Molecular Structure In Relation Research Articles

Starch molecular structures in relation to properties of ratoon rice produced by different ratooning practices

The development of forage-grain ratoon rice (RR) pattern could ensure food security and promote silage production. Herein three indica rice varieties were used to investigate the influence of different forage clipping stages (heading, milk-ripe, wax-ripe, and full-ripe) on starch molecular structures and RR properties. The apparent amylose contents (AAC) of starches increased, but pasting viscosities, gelatinization temperatures and starch sizes decreased with the postponement of clipping stages due to the retardation of endosperm development. The starches showed A-type crystalline structure with increased in vitro digestibility; however relative crystallinity decreased by 13.45 % to 23.89 %. The short fa (DP 6–12) chains of amylopectin increased while long fb3 (DP ≥ 37) chains decreased (p < 0.05). The proportions of amylose chains with DP 100–2000 increased but those with DP 2000–20,000 decreased. Rice grain strength was positively correlated with fb3 chains while negatively correlated with fa chain. The hardness of cooked RR was positively correlated with AAC while negatively correlated with fb2 (DP 25–36). RR clipping at milk-ripe stage had the highest grain strength and moderate texture properties. The elucidation of structure-property relationships is helpful for RR utilization and development of suitable cultivation conditions for RR production.

Molecular structure in relation to swelling, gelatinization, and rheological properties of lotus seed starch

Relationships between molecular structure and physicochemical properties of starch remain to be better defined. This research was a follow-up of previous studies aiming to fill this gap using lotus seed starch (LS) (a novel C-type starch source) as a model system. By means of correlation analysis, the effects of molecular structure on physicochemical properties of LS were revealed. Content and chain length of amylose affected mainly rheological properties of LS. Short and long B-chains differently affected the short-range ordered structure of starch granules, thermal properties, and the transmittance of starch paste. In addition to the influences of amylose and amylopectin internal structure, several “novel” relationships related to the effects of amylopectin external structure were found in the LS-based model system. For instance, the molar amount of clustered A-chains (Aclustered) in lotus seed amylopectin was significantly related to the short-range molecular order in the granules. Moreover, the importance of Aclustered-chains was reflected by their influences on various properties of LS upon gelatinization and retrogradation. Successive influences of the molar amount of Aclustered-chains on starch properties during pasting were revealed. This study highlighted the importance of amylopectin external structure in addition to the under-studied amylopectin internal structure in affecting starch physicochemical properties.

Starch Chemical Composition and Molecular Structure in Relation to Physicochemical Characteristics and Resistant Starch Content of Four Thai Commercial Rice Cultivars Differing in Pasting Properties.

Variations in starch pasting properties, considered an alternative potential quality classification parameter for rice starches, are directly controlled by the diverse starch molecular composition and structural features. Here, the starch characteristics of four rice cultivars (i.e., RD57, RD29, KDML105, and RD6) differing in pasting properties were assessed, and their relationship was determined. The results revealed that protein and moisture contents and their crystalline type were similar among the four rice starches. However, their molecular compositions and structures (i.e., reducing sugar and amylose contents, amylopectin branch chain-length distributions, granule size and size distribution, and degree of crystallinity) significantly varied among different genotypes, which resulted in distinct swelling, solubility, gelatinization, retrogradation, and hydrolytic resistance properties. The swelling power and gelatinization enthalpy (∆H) were positively correlated with C-type granule and relative crystallinity, but were negatively correlated with amylose content, B-type granule and median particle size (d(0.5)). Conversely, the water solubility and resistant starch content negatively correlated with C-type granule, but positively correlated with amylose content, B-type granule, and d(0.5). The gelatinization onset temperature (To(g)), and retrogradation concluding temperatures (Tc(r)), enthalpy (∆H(r)), and percentage (R%) were positively impacted by the amount of protein, amylose, and B1 chains (DP 13-24), while they were negatively correlated with short A chains (DP 6-12). Collectively, the starch physicochemical and functional properties of these Thai rice starches are attributed to an interplay between compositional and structural features. These results provide decisive and crucial information on rice cultivars' suitability for consumption as cooked rice and for specific industrial applications.

