Influence of wine pectic polysaccharides on the interactions between condensed tannins and salivary proteins

Alpha-amylase, a major human salivary protein, and IB8c, a representative of the proline-rich proteins, were obtained by isolation from saliva and by solid-phase synthesis, respectively. The interactions between these proteins and condensed tannins isolated from grape seeds were studied at different protein and tannin concentrations by measuring their aggregation. Pectic polysaccharides were isolated from wine, and their effect on protein tannin aggregation was assessed. The results presented in this study showed that the most acidic fractions of arabinogalactan proteins have the ability to inhibit the formation of aggregates between the grape seed tannins and the two different salivary proteins. Rhamnogalacturonan II has the same ability toward alpha-amylase but not IB8c under the conditions of the present study. Polysaccharides show effects at concentrations at which they are present in wine, which could mean an influence in wine astringency. The interaction between condensed tannins and alpha-amylase is differently affected by ionic strength when compared with IB8c.     

Tetramethylated dimeric procyanidins are detected in rat plasma and liver early after oral administration of synthetic oligomeric procyanidins

Procyanidins (PC) are of great interest in nutrition because they account for a major fraction of the total flavonoids ingested in Western diets and have health benefits in humans. However, it remains unknown which species of PC, namely, monomers, oligomers, or aromatic acid derivatives of gut microflora, are responsible for their beneficial effects in vivo. The high molecular complexity of PC extracts and PC-rich foods is a major problem in absorption studies. To circumvent this difficulty, we have synthesized oligomeric PC consisting of (-)-epicatechin units linked by ethyl bridges. The synthetic PC (SPC) only contains dimers, trimers, tetramers, and nanomers. After oral gavage of this SPC (200 mg/kg body weight) to male Wistar rats, tetramethylated dimeric PC (TDPC) were detected in plasma and liver. TDPC were detected in plasma as soon as 1 h after intake, reaching maximum concentrations (14 mg/L) 2 h after gavage. At this time, liver contained as much as 15 mug of TDPC per gram of tissue. In conclusion, orally administered dimeric PC are rapidly absorbed and internally methylated in rats. To our knowledge, this is the first time that methylated dimeric PC have been detected in plasma and liver. We consider that plasma and liver concentrations of TDPC are sufficient to exert a hormone-like effect and, therefore, that PC dimers are good candidates as agents of the biological activities of PC extracts and PC-rich foods.     

Molecular basis of the interaction between proteins of plant origin and proanthocyanidins in a model wine system

Plant proteins are being used as a replacement for animal proteins in wine fining. The surface hydrophobicity of plant proteins in four commercial preparations differing for their origin and processing was assessed by using a fluorescent hydrophobic probe in wine-like media. Displacement of the probe by addition of wine phenolics was measured as a way to compare and predict to some extent the efficiency of these proteins in wine fining. It was found that the binding of polyphenols was much more specific than that of the hydrophobic probe. Further analysis of the polyphenol pattern in protein-treated wine-like solutions pointed out two relevant facts: (1) proteins may interfere with the chemistry of the interactions between polyphenols and other wine components; (2) individual protein preparation having different surface hydrophobicities also have different specificities in binding different polymeric forms of the polyphenols and in their substitution products. These findings are related to the possible carry-over of transition metals and may be worth exploring for custom tailoring the fining process. Whether the practical application of the latter finding will call for production and/or screening of plant-derived proteins with features appropriate to this task remains to be investigated. However, the approaches presented in this study may be used for large-scale screening of protein suitability for fining application under laboratory conditions, providing guidelines for their use in actual winemaking applications.     

基于主成分和聚类分析法评价不同有机滴灌肥处理对酿酒葡萄和葡萄酒品质的影响

为研究追施有机滴灌肥在酿酒葡萄和葡萄酒品质上的应用效果,以5年生酿酒葡萄"赤霞珠"为试验材料,通过田间试验设置常规施肥(CK)、常规施肥+生物有机肥提取液(T1)、常规施肥+氨基酸肥(T2)、常规施肥+海藻肥(T3)、常规施肥+沼液肥(T4),分析不同有机滴灌肥处理下酿酒葡萄与葡萄酒品质状况。通过主成分和聚类分析,综合评价不同施肥处理下品质差异,采用最短距离法对各施肥处理进行系统聚类。结果表明,酿酒葡萄与葡萄酒的品质指标表现出显著或极显著的正相关关系;综合品质质量排序为T3T4T2T1CK;不同施肥处理下葡萄与葡萄酒品质质量可聚为3类,常规施肥处理单独聚为一类,品质质量为三等,常规施肥+生物有机肥提取液和常规处理+氨基酸两个处理聚为一类,品质质量为二等,常规施肥+海藻肥和常规施肥+沼液肥两个处理聚为一类,品质质量为一等,最好。综合评价,在常规处理基础上追施海藻肥对提高葡萄与葡萄酒品质的效果最为明显。     

