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1.
The caramel-like aroma compound, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) was quantified and verified by HPLC and GC-MS in the Maillard reaction based on methylglyoxal (MG). The reaction was performed in the 0.5 M phosphate buffer by heating MG with or without either glycine or cysteine at 120 degrees C for 1 h. MG alone or MG with cysteine could produce increased level of DMHF with pH increased, whereas MG with glycine had contrary trend. Experiments using a 1:1 mixture of [(13)C6]glucose and [(12)C6]glucose indicate that in the presence of glycine or cysteine, glucose skeleton kept intact during DMHF formation since a 1:1 mixture of [(13)C6]DMHF and [(12)C6]DMHF was formed. Acetylformoin was detected in the glucose with amino acid reaction system as a precursor of DMHF, while in the MG reaction systems, acetylformoin could not be identified. It is suggested different pathways of DMHF formation via MG and glucose.  相似文献   

2.
The inhibitory effects of tea catechins, the O-methylated derivatives of (-)-epigallocatechin-3-O-gallate (EGCG), and the polyphenol extracts from tea leaves (Camellia sinensis L.) on oxazolone-induced type IV allergy in male ICR mice were investigated. Four major tea catechins and two O-methylated derivatives, (-)-epigallocatechin-3-O-(3-O-methyl)gallate (EGCG3' 'Me) and (-)-epigallocatechin-3-O-(4-O-methyl)gallate (EGCG4' 'Me), showed significant inhibitory effects on mouse type IV allergy after a percutaneous administration at a dose of 0.13 mg/ear. Among tea catechins, the compounds including galloyl moieties, such as EGCG and (-)-epicatechin-3-O-gallate (ECG), showed the strongest inhibitory activities on mouse type IV allergy. The inhibitory activities of EGCG3' 'Me and EGCG4' 'Me were higher than that of EGCG at a dose of 0.05 mg/ear. Polyphenol extract from tea leaves of Benihomare cultivar, which includes EGCG3' 'Me, strongly inhibited mouse type IV allergy after percutaneous administration in comparison with that from Yabukita cultivar, which does not include EGCG3' 'Me, at doses of 0.05 and 0.13 mg/ear. EGCG3' 'Me is thought to contribute, at least in part, to the inhibitory ability of Benihomare tea leaves on mouse type IV allergy. EGCG and the polyphenol extracts from Benihomare and Yabukita tea leaves also inhibited mouse type IV allergy by oral administration at 1 h before the sensitization and at 1 h before the challenge with oxazolone. Therefore, daily intake of tea drinks could have potential to prevent type IV allergy.  相似文献   

3.
Solutions of L-cysteine (Cys) and N-acetyl-L-cysteine (AcCys), containing glucose or rhamnose, with or without arginine, were buffered to pH 3, 5, and 7 and incubated at 70 degrees C for 48 h. Cys and AcCys inhibited the formation of (hydroxymethyl)furfural (HMF) from glucose and methylfurfural (MF) from rhamnose under acidic conditions. AcCys inhibited the accumulation of 4-hydroxy-2, 5-dimethyl- 3(2H)-furanone (DMHF, Furaneol) from rhamnose, but Cys, under our experimental conditions, enhanced Furaneol accumulation from rhamnose. Cys and AcCys reacted directly with Furaneol but not with HMF or MF. Both Cys and AcCys inhibited nonenzymatic browning at pH 7. At pH 3, however, Cys reacted with both glucose and rhamnose to produce unidentified compounds that increased the visible absorbency.  相似文献   

4.
Three types of Korean black raspberry wine were produced via alcoholic fermentation from juice, juice-pulp, and juice-pulp-seed, respectively. These wines were compared in terms of their anti-inflammatory activities and polyphenol contents. The total content of polyphenol compounds in wines was increased by 22.4% after supplementation with pulp and by 56.7% after supplementation with both pulp and seed. The reduction rate of NO evolution was highest in the order juice-pulp-seed wine, juice-pulp wine, and juice wine. Addition of the juice-pulp-seed wine at a level of 62.5-500 mg/L decreased the NO evolution rate by 40.5-94.2%. Eight fractions were obtained from juice-pulp-seed wine via ethyl acetate extraction and silica gel chromatography. Of these, the AF fraction, which exhibited the highest in vitro anti-inflammatory activity, exerted inhibitory effects on ear edema, writhing response, and vein membrane vascular permeability in mice. 3,4-Dihydroxybenzoic acid accounted for 37.6% of the total polyphenol content in the AF fraction.  相似文献   

