Onion Oil Research Articles

Organosulfur chemistry of garlic and onion: Recent results

Abstract

Novel flavour components identified in the steam distillate of onion (Allium cepa L.)

Constituents of volatile steam-distilled onion oil were analysed by gas chromatography and gas chromatography/mass spectrometry. Among 49 identified components, 1-(methylthio)1-propanethiol, 1-(propylthio)1-propanethiol, 5,6-dihydro-2-methyl-4,6-diethyl-4H-1,3,5-dithiazine, 5,6-dihydro-6-methyl-2,4-diethyl-4H-1,3,5-dithiazine, 5,6-dihydro-2,4,6-triethyl-4H-1,3,5-dithiazine and 2,4,6-triethyl-1,3,5-trithiane are reported in the oil of onion (Allium cepa L.) for the first time. They account for 18.6% of the total volatiles. Reactions of fatty aldehydes, hydrogen sulphide, thiols and ammonia, induced by the distillation process, may be responsible for the formation of these compounds.

Chemoprevention of chemically induced skin tumor development by diallyl sulfide and diallyl disulfide.

Garlic and onion oil have been shown to inhibit chemically induced skin tumor development in mice. In the present study, the effects of diallyl sulfide and diallyl disulfide, oil-soluble constituents of garlic and onion, on 7,12-dimethylbenz(a)anthracene-induced and 12,O-tetradecanoylphorbol-13-acetate-promoted skin tumor formation were examined in SENCAR mice. Topical application of diallyl sulfide or diallyl disulfide significantly inhibited skin papilloma formation from the ninth week of promotion and significantly increased the rate of survival in the murine model. Our findings support earlier evidence that these naturally occurring compounds may be useful for the chemoprevention of certain types of tumors.

Inhibition of Germination, Outgrowth, and Vegetative Growth of Clostridium botulinum 67B by Spice Oils

The oils of clove, thyme, black pepper, pimenta, origanum, garlic, onion, and cinnamon were tested for their activity on germination, outgrowth, and vegetative growth of Clostridium botulinum 67B in broth media. Garlic, onion, cinnamon, thyme, origanum, and black pepper oils at a concentration of 100 ppm prevented germination of C. botulinum 67B spores. Clove and pimenta oils at a concentration of 150 ppm prevented germination. The effect of spice oils on spore germination was reversible. The oils of black pepper and clove had a greater inhibitory effect on vegetative growth than the other oils. None of the oils had a significant effect on outgrowth.

Papilloma and carcinoma production in DMBA‐initiated, onion oil‐promoted mouse skin

Groups of 20 females Ha/ICR mice were initiated with 25 micrograms 7,12-dimethylbenz[a]anthracene (DMBA) and promoted one week later with topical treatments three times per week of 5 micrograms phorbol myristate acetate (PMA) and/or onion oil or garlic oil. Promotion was continued for 49 weeks in most experiments. Promotion was continued for 60 weeks in the experiment that evaluated the effect of time intervals between PMA and garlic oil. All experiments were conducted with 0.2 ml acetone solutions of agents. Onion oil, but not garlic oil, was a weak promoter in mouse skin. A 1-mg dose produced five papillomas in three mice and one carcinoma in 330 days (18 survivors). The 10-mg dose was more effective; it produced cumulative yields of 56 papillomas in 14 mice and 7 carcinomas in 4 mice in 345 days (14 survivors). Onion oil is neither an initiator nor a whole carcinogen. The effects of intervals between PMA and a 1-mg dose of onion or garlic oil were determined. These intervals were -2 hrs, -1 hr, -0.5 hr, +0.5 hr, +1 hr, and +2 hrs with respect to time of PMA application. Maximal inhibition of papillomas by onion oil was observed at the +0.5-hr interval and was similar to that previously reported. Garlic oil is not a promoter. It inhibited papillomas at the +0.5-hr, +1.0-hr, and +2.0-hr intervals but did not appear to affect carcinoma production.

