Strawberry,loquat, mulberry,and bitter melon juices exhibit prophylactic effects on LPS-induced inflammation using murine peritoneal macrophages

We hypothesized the juices from strawberry, loquat, mulberry and bitter melon exhibit anti-inflammatory activities using lipopolysaccharide (LPS)-stimulated murine peritoneal macrophage cultures. Selected juices were administered as a prophylactic, postmortem or concurrent event relative to LPS stimulation to clarify the effective mechanisms. Selected fruits and vegetable juices were administered to macrophage cultures for 24 h prior to LPS stimulation (model A). Selected samples were administered to cell cultures at 24 h following LPS treatment (model B). Selected fruits and vegetable juices and LPS were simultaneously co-cultured with macrophages for 24 h (model C). The LPS-induced secretions of pro-inflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α and anti-inflammatory cytokine IL-10 were determined. The results showed that strawberry, loquat, mulberry and bitter melon administration increased IL-10 production by LPS-stimulated peritoneal macrophages in dose-dependent manners in experimental model A. Simultaneously, loquat, mulberry, and bitter melon administrations significantly (P < 0.05) decreased the levels of IL-1β, IL-6 and/or TNF-α. Administration with loquat and bitter melon to experimental model C significantly increased IL-10 production. This study suggests that strawberry, loquat, mulberry, and bitter melon juices exhibit a prophylactic effect on LPS-induced inflammation of peritoneal macrophages via increasing anti-inflammatory cytokine and/or decreasing pro-inflammatory cytokines secretions.     

Asymmetric dominance as a potential source of bias in hedonic testing

A large and growing body of evidence from marketing and behavioral economics suggests consumer preferences are not fixed but instead depend on the choice set. Although the idea that context alters perception is not new to psychophysicists or sensory scientists, we suggest that asymmetric dominance may represent a novel and potentially important source of bias in hedonic product testing and food choice research. In a series of six experiments using model systems, commercially available beverages and solid foods, we explored the possibility that asymmetric dominance effects may influence the results of food preference testing. Within a model system (experiments 1-3), we failed to observe evidence of a bias arising from asymmetric dominance. In contrast, when perceptually complex beverages and foods were used (experiments 4-6), we found relative preference was altered by the introduction of an additional product into the choice set. Critically, we found this bias was able to induce a significant preference (experiments 4-5) or make a significant preference disappear (experiment 6). Implications of this potential source of bias are discussed in a context relevant to sensory scientists and product developers.     

苦盐、高温盐、混合卤掺兑工艺的研究

文章根据不同温度下 ,Na+,K+ Cl- ,SO2 4—H2 O四元体系相图理论 ,采用苦盐与高温盐 ,混合卤与镁乳掺兑的生产工艺不仅能使苦盐中的氯化钠含量提高 10 %以上 ,而且能制得纯净的一水硫酸镁产品     

The extraction of yellow gentian root (Gentiana lutea L .)

 Several solvents have been investigated for the preparation of bitter compounds of gentian roots (Gentiana lutea L.) for food applications. The highest concentrations of the bitter compounds, amarogentin and gentiopicroside, were obtained with ethanol : water 55 : 45 (v/v), propylene glycol: water 30 : 70 (v/v) and ethanol: propylene glycol: water 20 : 20 : 60 (v/v/v). Enzyme treatment prior to solvent extraction gave a greater extract yield (3.5%) but the amarogentin and gentiopicroside concentrations remained the same. The volatile fraction was affected by the solvent used through the formation of esters of organic acids from the plant. Received: 22 January 1997 / Revised version: 18 March 1997     

Bioresponse-guided decomposition of roast coffee beverage and identification of key bitter taste compounds

