Absorption of N-phenylpropenoyl-L-amino acids in healthy humans by oral administration of cocoa (Theobroma cacao)

Besides flavan-3-ols, a family of N-phenylpropenoyl-L-amino acids (NPAs) has been recently identified as polyphenol/amino acid conjugates in the seeds of Theobroma cacao as well as in a variety of herbal drugs. Stimulated by reports on their biological activity, the purpose of this study was to investigate if these amides are absorbed by healthy volunteers after administration of a cocoa drink. For the first time, 12 NPAs were quantified in human urine by means of a stable isotope dilution analysis with LC-MS/MS (MRM) detection. A maximum amount was found in the urine taken 2 h after the cocoa consumption. The highest absolute amount of NPAs excreted with the urine was found for N-[4'-hydroxy-(E)-cinnamoyl]-L-aspartic acid (5), but the highest recovery rate (57.3 and 22.8%), that means the percentage amount of ingested amides excreted with the urine, were determined for N-[4'-hydroxy-(E)-cinnamoyl]-L-glutamic acid (6) and N-[4'-hydroxy-3'-methoxy-(E)-cinnamoyl]-L-tyrosine (13). In order to gain first insights into the NPA metabolism in vivo, urine samples were analyzed by LC-MS/MS before and after beta-glucuronidase/sulfatase treatment. As independent of the enzyme treatment the same NPA amounts were found in urine, there is strong evidence that these amides are metabolized neither via their O-glucuronides nor their O-sulfates. In order to screen for caffeic acid O-glucuronides as potential NPA metabolites, urine samples were screened by means of LC-MS/MS for caffeic acid 3-O-beta-D-glucuronide and 4-O-beta-D-glucuronide. But not even trace amounts of one of these glucuronides were detectable, thus excluding them as major NPA metabolites and underlining the importance of future investigations on a potential O-methylation or reduction of the N-phenylpropenoyl moiety in NPAs.     

Thermodynamic characteristics of copigmentation reaction of acylated anthocyanin isolated from blue flowers of Scutellaria baicalensis Georgi with copigments

Anthocyanin extracts are increasingly used as food colorants. So far, anthocyanins have not been broadly used in foods and beverages, since they are not as stable as synthetic dyes. Copigmentation between anthocyanins and copigments is the main colour‐stabilizing mechanism. The process of copigmentation between isolated acylated anthocyanin and rutin, QSA or baicalin has been observed using UV–vis spectrophotometry. The thermodynamic parameters were correlated to the structure and position of the substituents in the interacting molecules. The acylated anthocyanin was isolated from cultivars of Scutellaria baicalensis Georgi flowers and purified by column chromatography by our own method and has been identified by ¹H‐/¹³C‐NMR spectroscopy and electrospray mass spectrometry as delphinidin‐3‐O‐(6‐O‐malonyl)‐β‐D ‐glucopyranosyl‐5‐O‐β‐D ‐glucopyranoside. Copyright © 2004 Society of Chemical Industry     

Degradation of N‐(1‐Deoxy‐d‐xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d‐xylulos‐1‐yl)proline using thermal treatment

The formation and degradation of N‐(1‐Deoxy‐d ‐xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d ‐xylulos‐1‐yl)proline, derived from the secondary amine Maillard reaction in xylose‐amino acid model solutions, were detailed in this study. The identification and quantitative analysis of N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline were carried out using high‐performance anion‐exchange chromatography and high‐performance liquid chromatography. The formation of intermediate and advanced products derived from N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline was also tested using an UV‐Vis spectrophotometer to gain a better comparing of the degradation process of the two important Maillard reaction products using thermal treatment. Results showed that the degradation of N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine was more significant than N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline. Moreover, xylose was tested in the degradation products of both N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)glycine and N‐(1‐Deoxy‐d‐ xylulos‐1‐yl)proline, which indicated that the degradation of N‐substituted 1‐amino‐1‐deoxyketoses was a reversible reaction to form reducing sugar.     

The impact of the various chemical and physical factors on the degradation rate of bronopol

Bronopol (2‐bromo‐2‐nitropropane‐1,3‐diol) is used as preservative in cosmetic industry. Its main role in commercial products consists in protection of the cosmetic composition stability by inhibiting the development of micro‐organisms. Unfortunately, preservatives can also undergo the degradation processes. The aim of examinations was to prove that bronopol decomposes in aqueous solutions and storage conditions have a significance influence on its degradation rate. High‐performance liquid chromatography method (methanol/water with hydrochloric acid 5:95 v/v) with spectrophotometric detection (210 nm) was used for examining the decomposition rate of bronopol. The impact of chemical (addition of cosmetics components: citric acid and/or sodium dodecylsulfate) and physical (elevated and ambient temperature, sunlight or ultraviolet radiation and air access) factors has been elaborated. Bronopol decomposes most rapidly (independently on the sample surrounding conditions) when it is in solution with sodium dodecylsulfate, the inverse dependence is observed in the presence of two compounds – citric acid and sodium dodecylsulfate. Additionally, the elevated temperature causes the acceleration of decomposition. Bronopol degradation by‐products were also identified as methanol, formic acid, tris(hydroxymethyl)methane and 2‐bromo‐2‐nitroethanol.     

