Carbonyls emitted from essential oils can affect the air quality when they are used in indoors, e... more Carbonyls emitted from essential oils can affect the air quality when they are used in indoors, especially under poor ventilation conditions. Lavender, lemon, rose, rosemary, and tea tree oils were selected as typical and popular essential oils to investigate in terms of composition, thermal characteristics and fifteen carbonyl constituents. Based on thermogravimetric (TG) analysis, the activation energy was 7.6–8.3 kcal mol−1, the reaction order was in the range of 0.6–0.7 and the frequency factor was 360–2838 min−1. Formaldehyde, acetaldehyde, acetone, and propionaldehyde were the dominant carbonyl compounds, and their concentrations were 0.034–0.170 ppm. The emission factors of carbonyl compounds were 2.10–3.70 mg g−1, and acetone, propionaldehyde, acetaldehyde, and formaldehyde accounted for a high portion of the emission factor of carbonyl compounds in essential oil exhaust. Some unhealthy carbonyl species such as formaldehyde and valeraldehyde, were measured at low-temperature during the vaporization of essential oils, indicating a potential effect on indoor air quality and human health.
Introduction Chronic hypokalemia is the main finding in patients with Gitelman's syndrome. Exogen... more Introduction Chronic hypokalemia is the main finding in patients with Gitelman's syndrome. Exogenous factors can trigger deterioration of the patient's condition and provoke clinical symptoms. We discuss the pathophysiology of and therapy for Gitelman's syndrome, with a focus on dietary factors which may aggravate the disease. Case presentation We describe the case of a 31-year-old, previously apparently healthy Caucasian Swiss man who presented to our hospital with gait disturbance of subacute onset and a potassium level of 1.5 mmol/L. A detailed medical history revealed that he had been consuming large amounts of licorice (in the form of Fisherman's Friend menthol eucalyptus lozenges). Despite discontinuing the intake of glycyrrhizinic acid, his potassium level remained low. Biochemical investigations showed refractory hypokalemia and secondary hyperaldosteronism, suggestive of Gitelman's syndrome. Despite treatment with supplementation of potassium and magnesium in combination with an aldosterone antagonist, further clinically symptomatic episodes occurred. Triggers could be identified only by repeated detailed history taking. In response to the patient's dietary excesses (ingestion of relevant amounts of alcohol, lemon juice and iced tea), his hypokalemia was aggravated and provoked clinical symptoms. Finally, vomiting and failure to replace salt led to volume depletion and hypokalemic crisis, with a plasma potassium level of 1.0 mmol/L and paralysis with respiratory failure necessitating not only infusion of saline and potassium but also temporary mechanical ventilation. Conclusion Dietary preferences may have a much larger impact than any drug treatment on the symptoms of this chronic syndrome. Individual (mainly dietary) preferences must be monitored closely, and patients should be given dietary advice to avoid recurrent aggravation of hypokalemia with muscular weakness.