PSXII-5 Feed processing-induced changes in protein molecular structure in relation to nutrient utilization and availability of warm-season Sorghum grain (Sorghum bicolor) in ruminants

Abstract The objective of this study was reveal heat related processing (HP) induced changes in protein molecular structure in relation to nutrient utilization and availability of warm-season sorghum grain (Sorghum bicolor) in dairy cows. Three new warm-season genotypes of sorghum grain (Sorghum bicolor) were studied. The nutrient utilization and availability of sorghum grain (Sorghum bicolor) in dairy cows include: protein subfractions, energy values, rumen degradation, and intestinal digestibility of rumen undegraded protein. The protein structure change on molecular level were revealed with cutting edge non-invasive vibrational ATR-FTIR molecular spectroscopy. The warm-season sorghum grains were either maintained in their raw state (as control) or treated with for 80 min at 121°C with the Lindberg/Blue M™. The RCBD data were analyzed using SAS9.4 with Mixed model procedure. Tukey method was used for mean separation. The results showed that compared with the control, the HP treatment altered (P &amp;lt; 0.05) nutrient profiles and utilization and availability in dairy cows and increased (P &amp;lt; 0.05) metabolizable energy and net energy values in dairy cows. The HP treatment also altered (P &amp;lt; 0.05) the protein molecular structure profile of the warm-season sorghum grain. It increased (P &amp;lt; 0.05) the ratio of protein Amide I and Amide II height and decreased (P &amp;lt; 0.05) the ratio of α-helix to β-sheet. In conclusion, the HP treatment altered molecular structure and nutrient profiles without negatively affecting the nutritive value and digestion of warm-season sorghum grain. The molecular spectral profiles revealed by rapid and non-invasive ATR-FTIR molecular spectroscopy could be used as a fast predictor for the warm-season sorghum grain utilization and digestion in dairy cows.

Protein molecular structure in relation to predicted biodegradation and nutrient supply of feedstocks and co-products from bio-oil processing with CNCPS system: Comparison Crusher Plants within Canada and within China as well as between Canada and China

Recently, rapid non-invasive advanced vibrational molecular spectroscopy has been developed to detect tissue inherent molecular structure. However, this advanced technique is seldom known by animal scientists and seldom used to study feed molecular structure in relation to nutrient utilization and availability in animals. The objectives of this study were to 1) detect the interactive association between the processing-induced protein molecular structure changes and biodegradation and intestinal digestion in ruminants using advanced vibrational molecular spectroscopy, and 2) develop a model to predict protein and carbohydrate degradation and digestions based on feed inherent protein molecular structure. The feed used for this study were various sources of feedstock (oil seeds) and co-products (canola meal, canola pellets) from ten different crushing plants in Canada and China with multi-source samples from each crushing plant. The predictable protein and carbohydrate degradable sub-fractions and nutrient supply of sub-fractions to dairy cows were evaluated with the updated Cornell Net Carbohydrate and Protein System (CNCPS 6.5). The protein molecular structure was revealed using advanced vibrational molecular spectroscopy (FT/IR-ATR). The molecular structure spectral analyses were carried out using uni- and multi-variate molecular spectral analyses. The model variable selection was carried out using SAS with a Stepwise option. The results showed that protein molecular structure spectral characteristics could be used to predict CNCPS protein and carbohydrate nutrient supply to dairy cows. Strong positive correlation was found in canola meal between rumen degraded PA2 and amide I area (r = 0.67, P < 0.001), amide I height (r = 0.73, P < 0.001), and α-helix height (r = 0.83, P < 0.001). RDPB2 was negatively correlated with α-helix height (r = −0.69, P < 0.001). Moreover, TRDC was negatively correlated with amide I area (r=-0.64, P < 0.001), amide I height (r = −0.65, P < 0.001), and α-helix height (r = −0.62, P < 0.001). It was concluded that protein and carbohydrate degradable and undegradable sub-fractions had interactive associations with the processing-induced protein molecular structure changes in co-products from bio-oil processing.

