Novel prediction method of beer foam stability using protein Z, barley dimeric alpha-amylase inhibitor-1 (BDAI-1) and yeast thioredoxin

Foam stability is an important quality trait of beer. Our previous results of two-dimensional gel electrophoresis (2DE) analyses of beer proteins implied a relationship between barley dimeric alpha-amylase inhibitor-1 (BDAI-1) and beer foam stability as judged by the NIBEM-T analyzer. To develop a novel prediction method of beer foam stability under different conditions of barley cultivar and malt modification, multiple linear regression analysis was applied. The spot intensities of major beer proteins on 2DE gel were quantified and used as explanatory variables. The foam stabilities of 25 beer samples each brewed from malt with different malt modification in one of the three cultivars (cultivars A, B, and C) were explained by the spot intensities of BDAI-1 at the 5% significance level ( r = 0.421). Furthermore, two other major protein spots (b0 and b5) were observed on the 2DE gels of Japanese commercial beer samples with different foam stability. Then, multiple regression for foam stability was calculated using these three spot intensities as explanatory variables. As a result, 72.1% of the beer foam stability in 25 beer samples was explained by a novel multiple regression equation calculated using spot b0 and BDAI-1 as positive explanatory variables and spot b5 as a negative variable. To verify the validity of the multiple regression equation and the explanatory variables, the beer foam stability in practical beer samples was analyzed. As a result, 81.5% of the beer foam stability in 10 Japanese commercial beer samples was also explained by using spot b0 and BDAI-1 as positive explanatory variables and spot b5 as a negative variable. Mass spectrometry analyses followed by database searches revealed that protein spots b0 and b5 were identified as protein Z originated from barley and thioredoxin originated from yeast, respectively. These results confirm that BDAI-1 and protein Z are foam-positive factors and identify yeast thioredoxin as a possible novel foam-negative factor.     

Effects of the combination of hydrophobic polypeptides, iso-alpha acids, and malto-oligosaccharides on beer foam stability

The influence of hydrophobic polypeptides concentrated in beer foam, together with the composition of iso-alpha acids and the content of malto-oligosaccharides in beer on foam stability, has been investigated. The objective was to find out whether a shortage of one of these positive contributors to foam stability could be compensated for by an increased presence of another or whether optimum levels of each contributor is necessary. For that purpose, an image analysis method to evaluate beer foam quality was developed. The foam collapse time was the parameter chosen to group beers according to their foam stability. Profiles of hydrophobic polypeptides that concentrate in beer foam, iso-alpha acids, and malto-oligosaccharides of 14 beer brands were acquired by high-performance liquid chromatography. Principal component analysis (PCA) was performed to show the relationship between beer brands and its composition. Beers that contained propylene glycol alginate as a foam enhancer showed high foam stability except for one beer, which had a low content of hydrophobic polypeptides, thereby highlighting the requirement of threshold levels of hydrophobic polypeptides to obtain stable foam. The data of samples that were devoid of a foam additive were subjected to a discriminant statistical analysis. Foam stability declined in proportion to decreases in hydrophobic polypeptides and to a lesser extent to decreases in iso-alpha-acid contents. Apparently, the content of malto-oligosaccharides were found to have no major influence on foam stability. The model of discriminate analysis was found to explain 100% of the variance in data with 85.2% success in classifying all samples according to the model, suggesting that foam stability is mainly governed by the beer constituents evaluated in this study.     

Stability of barley and malt lipid transfer protein 1 (LTP1) toward heating and reducing agents: relationships with the brewing process

Barley lipid transfer protein (LTP1) is a heat-stable and protease-resistant albumin that concentrates in beer, where it participates in the formation and stability of beer foam. Whereas the barley LTP1 does not display any foaming properties, the corresponding beer protein is surface-active. Such an improvement is related to glycation by Maillard reactions on malting, acylation on mashing, and structural unfolding on brewing. The structural stability of purified barley and glycated malt LTP1 toward heating has been analyzed. Whatever the modification, lipid adduction or glycation, barley LTP1s are highly stable proteins that resisted temperatures up to 100 degrees C. Unfolding of LTP1 occurred only when heating was conducted in the presence of a reducing agent. In the presence of sodium sulfite, the lipid-adducted barley and malt LTP1 displayed higher heat stability than the nonadducted protein. Glycation had no or weak effect on heat-induced unfolding. Finally, it was shown that unfolding occurred on wort boiling before fermentation and that the reducing conditions are provided by malt extract.     

