scholarly journals Anaerobic Production of Methanethiol and Other Compounds by Brassica Vegetables

HortScience ◽  
1999 ◽  
Vol 34 (4) ◽  
pp. 696-699 ◽  
Author(s):  
Charles F. Forney ◽  
Michael A. Jordan
Keyword(s):  
Brassica Oleracea ◽  
Brassica Rapa ◽  
Dimethyl Disulfide ◽  
Anaerobic Conditions ◽  
Brussels Sprouts ◽  
Pak Choi ◽  
Brassica Vegetables ◽  
Headspace Concentration ◽  
Highly Correlated ◽  
Anaerobic Production

Methanethiol (MT) is a volatile compound responsible for the unpleasant odor evolved when fresh broccoli (Brassica oleracea L., Italica group) is held under anaerobic conditions. Inductive atmospheres can develop in storage, transportation containers, or modified atmosphere packages, resulting in reduced quality. To determine if related vegetables are capable of producing MT, 12 different vegetables from the genus Brassica were cut into ready-to-eat forms. Fifty-gram samples were sealed in 500-mL glass jars and flushed with N2. After 24 h in the dark at 20 °C, headspace samples from the jars were analyzed for MT and other volatiles. Headspace concentration of MT was greatest in broccoli florets, followed by pak choi (Brassica rapa L., Chinensis group) leaf blades, savoy cabbage (Brassica oleracea L., Capitata group), broccoflower (Brassica oleracea L., Botrytis group), and green and red cabbage (Brassica oleracea L., Capitata group). Broccoli stems, kale (Brassica oleracea L., Acephala group), Brussels sprouts (Brassica oleracea L., Gemmifera group), pak choi petioles, rutabaga (Brassica napus L., Napobrassica group) root, cauliflower (Brassica oleracea L., Botrytis group) florets, Chinese cabbage (Brassica rapa L., Pekinensis group), and kohlrabi (Brassica oleracea L., Gongylodes group) tubers produced <3% of the MT produced by broccoli florets. Green tissues appeared to have a greater capacity to produce MT than nongreen tissues. Anaerobic production of CO2 and ethanol did not relate to the vegetable's ability to produce MT. The production of dimethyl disulfide (DMDS) and dimethyl trisulfide (DMTS) were also induced by the anaerobic conditions. Green cabbage produced the greatest concentration of DMDS, followed by savoy cabbage and broccoli florets. Production of DMTS was similar to the pattern observed for MT, but DMDS production was not highly correlated with MT production.

scholarly journals Methanethiol Production by Brassica Vegetables Held in Anaerobic Atmospheres

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 823C-823
Author(s):  
Charles F. Forney ◽  
Michael A. Jordan
Keyword(s):  
Chinese Cabbage ◽  
Volatile Compound ◽  
Dimethyl Disulfide ◽  
Modified Atmosphere ◽  
Flower Buds ◽  
Brussels Sprouts ◽  
Pak Choi ◽  
Dimethyl Trisulfide ◽  
Brassica Vegetables ◽  
Headspace Concentration

Methanethiol (MT) is a volatile compound responsible for the strong off-odor that is evolved when fresh broccoli is held under anaerobic atmospheres. Inductive atmospheres can develop in modified-atmosphere packages, resulting in reduced quality. To determine if related vegetables are capable of producing MT, 12 different vegetables from the genus Brassica were cut into ready-to-eat forms. Fifty-gram samples of these cut vegetables were sealed in 500-ml glass jars and flushed with N2. After flushing, jars were held for 24 h at 20C in the dark. Headspace samples from the jars then were analyzed for MT and other volatiles using a GC-MS> The concentration of MT was greatest in jars containing broccoli florets. Broccoli flower buds removed from florets produced 40 times more MT than peduncle and stem tissues (38.3 vs. 0.87 mmol·m–3). Headspace concentration of MT (mmol·m–3) in jars containing these different vegetables was: broccoli florets, 22.7; pak choi leaf blades, 17.8; savoy cabbage, 12.4; broccoflower, 7.5; green storage cabbage, 5.2; red cabbage, 2.7; kale, 0.81; Brussels sprouts, 0.36; pak choi petioles, 0.28; rutabaga root, 0.26; cauliflower florets, 0.18; Chinese cabbage, 0.03; and kohlrabi tubers, 0.02. In addition to MT, ethanol, dimethyl disulfide, and dimethyl trisulfide were detected in the headspace over each of the 12 vegetables. The contribution of these induced compounds to off-odor development in packaged, precut vegetables will be discussed.

