This research was conducted to evaluate glucosinolate profiles, vitamin C, total phenol, total flavonoid, and free sugar (glucose, fructose, and sucrose) content, fatty acid composition, and antioxidant activity in floret and leaf of six cauliflower and broccoli cultivars. The level of chemical constituents as well as antioxidants significantly varied among crop types, cultivars, and their different parts, in that phytochemicals such as glucosinolate were statistically higher in florets compared with leaves in both broccoli and cauliflower cultivars. In contrast, total flavonoid and free sugar were found at higher levels in the leaf parts. The Asia purple cultivar exhibited statistically higher vitamin C (649.7 mg·100 g ) contents, respectively compared with other cultivars. Likewise, the major fatty acids were palmitic (23.52%-38.42%), linoleic (13.09%-18.97%), and linolenic (26.32%-51.80%) acids, which comprised the highest compositional ratio (more than 50%) of polyunsaturated fatty acids (PUFAs) in most cultivars. Among the antioxidants, total phenol exhibited the most significant positive correlation (r = 0.698 **) with antioxidant activity, followed by vitamin C (r = 0.522 **) and total flavonoid (r = 0.494 **), indicating their significant contributions to total antioxidant activity.

The aim of this study was to quantify the contents of individual quercetin glycosides in red, yellow and chartreuse onion by High Performance Liquid Chromatography (HPLC) analysis. Acid hydrolysis of individual quercetin glycosides using 6 M hydrochloric acid guided to identify and separate quercetin 7,4'-diglucoside, quercetin 3-glucoside, quercetin 4'-glucoside, and quercetin. The contents of total quercetin glycosides varied extensively among three varieties (ranged from 16.10 to 103.93 mg/g DW). Quercetin was the predominant compound that accounted mean 32.21 mg/g DW in red onion (43.6% of the total) and 127.92 mg/g DW in chartreuse onion (78.3% of the total) followed by quercetin 3-glucoside (28.83 and 24.16 mg/g DW) respectively. Quercetin 3-glucoside levels were much higher in yellow onion (43.85 mg/g DW) followed by quercetin 30.08 mg/g DW. Quercetin 4'-glucoside documented the lowest amount that documented mean 2.4% of the total glycosides. The varied contents of glycosides present in the different onion varieties were significant.

No abstract

This study was performed to monitor glucosinolate (GSL) profile, total phenol, ascorbic acid, total flavonoid contents, and antioxidant activity in florets of six broccoli (Brassica oleracea L. var. italica Plenck) genotypes at three different inflorescence developmental stages. The level of phytochemicals and antioxidant activities varied significantly among genotypes and developmental stages. Out of the eight GSLs identified in this study, only five were present in all genotypes and their respective developmental stages. Glucoraphanin (GRA), a major GSL, was significantly increased towards the later stages of development (1.41 μg g-1 in immature stage of 'Koyoshi' to 10.57 μg g-1 in commercial stage of '09FA-M295'), whereas glucobrassicin (BRA) showed a reverse accumulation pattern with the highest value at the immature stage (5.10-7.97 μg g-1). Other minor GSLs varied depending on the genotype. Total phenolic and ascorbic acid content increased significantly as maturity progressed in all the genotypes with a relatively higher increment observed in ascorbic acid (65.8%-100.9%) than phenolic content (10.2%-31.2%). Flavonoid content, on the other hand, showed a cultivardependent accumulation pattern throughout the developmental stages. However, although antioxidant activity increased with inflorescence development, the increment was higher and lower than in total phenol and ascorbic acid content, respectively. The highest value for GRA (10.57 μg g-1), ascorbic acid (502.3 mg 100 g-1), total phenol (523.7 mg 100 g-1) and antioxidant activities was obtained for '09FA-M295' at the commercial stage. Taken together, these results indicate that phytochemicals in broccoli have a differential accumulation pattern during inflorescence development. Regardless of genotypes and inflorescence developmental stage, total phenolic content showed the highest correlation with antioxidant activity (r = 0.779**), followed by ascorbic acid (r = 0.674**) and flavonoid content (r = 0.602**), whereas total GSLs showed a nonsignificant correlation with antioxidant activity.