Thaumatin-like proteins and chitinases, the haze-forming proteins of wine, accumulate during ripening of grape (Vitis vinifera) berries and drought stress does not affect the final levels per berry at maturity

Thaumatin-like proteins and chitinases, which are pathogenesis-related (PR) proteins, were the major soluble protein components of grapes from five cultivars of Vitis vinifera. This dominance of PR proteins was apparent at berry softening (véraison) and then throughout berry development for the Muscat of Alexandria, Sultana, and Shiraz cultivars and in the berries of the Sauvignon Blanc and Pinot Noir cultivars examined at commercial maturity. The M(r) of the major thaumatin-like protein from Muscat of Alexandria grapes was 21 272, and those of the three major chitinases from this cultivar, ChitB, ChitC, and ChitD, were 25 588, 25 410, and 25 457, respectively. The vines in the study were irrigated and showed no obvious signs of disease. Shiraz vines that had not been irrigated throughout the season were clearly water stressed, but had levels of PR proteins in the berry similar to vines that had been fully irrigated. It appears that the production of PR proteins that cause protein instability in wines by grapes may be little influenced by environmental conditions.     

Attitudes of hunters, locals, and the general public in Sweden now that the wolves are back

The wolf population in Scandinavia has increased from functionally extinct to about 100 wolves since the 1970s. In 2001 we surveyed four groups of Swedes to analyze the relationship between experience, knowledge, and people's attitude toward wolves. Although all groups support the right of wolves to exist, Swedes who live in areas where wolves have been restored have more negative attitudes than the general public. Attitudes toward wolves are not strong among the general public, thus changes are possible. Experience with wolf predation leads to more negative attitudes toward wolves. Hunters in areas with wolves have the most accurate knowledge about wolves but at the same time the most negative attitudes. But within all four groups as knowledge increases attitudes become more positive. Still, the most knowledgeable local hunters have less favorable attitudes than the least knowledgeable members of the general public. High proportions of the population do not care about wolves which makes it difficult to reach them with information, but does make them susceptible to rapid changes if wolves become a media topic. With the restoration of wolves, hunters, the strongest supporters of wolves in the 1970s, are now less supportive than the general public.     

Identification and quantification of the conjugated metabolites derived from orally administered hesperidin in rat plasma

Hesperidin is a biologically effective flavonoid. Several studies have reported that dietary hesperidin was converted to conjugated metabolites, such as hesperetin-glucuronides and sulfoglucuronides, during absorption and metabolism. However, the chemical structures of the conjugated metabolites, especially the sites of glucuronidation and sulfoglucuronidation in plasma, were unconfirmed. Therefore, the concentrations of the metabolites conjugated at various sites in plasma could not be individually quantified. In the present study, we identified the chemical structures and concentrations of the major conjugated metabolites in rat plasma after oral administration of hesperidin. Two hesperetin-glucuronides were prepared and identified as hesperetin-7-O-beta-D-glucuronide and hesperetin-3'-O-beta-D-glucuronide. Using these authentic compounds, the concentrations of hesperetin-7-O-beta-D-glucuronide and hesperetin-3'-O-beta-D-glucuronide in rat plasma were individually determined by liquid chromatography-mass spectrometry. In rat plasma, hesperetin-glucuronides were primarily comprised of hesperetin-7-O-beta-D-glucuronide and hesperetin-3'-O-beta-D-glucuronide. The concentration of hesperetin-7-O-beta-D-glucuronide was slightly higher than that of hesperetin-3'-O-beta-D-glucuronide. Furthermore, not only hesperetin conjugates but also homoeriodictyol conjugates were observed in rat plasma. The present study is the first report elucidating the chemical structures and changes in individual concentrations in rat plasma of glucuronides derived from orally administered hesperidin.     