5.
OBJECTIVES: To examine the efficiency of the Bangladesh Integrated Nutritional Program (BINP) in identifying which infants should be supplemented, whether full supplementation was given for the stipulated period of time, and whether the correct exit criteria from the supplementation programme were used. To test whether targeted food supplementation of infants between 6-12 months of age resulted in enhanced weight gain. SETTING: Mallickbari Union, Bhaluka, a rural area located about 100 km north of Dhaka, Bangladesh. PARTICIPANTS: Five hundred and twenty-six infants followed for 6 to 12 months. RESULTS: Of the 526 infants studied, 368 should have received supplementation based on BINP criteria but only 111 infants (30%) did so, while a further 13% were incorrectly given supplementation. So in total over half (52.8%) of the sample was incorrectly identified for supplementation. In addition, less than a quarter of the infants received the full 90 days of supplementation and close to half of the infants exited the programme without the requisite weight gain. Infants were assigned to one of four groups: correctly supplemented, correctly non-supplemented, incorrectly supplemented or incorrectly non-supplemented. This classification provided natural controls; the correctly supplemented infants versus the incorrectly non-supplemented infants, and the correctly non-supplemented infants versus the incorrectly supplemented infants. There were no significant differences in weight gain between the correctly supplemented group and the incorrectly non-supplemented group or between the correctly non-supplemented and the incorrectly supplemented groups, nor was there any evidence of growth faltering in the incorrectly non-supplemented group. CONCLUSIONS: This study found serious programmatic deficiencies - inability to identify growth faltering in infants, failure to supplement for the full time period and incorrect exit procedures. There was no evidence that food supplementation had any impact on improving infant weight gain.  相似文献   

6.
Thermal treatment of a 1 + 1 mixture of glucose and L-proline led to the development of an intense bitter taste being reflected in high amounts of the bitter-tasting bispyrrolidino- (1) and pyrrolidinohexose reductones (2) formed. Heating the reaction mixture in the presence of L-cysteine drastically reduced the amounts of these aminohexose reductones and, thereby, the intensity of the bitter taste. Studies on the mechanism of the cysteine-induced reduction of the bitter taste revealed that the precursor of the aminohexose reductones, the hexose-derived acetylformoin (3), reacted more easily with L-cysteine to form the 7-hydroxy-4a,6-dimethyl-2H,3H,4aH-furo[2,3-b]thiazine (4), a previousely unknown Maillard reaction product, than with L-proline to the aminohexose reductones 1 and 2, thereby blocking the formation of bitter-tasting compounds.  相似文献   

7.
The objective of this study was to determine the effects of muscadine grape or wine (cv. Noble) phytochemicals on obesity and associated metabolic complications. Muscadine grape or wine phytochemicals were extracted using Amberlite FPX66 resin. Male C57BL/6J mice were given a low-fat diet (LF, 10% kcal fat), high-fat diet (HF, 60% kcal fat), HF + 0.4% muscadine grape phytochemicals (HF+MGP), or HF + 0.4% muscadine wine phytochemicals (HF+MWP) for 15 weeks. At 7 weeks, mice fed HF+MGP had significantly decreased body weights by 12% compared to HF controls. Dietary MGP or MWP supplementation reduced plasma content of free fatty acids, triglycerides, and cholesterol in obese mice. Inflammation was alleviated, and activity of glutathione peroxidase was enhanced. Consumption of MGP or MWP improved insulin sensitivity and glucose control in mice. Thus, consumption of muscadine grape and wine phytochemicals in the diet may help to prevent obesity-related metabolic complications.  相似文献   