Composition and stability of anthocyanins from purple Solanum tuberosum and their protective influence on Cr(VI) targeted to bovine serum albumin

Anthocyanins from the purple Solanum tuberosum newly cultivated by the Taian Academy of Agricultural Sciences were extracted and analyzed using high-performance liquid chromatography (HPLC) and UV-vis spectroscopy. Four individual anthocyanins were detected as the major components, and the total anthocyanin content was 273.5 ± 14.3 mg of cyanidin-3-glucoside equiv/100 g of dry seeds. Results of color stability showed that the purple S. tuberosum anthocyanins (PSTAs) are more stable under low pH and temperatures. Heat and general food additives have fine compatibility with PSTAs; however, they are very sensitive with oxidant and reduction. The influence of PSTAs on Cr(VI) targeted to bovine serum albumin (BSA) was also studied. The quenching of BSA fluorescence caused by Cr(VI) could be delayed by PSTAs. UV-vis and circular dichroism (CD) data suggested that PSTAs can protect the secondary and tertiary structures of BSA by probably interacting with Cr(VI) in advance.     

The modular integrated utility system (MIUS) as a potential influence on community development

The Department of Housing and Urban Development (HUD) is conducting the Modular Integrated Utility System (MIUS) Program devoted to development and demonstration of the technical, economic, and institutional advantages of integrating the systems for providing all or several of the utility services for a community. Possible utility services include the provision of electric power, domestic heating and cooling, potable water, fire protection water, liquid waste treatment, and solid waste management. The objective of the MIUS concept is to provide the desired utility services in a way that is consistent with reduction in the use of critical natural resources, protection of the environment, and minimization of cost. A MIUS might be sized to accommodate several hundred or a few thousand multifamily dwelling units, nearby single-family housing, and associated commercial facilities. The MIUS is modular in that it can be installed near appropriate users in phase with the actual demands of community development or redevelopment. It uses an integrated systems approach whereby some resource requirements of one service are met by utilizing the effluent of another. For example, heat rejected from electrical generation might be used for residential space heating, and the efflluent from liquid waste treatment might be used for fire protection and/or cooling tower water. This paper summarizes the MIUS concept and the type and extent of potential application. Possible interactions between MIUS and the local community are identified from a comparison of technological and physical characteristics of MIUS with alternative conventional utilities. Possible impacts on land use and patterns of community development are emphasized.     

The influence of lime and manure on the stability of the soil

It is an effective way on one hand, for erosion control of the soil, to keep the influence of wind, rain, and running water away from the soil, and on the other, it is thought more essential for this to give the soil the quality of counter-erosion.     

Regional patterns of contaminants (PAH,pesticides and trace metals) in snow of Northeast Bavaria and their relationship to human influence and orographic effects

In January 1978, 31 snow samples were collected throughout NE-Bavaria and were analyzed for trace metals (Zn, Pb, Cd, Cu), pesticides (α-BHC, Lindane, Aldrin, Dieldrin) and polycyclic aromatic hydrocarbons (PAH) (3,4-benzopyrene, 1,12-benzoperylene, fluoranthene and 3,4-(o-phenylene)-pyrene). The regional pattern of PAH-concentrations can be explained as follows: above urban areas and through orographic uplifting of the air, PAH's are scavenged from the atmosphere by snow. The trace metals and specific conductance show similar regional patterns, although the pattern for Pb is influenced by automobile traffic as well as by glass and ceramic industries. The pesticides show less distinct patterns relative to the other two groups of contaminants. Using multivariate statistics it was shown that the trace metals with the exception of Pb and the PAH's had regional patterns similar to each other but distinct from the pesticides. Although orography, urbanization and industries are shown to affect the regional patterns of PAH's and the trace metals, this is not the case for pesticides. They originate from diffuse sources in agricultural and f forested lands.     

