑,50 mmol/L MgSO4对于提高西兰花芽苗菜 的营养价值和保健功能是较适合的浓度。     

Bitter taste of Brassica vegetables: The role of genetic factors,receptors, isothiocyanates,glucosinolates, and flavor context

ABSTRACT

It is well known that consumption of Brassica vegetables has beneficial effect on human's health. The greatest interest is focused on glucosinolates and their hydrolysis products isothiocyanates, due to their potential as cancer preventing compounds. Brassica vegetables are also rich in flavor compounds belonging to many chemical groups. The main sensory sensation related to these vegetable is their characteristic sharp and bitter taste, and unique aroma. Because of these features this group of vegetables is often rejected by consumers. Interestingly, for some people unpleasant sensations are not perceived, suggesting a potential role of inter-individual variability in bitter taste perception and sensibility. Receptors responsible for bitter sensation with the emphasis on Brassica are reviewed, as well as genetic predisposition for bitterness perception by consumers. Also the role of glucosinolates and isothiocyanates as compounds responsible for bitter taste is discussed based on data from the field of food science and molecular biology. Isothiocyanates are shown in broaded context of flavor compounds also contributing to the aroma of Brassica vegetables.