8.
The inhibitory effects of C-2 epimeric isomers of (-)-epigallocatechin-3-O-gallate (EGCG) and two O-methylated EGCG derivatives, (-)-epigallocatechin-3-O-(3-O-methyl)gallate (EGCG3'Me) and (-)-epigallocatechin-3-O-(4-O-methyl)gallate (EGCG4'Me), against oxazolone-induced type IV allergy in male mice were investigated. These compounds exhibited strong antiallergic effects by percutaneous administration at a dose of 0.13 mg/ear. The inhibition rates of (-)-gallocatechin-3-O-gallate (GCG), (-)-gallocatechin-3-O-(3-O-methyl)gallate (GCG3'Me), and (-)-gallocatechin-3-O-(4-O-methyl)gallate (GCG4'Me) on mouse type IV allergy were 52.1, 53.3, and 54.8%, respectively. However, the antiallergic effects were weaker than those of their corresponding original tea catechins (2R,3R type). The inhibition rates of those were 88.0, 73.2, and 77.6%, respectively. For all of the catechins tested, oral administration at a dose of 50 mg/kg body weight significantly suppressed the allergic symptoms. The inhibitory rates varied from 24.0 to 60.6%. No significant differences were observed between the effects of the epimers (2S,3R type) and their corresponding original catechins (2R,3R type). The antiallergic effects of tea catechins and their C-2 epimers observed in this study were dose-dependent. These results suggest that C-2 epimers of tea catechins, which are produced during heat processing at high temperatures, could be disadvantageous for the antiallergic effects on type IV allergy.  相似文献   

9.
The adjuvant activity of Chenopodium quinoa (quinoa) saponins on the humoral and cellular immune responses of mice subcutaneously immunized with ovalbumin (OVA) was evaluated. Two quinoa saponin fractions were obtained, FQ70 and FQ90, and 10 saponins were determined by UPLC/Q-TOF-MS. Mice were immunized subcutaneously with OVA alone or adjuvanted with Quil A (adjuvant control), FQ70, or FQ90. FQ70 and FQ90 significantly enhanced the amount of anti-OVA-specific antibodies in serum (IgG, IgG1, and IgG2b) in immunized mice. The adjuvant effect of FQ70 was significantly greater than that of FQ90. However, delayed type hypersensitivity responses were higher in mice immunized with OVA adjuvanted with FQ90 than mice treated with FQ70. Concanavalin A (Con A)-, lipopolysaccharide-, and OVA-stimulated splenocyte proliferation were measured, and FQ90 significantly enhanced the Con A-induced splenocyte proliferation. The results suggested that the two quinoa saponin fractions enhanced significantly the production of humoral and cellular immune responses to OVA in mice.  相似文献   

10.
Quillaja saponin is the extract from the balk of a South American tree, and it is considered to modulate immunological responses. We hypothesized that Quillaja saponin may change allergy-associated cytokine profile and antigen-specific immune responses. The purpose of this study is to investigate whether Quillaja saponin can suppress ovalbumin (OVA)-induced IgE-mediated allergic responses through promoting a dominant Th1 immune response. The spleen cells from BALB/c mice, which were primed by OVA, were used for an in vitro challenge test. The level of total and OVA-specific IgE, IL-4, IFN-gamma, and IL-12 was determined by enzyme-linked immunosorbent assay (ELISA). BALB/c mice were orally administered with saponin for 35 days. The mice were immunized intraperitoneally with OVA on days 14 and 21. After intraperitoneal challenge with OVA on day 35, anaphylactic symptoms were monitored. Total and specific IgE and IgG, specific IgG1 and IgG2a, and histamine levels in serum were analyzed by ELISA. The increase of IL-12 and IFN-gamma levels was observed in the presence of Quillaja saponin, while the IL-4 level was decreased. Furthermore, Quillaja saponin suppressed total and OVA-specific IgE secretion in spleen cells. Balb/c mice that were orally administered Quillaja saponin exhibited lower total and OVA-specific IgE and OVA-specific IgG secretions, whereas total IgG levels remained unchanged. Suppression of OVA-specific IgG1 and an increase of OVA-IgG2a were observed in mice fed saponin. Quillaja saponin also decreased serum histamine levels and diminished anaphylactic symptoms. The present study indicates that Quillajasaponin can suppress allergen-specific IgE-mediated reactivity in a murine model of food allergy, which results from shifting from a Th2-dominated to a Th1-dominated immune response.  相似文献   