Inhibition of DMBA‐induced mouse skin tumorigenesis by garlic oil and inhibition of two tumor‐promotion stages by garlic and onion oils

A single 2-mg dose of garlic oil applied 30 minutes before a single carcinogenic dose of 7,12-dimethylbenz[a]-anthracene (DMBA) inhibited papilloma production in Sencar mice. The three groups were controls (Group 1), garlic oil applied 30 minutes before DMBA (Group 2), and garlic oil applied 30 minutes after DMBA (Group 3). The percents of mice with papillomas at 20 weeks were 94, 72, and 79, respectively. The decreases in Groups 2 and 3 were significant. The number of papillomas per mouse was 4.2 +/- 0.5 (Group 1), 2.3 +/- 0.8 (Group 2), and 3.4 +/- 0.6 (Group 3). The decrease in Group 2 was significant. A single 5-mg dose of garlic oil maximally inhibited DMBA-induced epidermal DNA synthesis by 86% when applied two hours before the carcinogen. Two-stage promotion in DMBA-initiated Sencar mice was achieved by twice-weekly applications of 8.5 nmol of 12-O-tetradecanoylphorbol-13-acetate (TPA) for 2 weeks followed by twice-weekly applications of 8.5 nmol of mezerein for 18 weeks. The oils were applied 30 minutes after each promotion by TPA or mezerein. Single doses of 1 mg onion or garlic oil inhibited the first and second stages of promotion. The groups used were control (Group 1), garlic oil applied after stage 1 (Group 2), onion oil applied after stage 1 (Group 3), propenyl sulfide applied after stage 1 (Group 4), garlic oil applied after stage 2 (Group 5), onion oil applied after stage 2 (Group 6), and propenyl sulfide applied after stage 2 (Group 7). The percent of mice with papillomas was significantly decreased by all agents in Groups 2-7. The data are 81, 83, 91, 68, 96, and 86, respectively. The number of papillomas per mouse was significantly reduced by onion and garlic oils but not by propenyl sulfide. The data are 9.4 +/- 0.8, 6.3 +/- 0.7, 7.4 +/- 0.5, 9.2 +/- 1.2, 3.7 +/- 0.9, 6.2 +/- 0.6, and 9.1 +/- 1.4 for Groups 1-7, respectively. Onion and garlic oils inhibited the TPA-stimulated DNA synthesis when given as single doses of 5 mg one hour before TPA. The inhibition by garlic oil was most effective when given one hour before TPA but was evident when given from two hours before to two hours after TPA. These results, and those of others (AS Sadhana, Cancer Lett, 40, 193-197, 1988), who obtained inhibition of initiation, indicate that onion and garlic oils inhibit all stages of mouse skin tumorigenesis.(ABSTRACT TRUNCATED AT 400 WORDS)

Onion essential oil chemistry. Cis-and trans-2-mercapto-3,4-dimethyl 2,3-dihydrothiophene from pyrolysis of bis(1-propenyl) disulfide

Heating the onion oil component bis(1-propenyl) disulfide gives cis/-and trans-2-mercapto-3,4-dimethyl-2,3-dihydrothiophene which can lose H 2S upon further heating giving 3,4-dimethylthiophene. A dithio-Claisen rearrangement is proposed for the key step.

Inhibition of soybean lipoxygenase and mouse skin tumor promotion by onion and garlic components

Onion and garlic essential oils were previously shown to inhibit mouse skin tumor promotion, as were the enzymes, lipoxygenase, and cyclooxygenase. In the present study, the inhibition of soybean lipoxygenase (EC 1.13.11.12) by onion and garlic components and related compounds was investigated. The IC50 values as well as the kinetic inhibition constants were determined for the most active compounds. Di-(1-propenyl) sulfide, an analog of the substrate moiety required for oxygenase action, was the only irreversible inhibitor observed with Ki = 59 microM and k3 = 0.53/min. Inhibition in the presence of substrate was uncompetitive at 88 and 132 microM linoleic acid with Ki = 129 microM. At 173 microM linoleic acid, however, inhibition was competitive with Ki = 66 microM. Dially trisulfide, allyl methyl trisulfide, and diallyl disulfide were competitive inhibitors, while 1-propenylpropyl sulfide and (E, Z)-4,5,9-trithiadodeca-1,6,11-triene 9-oxide (ajoene) were mixed inhibitors. Nordihydroguaiaretic acid (NDGA), the most potent lipoxygenase inhibitor, was a competitive inhibitor with Ki = 0.29 microM. The results indicate a relative potency of inhibition for structural features in the following order: di(1-propenyl) sulfide greater than an alkenyl trisulfide greater than an alkenyl disulfide. Di(n-propyl) disulfide, a major onion oil component, inhibited neither lipoxygenase nor promotion. Di(1-propenyl) sulfide and ajoene inhibited both. This suggests that the inhibition of lipoxygenase may be involved in antipromotion.

Protease inhibitors interfere with the necessary factors of carcinogenesis.