On a Molecular Basis, Investigate Association of Molecular Structure with Bioactive Compounds, Anti-Nutritional Factors and Chemical and Nutrient Profiles of Canola Seeds and Co-Products from Canola Processing: Comparison Crusher Plants within Canada and within China as well as between Canada and China

The objectives of this study were to: (1) Use molecular spectroscopy as a novel technique to quantify protein molecular structures in relation to its chemical profiles and bioenergy values in oil-seeds and co-products from bio-oil processing. (2) Determine and compare: (a) protein molecular structure using Fourier transform infrared (FT/IR-ATR) molecular spectroscopy technique; (b) bioactive compounds, anti-nutritional factors, and chemical composition; and (c) bioenergy values in oil seeds (canola seeds), co-products (meal or pellets) from bio-oil processing plants in Canada in comparison with China. (3) Determine the relationship between protein molecular structural features and nutrient profiles in oil-seeds and co-products from bio-oil processing. Our results showed the possibility to characterize protein molecular structure using FT/IR molecular spectroscopy. Processing induced changes between oil seeds and co-products were found in the chemical, bioenergy profiles and protein molecular structure. However, no strong correlation was found between the chemical and nutrient profiles of oil seeds (canola seeds) and their protein molecular structure. On the other hand, co-products were strongly correlated with protein molecular structure in the chemical profile and bioenergy values. Generally, comparisons of oil seeds (canola seeds) and co-products (meal or pellets) in Canada, in China, and between Canada and China indicated the presence of variations among different crusher plants and bio-oil processing products.

Process-induced water-soluble biopolymers from broccoli and tomato purées: Their molecular structure in relation to their emulsion stabilizing capacity

The emulsification capacity of process-induced tomato and broccoli sera, containing proteins and pectin with distinct molecular structures, was investigated. Targeted pectin molecular modifications were induced by applying combinations of treatments to prepare the purées, and subsequently, the serum pectin-protein mixtures were isolated and assessed in terms of their capacity to stabilize oil-in-water (o/w) emulsions at different pH conditions (pH 3.5 or 6.0). Regardless of the processing applied, broccoli sera presented a better emulsion stabilizing capacity than tomato sera due to the higher protein content and probably the presence of more acetylated and branched pectin. In tomato sera, where a low amount of protein was detected, differences in emulsification capacity were identified depending on pectin molecular structure. Tomato sera, obtained from purées treated at low temperature for the stimulation of pectin-related enzymes which led to pectin with a high molecular weight, low degree of methyl-esterification and relatively high degree of acetylation, formed stable o/w emulsions. The vegetable sera exhibited higher capacity to form stable emulsions at pH 3.5 compared to pH 6.0, which can be attributed to a lower dissociation of the pectin carboxylic groups at low pH leading to less intramolecular repulsions resulting in a more compact conformation of the adsorbed species at the oil-water interface and better electrostatic interactions with positively-charged proteins. Thus, selective processing of vegetable purées is a promising strategy to induce molecular changes in water-soluble biopolymers with potential use as natural emulsifiers in acid/acidified foods.

Amylopectin molecular structure in relation to physicochemical properties of quinoa starch

Structure-function relationships of starch components remain a subject of research interest. Quinoa starch has very small granules (∼2μm) with unique properties. In this study, nine quinoa starches varied greatly in composition, structure, and physicochemical properties were selected for the analysis of structure-function relationships. Pearson correlation analysis revealed that the properties related to gelatinization such as swelling power, water solubility index, crystallinity, pasting, and thermal properties are much affected by the amylopectin chain profile and amylose content. The parameters of gel texture and amylose leaching are much related to amylopectin internal structure. Other properties such as enzyme susceptibility and particle size distribution are also strongly correlated with starch composition and amylopectin structure. Interesting findings indicate the importance of amylopectin internal structure and individual unit chain profile in determining the physicochemical properties of starch. This work highlights some relationships among composition, amylopectin structure and physicochemical properties of quinoa starch.