The aim of this study was to evaluate the antimicrobial activity of commercial essential oils: la... more The aim of this study was to evaluate the antimicrobial activity of commercial essential oils: lavender, tea tree and lemon, antimicrobials in washing liquid and O/W soft body balm. The inhibition efficacy of essential oils in washing liquid (1% alone or in mixtures), in soft body balm (0.5% alone), as well as combined with the synthetic preservative DMDM hydantoin and 3-iodo-2-propynyl butyl carbamate mixture (0.1 and 0.3%), was tested against S. aureus ATCC 6538, P. aeruginosa ATCC 9027, Candida sp. ŁOCK 0008 and A. niger ATCC 16404 in compliance with the European Pharmacopoeia standards. The components of the system preserving soft body balm were supplemented with a solubilizer. Washing liquids containing only essential oils met Criterion A E.P. only for S. aureus, Candida sp. and A. niger. In soft body balm formulations, oils at a concentration of 0.5% did not reveal any preserving activity. The introduction of a solubilizer to a system containing 0.5% tea tree oil led to a substantial increase in the bacteriostatic activity of the formulation, but did not significantly affect its fungistatic properties. A combination of 0.5% tea tree oil, 5% solubilizer and 0.3% synthetic preservative ensured the microbiological stability of soft body balm in accordance with Criterion A E.P.Le but de ce travail était de déterminer l’activité antibactérienne des huiles essentielles commercials tels que: l’huile de lavande, l’huile d’arbre à thé et l’huile citrique en tant que composés d’un système conservateur dans des liquides de nettoyage de type eau/huile et dans les crème corporels de type huile/eauL’efficacité d’inhibition des huiles essentielles dans le mélange de nettoyage (1% seul ou dans le mélange); dans les crèmes corporels (0.5% seul) aussi bien que combiné avec des conservateurs synthétique comme le mélange de DMDM hydantoine et 3-iodo-2-propynyle butyle carbamate (0.1 et 0.3%) a été testée contre S. aureus ATCC 6538, P. aeruginosa ATCC 9027, Candida sp. ŁOCK 0008 et A. niger ATCC 16404 dans la conformité avec les standards de la Commission de la Pharmacopée Européenne.Soubilisator a été rajouté dans les composés du système conservatoire des crèmes corporels. Des liquides de nettoyage contenant ces huiles essentielles sont compatibile de la législation Criterion A E. P. uniquement pour les bactéries du genre S. aureus ainsi que les champignons du genre Candida sp. et A. niger. Les crèmes corporels contenant des huiles essentielles à la concentration de 0.5% ne se conservent pas bien. Rajout d’un soubilisator dans le système contenant l’huile d’arbre à théà 0.5% a provoqué une augmentation importante de l’activité bactériostatique de cette solution, mais cela n’a pas changé significativement leur propriété fongicide. Le mélange d’une huile de l’arbre à théà la concentration de 0.5%, soubilisator et GPL à la concentration de 0.3% a fournit la stabilité microbiologique de la crème corporel conforme à la norme Criterion A E.P.
The efficiencies of different solvents in the extraction of phenolics from bagged and loose leave... more The efficiencies of different solvents in the extraction of phenolics from bagged and loose leaves of white and green tea, after different extraction times, as well as the antioxidative capacity of the obtained extracts, were investigated. The developed HPLC method has the potential to separate and determinate 17 phenolics widely distributed in plants, but in investigated tea extracts only four catechins and traces of three flavonols and one flavone were separated and detected based on comparison with authentic standards. The extraction efficiency of phenolics depended strongly on the time of extraction and the solvents used. The extraction of catechins from green tea was significantly affected by the form (bagged or loose) of the tea, whereas this effect was shown not to be statistically significant for white tea. Green tea was a richer source of phenolics than was white tea. The extraction of phenolics from white tea by water could be accelerated by the addition of lemon juice. Aqueous ethanol (40%) was most effective in the prolonged extraction of catechins. The antioxidative capacity of the investigated tea extracts correlated with their phenolic content.
Objective To determine the strength of association (expressed as Odds Ratios) of potential risk f... more Objective To determine the strength of association (expressed as Odds Ratios) of potential risk factors with erosion and tooth wear in 14-year-old schoolchildren.Design A random sample of 2,385 children were selected by a stratified two-stage technique based on schools and children.Setting Schools in NW England.Methods Tooth wear was assessed by one examiner on three surfaces of all 12 anterior teeth (labial, incisal and palatal) and the occlusal surface of all four first molars using a four-point scale. Enamel wear was scored 0, dentine exposure 1/3 scored 2 and secondary dentine or pulpal exposure, scored 3. A questionnaire enquired about general health, dental health, habits and the frequency of intake of a wide range of foods and drinks.Results The Odds Ratios for tooth wear on any surface for habits, reflux and certain foods were: bruxism, 1.10; stomach upset, 1.45; pickles 1.86; vinegar 1.36; salt and vinegar crisps 1.33; brown/other sauces 1.57. Similarly, the odds ratios for potentially erosive drinks were: fizzy drinks 1.32; sport drinks 1.58; herbal/lemon tea 3.97. The frequency of intake was bi-modal with 397 children drinking a can per day and 207 drinking two cans per day. A significant number drank acidic beverages at bedtime but this was not associated with dental erosion.Conclusion Although odds ratios greater than unity indicate an association, this was not high for carbonated beverages and many other acidic foods or drinks. Examining at fourteen years may not be ideal, as the determinants of erosion/tooth wear have not acted for long, the indices do not discriminate sufficiently and proportionately few subjects have dentine exposed on smooth surfaces.
