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Glucosinolates with Brassica genus as secondary metabolites have a lot of functions and effects. Glucosinolates form less than 2% of the overall sulphur content at the beginning of vegetation in different parts of the plants and during growth their content is decreasing and forms less than 0.1%. This low representation doubts their storage function. With its chemical composition, they are ranked among natural pesticides with active and passive resistance against diseases and pests. They show repellent effects and properties of natural biofumigators in soil after ploughing in their biomass as green fertilizing, or after ploughing in after harvest the leftovers of rape. The principle of these effects is decomposition products of glucosinolates-bioactive isothiocyanates. Very important from this point of view are turnip rape Rex and Brassica juncea, whose content of these compounds is the highest one and they are resistant against the attack of Ceutor-rhynchus pleurostigma. The same effect showed also when attacked by Phoma lingam. With other winter Brassicas either hybrid or linea and summer rape is this defensive system suppressed because of their lowered content due to breeding interferences, leading to limitation of their anti-nutritional negative effects. It is possible to state the final result after finding out the production of the above matter, roots, and after evaluation of the sorbal characteristics of the soil and evaluation of the state of health of the following crop or vegetable. After this overall analysis, it will be possible to evaluate the biofumigation properties of accessible varieties of the Brassica genus.

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The bitterness associated with certain cultivars of Brussels sprouts has been shown to be linked to the presence of the glucosinolates, sinigrin and progoitrin. Whereas the former compound is bitter per se, the bitterness associated with the latter compound is due to its decomposition product, the goitrogen (-)5-vinyloxazolidine-2-thione. A method is described for the screening of cultivars of this, and other, Brassica vegetables for potential bitterness.

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Abstract:In the Iberian Peninsula, Brassica crops are grown throughout the year and may be consumed at immature stages or leaves may be harvested by 'picking-over' during plant growth. Consumption of Brassicas in Portugal is high but there is no information on the levels of glucosinolates in such material. Changes in the total and individual glucosinolate concentrations of four Brassica oleracea types (two cultivars of Portuguese cabbage, one Portuguese kale type and one hybrid white cabbage) and one Portuguese Brassica napus type were monitored throughout two growing seasons, spring/summer (SS) and summer/ winter (SW). Glucosinolates were determined between sowing and maturity corresponding to nine sampling dates in the leaves and five harvests in the heads. The main glucosinolates in B oleracea types were 3-methylsulphinylpropyl-, allyland indol-3-ylmethyl-whereas in the B napus type pent-4-enyl-, 2-hydroxybut-3-enyl-and but-3-enylglucosinolate predominated. In the leaves of B oleracea types, the highest concentration of total glucosinolates and of most of the individual glucosinolates was observed at 14 days after sowing whilst, in the heads the highest levels were noted at the start of head formation. In the B napus, the highest total and individual glucosinolate concentration was generally observed at the end of the growing season. Both for the total and for the main individual glucosinolates there were significant differences (P c 0.001) between the nine harvest dates and between growing seasons. Between the two seasons, the glucosinolate levels in SS were generally higher than in SW. A comparison of cultivars showed the hybrid cabbage to have generally higher glucosinolate levels than the Portuguese types, except for B napus.

Abstract:The concentrations of individual and total glucosinolates were measured in four types of Portuguese cabbage and in one hybrid white cabbage before and after cooking. Typical Portuguese culinary procedures include boiling the cabbage for 10 min but for particular kale types the leaves are first shredded then boiled for 5 min (Culdo verde). Analysis of the fresh cabbage, cooked leaves and cooking water showed that the glucosinolate content of the cabbages is reduced by more than 50 %. Almost all of this loss is accounted for as intact glucosinolates in the cooking water, normally used for soups in Portugal.

This paper surveys the literature concerning biological properties of rapeseed glucosinolates, chiefly the goitrogenic activity of these compounds and their influence on the morphological and histological abnormalities of internal organs in animals. An attempt has been made to establish threshold glucosinolate levels in diet which trigger the onset or increase of internal organs impairment in animals depending on their species and breeding.