Sensory-guided fractionation of a roasted coffee brew by means of sequential solvent extraction, ultrafiltration, and RP-HPLC demonstrated a group of ethyl acetate soluble compounds formed from O-hydroxycinnamoyl quinic acid derivatives upon coffee roasting as the key compounds contributing to the bitter taste of roasted coffee beverages. LC-MS/MS studies, 1D- and 2D-NMR spectroscopy, syntheses, and model roast experiments with 5-O-caffeoyl- and 5-O-feruloylquinic acid led to the unequivocal identification of 3-O-caffeoyl-γ-quinide (2a), 4-O-caffeoyl-γ-quinide (3a), 5-O-caffeoyl-epi-δ-quinide (4a), 4-O-caffeoyl-muco-γ-quinide (5a), 5-O-caffeoyl-muco-γ-quinide (6a), 3-O-feruloyl-γ-quinide (2b), and 4-O-feruloyl-γ-quinide (3b) as intense coffee bitter tastants. Besides these individual bitter compounds, a highly complex and intensely bitter HPLC fraction was isolated from the ethyl acetate extractables of coffee brew. Application of COSY spectroscopy and alkaline hydrolytic degradation gave strong evidence that the bitter taste of that fraction is due to a multiplicity of rather complex quinic acid lactone isomers multiply esterified with p-coumaric acid, caffeic acid, ferulic acid, 3,4-dimethoxycinnamic acid, and quinic acid, respectively. As representatives of this fraction, 3,4-O-dicaffeoyl-γ-quinide (10), 3,5-O-dicaffeoyl-epi-δ-quinide (11), and 4,5-O-dicaffeoyl-muco-γ-quinide (12) have been isolated, purified, and identified as strongly bitter-tasting compounds in roasted coffee. For the first time, bitter taste recognition thresholds were determined for the individual compounds showing that, strongly depending on their chemical structure, the bitter threshold levels ranged between 9.8 and 180 μmol/l (water).     

Sensory and Analytical Characterisation of Reduced,Isomerised Hop Extracts and Their Influence and Use in Beer

The use of reduced, isomerised hop extracts became very popular during the last decade in terms of achieving both better foam and light stability. Today the most common products are those with tetra‐hydro‐iso‐α‐acids (THIA) or rho‐iso‐α‐acids (RHIA). There is still not clarity concerning the taste properties of these products in comparison with iso‐α‐acid Bitter Units (BU). The experiments conducted showed that the bitter conversion factors determined in previous work (1.6 for THIA and 0.7 for RHIA) represented only perceived bitterness when presented in tap water. In the test beers a bitter conversion factor of 1.0–1.1 for THIA was determined and the factor of 0.7 for RHIA in beer was confirmed. Photometric methods led to considerable deviations when used for the determination of THIA and RHIA, whereas the HPLC method, in combination with either Solid Phase Extraction (SPE) or Liquid Liquid Extraction (LLE), led to very good results. RHIA was found to have a foam stabilising effect and it was also shown that the foam stabilising effect of THIA in unhopped beer was higher than in hopped beer. The quality of bitterness decreased with an increase of THIA and RHIA. A dependency on the alcohol content in regard to the bitter intensity was ascertained.     

啤酒风味物质研究进展

近年来,啤酒产业不断发展,人们对啤酒的风味要求不断提高。啤酒的风味是衡量其品质的关键指标,种类繁多的挥发性和非挥发性成分是啤酒具有特有风味的主要原因。啤酒因原料、酵母、发酵工艺、贮藏等条件的不同,成品风味有很大差异。本文综述了啤酒风味物质的组成,从啤酒的香气成分、苦味成分和不良风味3个方面阐述风味物质的来源。啤酒花中萜烯类化合物、酵母发酵产生的酯和高级醇是啤酒重要的香气来源。麦汁、干加酒花、添加功能性原料、无醇的新型啤酒等新技术的应用也对啤酒的香气有一定协同作用。啤酒花中的α-酸、β-酸及多酚物质赋予啤酒特有的苦味。酒花添加量、添加时间,啤酒过滤和灭菌对啤酒苦味具有一定的影响。啤酒的酿造过程中产生的双乙酰、含硫化合物和贮藏期间产生的老化味会使啤酒产生不良风味。超高压技术对降低啤酒不良风味有一定作用。通过本综述,有望推动改进啤酒生产配方、提升啤酒风味、改进工艺和贮藏条件等方面研究的深入进行。     

Inhibitory effects of new varieties of bitter melon on lipopolysaccharide-stimulated inflammatory response in RAW 264.7 cells