Background: Use of essential oils for controlling Candida albicans growth has gained significance... more Background: Use of essential oils for controlling Candida albicans growth has gained significance due to the resistance acquired by pathogens towards a number of widely-used drugs. The aim of this study was to test the antifungal activity of selected essential oils against Candida albicans in liquid and vapour phase and to determine the chemical composition and mechanism of action of most potent essential oil. Methods: Minimum Inhibitory concentration (MIC) of different essential oils in liquid phase, assayed through agar plate dilution, broth dilution & 96-well micro plate dilution method and vapour phase activity evaluated through disc volatilization method. Reduction of C. albicans cells with vapour exposure was estimated by kill time assay. Morphological alteration in treated/untreated C. albicans cells was observed by the Scanning electron microscopy (SEM)/Atomic force microscopy (AFM) and chemical analysis of the strongest antifungal agent/essential oil has been done by GC, GC-MS. Results: Lemon grass (Cymbopogon citratus) essential oil exhibited the strongest antifungal effect followed by mentha (Mentha piperita) and eucalyptus (Eucalyptus globulus) essential oil. The MIC of lemon grass essential oil in liquid phase (288 mg/l) was significantly higher than that in the vapour phase (32.7 mg/l) and a 4 h exposure was sufficient to cause 100% loss in viability of C. albicans cells. SEM/AFM of C. albicans cells treated with lemon grass essential oil at MIC level in liquid and vapour phase showed prominent shrinkage and partial degradation, respectively, confirming higher efficacy of vapour phase. GC-MS analysis revealed that lemon grass essential oil was dominated by oxygenated monoterpenes (78.2%); α-citral or geranial (36.2%) and β-citral or neral (26.5%), monoterpene hydrocarbons (7.9%) and sesquiterpene hydrocarbons (3.8%).
Film-forming dispersions (FFD) and films, prepared by incorporating different concentrations of b... more Film-forming dispersions (FFD) and films, prepared by incorporating different concentrations of bergamot (BO), lemon (LO) and tea tree (TTO) essential oils into hydroxyproplymethylcellulose (HPMC) and chitosan (CH) were obtained and their physico-chemical properties were characterised. Results showed that the increment of essential oil (EO) content promoted significant changes in the size and surface charge of the FFD particles. As regards the film properties, the higher the EO content, the lower the water vapour permeability and the moisture sorption capacity. In general, the addition of EO into the HPMC or CH matrix leads to a significant decrease in gloss, transparency, tensile strength and elastic modulus of the composite films. Discriminant analyses of obtained data revealed that the polymer type was the main factor which defined the FFD and composite film behaviour. For a given polymer, although both the nature and concentration of the EO influenced FFD behaviour, the concentration played a more important role. In film properties, the discriminant analyses did not reveal different groups associated to the different nature or concentration of the essential oils, although composite films with BO appeared to differ slightly from the rest.
Antioxidant properties (AOP) of thirteen tropical and five temperate herbal teas were screened. C... more Antioxidant properties (AOP) of thirteen tropical and five temperate herbal teas were screened. Comparisons were made with green, oolong and black teas of Camellia sinensis. The AOP studied were total phenolic content, radical-scavenging activity, ferric-reducing power and ferrous ion-chelating (FIC) ability. Tropical herbal teas were more diverse in types and more variable in AOP values than temperate herbal teas. Herbal teas generally had lower antioxidant values than teas of C. sinensis. Exceptions were lemon myrtle, guava and oregano teas with AOP comparable to black teas. FIC ability of mint and peppermint teas was significantly stronger than all C. sinensis teas.