Many tumor promoters are inflammatory agents that stimulate the formation of oxygen radicals (.O2-) and hydrogen peroxide (H2O2) in phagocytic neutrophils. The neutrophils use the oxygen radicals to kill bacteria, which are recognized by the cell membrane of phagocytic cells causing a signal to mount the oxygen response. The tumor promoter isolated from croton oil, 12-O-tetradecanoylphorbol-13-acetate (TPA), mimics the signal, causing an oxygen radical release that is intended to kill bacteria; instead, it injures cells in the host. Oxygen radicals cause single strand breaks in DNA and modify DNA bases. These damaging reactions appear to be related to tumor promotion, as three types of chemopreventive agents, retinoids, onion oil, and protease inhibitors, suppress the induction of oxygen radicals in phagocytic neutrophils and suppress tumor promotion in skin cancer in mice. Protease inhibitors also suppress breast and colon cancers in mice. Protease inhibitors capable of inhibiting chymotrypsin show a greater suppression of the oxygen effect and are better suppressors of tumor promotion. In addition, oxygen radicals may be one of the many agents that cause activation of oncogenes. Since retinoids and protease inhibitors suppress the expression of the ras oncogene in NIH 3T3 cells, NIH 3T3 cells may serve as a relatively facile model for finding and measuring chemopreventive agents that interfere with the carcinogenic process.

Investigation on the volatile oil of Makó onions

AbstractThe authors have developed a method for determining the volatile oil content of onions. Using this method they found in the Hungarian Makó onions 0.019—0.031 % volatile oil, depending on storage. The composition of onion oil was studied by GC; GC‐MS and TLC methods.GC‐MS revealed 20 volatile sulphur compounds identified as 10 trisulphides, 6 disulphides, 3 tetrasulphides, and 1 thiophene derivative as well as one unsaturated aldehyde. Three of these: ethyl cis‐1‐propenyl trisulphide, ethyl trans‐1‐propenyl trisulphide, and butyl methyl trisulphide were described for the first time in onions. Carbonyl compounds were studied in the form of derivatives obtained with 2,4‐dinitrophenyl hydrazine. On the basis of Rf‐values and by addition, propanal, butanal, pentanal and hexanal were identified in the aldehyde fraction, while in the dicarbonyl fraction — beside an unknown compound — glyoxal and methyl glyoxal were identified. The presence of these two compounds in onion oil has been reported for the first time.

Antiasthmatic Effects of Onions

Lyophilized onion extract and ether extracts of onions were separated by chromatographic methods into several subfractions and tested for their effects on asthmatic reactions of guinea pigs to allergen, histamine, acetylcholine and platelet-activating factor (PAF) inhalation as well as on thromboxane biosynthesis of human platelets and lung fibroblasts. Onion oils are counteracting the bronchial obstruction due to PAF inhalation.

Stimulation of cell growth and proliferation in NIH-3T3 cells by onion and garlic oils.

Onion and garlic oil were seen to shorten the cell-doubling time and stimulate the growth and proliferation of NIH-3T3 cells. Following treatment with either onion or garlic oil, an increase in the growth rate and almost a 2-fold increase in cell number over the control was observed within a 24-hour period. Phorbol myristate acetate when given simultaneously with either oil appeared to nullify both effects. Following exposure to low doses (less than 10 micrograms/ml) of either oil, an increase in cell survival, not seen with the oil control tricaprylin, was observed following a 5-day exposure period. At higher concentrations cell survival decreased proportionately in all cases. The appearance of multinucleated cells, which increased with dose and time, was also observed following treatment with both garlic and onion oil.

The genus Allium. Part 2.

Allium is a genus of some 500 species belonging to the family Liliaceae. However only a few of these are important as food plants, notably onion, garlic, chive, leek, and rakkyo. Such plants have been used for many centuries for the pungency and flavoring value, for their medicinal properties, and, in some parts of the world, their use also has religious connotations. The flavors of members of the genus Alliums, in addition to having certain characteristics, are also complex, being derived enzymically from a number of involatile precursors. In addition to there being variation of flavor between different alliums, there are also considerable changes that occur as a result of cooking and processing. Of course, these are of importance to the consumer and food technologist-processor. The review will introduce the subject by an historical perspective and will set this against data on the present cultivation and usage of commercially cultivated alliums. The chemical composition of these plants will be discussed, emphasis being given to nonvolatile constituents which are, perhaps, less often considered. Discussion of the volatile constituents, which will include mention of the methods currently used for their analysis and for the determination of "flavor strength", will be mainly concerned with literature taken from the last 5 years. In considering the extent and nature of allium cultivation and processing, factors affecting the nutritional value and quality will be highlighted. The medicinal properties of garlic and onion oils have been much studied over the last decade and the review will include critical assessment of this area and also will touch on the more general properties (antimicrobial, antifungal, antibacterial, and insecticidal) of these oils. Finally mention will be made of the antinutritional, toxic, or otherwise undesirable effects of alliums, for example, as inadvertent components of animal diets, tainting of milk and other food products. It is our intention to review the literature up to mid-1984.