Bitter melon is widely used as a food and a traditional herbal medicine for the treatment of diabetes; it also possesses antioxidant, anti-tumour, anti-bacterial, anti-obesity, and anti-hypertension activities. The aim of this work was to study the in vitro anti-inflammatory effects of different solvent extracts of the seeds and fruits of new varieties of bitter melon. Of the 30 bitter melon extracts tested, the ethyl acetate extract of the fruit of Momordica charantia MDS72 (EAEF-MCMDS72) exhibited the strongest anti-inflammatory activity. EAEF-MCMDS72 significantly inhibited the production of NO, IL-6, PGE₂, TNF-α, and MCP-1 in lipopolysaccharide (LPS)-treated RAW 264.7 cells. The expression levels of the iNOS and COX-2 proteins in LPS-stimulated RAW 264.7 cells were inhibited by EAEF-MCMDS72. Real-time RT-PCR analysis indicated that the mRNA expression levels of iNOS, COX-2, IL-6, and TNF-α were suppressed by EAEF-MCMDS72. Moreover, four known triterpene compounds including (23E)-cucurbita-5,23,25-triene-3β,7β-diol (1), (23E)-25-methoxycucurbit-23-ene-3β,7β-diol (2), (23E)-5β,19-epoxycucurbita-6,23-diene-3β,25-diol (3), and 3,7-dioxo-23,24,25,26,27-pentanorcucurbit-5-en-22-oic acid (4) were isolated from the fruit of M. charantia MDS72. Compounds 2, 3, 4 suppressed the LPS-induced NO production in RAW 264.7 cells. Furthermore, the present study may contribute to our understanding of the anti-inflammatory effects of EAEF-MCMDS72 and its triterpene compounds.     

Identification of (furan-2-yl)methylated benzene diols and triols as a novel class of bitter compounds in roasted coffee

Preliminary studies demonstrated that the identification of unknown bitter taste compounds in roasted coffee, by means of an analytical fractionation approach, is hampered by their limited oxidative, as well as chemical stability. A synthetic-constructive strategy was followed in the present investigation by performing targeted reactions of putative coffee-related precursors to give candidate bitter taste molecules. Binary mixtures of a di and trihydroxybenzene, namely pyrogallol, hydroxyhydroquinone, catechol, or 3- and 4-methylcatechole, and a furan derivative, namely furfuryl alcohol, furan-2-aldehyde, or 5-(hydroxymethyl)furan-2-aldehyde, all of which are known to be present in roasted coffee, were thermally treated. The reaction products were identified as (furan-2-yl)methylated benzene diols and triols, by means of LC–MS and NMR experiments, and their bitter taste thresholds determined by means of sensory analysis. Finally, LC–MS/MS studies verified the natural occurence of 4-(furan-2-ylmethyl)benzene-1,2-diol, 4-(furan-2-ylmethyl)benzene-1,2,3-triol, 4-(furan-2-ylmethyl)-5-methylbenzene-1,2-diol, and 3-(furan-2-ylmethyl)-6-methylbenzene-1,2-diol as a novel class of bitter taste compounds in roasted coffee. Depending on their chemical structure, the bitter taste recognition threshold of these compounds ranged between 100 and 537 μmol/l.     

Protein extraction optimisation,characterisation, and functionalities of protein isolate from bitter melon (Momordica charantia) seed

Bitter melon seeds are a rich source of protein. Optimum conditions for protein extraction from the seeds, determined using a response surface design, were at a pH 9.0 and 1.3 M NaCl. Soy protein isolate (SPI) was included for comparison. Surface hydrophobicity of bitter melon seed protein isolate (BMSPI) (690) was significantly higher than that of SPI (399). Electrophoretograms of BMSPI showed bands at 40 and 55 kDa, and at 22, 25, and 35 kDa in non-reducing and reducing buffers, respectively. BMSPI had most of the essential amino acids and hence could be considered as a high quality protein. BMSPI had a single denaturation temperature (113.1 °C) while SPI had two denaturation temperatures (78.0 and 94.8 °C). The proteins exhibited U-shaped curves with solubilities ranging from 62.0% to 67.5% for BMSPI and 86.7% to 90.1% for SPI at pH ? 7.0. BMSPI had lower emulsifying activity (0.36 vs. 0.73), foaming capacity (39.6 vs. 61.0 ml), and foaming stability (21.5 vs. 25.5 min) than had SPI.