Analysis of total glucosinolates and chromatographically purified benzylglucosinolate in organic and conventional vegetables

Abstract

The limited availability of foods that are free of pesticides has led Brazil to search for alternative production methods to meet the desires of consumers. Currently, organic cultivation represents a production system that complies with general expectations of producers and consumers. Organic cultivation is particularly interesting mainly because of its effect on plant secondary metabolite content, which may help plants to naturally combat pests; in humans, these substances can also contribute to the prevention of chronic diseases. We report on the extraction of glucosinolates (both as total glucosinolates and as benzylglucosinolate) with trifluoracetic acid addition in a 70:30 MeOH:water (v/v). Total glucosinolates, determined by a thioglucosidase coupled assay, were measured in different Brassicaceae species and were similar to values reported in the literature. For broccoli, analyses were carried out separately on inflorescences, leaves and stalks; analyses were also conducted on thermally processed samples to simulate cooking. Furthermore, when the analysis was conducted on conventional and organic products, the highest concentrations of these substances were most often found in organically cultivated Brassicaceae. The benzylglucosinolate concentrations were evaluated on the same samples using HPLC. The concentration of benzylglucosinolate was significantly higher in organically cultivated vegetables, as well

Glucosinolates, Carotenoids, and Vitamins E and K Variation from Selected Kale and Collard Cultivars

“…The profile of glucosinolates of kale has been shown to vary depending on crop, cultivar, maturity, or plant tissue [8,9]. However, the glucosinolate profile in collard has only been reported relatively recently and there is a large variation in glucosinolate content, partially due to different cultivars investigated [10][11][12].…”

Conventional and Organic Farming — Does Organic Farming Benefit Plant Composition, Phenolic Diversity and Antioxidant Properties?

“…Apple Polyphenols Higher in organic production [86] Chinese cabbage Flavonoids Higher in organic production [87] Spinach Flavonoids Higher in organic production [87] Green pepper Flavonoids Higher in organic production [87] Pear Polyphenols Higher in organic production [88] Yellow plum Quercetin Lower in organic production [89] Apple Anthocyanins Higher in organic production [90] Tomato Lycopene Similar content in both systems [91] Broccoli Total glucosinolates Lower in organic production [92] Strawberry Polyphenols Similar content in both systems [93] Tomato Carotenes Higher in organic production [94] Tomato Polyphenols Lower in organic production [95] Blueberry Polyphenols Higher in organic production [96] Tomato β-carotene Higher in organic production [42] Tomato Lycopene Lower in organic production [42] Carrot Carotenoids Similar content in both systems [97] Egg-plant pulp Phenolics Similar content in both systems [98] Cauliflower Glucosinolates Similar content in both systems [48] Strawberry Anthocyanins Higher in organic production [79] Soybeans Isoflavones Lower in organic production [99] Broccoli and collard greens Glucosinolates Higher in organic production [100] Watercress Glucosinolates Lower in organic production [100] Broccoli Glucosinolates Lower in organic production [80] Tomato Polyphenols and lycopene Higher in organic production [53] Pepper Higher Lower in organic production [101] Broccoli Polyphenols Similar content in both systems [102] Broccoli Glucosinolates Higher in organic production [102] Table 4. Summary of studies comparing phytochemical contents in fruits and vegetables from organic and conventional production…”

Three in One: The Potential of Brassica By-Products against Economic Waste, Environmental Hazard, and Metabolic Disruption in Obesity

“…Table 1 shows the main compounds present in broccoli leaves and stems. Several compounds can vary in concentration depending on the part of the plant being studied [80], type of culture [81], the season of harvest [80], and several other factors [82]. For example, glucosinolates exist in greater quantity in the stems than in the leaves [80,81,83].…”