Oral habituation is a relatively long-lasting decrease in oral responsiveness that results from t... more Oral habituation is a relatively long-lasting decrease in oral responsiveness that results from the repeated presentation of a single stimulus. The purpose of this study was to evaluate the degree of habituation to sweet-tasting foods and to determine whether there are differences in the rate of habituation between African Americans and European Americans. These two groups were compared because the prevalence of obesity and obesity-related disorders such as diabetes and hypertension is significantly higher among African Americans than among European Americans. Nine different commercial foods and beverages that differed in sweetness intensity and caloric density served as stimuli. Subjects tasted and rated each food once per minute for a 30-min period on scales related to desire for another taste of the same sample and desire for a different taste. The stimuli and portion size for each of the 30 samples were two candy bars (Ultra Slim-Fast Cocoa Almond Crunch Bar, 1/16 of a bar; Natural Nectar Peanut Butter Granola Bar, 1/16 of a bar), three beverages (Nestea Lemon Flavored Instant Tea with NutraSweet, 5 mL; Welch’s Grape Juice, 5 mL; Pink Swimmingo Kool-Aid, 5 mL), two gelatin desserts (Cherry Flavored Jell-O Gelatin, 5 g; Cherry Flavored Jell-O Gelatin with NutraSweet, 5 g), one enteral nutrition drink (Vanilla Ensure Plus, 5 mL), and one pudding (Ultra Slim-Fast Chocolate Pudding, 5 g). Subjects consumed the entire portion of each sample. Habituation occurred for seven of the nine foods as judged by a decrease in the desire for another taste of the same food. The degree of habituation for European Americans and African Americans was similar except for the sweetest food (Cherry Flavored Jell-O Gelatin with NutraSweet), for which African Americans showed no habituation. The degree of habituation in both groups was unrelated to caloric density. Overall, young African Americans had a significantly greater desire for another taste of the same food than did young European Americans for seven of the nine foods, and this desire was strongly correlated with the sweetness intensity for young African Americans but not for young European Americans. Furthermore, young African Americans had a greater desire than young European Americans for a different taste for seven of nine foods. The greater desire for intense sweet tastes may be a factor in the elevated incidence of obesity and diabetes in African Americans. In addition, young African Americans had greater perceived stress in this study than did young European Americans. If African Americans use sweet taste to compensate for feelings of stress, this compensation may also contribute to weight gain.
There is inadequate published data referring to bioactivity of lemon balm tea and its Kombucha. T... more There is inadequate published data referring to bioactivity of lemon balm tea and its Kombucha. The aim of this study, therefore, was to investigate antimicrobial, antiproliferative, genotoxic, and antigenotoxic potential of lemon balm tea and its Kombucha with consuming acidity. Antimicrobial activity was determined by agar-well diffusion method. Cell growth effects were determined in HeLa, MCF7, and HT-29 human tumor cell lines. Genotoxic and antigenotoxic effects were determined using chromosome aberration assay in Chinese hamster cell line CHO-K1. Differences between control and treated groups were evaluated using analysis of variance, at significance level of p < 0.05. Kombucha from lemon balm tea (Melissa officinalis L.) exibited antimicrobial activity against prokaryotic microorganisms independently of their cell wall structure (both Gram-positive and Gram-negative bacteria), while there was no observed activity against eukaryots (yeasts and moulds). There was absence of genotoxic effects while antigenotoxic effects of lemon balm Kombucha and tea were confirmed on MMC-damaged CHO-K1 cells. For the explanation of cell growth effects that were not concentration dependent, concept of hormesis was used. Antiproliferative activity was lower compared with traditional Kombucha and Satureja montana L. Kombucha, with lemon balm tea showing higher activity than its Kombucha.