Purification and identification of barley (Hordeum vulgare L.) proteins that inhibit the alkaline serine proteinases of Fusarium culmorum

It has been proposed that microbial proteinase inhibitors, which are present in abundance in cereal grains, protect the seed against plant pathogens. So far, however, very little is known about the interactions of those inhibitors with the proteinases of phytopathogenic microbes. The increased alkaline proteinase activities of Fusarium head blight (FHB) diseased wheat and barley grain imply that the Fusarium fungi synthesize those enzymes during the colonization of the kernel. To study which barley proteins can inhibit Fusarium proteinases, and hence, possibly protect the seed from FHB, the proteins of a grain extract have been separated and tested for their abilities to inhibit two alkaline serine proteinases that we previously isolated from F. culmorum. The proteins were separated by size exclusion, ion exchange, and reversed-phase-HPLC chromatographies. The purified inhibitors were identified by their molecular masses and N-terminal amino acid sequences. The proteins that inhibited the subtilisin-like Fusarium proteinase were the chymotrypsin/subtilisin (CI) inhibitors 1A, 1B, and 2A and the barley alpha-amylase/subtilisin inhibitor (BASI). Only one of the purified proteins inhibited the trypsin-like proteinase, the barley Bowman-Birk inhibitor (BBBI). No novel inhibitors were detected.     

Red wine polyphenols alone or in association with ethanol prevent hypertension, cardiac hypertrophy, and production of reactive oxygen species in the insulin-resistant fructose-fed rat

The effects of a red wine polyphenolic extract (RWPE), ethanol, or both combined were evaluated in insulin resistant rats. Rats were fed for 6 weeks with fructose (60%)-enriched food and force-fed with (a) water only (F group), (b) aqueous solution of RWPE (100 mg/kg, FP group), (c) 10% (v/v) mixture of ethanol and water (FE group), or (d) solution containing the same amount of the RWPE and ethanol (FPE group). Animals fed a standard chow (C group) were used for comparison purpose. After 6 weeks, blood pressure was higher in F (130.0 x b1 1.7 mm Hg) than in C animals (109.6 x b1 0.9 mm Hg) and similar to the C group in all other fructose-fed treatment groups. Relative heart weight was higher in F (3.10 x b1 0.05) than in C (2.78 x b1 0.07) and significantly lower in FP (2.92 x b1 0.04) and FPE (2.87 x b1 0.08 mg/g) than in F animals. Left ventricle and aorta productions of reactive oxygen species (O2*-) were higher in F than in C groups and lowered by the RWPE but not by the ethanol treatment. Ethanol but not the RWPE treatment reduced the degree of insulin resistance in the fructose-fed rats. In summary, our study showed that polyphenols are able to prevent cardiac hypertrophy and production of reactive oxygen species in the insulin resistant fructose-fed rat.     

Occurrence of the free and Peptide forms of pyroglutamic acid in plasma from the portal blood of rats that had ingested a wheat gluten hydrolysate containing pyroglutamyl peptides

In order to determine pyroglutamic acid levels in plasma, we developed a method based on precolumn derivatization of the carboxyl group of pyroglutamic acid with 2-nitrophenylhydrazine. Eight-week-old male SD strain rats were administered 200 mg of an acidic peptide fraction obtained from a commercial wheat gluten hydrolysate containing 0.63 mmol/g pyroglutamyl peptide. After administration, significant amounts of free pyroglutamic acid were observed in the ethanol-soluble fraction of the plasma from the portal vein. In addition, pyroglutamate aminopeptidase digestion of the ethanol-soluble fraction liberated significant amounts of pyroglutamic acid, which indicated the presence of the pyroglutamyl peptide. The presence of the pyroglutamyl peptide in the plasma was further confirmed by size exclusion chromatography. The levels of free and peptide forms of pyroglutamic acid increased significantly and reached a maximum (approximately 40 nmol/mL) at 15 and 30 min after administration, respectively.     

Influence of roads on the endangered Stephens' kangaroo rat (Dipodomys stephensi): are dirt and gravel roads different?

Roads can have major impacts on animal distribution and movement patterns by destroying or creating habitat, and by acting as both barriers and corridors for movement. Using a combination of live trapping and spool and line tracking, we compare the relative abundance, mass, and demographic turnover of the endangered Stephens' kangaroo rat (Dipodomys stephensi) on dirt and gravel roads in comparison with adjacent grassland habitat. D. stephensi was more active on dirt roads, and less so on gravel roads, relative to adjacent grassland habitat. Dirt roads were used extensively, and animals tended to move greater distances along dirt roads than in surrounding grasslands. In contrast, gravel roads were used much less extensively than adjacent grasslands. Animals using dirt roads were significantly lighter in mass than those on gravel roads and in adjacent grassland, suggesting greater use by juvenile animals. Dirt roads also had lower rates of recapture and higher rates of new arrivals than did adjacent habitat. These findings suggest that dirt roads provide potentially important landscape linkages for D. stephensi, whereas that gravel roads may act as movement barriers.     

Preface for the SUITMA10 Conference proceedings Soils of Urban,Industrial, Traffic,Mining, and Military Areas (SUITMAs) are essential resources that deserve our attention for the sustainable management of anthropized environments

Journal of Soils and Sediments -