scholarly journals Differences in Thermal Stability of Glucosinolates in Five Brassica Vegetables

2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S85-S88 ◽  
Author(s):  
M. Dekker ◽  
K. Hennig ◽  
R. Verkerk
Keyword(s):  
Thermal Stability ◽  
Brussels Sprouts ◽  
Pak Choi ◽  
Red Cabbage ◽  
Indole Glucosinolates ◽  
First Order Kinetics ◽  
Degradation Rates ◽  
Brassica Vegetables ◽  
The Stability ◽  
Thermal Stability Of

The thermal stability of individual glucosinolates within five different Brassica vegetables was studied at 100°C for different incubation times up to 120 minutes. Three vegetables that were used in this study were <I>Brassica oleracea</I> (red cabbage, broccoli and Brussels sprouts) and two were <I>Brassica rapa</I> (pak choi and Chinese cabbage). To rule out the influence of enzymatic breakdown, myrosinase was inactivated prior to the thermal treatments. The stability of three glucosinolates that occurred in all five vegetables (gluconapin, glucobrassicin and 4-methoxyglucobrassicin) varied considerably between the different vegetables. The degradation could be modeled by first order kinetics. The rate constants obtained varied between four to twenty fold between the five vegetables. Brussels sprouts showed the highest degradation rates for all three glucosinolates. The two indole glucosinolates were most stable in red cabbage, while gluconapin was most stable in broccoli. These results indicate the possibilities for plant breeding to select for cultivars in which glucosinolates are more stable during processing.

scholarly journals A SEASON EXTENSION TECHNIQUE FOR COOL SEASON VEGETABLES USING POLY TUNNELS AND ROW COVERS

HortScience ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 269E-269
Author(s):  
Gloria McIntosh ◽  
Gerald Klingaman
Keyword(s):  
Brassica Oleracea ◽  
Brassica Rapa ◽  
Spinacia Oleracea ◽  
Fresh Weight ◽  
Cool Season ◽  
Pak Choi ◽  
Mild Winter ◽  
Row Covers ◽  
Additional Protection ◽  
Season Extension

Spunbonded polyester or polystyrene row covers were used as additional cold protection for spinach (Spinacia oleracea), kale (Brassica oleracea), pak choi (Brassica rapa) and P-types of lettuce (Lactuca savita) grown in ground beds under unheated polyethylene tunnels during the fall and winter of 1991 and 1992 in climatic zone 6. Temperatures inside poly tunnels averaged 2.4C warmer than outside. Average temperatures were 1.9C warmer than control under polystyrene and 1.5C warmer under spunbonded polyester. Average hourly temperatures showed both row covers offered significantly more cold protection than the greenhouse covering alone; but the two row covers offered similar protection from the cold. Row covers did not result in fresh weight differences in most of the species tested, except kale which had greater fresh weight in control. It may be concluded that during a similar mild winter, these cool season vegetables could be grown under unheated polyethylene tunnels with no additional protection necessary. When temperatures are lower, row covers could provide the protection required to produce these crops.

scholarly journals IDENTIFICATION OFVOLATILE COMPOUNDS RESPONSIBLE FOR OFF-ODORS PRODUCED BY BROCCOLI STORED IN ANAEROBIC CONDITIONS

HortScience ◽  
1991 ◽  
Vol 26 (6) ◽  
pp. 700G-701
Author(s):  
Charles F. Forney ◽  
James P. Mattheis ◽  
Rodney K. Austin
Keyword(s):  
Gas Chromatography ◽  
Hydrogen Sulfide ◽  
Ethyl Acetate ◽  
Volatile Compounds ◽  
Brassica Oleracea ◽  
Oxygen Concentration ◽  
Dimethyl Disulfide ◽  
Modified Atmosphere ◽  
Anaerobic Conditions ◽  
Primary Compound

Broccoli (Brassica oleracea L., ltalica Group) produces severe off-odors when it is stored under anaerobic conditions which can develop in modified atmosphere packages. The compounds responsible for these off-odors, which render the broccoli unmarketable, were produced after sealing 50 g of fresh broccoli florets in glass pint jars held at 15C. Twenty-four hours after sealing oxygen concentration dropped to around 0.5% and remained at this concentration for 6 days. Volatile compounds found in the head space of the jars were identified using gas chromatography with flame photometric and mass spectroscopic detection. Volatile compounds produced were identified as methanethiol, hydrogen sulfide, dimethyl disulfide, acetaldehyde, acetone, ethanol, and ethyl acetate. Methanethiol was detected 48 hours after sealing and appears through olfactory evaluation to be the primary compound responsible for the objectionable odor.