Urinary 2-ethyl-3-oxohexanoic acid as major metabolite of orally administered 2-ethylhexanoic acid in human

Human metabolism of 2-ethylhexanoic acid (2-EHA), which is a known metabolite of important phthalates, was investigated using 2-EHA-contaminated food. The results of our studies reveal that the major catabolic pathway of 2-EHA in human is beta-oxidation. The dominant final urinary metabolite was identified and quantified as 3-oxo-2-ethylhexanoic acid (3-oxo-2-EHA), but only after immediate methylation of the extract from urine and prior to GC-MS analysis. Former studies without the precaution of immediate methylation had found 4-heptanone as the major metabolite, which is obviously an artifact arising from the decarboxylation of 3-oxo-2-EHA.     

Identifications of inhibitors of IgE production by human lymphocytes isolated from ‘Cha Chuukanbohon Nou 6’ tea leaves

BACKGROUND: Tea (Camellia sinensis L.) is consumed all over the world and in especially large quantities in Japan and China, where it has been used not only as a daily beverage but also for medicinal purposes for thousands of years. Tea has been found to exhibit various bioregulatory activities, including antiallergic, anticarcinogenic, antimetastatic, antioxidative, antihypertensive, antihypercholesterolemic, anti‐dental caries and antibacterial effects, and to influence intestinal flora. RESULTS: Cha Chuukanbohon Nou 6 is a tea cultivar improved by the National Institute of Vegetable and Tea Science (NIVTS) in Japan. On comparing chemical constituents of 11 varieties of tea leaves by high‐performance liquid chromatography, we found two new major compounds in Cha Chuukanbohon Nou 6. Nuclear magnetic resonance spectroscopy revealed these compounds to be theogallin and 1,2‐di‐O‐galloyl‐4,6‐O‐(S)‐hexahydroxydiphenoyl‐β‐D ‐glucopyranose. The two were similar in chemical structure to strictinin, an inhibitor of immunoglobulin (Ig) production. Thus their effects on the production of Igs by peripheral blood lymphocytes were tested. Both compounds, like strictinin, inhibited IgE production. CONCLUSION: The results suggest Cha Chuukanbohon Nou 6 to be the basis of an antiallergic beverage. Copyright © 2009 Society of Chemical Industry     

In vitro antioxidant activity of different cultivars of banana flower (Musa paradicicus L.) extracts available in India

Abstract: Six different cultivars of banana flowers (Musa paradicicus) (Kathali, Bichi, Shingapuri, Kacha, Champa, and Kalabou) were analyzed for the content of polyphenol expressed as gallic acid equivalent and flavonoid expressed as quercetein equivalent, and the in vitro total antioxidative activities of the flower extracts were compared with standard and expressed as trolox equivalent. The reducing power, 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and 2,2‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) radical cation (ABTS?⁺) scavenging activities, inhibition of lipid peroxidation in a linoleic acid emulsion system, and liposome peroxidation system were measured and compared with respective standard antioxidants. Iron‐mediated Fenton reaction was carried out to evaluate the protective effect of the extract of banana flower (Kacha cultivar) against H₂O₂‐induced DNA damage. The Kacha variety contains the maximum amount of polyphenol (11.94 ± 0.03 mg of gallic acid equivalent/g of dry weight) and flavonoid (0.174 ± 0.001 g of quercetin equivalent/g of polyphenol). It also has the highest total antioxidant capacity, DPPH radical scavenging activity, and ABTS?⁺ radical scavenging activity with a least EC₅₀ value of 0.051 mg/mL. Hepatic cell damage in iron‐mediated Fenton reaction caused by free radicals is reduced by the banana flower extract. On the basis of the results obtained, the banana flowers are found to be a potential source of natural antioxidants. This is the first report on the antioxidant properties of the extracts from banana flowers. The study suggests that the flowers of M. paradicicus that are found in India and consumed as vegetable can provide valuable functional ingredients that help in the prevention of oxidative stress.     

Systematic studies of structure and physiological activity of alapyridaine. A novel food-born taste enhancer

By application of taste dilution analysis (+)-(S)-1-(1-carboxyethyl)-5-hydroxy-2-(hydroxymethyl)-pyridinium inner salt was recently successfully identified as a multimodal taste enhancer in beef bouillon. While being taste-less on its own, this so-called alapyridaine was found to intensify the human perception of sweet, salty, and umami taste. To gain information on the molecular requirements of this novel class of taste enhancer, a range of structurally related pyridinium betaines were synthesized, purified, and their physiological activities sensorially evaluated. Removal or modification of the hydroxyl and the hydroxymethyl group, respectively, induced a loss in bioactivity, thus indicating the 2-(hydroxymethyl)-5-hydroxypyridinium moiety as an essential structural element for taste enhancement. Regarding the amino substituent, neither the prolongation or removal of the alkyl chain or the carboxy function in the 1-(1-carboxy-2-ethyl)-moiety, nor the incorporation of an additional carboxy function led to any active derivative, thus demonstrating that also the structure of the nitrogen substituent is rather conserved for taste enhancement. But substitution of the methyl group by a benzyl group yielded a compound showing similar taste enhancing activities as found for alapyridaine. Interestingly, additional insertion of glycine between the 1-(1-carboxy-2-phenylethyl)-moiety and the pyridinium ring resulted in a compound eliciting comparable taste enhancing effects as shown for the compound lacking the glycine spacer. In contrast to these multimodal taste enhancers, substitution of the alanine moiety in alapyridaine by an arginine moiety revealed an one-dimensional taste enhancer exclusively increasing the human sensitivity for salty taste.     