The genus Allium--Part 3.

Allium is a genus of some 500 species belonging to the family Liliaceae. However, only a few of these are important as food plants, notably onion, garlic, chive, leek, and rakkyo. Such plants have been used for many centuries for their pungency and flavoring value, for their medicinal properties, and in some parts of the world, their use also has religious connotations. The flavors of members of alliums, in addition to being characteristic, are also complex, being derived enzymically from a number of involatile precursors. As well as there being variation of flavor between different alliums there are also considerable changes that occur as a result of cooking and processing. These are, of course, of importance to the consumer and food technologist/processor. The review will introduce the subject by an historical perspective and will set against this data on the present cultivation and usage of commercially cultivated alliums. The chemical composition of these plants will be discussed, emphasis being given to nonvolatile constituents which are, perhaps, less often considered. Discussion of the volatile constituents, which will include mention of the methods currently used for their analysis and for the determination of "flavor strength," will be mainly concerned with literature taken from the last 5 years. In considering the extent and nature of allium cultivation and processing, factors affecting the nutritional value and quality will be highlighted. The medicinal properties of garlic and onion oils have been extensively studied over the last decade and the review will include critical assessment of this area; it will also touch on the more general properties (antimicrobial, antifungal, antibacterial, and insecticidal) of these oils. Finally, mention will be made of the antinutritional, toxic, or otherwise undesirable effects of alliums, for example, as inadvertant components of animal diets, tainting of milk, and other food products. It is our intention to review the literature up to mid-1984.

Effects of essential oils and oleoresins of plants on ethanol production, respiration and sporulation of yeasts

Ethanol production, respiration, and sporulation of yeasts as effected by essential oils and oleoresins of allspice, cinnamon, clove, garlic, onion, oregano, savory, and thyme were investigated. Essential oils of allspice, cinnamon, and clove had little or no effect on ethanol production by Sacchraromyces cerevisiae. Oils of onion, oregano, savory, and thyme delayed and/or reduced the production of ethanol. Overall, essential oils effectively suppressed ethanol production by Hansenula anomala. At the highest concentrations tested (500 μg/ml), only cinnamon, clove, garlic and thyme oleoresins substantially delayed and/or reduced ethanol production by S. cerevisiae. Most of the essential oils (100 μm/ml) impaired the respiratory activity of S. cerevisiae as evidenced by a reduction in CO 2 production. Thyme oleoresin was the strongest inhibitor. Allspice and garlic oils impaired sporulation by H. anomala. All oils delayed sporulation of Lodderomyces elongisporus).

Effects of Essential Oils from Plants on Growth of Food Spoilage Yeasts

ABSTRACTThirty‐two essential oils from plants were screened for inhibitory effects on 13 food‐spoilage and industrial yeasts. Of these, essential oils of allspice, cinnamon, clove, garlic, onion, oregano, savory, and thyme were most inhibitory. Oils were subsequently tested for their effects on biomass production and pseudomycelium formation of eight genera of yeasts. Garlic oil was a potent inhibitor of yeast growth at concentrations as low as 25 ppm. The oils of onion, oregano and thyme were also strongly inhibitory. Essential oils (100 ppm) had no effect on pseudomycelium production by Candida lipolytica. However, all eight essential oils delayed pseudomycelium formation by Hansenula anomala, whereas six oils stimulated pseudomycelium production by Lodderomyces elongisporus. Cinnamon and clove oils were clearly stimulatory to pseudomycelium production by Saccharomyces cerevisiae.

Sensitivity of heat-stressed yeasts to essential oils of plants.