不同冬小麦品种氮素吸收运转特性及其与子粒蛋白质含量的关系

选用济南17、鲁麦22、泰山021三个产量水平相近,品质不同的冬小麦品种,利用15N同位素示踪技术研究氮素吸收运转特性及其与子粒蛋白质含量的关系。结果表明,小麦植株一生所吸收的氮素,72.51%～73.57%来自土壤氮,26.43%～27.49%来自肥料氮;其中11.43%来自底施氮,15.60%来自追施氮。开花期肥料氮和土壤氮在济南17中的积累量最高,泰山021最低,鲁麦22介于其间。开花后营养器官中积累的氮素向子粒转移,对子粒氮素积累的贡献为叶片>茎+叶鞘>颖壳+穗轴,品种间比较,鲁麦22转移率最高,泰山021最低,济南17介于其间。基于以上生理原因,鲁麦22最终获得最高子粒蛋白质含量。     

The influence of microrelief on the agrochemical properties of chernozems and the yield of spring wheat and barley

The influence of microrelief on the fertility of ordinary chernozems and the yield of cereal crops was studied in the Krasnoyarsk forest-steppe. The microrelief was shown to affect the humus state and the agrochemical properties of the chernozem. The productivity of the cereals was shown to differ by 1.3–2.6 times in the areas where the microrelief was strongly pronounced, and the yield of the cereal crops grown in depressions was lower by 1.1–1.8 times as compared to that on the flat areas. The correlation between the plant productivity and the humus content and the pH_salt in the soil was revealed. In order to take into account the influence of the microrelief and to reduce its effects on the yield of crops, the scale of soil and agrochemical investigations is recommended to be increased. Within the boundaries of the existing agricultural lands, the geochemical zones of removal, transport, and accumulation of soil material should be determined.     

Leaf surface sesquiterpene alcohols of the potato (Solanum tuberosum) and their influence on colorado beetle (Leptinotarsa decemlineata Say) feeding

The structures of two previously unknown sesquiterpene alcohols of the potato (Solanum tuberosum) were assigned. The potato alcohols were obtained by steam-distillation, preparative column chromatography, and separation into fractions by HPLC on a silica gel column. The fractions were studied by GC-FID, GC-MS, and NMR spectroscopy. The potato sesquiterpene alcohols were identified as kunzeaol (6-alpha-hydroxygermacra-1(10),4-diene) and ledol. These two compounds were used in feeding tests with larvae and beetles of the Colorado potato beetle (Leptinotarsa decemlineata Say). In a bioassay, kunzeaol was found to act as a feeding attractant for the beetles.     

Oryzacystatin-II, a cystatin from rice (Oryza sativa L. japonica), is a dimeric protein: possible involvement of the interconversion between dimer and monomer in the regulation of the reactivity of oryzacystatin-II

We examined the biochemical and structural properties of oryzacystatin-II, a phytocystatin in rice (Oryza sativa L. japonica), under heat-stress conditions. The enzyme inhibitory reactivity of oryzacystatin-II was enhanced by heating in a temperature-dependent manner and reached a maximum level by heating at 65 degrees C for 10 min. Size-exclusion chromatography showed that oryzacystatin-II forms a homodimer at ambient temperature and that the enhancement of inhibitory reactivity is due to the conversion of the dimeric to a monomeric form. The monomeric form of oryzacystatin-II reverted to the dimer during storage at 4 degrees C, suggesting that dimerization is an intrinsic property of oryzacystatin-II. The affinity of the monomer for cysteine proteinases was significantly higher than that of the dimer. This is the first paper to describe the noncovalent dimerization for a cystatin under nonstress conditions.     