11.
This study evaluates the effects of replacing beef tallow added to rabbit feeds (3% w/w) by different doses (0%, 1.5% and 3% w/w) of n-6- or n-3-rich vegetable fat sources (sunflower and linseed oil, respectively) and alpha-tocopheryl acetate supplementation (0 and 100 mg/kg) on the fatty acid composition, alpha-tocopherol content, and oxidation levels [assessed by analyzing thiobarbituric acid (TBA) and lipid hydroperoxide values] in rabbit meat. We also measured these parameters after cooking and refrigerated storage of cooked rabbit meat. Both dietary alpha-tocopheryl acetate supplementation and the dose and source of fat added to feeds influenced meat fatty acid composition, modifying the n-6/n-3 ratio, which was more nutritionally favorable when linseed oil was used. Furthermore, the addition of linseed oil and the supplementation with alpha-tocopheryl acetate enhanced long-chain PUFA biosynthesis. However, the addition of 3% linseed oil increased meat oxidation, and although it was reduced by dietary supplementation with alpha-tocopheryl acetate in raw meat, this reduction was not as effective after cooking. Therefore, dietary supplementation with 1.5% linseed oil plus 1.5% beef tallow and with alpha-tocopheryl acetate would be recommended to improve the nutritional quality of rabbit meat.  相似文献   

12.
Oral allergy syndrome is an immediate food allergic event that affects lips, mouth, and pharynx, is often triggered by fruits and vegetables, and may be associated with pollinosis. Here, we report on the allergenic pattern of different varieties of cherry (Prunus avium) and results obtained by applying several technological processes to the selected varieties. Whole cherries were submitted to chemical peeling, thermal treatment, and syruping processes, and the relative protein extracts were analyzed by in vitro (sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting analysis) and in vivo tests (skin prick test). Electrophoretic analyses demonstrated that there was no marked difference among cherry cultivars. Chemical peeling successfully removed Pru av 3, a lipid transfer protein (LTP) responsible for oral allergy syndrome in patients without pollinosis, leading to the industrial production of cherry hypoallergenic derivatives. Furthermore, the syruping process removed almost all allergenic proteins to whom patients with pollinosis are responsive. In vivo tests confirmed electrophoretic results.  相似文献   

13.
The effects of concentrated carrot protein (CCP) containing 15.4% (w/w) carrot (Daucus carota) antifreeze protein on texture properties of frozen dough and volatile compounds of crumb were studied. CCP supplementation lowered the freezable water content of the dough, resulting in some beneficial effects including holding loaf volume steadily and making the dough softer and steadier during frozen storage. Furthermore, SPME-GC-MS analysis showed CCP supplementation did not give any negative influences on volatile compounds of crumb and gave a pleasant aroma felt like Michelia alba DC from trans-caryophyllene simultaneously. Combining our previous results that CCP supplementation improves the fermentation capacity of the frozen dough, CCP could be used as a beneficial additive for frozen dough processing.  相似文献   

14.
The allergens associated with cashew food allergy have not been well-characterized. We sought to identify the major allergens in cashew nut by performing IgE immunoblots to dissociated and reduced or nonreduced cashew protein extracts, followed by sequencing of the peptides of interest. Sera from 15 subjects with life-threatening reactions to cashews and 8 subjects who tolerate cashews but have life-threatening reactions to other tree nuts were compared. An aqueous cashew protein extract containing albumin/globulin was separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and subjected to IgE immunoblotting using patient sera. Selected IgE reactive bands were subjected to N-terminal amino acid sequencing. Each of the 15 sera from cashew-allergic subjects showed IgE binding to the cashew protein extract. The dominant IgE-binding antigens in the reduced preparations included peptides in the 31-35 kD range, consistent with the large subunits of the major storage 13S globulin (legumin-like protein). Low-molecular-weight polypeptides of the 2S albumin family, with similarity to the major walnut allergen Jug r 1, also bound IgE. The sera from eight patients who tolerate cashew but displayed allergies to other tree nuts showed only minimal or no IgE binding to cashew. Cashew food allergy is associated with the presence of IgE directed against the major seed storage proteins in cashew, including the 13S globulin (legumin group) and 2S albumins, both of which represent major allergen classes in several plant seeds. Thus, the legumin-group proteins and 2S albumins are again identified as major food allergens, which will help further research into seed protein allergenicity.  相似文献   