Eight strains of yeasts (Candida lipolytica, Debaryomyces hansenii, Hansenula anomala, Kloeckera apiculata, Lodderomyces elongisporus, Rhodotorula rubra, Saccharomyces cerevisiae, and Torulopsis glabrata) were examined for changes in sensitivity to eight essential oils of plants (allspice, cinnamon, clove, garlic, onion, oregano, savory, and thyme) after being sublethally heat stressed. With the exception of garlic oil for all test yeasts, onion oil for S. cerevisiae, and oregano oil for R. rubra, the essential oils at concentrations of up to 200 ppm in recovery media did not interfere with colony formation by unheated cells. However, some oils, at concentrations as low as 25 ppm in recovery media, reduced populations of sublethally heat-stressed cells compared to populations recovered in media containing no test oils. This demonstrates that the yeasts were either metabolically or structurally damaged as a result of being exposed to elevated temperatures and that essential oils prohibited repair of injury. The size (diameter) of colonies produced on oil-supplemented recovery agar by heat-stressed cells was reduced compared to that observed on unsupplemented agar. Pigment production by heated R. rubra was inhibited by oils of oregano, savory, and thyme, but enhanced by garlic and onion oils. The influence of essential oils on survival of yeasts in thermally processed foods and in the enumeration of stressed cells in these foods should not be minimized.

Hypolipidemic action of onion and garlic unsaturated oils in sucrose fed rats over a two-month period.

The feeding of a high-sucrose diet to normal rats for a period of 2 months increased serum and tissue cholesterol and triglycerides very significantly. Simultaneous feeding of the unsaturated oils of onion or garlic with the sucrose diet counterated these effects of sucrose. However, along with the lipid-reducing effects, a small but significant tissue-protein reducing effect of the oils were also observed. The hypolipidemic action of the oils may be related to their action on both lipid and protein synthesis.

Treatment of muck soil with onion oil to control onion white rot

Treatment of muck soil with onion oil to control onion white rot

Stimulation of germination of sclerotia of Sclerotium cepivorum at different depths in soil by artificial onion oil

The influence of depth of inoculum on white rot and plant growth, and the response of sclerotia ofSclerotium cepivorum Berk. to artificial onion oil, at various depths in soil, was investigated. Field tests showed that effects of depth of inoculum were apparent 12 weeks after sowing and by week 14, sclerotia buried at 0–2, 10–12 and 18–20 cm reduced onion growth by 75, 56 and 37% in comparison with controls. The results indicate the importance of correct placement of treatments, such as onion oil, in soil to achieve maximum levels of disease control. In vitro tests in closed containers at 15°C showed that between 50–70% of sclerotia ofS. cepivorum germinated on soil treated with artificial onion oil. Production of secondary sclerotia was restricted to 0.5% of those which germinated. Application of oil at 10 cm depths in columns of soil caused germination of 60–70% of sclerotia at 3, 6, 14 and 17 cm over 4 weeks at 15°C. Germination at the soil surface was reduced. In field plots onion oil and one of its components, diallyl disulphide, reduced recovery of introduced sclerotia by 70%. Het effect van de diepte in grond waarop het inoculum vanSclerotium cepivorum berk. zich bevindt op het optreden van witrot in ui en op de ontwikkeling van de uieplant werd onderzocht. Ook werd de uitwerking van in grond geinjecteerde uienolie op de op verschillende diepten in grond geplaatste sclerotien bestudeerd. In veldexperimenten werd na 12 weken een duidelijk effect van de diepte van het inoculum op de ontwikkeling van de planten waarneembaar. Na 14 weken bleken sclerotien die op 0–2, 10–12 en 18–20 cm diepte in grond waren geplaatst de groei van de uieplanten met respectievelijk 75, 56 en 37% te hebben verminderd ten opzichte van de controleplanten. Deze resultaten wijzen er op, dat voor een zo goed mogelijke bestrijding van witrot, de diepte in grond waar middelen zoals uienolie moeten worden toegediend, van grote betekenis kan zijn. Bij in vitro toetsen in gesloten Conway-schalen bij 15°C kiemde 50–70% van de sclerotien vanS. cepivorum op het oppervlak van grond die behandeld was met synthetische uienolie. De vorming van secundaire sclerotien beperkte zich tot 0,5% van het aantal gekiemde sclerotien. Toediening van uienolie op 10cm diepte in grondkolommen veroorzaakte de kieming van 60–70% van de sclerotien op 3, 6, 14 en 17 cm diepte over een periode van 4 weken bij 15°C. Bij het grondoppervlak was de kieming lager. In veldexperimenten werd na behandeling van grond met uienolie en met een bestanddeel daarvan, diallyl-disulfide, het aantal in grond geintroduceerde sclerotien dat kon vorden teruggevonden, met 70% gereduceerd.