Carbonyls emitted from essential oils can affect the air quality when they are used in indoors, e... more Carbonyls emitted from essential oils can affect the air quality when they are used in indoors, especially under poor ventilation conditions. Lavender, lemon, rose, rosemary, and tea tree oils were selected as typical and popular essential oils to investigate in terms of composition, thermal characteristics and fifteen carbonyl constituents. Based on thermogravimetric (TG) analysis, the activation energy was 7.6–8.3 kcal mol−1, the reaction order was in the range of 0.6–0.7 and the frequency factor was 360–2838 min−1. Formaldehyde, acetaldehyde, acetone, and propionaldehyde were the dominant carbonyl compounds, and their concentrations were 0.034–0.170 ppm. The emission factors of carbonyl compounds were 2.10–3.70 mg g−1, and acetone, propionaldehyde, acetaldehyde, and formaldehyde accounted for a high portion of the emission factor of carbonyl compounds in essential oil exhaust. Some unhealthy carbonyl species such as formaldehyde and valeraldehyde, were measured at low-temperature during the vaporization of essential oils, indicating a potential effect on indoor air quality and human health.
Introduction Chronic hypokalemia is the main finding in patients with Gitelman's syndrome. Exogen... more Introduction Chronic hypokalemia is the main finding in patients with Gitelman's syndrome. Exogenous factors can trigger deterioration of the patient's condition and provoke clinical symptoms. We discuss the pathophysiology of and therapy for Gitelman's syndrome, with a focus on dietary factors which may aggravate the disease. Case presentation We describe the case of a 31-year-old, previously apparently healthy Caucasian Swiss man who presented to our hospital with gait disturbance of subacute onset and a potassium level of 1.5 mmol/L. A detailed medical history revealed that he had been consuming large amounts of licorice (in the form of Fisherman's Friend menthol eucalyptus lozenges). Despite discontinuing the intake of glycyrrhizinic acid, his potassium level remained low. Biochemical investigations showed refractory hypokalemia and secondary hyperaldosteronism, suggestive of Gitelman's syndrome. Despite treatment with supplementation of potassium and magnesium in combination with an aldosterone antagonist, further clinically symptomatic episodes occurred. Triggers could be identified only by repeated detailed history taking. In response to the patient's dietary excesses (ingestion of relevant amounts of alcohol, lemon juice and iced tea), his hypokalemia was aggravated and provoked clinical symptoms. Finally, vomiting and failure to replace salt led to volume depletion and hypokalemic crisis, with a plasma potassium level of 1.0 mmol/L and paralysis with respiratory failure necessitating not only infusion of saline and potassium but also temporary mechanical ventilation. Conclusion Dietary preferences may have a much larger impact than any drug treatment on the symptoms of this chronic syndrome. Individual (mainly dietary) preferences must be monitored closely, and patients should be given dietary advice to avoid recurrent aggravation of hypokalemia with muscular weakness.