Effect of glycosylation modification (N-Q-(108)I --> N-Q-(108)T) on the freezing stability of recombinant chicken Cystatin overexpressed in Pichia pastoris X-33

The cDNAs encoding chicken cystatin and its N-glycosylation-modified mutant (Asn(106)-Ile(108)-->Asn(106)-Thr(108)) were cloned into the pGAPZ alpha C expression vector, using the GAP as promoter and Zeocin as resistant agent, and transformed into Pichia pastoris X-33 expression host. The effect of N-glycosylation on the stability of recombinant chicken cystatin was investigated. A large quantity of recombinant chicken cystatin and the Asn(106)-glycosylated cystatins were expressed and secreted into broth using alpha-factor preprosequence. The K(i) of the recombinant chicken cystatin (0.08 nM) was similar to that of wild-type chicken cystatin (0.05 nM). They acted as a competitive inhibition reaction against papain. According to the K(i), the inhibition ability of Asn(106)-glycosylated mutant cystatin (K(i) = 9.5 nM) was weaker than that of the wild-type one. However, N-glycosylation at Asn(106) substantially enhanced the freezing stability of recombinant chicken cystatin overexpressed in P. pastoris.     

Influence of feeding malt, bread crust, and a pronylated protein on the activity of chemopreventive enzymes and antioxidative defense parameters in vivo

The aim of the present study was to investigate whether feeding of malt, bread crust, and a pronylated albumin modulates chemoprevention enzymes, such as glutathione-S-transferase (GST) and UDP-glucuronyl-transferase (UDP-GT), and antioxidative defense parameters in vivo and whether the intake of these foods rich in Maillard reaction compounds results in an accumulation of compounds formed in in vivo glycation reactions. After quantitation of pronylated lysine in malt and bread crust, male Wistar rats were fed a standard chow supplemented with 28% of protein containing different amounts of casein, bread crust, caraffa malt, or pronyl bovine serum albumin (BSA) for 15 days. GST activity in the kidneys was increased by 18% (p > 0.05) in animals of the bread crust group, while UDP-GT activity was elevated by 27% in the liver of animals administered pronyl-BSA. Contents of tocopherol in plasma were increased by 33, 14, and 14% in the bread crust, malt, and pronyl-BSA group compared to the control group, while the levels of thiobarbituric acid reactive substances were decreased and the total antioxidant capacity was increased. Parameters of endogenous glycation indicated a 32 and 46% higher load of advanced glycation end products in the kidneys after administration of the malt and the pronyl-BSA containing diet. However, the main systemic effects of dietary malt, bread crust, and pronyl-BSA were, for the first time, demonstrated to be the enhanced antioxidant capacity and the particulate increase in chemopreventive enzymes.     

Nitrogenous constituents in nest soils of harvester ants (messov ebeninus) and their influence on plant growth

Abstract

As a corollary of a detailed study on the ecology of the Harvester ants in soils of semi‐arid natural pastures, samples from a loessial Arid Brown soil were analyzed for the content of nitrogenous constituents (humic compounds, amino acids, nitrates, ammonia) as well as phenols and carbohydrates and the nutrient status of the soil.

While there was a significant increase in fulvic and humic acids in the ant nests, the simultaneous decrease in amino acids ‐ in relation to the surrounding soil ‐ indicates that the humic substances have been synthesized from amino acids and the abundantly present phenols and possibly carbohydrates.

The much higher concentration of nitrogen compounds in the ant mounds supports the idea that the soil mixing activity of the Harvester ants enhances microbiological processes and in turn the fertility of the mounds, as evident in the better growth of the pasture plants.     

The influence of soil characteristics on the toxicity of four chemicals to the earthworm Eisenia fetida andrei (Oligochaeta)

Summary The acute toxicity of Cd (chloride), chloroacetamide, 3,4-dichloroaniline and pentachlorophenol to the earthworm Eisenia fetida andrei was determined using the OECD (1984) artificial soil and contact testing procedures. To investigate the influence of two soil characteristics (pH and organic-matter content), the toxicity of the chemicals was also determined in two natural sandy soils. It is concluded that the filter-paper contact test cannot be recommended to predict earthworm toxicity of these chemicals in soil. Toxicity in soil was influenced by both pH and organic-matter content. Differences between LC₅₀ values in the high-organic-matter artificial soil and in an acid, low-organic-matter sandy soil were, however, not greater than a factor of 3–4. The results of this study therefore support the use of a well-defined artificial soil substrate for standardized earthworm toxicity tests.     