15.
采用密闭箱法结合42 C型 NO-NO2-NOX 分析仪的快速线检测系统,在气候箱严密控光(L1)和室内自然光暗处理(L2)条件下,研究了分蘖期水稻地上部和空气间的NOX(NO, NO2 )交换作用,结果表明: 1)试验用水稻品种具有较强的NO挥发能力,在L1、L2条件下水稻NO平均挥发速率 [按鲜质量(g, FW)计算] 分别达到0.0188、0.0239 g/(g·h),并在环境空气NO浓度达100 g/m3条件下水稻也能净排放NO;2)水稻能吸收空气NO2,L1、L2条件下水稻NO2平均净吸收速率为0.00084、0.00165 g/(g·h);3)施氮能增强水稻NO挥发,在气候箱严密控光(L1)条件下,短期内(1~2 d)施氮在日间 6:00~10:00 弱光时段和 10:00~14:00强光时段有刺激水稻NOX (NO, NO2 )挥发的效应, 但在14:00~18:00 时段,持续强光能削弱施氮对水稻NO挥发的刺激作用而增强水稻对NO2吸收。4)室内自然弱光条件下(L2),施氮能提高日间水稻的NO净挥发速率,水稻NO2净吸收速率随着有光时间的延长而上升。夜间暗处理条件下,施氮对促进水稻NO的挥发无明显作用,水稻NO2吸收速率下降。试验结果显示,水稻地上部从空气中净吸收NO2的平均速率远低于NO净挥发速率,分蘖期水稻地上部分与空气间的NOX (NO, NO2 )交换作用主要表现为NO的净挥发,相当于净损失纯N 10.95~12.5 g/(hm2 ·d)。  相似文献   

16.
Lipid transfer proteins (LTPs) are a family of low molecular mass (7-9 kDa) polypeptides, the members of which share 35-95% sequence homology. These proteins are widely distributed throughout the plant kingdom and are receiving attention for their biochemical characteristics and biological activity. LTPs are indeed studied in different research fields varying from allergy to food technology, and numerous molecules belonging to this class are progressively being identified and investigated. Proteins from pomegranate juice were fractioned by cation exchange chromatography and analyzed by SDS-PAGE. Two proteins were identified as putative LTPs on the basis of their molecular weights and their electrophoretic behaviors under reducing and nonreducing conditions. Finally, proteins were purified and characterized by mass spectrometry. This analysis confirmed that the two polypeptides are LTPs on the basis of an amino acid sequence common to LTPs from other plant sources and cysteine content. The two proteins, named LTP1a and LTP1b, showed similar molecular masses but different immunological profiles when immunodetected with rabbit antibodies specific for Pru p 3 and human IgE from a patient suffering from pomegranate allergy. The demonstration of the existence of two immunologically unrelated LTPs in pomegranate confirms the variability and the complexity of the plant LTP family. This should be taken into account when the role of these proteins as elicitors of allergies to fruits is investigated and could help to explain the contradictory literature data on pomegranate allergy.  相似文献   

17.
The effect of a wild blueberry-enriched diet on vasoconstriction and vasorelaxation was examined in the adult, 20-week-old spontaneously hypertensive rat (SHR) after 8 weeks of a control (C) or an 8% wild blueberry (WB) diet. Nitric oxide (NO)- and cyclooxygenase (COX)-mediated aortic responses were examined ex vivo with the agonists L-phenylephrine (Phe) and acetylcholine (Ach), in the absence or presence of the NO synthase (NOS) inhibitor L-NG-monomethyl arginine (L-NMMA) or the COX inhibitor mefenamic acid (MFA). The vasoconstriction elicited by Phe was reduced in the WB group, attributed to the NO pathway, favoring a lower vascular tone under basal conditions. Acetylcholine-induced vasorelaxation in the WB group was possibly mediated through the COX, but not the NO pathway. These findings document the potential of wild blueberries to modify major pathways of vasomotor control and improve the vascular tone in the adult SHR with endothelial dysfunction.  相似文献   