The aim of this study was to evaluate the antimicrobial activity of commercial essential oils: la... more The aim of this study was to evaluate the antimicrobial activity of commercial essential oils: lavender, tea tree and lemon, antimicrobials in washing liquid and O/W soft body balm. The inhibition efficacy of essential oils in washing liquid (1% alone or in mixtures), in soft body balm (0.5% alone), as well as combined with the synthetic preservative DMDM hydantoin and 3-iodo-2-propynyl butyl carbamate mixture (0.1 and 0.3%), was tested against S. aureus ATCC 6538, P. aeruginosa ATCC 9027, Candida sp. ŁOCK 0008 and A. niger ATCC 16404 in compliance with the European Pharmacopoeia standards. The components of the system preserving soft body balm were supplemented with a solubilizer. Washing liquids containing only essential oils met Criterion A E.P. only for S. aureus, Candida sp. and A. niger. In soft body balm formulations, oils at a concentration of 0.5% did not reveal any preserving activity. The introduction of a solubilizer to a system containing 0.5% tea tree oil led to a substantial increase in the bacteriostatic activity of the formulation, but did not significantly affect its fungistatic properties. A combination of 0.5% tea tree oil, 5% solubilizer and 0.3% synthetic preservative ensured the microbiological stability of soft body balm in accordance with Criterion A E.P.Le but de ce travail était de déterminer l’activité antibactérienne des huiles essentielles commercials tels que: l’huile de lavande, l’huile d’arbre à thé et l’huile citrique en tant que composés d’un système conservateur dans des liquides de nettoyage de type eau/huile et dans les crème corporels de type huile/eauL’efficacité d’inhibition des huiles essentielles dans le mélange de nettoyage (1% seul ou dans le mélange); dans les crèmes corporels (0.5% seul) aussi bien que combiné avec des conservateurs synthétique comme le mélange de DMDM hydantoine et 3-iodo-2-propynyle butyle carbamate (0.1 et 0.3%) a été testée contre S. aureus ATCC 6538, P. aeruginosa ATCC 9027, Candida sp. ŁOCK 0008 et A. niger ATCC 16404 dans la conformité avec les standards de la Commission de la Pharmacopée Européenne.Soubilisator a été rajouté dans les composés du système conservatoire des crèmes corporels. Des liquides de nettoyage contenant ces huiles essentielles sont compatibile de la législation Criterion A E. P. uniquement pour les bactéries du genre S. aureus ainsi que les champignons du genre Candida sp. et A. niger. Les crèmes corporels contenant des huiles essentielles à la concentration de 0.5% ne se conservent pas bien. Rajout d’un soubilisator dans le système contenant l’huile d’arbre à théà 0.5% a provoqué une augmentation importante de l’activité bactériostatique de cette solution, mais cela n’a pas changé significativement leur propriété fongicide. Le mélange d’une huile de l’arbre à théà la concentration de 0.5%, soubilisator et GPL à la concentration de 0.3% a fournit la stabilité microbiologique de la crème corporel conforme à la norme Criterion A E.P.
The efficiencies of different solvents in the extraction of phenolics from bagged and loose leave... more The efficiencies of different solvents in the extraction of phenolics from bagged and loose leaves of white and green tea, after different extraction times, as well as the antioxidative capacity of the obtained extracts, were investigated. The developed HPLC method has the potential to separate and determinate 17 phenolics widely distributed in plants, but in investigated tea extracts only four catechins and traces of three flavonols and one flavone were separated and detected based on comparison with authentic standards. The extraction efficiency of phenolics depended strongly on the time of extraction and the solvents used. The extraction of catechins from green tea was significantly affected by the form (bagged or loose) of the tea, whereas this effect was shown not to be statistically significant for white tea. Green tea was a richer source of phenolics than was white tea. The extraction of phenolics from white tea by water could be accelerated by the addition of lemon juice. Aqueous ethanol (40%) was most effective in the prolonged extraction of catechins. The antioxidative capacity of the investigated tea extracts correlated with their phenolic content.
Objective To determine the strength of association (expressed as Odds Ratios) of potential risk f... more Objective To determine the strength of association (expressed as Odds Ratios) of potential risk factors with erosion and tooth wear in 14-year-old schoolchildren.Design A random sample of 2,385 children were selected by a stratified two-stage technique based on schools and children.Setting Schools in NW England.Methods Tooth wear was assessed by one examiner on three surfaces of all 12 anterior teeth (labial, incisal and palatal) and the occlusal surface of all four first molars using a four-point scale. Enamel wear was scored 0, dentine exposure 1/3 scored 2 and secondary dentine or pulpal exposure, scored 3. A questionnaire enquired about general health, dental health, habits and the frequency of intake of a wide range of foods and drinks.Results The Odds Ratios for tooth wear on any surface for habits, reflux and certain foods were: bruxism, 1.10; stomach upset, 1.45; pickles 1.86; vinegar 1.36; salt and vinegar crisps 1.33; brown/other sauces 1.57. Similarly, the odds ratios for potentially erosive drinks were: fizzy drinks 1.32; sport drinks 1.58; herbal/lemon tea 3.97. The frequency of intake was bi-modal with 397 children drinking a can per day and 207 drinking two cans per day. A significant number drank acidic beverages at bedtime but this was not associated with dental erosion.Conclusion Although odds ratios greater than unity indicate an association, this was not high for carbonated beverages and many other acidic foods or drinks. Examining at fourteen years may not be ideal, as the determinants of erosion/tooth wear have not acted for long, the indices do not discriminate sufficiently and proportionately few subjects have dentine exposed on smooth surfaces.