Improved determination of D-glucosamine hydrochloride in health foods by HPLC using 7-fluoro-4-nitrobenzo-2-oxa-l,3-diazole as a derivative

Abstract: This article presents an improved method to detect d ‐glucosamine hydrochloride in health foods. A simple precolumn derivatization procedure with 7‐flouro‐4‐nitrobenzo‐2‐oxa‐1,3‐diazole (NBD‐F) reagent was employed. The separation of the derivatized d ‐glucosamine hydrochloride (NBD‐d ‐glucosamine hydrochloride) was performed using a mobile phase consisting of acetonitrile, potassium dihydrogen phosphate (0.01 mol/L), and trifluoroacetic acid (350:649.74:0.26, volume ratio) at a flow rate of 1.0 mL/min with the column temperature 35 °C. Under the optimum chromatographic conditions, the peak area of NBD‐d ‐glucosamine hydrochloride compared with its absolute value of the peak area of NBD‐d ‐glucosamine hydrochloride in a standard solution concentration range from 1.0 to 500.0 mg/L showed a good linear calibration (R = 0.9999). Recoveries, at spiked concentrations of 10.0, 40.0, and 500.0 mg/L, varied between 97.2% and 102.6% with relative standard deviations ranging from 0.4% to 1.5%. The present method provides sufficient sensitivity as reflected by the values of limit of detection (LOD) and limit of quantification (LOQ). LOD was determined from the signal‐to‐noise ratios (S/N) of NBD‐d ‐glucosamine hydrochloride peak of at least 3 in the recovery test at 0.02 mg/L, and the estimated LOQ was 0.06 mg/L (S/N = 10). The proposed method was successfully applicable to detect d ‐glucosamine hydrochloride in health foods and drugs containing a variety of complex materials.     

Physicochemical and antioxidative properties of Korean nanopowdered white ginseng

This study was carried out to investigate physicochemical and antioxidative properties of Korean nano white ginseng powder. The particle size of nanopowdered ginseng (NPG) was in the range from 600 to 1000 nm which was significantly smaller than the regular powdered ginseng (PG) which was in the range from 300 to 500 μm. Carbohydrate content was found to be significantly higher in NPG than PG (P < 0.05). Higher L value of NPG was mostly due to the higher light‐scattering effect of bright ginseng powder. In oil‐holding capacity, NPG was significantly higher than PG (P < 0.05). Total polyphenol content was not significantly different between NPG and PG, and it was in the range of 52.5% (P > 0.05). However, DPPH and ABTS studies showed that NPG has higher antioxidative properties than PG. In overall, NPG showed much higher antioxidative properties compared with PG. Thus, NPG enhances the functional value of Korean white ginseng powder.     

Production of an Alcoholic Beverage by Fermentation of Whey Permeate with Kluyveromyces fragilis II: Aroma Composition

Whey permeate was used for an alcoholic fermentation with Kluyveromyces fragilis (CECT 1123). The aim of the present study was the production of an alcoholic beverage of low alcoholic proof with acceptable concentrations of fusel alcohols. The effects of temperature and agitation on the concentration of volatile compounds was assayed in batch cultures. In addition, the production of acetaldehyde, ethyl acetate and fusel alcohols was studied in continuous culture because of interest in a continuous industrial process. Final concentrations of fusel alcohol were slightly lower at higher temperatures, while the specific production rate increased with temperature. Concentrations were suitable, in all cases, for a beverage. When agitation was assayed, an important increase in fusel alcohol concentrations was found at higher agitations. In continuous culture, the acetaldehyde, ethyl acetate and fusel alcohol concentrations were normal for an alcoholic beverage.     

Effect of UV‐C Disinfection of Beer — Sensory Analyses and Consumer Ranking

Ultraviolet (UV‐C) light irradiation is gaining rapid acceptance within the food and beverage industry as a non‐thermal disinfection technique. A series of trials, using a pilot scale UV‐C treatment system, were conducted to investigate the effect of UV‐C on beer with specific attention to lightstruck flavour formation. Both commercial and micro‐brewed beers were treated with UV‐C light at 254 nm. Samples were analysed by consumer and trained panels. Sensory analyses revealed that at a low UV‐C level, lightstruck flavour was apparent and this increasingly gave way to a more intense burnt rubber off‐flavour as the UV‐C exposure was increased. A sample enrichment probe technique coupled with a gas chromatography‐mass spectrometry (SEP/GCMS) revealed the presence of lightstruck flavour in all the treated beers.