18.
Oral immunotherapy (OIT) is a promising therapeutic approach for treating food allergy. The treatment with heated ovomucoid-depleted egg white (HOMEW) in egg-allergic patients is noteworthy; however, OIT protocols are still experimental, and a better knowledge of the underlying mechanism is required. The objective of this work was to investigate the immunomodulatory effects of HOMEW and characterize the underlying mechanism in a BALB/c mouse model of egg allergy. Mice were sensitized with EW and treated with HOMEW. Post treatment, mice were challenged with EW and euthanized for collecting blood and spleen. Markers of allergic clinical outcomes were measured as histamine concentration, serum antibody activity, and cytokine production from cultured splenocytes. Digestibility of HOMEW was assessed mimicking physiological conditions in vitro. The HOMEW demonstrated high digestibility. The treatment induced a marked increase of the Th1/Th2 ratio in the high-dose treatment group. Treated mice had significantly less histamine, EW-specific IgE, and IL-4 and more IFN-γ and IL-10. This study confirms the mechanisms involved in successful tolerance induction with OIT using HOMEW and allows understanding of the vital role of surrogate allergy markers involved in immune modulation.  相似文献   

19.
Chicken egg yolk immunoglobulin Y (IgY) is a promising alternative for the prevention of enteric gliadin absorption, the predisposing factor of celiac disease (CD). IgY antibody was produced from the egg yolk of Single Comb White Leghorn chickens during the immunization period for the development of an oral immunotherapeutic agent. Here, we report the potential use of spray dried IgY antibody formulation using sugar protectants (mannitol, sorbitol, or microcrystalline cellulose powder (MCCP)). The long-term stability of the spray dried egg yolk powder formulated with 37.5% mannitol (EYP-M) preserved IgY antibody activity at 99.9%, which was significantly higher than that with other protectants (p < 0.05). In a dissolution test, the EYP-M shows 82.4% IgY activity after 2 h in simulated gastric fluid (SGF). A competitive ELISA at 50% inhibition (IC(50)) shows that 1.6 mg/mL EYP-M bound to 7.6 mg/mL and 10.5 mg/mL gliadin in SGF without and with food matrix conditions, respectively, whereas in simulated intestinal fluid, the formulation bound to 10 mg/mL gliadin, regardless of a food matrix. In-vivo study: BALB/c mice fed with EYP-M and gliadin at a ratio of 1:5 (w/w) demonstrated that gliadin absorption in the gastrointestinal tract was minimal at <1%. Thus, EYP-M containing IgY antibody may be used in CD patients to eliminate the effects of ingested toxic gliadin.  相似文献   

20.
Percentage germination, plant height, leaf area, relative dry matter yield, plant nutrient concentration, soil chemical characteristics and source/sink relationship were assessed for maize (Zea mays L TZ-SR-Y) planted in a soil polluted with 3% (v/w) crude oil or 0% (untreated soil), after remediation of soil with different organic (Poultry manure, peptone water, sawdust and yeast extract) and inorganic (NPK, KNO3, NH4H2PO4 and (NH4)2SO4) nutrient supplements applied 7 days after oil treatment. Germination of maize in oil polluted soil was not significantly affected by nutrient supplementation (P=0.05). Maize performance in terms of other studied parameters was highest in the oil polluted soil supplemented with poultry manure, and least in oil polluted soil supplemented with sawdust. Oil treatment correlated significantly with organic C, N, Na, Mg and ferrous in the soil (P=0.05) and with nutrient composition in maize plant tissues (P=0.05). For nutrient uptake, significant correlation was only established between soil N and plant N. Population of petroleum hydrocarbon tolerant microbes increased initially but decreased with time. There is every indication that nutrient supplementation of oil polluted soil especially with organic nutrient sources is beneficial for maize growth, because the C/N ratio is narrowed while the rate of biodegradation of oil and soil recovery is also enhanced. Poultry manure is recommended, however sawdust is not recommended since it tends to impose adverse effect by widening the C/N ratio in soil.  相似文献   

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