Background: Use of essential oils for controlling Candida albicans growth has gained significance... more Background: Use of essential oils for controlling Candida albicans growth has gained significance due to the resistance acquired by pathogens towards a number of widely-used drugs. The aim of this study was to test the antifungal activity of selected essential oils against Candida albicans in liquid and vapour phase and to determine the chemical composition and mechanism of action of most potent essential oil. Methods: Minimum Inhibitory concentration (MIC) of different essential oils in liquid phase, assayed through agar plate dilution, broth dilution & 96-well micro plate dilution method and vapour phase activity evaluated through disc volatilization method. Reduction of C. albicans cells with vapour exposure was estimated by kill time assay. Morphological alteration in treated/untreated C. albicans cells was observed by the Scanning electron microscopy (SEM)/Atomic force microscopy (AFM) and chemical analysis of the strongest antifungal agent/essential oil has been done by GC, GC-MS. Results: Lemon grass (Cymbopogon citratus) essential oil exhibited the strongest antifungal effect followed by mentha (Mentha piperita) and eucalyptus (Eucalyptus globulus) essential oil. The MIC of lemon grass essential oil in liquid phase (288 mg/l) was significantly higher than that in the vapour phase (32.7 mg/l) and a 4 h exposure was sufficient to cause 100% loss in viability of C. albicans cells. SEM/AFM of C. albicans cells treated with lemon grass essential oil at MIC level in liquid and vapour phase showed prominent shrinkage and partial degradation, respectively, confirming higher efficacy of vapour phase. GC-MS analysis revealed that lemon grass essential oil was dominated by oxygenated monoterpenes (78.2%); α-citral or geranial (36.2%) and β-citral or neral (26.5%), monoterpene hydrocarbons (7.9%) and sesquiterpene hydrocarbons (3.8%).
Film-forming dispersions (FFD) and films, prepared by incorporating different concentrations of b... more Film-forming dispersions (FFD) and films, prepared by incorporating different concentrations of bergamot (BO), lemon (LO) and tea tree (TTO) essential oils into hydroxyproplymethylcellulose (HPMC) and chitosan (CH) were obtained and their physico-chemical properties were characterised. Results showed that the increment of essential oil (EO) content promoted significant changes in the size and surface charge of the FFD particles. As regards the film properties, the higher the EO content, the lower the water vapour permeability and the moisture sorption capacity. In general, the addition of EO into the HPMC or CH matrix leads to a significant decrease in gloss, transparency, tensile strength and elastic modulus of the composite films. Discriminant analyses of obtained data revealed that the polymer type was the main factor which defined the FFD and composite film behaviour. For a given polymer, although both the nature and concentration of the EO influenced FFD behaviour, the concentration played a more important role. In film properties, the discriminant analyses did not reveal different groups associated to the different nature or concentration of the essential oils, although composite films with BO appeared to differ slightly from the rest.
Antioxidant properties (AOP) of thirteen tropical and five temperate herbal teas were screened. C... more Antioxidant properties (AOP) of thirteen tropical and five temperate herbal teas were screened. Comparisons were made with green, oolong and black teas of Camellia sinensis. The AOP studied were total phenolic content, radical-scavenging activity, ferric-reducing power and ferrous ion-chelating (FIC) ability. Tropical herbal teas were more diverse in types and more variable in AOP values than temperate herbal teas. Herbal teas generally had lower antioxidant values than teas of C. sinensis. Exceptions were lemon myrtle, guava and oregano teas with AOP comparable to black teas. FIC ability of mint and peppermint teas was significantly stronger than all C. sinensis teas.