Florets, leaves, and stems of twelve commercial broccoli cultivars grown in the spring and fall seasons at the National Institute of Horticultural and Herbal Science (NIHHS), Rural Development Administration (RDA), Suwon, South Korea were evaluated for glucosinolates, vitamin C, total phenol, and total flavonoid contents and antioxidant activity. The levels of all phytochemicals and antioxidant activity were significantly influenced by cultivar (C), plant part (P), and growing season (S). Among the glucosinolates, glucoraphanin and glucobrassicin were the major constituents. The highest total glucosinolate content was found in the florets of plants grown in both seasons. Phenols and flavonoids were highest levels in leaves, while vitamin C was highest in stems, suggesting that broccoli leaves and stems may be good sources of such phytochemicals. The levels of all phytochemicals were generally higher in florets in the spring than in the fall, but were higher in leaves and stems during the fall than the spring. Furthermore, higher cultivar-dependent and tissue-dependent variation was observed in the spring than in the fall. Total phenol content exhibited a strong positive correlation (r = 0.674**) with antioxidant activity, followed by total flavonoid content (r = 0.497**), indicating their significant contribution to total antioxidant activity.

Embryos derived from isolated microspore culture are of great importance for producing homozygous plants for breeding. Microspore culture can reduce time and laborious effort in the breeding of Brassica plants. Microspore derived embryos (MDE) formation in broccoli (Brassica oleracea L. var. italica Plenck) was studied with different plant growth regulators (PGRs), activated charcoal, and silver nitrate (AgNO3) to determine the optimal chemical conditions in the microspore culture. A 6-benzylaminopurine (BA) concentration of 0.05 mg L -1 resulted in increased MDE formation compared to those at other BA concentrations. Compared to the 0.05 mg L -1 BA concentration, fewer MDEs were formed in BA concentrations exceeding 0.1 mg L -1 , similar to those cultured on medium without BA. However, 0.5× Nitsch & Nitsch (NLN) liquid medium supplemented with 0.05 mg L -1 napthalene acetic acid (NAA) and BA was more effective in inducing MDE formation than was BA alone. The higher MDE formation rate was observed in 0.5× NLN liquid culture medium containing 0.05 mg L -1 NAA and 0.01 mg L -1 BA. The MDE yield was significantly higher in all concentrations when activated charcoal was added to the microspore culture media. The optimal concentration of activated charcoal was 1.0 mg per petri dish, and the optimum AgNO3 concentration was 0.1 mg L -1 , which induced MDE formation to 26.2 embryos, compared to 11.6 embryos without AgNO3.

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Seasonal variation in the contents of sugars (fructose, glucose, and sucrose) in the floret, leaf, and stem of broccoli were studied in ten commercial broccoli cultivars. Plants were grown in the spring and fall seasons in 2011. In both seasons, glucose was the major constituent, comprising about 50% of the total sugar content in the floret and leaf tissue of most cultivars, whereas the broccoli stem showed an unusual pattern of accumulation. Sucrose exhibited greater cultivar dependency as well as seasonal variation compared to fructose and glucose in floret and leaf tissues. The floret tissue had a higher total content of sugar in the spring compared to the fall due to an increase in glucose and fructose. However, most of the leaf and stem tissues of broccoli had a higher total sugar content in the fall compared to the spring. Furthermore, stem and leaf tissues possessed a relatively higher total sugar content compared to floret tissue in both seasons. 'Grandeur' broccoli contained a significantly greater amount of total sugar in both floret and leaf tissues in both seasons, whereas 'YuDoRi No.1' broccoli exhibited the highest total content of sugar in stem tissue. At overall, the results showed significant influences of genotype, plant part and growing season on sugar content in broccoli.