Current studies on onion and its pungency Part 2. Interactive effects of sulfur fertilization and drying under the aspect of solar energy utilization

Bakr, Anar A.

doi:10.1002/(sici)1521-3803(199804)42:02<94::aid-food94>3.0.co;2-h

Cited by 3 publications

(2 citation statements)

References 6 publications

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“…The effect of each counter anion on the quality of vegetables has been reported as follows: depression in the uptake and accumulation of nitrate, which may be hazardous to human health (Maynard et al, 1976), in several types of vegetables due to chloride application (Katoh et al, 2006;Liu and Shelp, 1996;Maynard et al, 1976); increase in the concentrations of glucosinolate or isothiocyanate, which are indicators of the degree of pungency and bitterness in radish and turnip, due to sulfate application (Ishii and Saijo, 1987;Kim et al, 2002); and increase in the concentration of pyruvate, which is an estimator of the degree of pungency in onions, due to sulfate application (Bakr and Gawish, 1998;Randle and Bussard, 1993).…”

Section: Introductionmentioning

confidence: 99%

Concentrations of Nitrate, Organic Acids, Free Amino Acids, Cations and Sugars in Komatsuna (Brassica campestris var. perviridis) Grown with Carbonate, Sulfate and Chloride Application

Nakagawa¹,

Kikegawa²,

Nomura³

2008

J. Japan. Soc. Hort. Sci.

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This study compared the concentrations of components such as nitrate, organic acids, free amino acids, cations and sugars in komatsuna (Brassica campestris var. perviridis) grown with carbonate, sulfate and chloride application (CO 3 -TK, SO 4 -TK and Cl-TK, respectively). The komatsuna was cultivated in 1/2000-a Wagner pots (6 hills per pot) filled with light-colored Andosol in a glasshouse for 37 days at soil water potential (SWP) right before harvesting of −6.2 and −62 kPa. And 26.5 mmol c of carbonate, sulfate or chloride in the form of potassium salts was applied to each pot. Chloride application to the komatsuna induced relatively high concentrations of potassium, calcium and magnesium ions, and the low concentrations of malate, glucose and fructose on a dry weight basis (DWB). Carbonate application induced relatively high concentrations of malate and low concentrations of nitrate. Sulfate was almost between chloride and carbonate. Concentration variation was not substantial in free amino acids. Those tendencies were almost the same in both SWPs. Most of the variations in component concentrations were attributed to the regulation of ionic and osmotic balance to respond to chloride, nitrate and sulfate absorption, as judged from quantitative relationships among the components and water in the komatsuna. It seems that the absorption of nitrate is influenced by the pH of the soil. There were clear differences in glucose, fructose and malate concentrations among CO 3 -TK, SO 4 -TK and Cl-TK on a fresh weight basis just as on a DWB.

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Section: Introductionmentioning

confidence: 99%

Concentrations of Nitrate, Organic Acids, Free Amino Acids, Cations and Sugars in Komatsuna (Brassica campestris var. perviridis) Grown with Carbonate, Sulfate and Chloride Application

Nakagawa¹,

Kikegawa²,

Nomura³

2008

J. Japan. Soc. Hort. Sci.

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“…In addition, hydroponic studies have also shown that nitrogen supply can affect flavour precursor levels (Coolong and Randle, 2003;Randle, 2000). However, surprisingly few field-based studies have demonstrated effects of S (or N) nutrition on pungency (Bakr and Gawish, 1998;Kumar and Sahay, 1954).…”

Section: Introductionmentioning

confidence: 99%

Sulfur and nitrogen fertility affects flavour of field-grown onions

et al. 2005

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Although glasshouse studies have conclusively demonstrated that S nutrition can affect onion (Allium cepa L.) pungency this has been rarely observed in field-based studies due to difficulties in controlling S nutrition and lack of efficient methods for measurement of flavour bioactives. We have developed a rapid automated method for determination of onion lachrymatory factor ((Z, E)-thiopropanal-S-oxide; LF) based on juice extraction into dichloromethane and gas chromatography (GC) analysis with flame photometric detection. We evaluated this in a field trial of a mild (cv. 'Encore') and a pungent (cv. 'Kojak') onion cultivar grown on a low S soil with and without S addition, under high or low N treatments. No treatments significantly affected bulb fresh weight but S fertilisation significantly increased bulb total S, sulfate, pungency, LF and flavour precursor levels in both varieties. Analysis of bulb flavour precursors by HPLC confirmed that juice LF levels paralleled levels of the flavour precursor S-1-propenyl cysteine sulfoxide. The pungent cultivar also exhibited significant N main effects on bulb LF, total S and sulfate. We also assayed the key S-assimilatory enzyme, APS reductase (APR) in leaves before and during bulbing. Specific activities in the range of 1 to 11 nmol mg −1 ·min −1 were observed in youngest leaves, but only the milder cultivar exhibited significant stage × N × S effects. These findings suggest that sulfur metabolism of mild and pungent onions respond differently to N fertility, and that GC of LF is practical for field-based studies of onion flavour.Abbreviations: ACSO -alkyl cysteine sulfoxide; APR -adenosine 5 phosphosulfate reductase (EC 1.8.99.2); EPY -enzymatically produced pyruvic acid; FID -flame ionisation detector; FPD -flame photometric detector; GC-MS -gas chromatography-mass spectroscopy; HPLC -high performance liquid chromatography; LFlachrymatory factor (Z, E)-thiopropanal-S-oxide; MCSO -S-methyl-L-cysteine sulfoxide; PrCSO -S-1-propenyl cysteine sulfoxide.

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