Oral habituation is a relatively long-lasting decrease in oral responsiveness that results from t... more Oral habituation is a relatively long-lasting decrease in oral responsiveness that results from the repeated presentation of a single stimulus. The purpose of this study was to evaluate the degree of habituation to sweet-tasting foods and to determine whether there are differences in the rate of habituation between African Americans and European Americans. These two groups were compared because the prevalence of obesity and obesity-related disorders such as diabetes and hypertension is significantly higher among African Americans than among European Americans. Nine different commercial foods and beverages that differed in sweetness intensity and caloric density served as stimuli. Subjects tasted and rated each food once per minute for a 30-min period on scales related to desire for another taste of the same sample and desire for a different taste. The stimuli and portion size for each of the 30 samples were two candy bars (Ultra Slim-Fast Cocoa Almond Crunch Bar, 1/16 of a bar; Natural Nectar Peanut Butter Granola Bar, 1/16 of a bar), three beverages (Nestea Lemon Flavored Instant Tea with NutraSweet, 5 mL; Welch’s Grape Juice, 5 mL; Pink Swimmingo Kool-Aid, 5 mL), two gelatin desserts (Cherry Flavored Jell-O Gelatin, 5 g; Cherry Flavored Jell-O Gelatin with NutraSweet, 5 g), one enteral nutrition drink (Vanilla Ensure Plus, 5 mL), and one pudding (Ultra Slim-Fast Chocolate Pudding, 5 g). Subjects consumed the entire portion of each sample. Habituation occurred for seven of the nine foods as judged by a decrease in the desire for another taste of the same food. The degree of habituation for European Americans and African Americans was similar except for the sweetest food (Cherry Flavored Jell-O Gelatin with NutraSweet), for which African Americans showed no habituation. The degree of habituation in both groups was unrelated to caloric density. Overall, young African Americans had a significantly greater desire for another taste of the same food than did young European Americans for seven of the nine foods, and this desire was strongly correlated with the sweetness intensity for young African Americans but not for young European Americans. Furthermore, young African Americans had a greater desire than young European Americans for a different taste for seven of nine foods. The greater desire for intense sweet tastes may be a factor in the elevated incidence of obesity and diabetes in African Americans. In addition, young African Americans had greater perceived stress in this study than did young European Americans. If African Americans use sweet taste to compensate for feelings of stress, this compensation may also contribute to weight gain.
There is inadequate published data referring to bioactivity of lemon balm tea and its Kombucha. T... more There is inadequate published data referring to bioactivity of lemon balm tea and its Kombucha. The aim of this study, therefore, was to investigate antimicrobial, antiproliferative, genotoxic, and antigenotoxic potential of lemon balm tea and its Kombucha with consuming acidity. Antimicrobial activity was determined by agar-well diffusion method. Cell growth effects were determined in HeLa, MCF7, and HT-29 human tumor cell lines. Genotoxic and antigenotoxic effects were determined using chromosome aberration assay in Chinese hamster cell line CHO-K1. Differences between control and treated groups were evaluated using analysis of variance, at significance level of p < 0.05. Kombucha from lemon balm tea (Melissa officinalis L.) exibited antimicrobial activity against prokaryotic microorganisms independently of their cell wall structure (both Gram-positive and Gram-negative bacteria), while there was no observed activity against eukaryots (yeasts and moulds). There was absence of genotoxic effects while antigenotoxic effects of lemon balm Kombucha and tea were confirmed on MMC-damaged CHO-K1 cells. For the explanation of cell growth effects that were not concentration dependent, concept of hormesis was used. Antiproliferative activity was lower compared with traditional Kombucha and Satureja montana L. Kombucha, with lemon balm tea showing higher activity than its Kombucha.
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