The influence of the soil conditioner ‘Agri-SC' on splash detachment and aggregate stability

The influence of the soil conditioner ‘Agri-SC' on splash detachment and water-stable aggregation of an erodible clay Vertisol from Oahu, HI, was assessed. Laboratory rainfall simulation was used to assess splash detachment from soil treated with 0 (untreated control), 0.3, 3.0, 30, and 300 l ha⁻¹ of Agri-SC. Results indicated that the quantity of sediment splashed was significantly lower for Agri-SC application rates of 0.3 and 3.0 l ha⁻¹ (rates are equivalent to 1 and 10 times the manufacturer's recommended rates, respectively), than for the control, or for Agri-SC applied at 30 and 300 l ha⁻¹ (100 and 1000×, respectively). A second experiment was designed to test the influence of Agri-SC on water-stable aggregation of the Vertisol. Aggregates were subjected to rapid immersion in solution, shaken and washed through a series of sieves. Data indicated that there were no statistically significant differences in geometric mean aggregate diameter between the untreated and treated aggregates. The effect of the active ingredient, ammonium laureth sulfate (an anionic surface active agent) on splash and erodibility are discussed. These preliminary results indicate that further testing of Agri-SC is warranted on a variety of soils with different textures and mineralogies.     

Reactivity of beer bitter acids toward the 1-hydroxyethyl radical as probed by spin-trapping electron paramagnetic resonance (EPR) and electrospray ionization-tandem mass spectrometry (ESI-MS/MS)

The iso-α-acids or isohumulones are the major contributors to the bitter taste of beer, and it is well-recognized that they are degraded during beer aging. In particular, the trans-isohumulones seem to be less stable than the cis-isohumulones. The major radical identified in beer is the 1-hydroxyethyl radical; however, the reactivity between this radical and the isohumulones has not been reported until now. Therefore, we studied the reactivity of isohumulones toward the 1-hydroxyethyl radical through a competitive kinetic approach. It was observed that both cis- and trans-isohumulones and dihydroisohumulones are decomposed in the presence of 1-hydroxyethyl radicals, while the reactivities are comparable. On the other hand, the tetrahydroisohumulones did not react with 1-hydroxyethyl radicals. The apparent second-order rate constants for the reactions between the 1-hydroxyethyl radical and these compounds were determined by electron paramagnetic resonance (EPR) spectroscopy and electrospray ionization-tandem mass spectrometry [ESI(+)-MS/MS]. It follows that degradation of beer bitter acids is highly influenced by the presence of 1-hydroxyethyl radicals. The reaction products were detected by liquid chromatography-electrospray ionization-ion trap-tandem mass spectrometry (LC-ESI-IT-MS/MS), and the formation of oxidized derivatives of the isohumulones was confirmed. These data help to understand the mechanism of beer degradation upon aging.     

The soils of the eastern hilly area and their suitability to vineyard in Friuli (Italy)

Typic Eutrochrepts (from “Flysch”), Typic Udifluvents (from alluvial deposits), Dystric Eutrochrepts and Plinthic Paleudults on old alluvial deposits and terraces were characterized. All soils investigated fall in the suitability class S2 or S3 for grape cultivation. Imperfect drainage and acidic reaction are most prominent soil limitations. Fertilization with organic matter, N and some microelements such as Zn, as well as drainage improvement, are the suggestions proposed in order to increase the soil fertility and the wine production.     

Volatile composition of coffee berries at different stages of ripeness and their possible attraction to the coffee berry borer Hypothenemus hampei (Coleoptera: Curculionidae)

The analysis of volatile emissions of coffee berries in different physiological states of ripeness was performed using dynamic headspace and gas chromatography/mass spectrometry analysis for Coffea arabica, var. Colombia. The composition of the volatiles emitted by coffee berries is dominated by very high levels of alcohols, mainly ethanol, in all stages of ripeness in comparison with other compounds. Overripe coffee berries have high volatile emissions and show a composition dominated mainly by esters followed by alcohols, ketones, and aldehydes. The lowest level compounds were monoterpenes. 2-Methyl furan was detected in various ripening stages; this compound has not been previously reported as a coffee berry volatile. The presence of ethanol and other alcohols in the volatile composition might explain the effectiveness of using traps with mixed alcohols for detection and capture of coffee berry borers.