Resynthesis of Brassica napus with Brassica oleracea or Brassica rapa Cytoplasm

2010 ◽  
Vol 36 (8) ◽  
pp. 1280-1285 ◽  
Author(s):  
Jun LI ◽  
Li-Xia LUO ◽  
Zhuan WANG ◽  
Jun LI ◽  
Kun-Rong CHEN ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Brassica Oleracea ◽  
Brassica Rapa

scholarly journals Metabolomic analysis reveals the interaction of primary and secondary metabolism in white, pale green, and green pak choi (Brassica rapa subsp. chinensis)

2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Hyeon Ji Yeo ◽  
Seung-A Baek ◽  
Ramaraj Sathasivam ◽  
Jae Kwang Kim ◽  
Sang Un Park
Keyword(s):  
Secondary Metabolites ◽  
Brassica Rapa ◽  
High Performance ◽  
Reducing Power ◽  
Total Phenolic ◽  
Pak Choi ◽  
Primary And Secondary Metabolites ◽  
Chlorophyll Contents ◽  
Significant Difference ◽  
Pale Green

AbstractThis study aimed to comprehensively analyze primary and secondary metabolites of three different-colored (white, pale green, and green) pak choi cultivars (Brassica rapa subsp. chinensis) using gas chromatography attached with time-of-flight mass spectrometry (GC-TOFMS) and high-performance liquid chromatography (HPLC). In total, 53 primary metabolites were identified and subjected to partial least-squares discriminant analysis. The result revealed a significant difference in the primary and secondary metabolites between the three pak choi cultivars. In addition, 49 hydrophilic metabolites were detected in different cultivars. Total phenolic and glucosinolate contents were highest in the pale green and green cultivars, respectively, whereas total carotenoid and chlorophyll contents were highest in the white cultivar. Superoxide dismutase activity, 2,2-diphenyl-1-picrylhydraz scavenging, and reducing power were slightly increased in the white, pale green, and green cultivars, respectively. In addition, a negative correlation between pigments and phenylpropanoids was discovered by metabolite correlation analysis. This approach will provide useful information for the development of strategies to enhance the biosynthesis of phenolics, glucosinolates, carotenoids, and chlorophyll, and to improve antioxidant activity in pak choi cultivars. In addition, this study supports the use of HPLC and GC-TOFMS-based metabolite profiling to explore differences in pak choi cultivars.

scholarly journals Identification and Functional Characterization of a Cold-Related Protein, BcHHP5, in Pak-Choi (Brassica rapa ssp. chinensis)

2018 ◽  
Vol 20 (1) ◽  
pp. 93
Author(s):  
Jin Wang ◽  
Feiyi Huang ◽  
Xiong You ◽  
Xilin Hou
Keyword(s):  
Brassica Rapa ◽  
Abiotic Stresses ◽  
Quantitative Polymerase Chain Reaction ◽  
Functional Characterization ◽  
Regulation Mechanism ◽  
Pak Choi ◽  
Negative Effect ◽  
Polymerase Chain ◽  
Related Proteins

In plants, heptahelical proteins (HHPs) have been shown to respond to a variety of abiotic stresses, including cold stress. Up to the present, the regulation mechanism of HHP5 under low temperature stress remains unclear. In this study, BcHHP5 was isolated from Pak-choi (Brassica rapa ssp. chinensis cv. Suzhouqing). Sequence analysis and phylogenetic analysis indicated that BcHHP5 in Pak-choi is similar to AtHHP5 in Arabidopsis thaliana. Structure analysis showed that the structure of the BcHHP5 protein is relatively stable and highly conservative. Subcellular localization indicated that BcHHP5 was localized on the cell membrane and nuclear membrane. Furthermore, real-time quantitative polymerase chain reaction (RT-qPCR) analysis showed that BcHHP5 was induced to express by cold and other abiotic stresses. In Pak-choi, BcHHP5-silenced assay, inhibiting the action of endogenous BcHHP5, indicated that BcHHP5-silenced might have a negative effect on cold tolerance, which was further confirmed. All of these results indicate that BcHHP5 might play a role in abiotic response. This work can serve as a reference for the functional analysis of other cold-related proteins from Pak-choi in the future.

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