Using vibrational infrared biomolecular spectroscopy to detect heat-induced changes of molecular structure in relation to nutrient availability of prairie whole oat grains on a molecular basis.

BackgroundTo our knowledge, there is little study on the interaction between nutrient availability and molecular structure changes induced by different processing methods in dairy cattle. The objective of this study was to investigate the effect of heat processing methods on interaction between nutrient availability and molecular structure in terms of functional groups that are related to protein and starch inherent structure of oat grains with two continued years and three replication of each year.MethodThe oat grains were kept as raw (control) or heated in an air-draft oven (dry roasting: DO) at 120 °C for 60 min and under microwave irradiation (MIO) for 6 min. The molecular structure features were revealed by vibrational infrared molecular spectroscopy.ResultsThe results showed that rumen degradability of dry matter, protein and starch was significantly lower (P <0.05) for MIO compared to control and DO treatments. A higher protein α-helix to β-sheet and a lower amide I to starch area ratio were observed for MIO compared to DO and/or raw treatment. A negative correlation (−0.99, P < 0.01) was observed between α-helix or amide I to starch area ratio and dry matter. A positive correlation (0.99, P < 0.01) was found between protein β-sheet and crude protein.ConclusionThe results reveal that oat grains are more sensitive to microwave irradiation than dry heating in terms of protein and starch molecular profile and nutrient availability in ruminants.

Coordination capabilities of anthracene ligand in binuclear sandwich complexes: DFT investigation

DFT calculations with full geometry optimization using BP86 and mPW1PW91 functionals have been carried out on binuclear hypothetical compounds of the type M2(Ant)2 (Ant = anthracene). This work investigates the possibility for such compounds to exist for the M = Ti–Ni series. The analysis of their electronic and molecular structures in relation to their electron counts allows a comprehensive rationalization of the bonding of these compounds. A very rich coordination chemistry of anthracene has been highlighted. This richness comes from the very large electronic and structural flexibility of anthracene, which is able to adapt itself to the electronic demand of metals. Each of the C6 rings of anthracenes can be coordinated in various hapticities and symmetries depending on the nature of the metal and the structure’ spin state. This flexibility favors the possibility of existence of several isomers closeness in energy. The asymmetry between the two anthracenes causes binuclear complexes to exhibit very different coordination with different oxidation states. In some cases, the M–M bonding is not privileged despite the metals’ electronic deficiency.

Vibrational spectroscopic investigation of heat-induced changes in functional groups related to protein structural conformation in camelina seeds and their relationship to digestion in dairy cows

The objective of this study was to use Fourier transform/infrared-attenuated total reflectance (FT/IR-ATR) molecular spectroscopy to quantify the heat-induced changes in feed protein molecular structures in relation to protein digestion in dairy cows. Camelina seeds were evaluated in this study as a model for feed protein. The seeds were either heated in air-draft oven (dry heating) or in autoclave (moist heating) at 120°C for 60 min or kept as raw (control). The parameters evaluated were Cornell net protein and carbohydrate system (CNCPS) subfractions, in situ ruminal degradation kinetics, intestinal digestibility of rumen undegraded protein (RUP) and protein molecular structures. Moist heating decreased (P &lt; 0.05) the content of total rumen degradable (RDP) crude protein (CP) subfractions and increased the content of total RUP subfractions compared with raw seeds, indicating a significant shift at the site of protein digestion from rumen to post-ruminal tract. The decrease in RDP was mainly related to the marked decrease in rapidly solubilised (PA) and degradable (PB1) fractions, whereas the moderately degradable (PB2) and slowly degradable (PB3) fractions increased, suggesting a decrease in degradation rate of RDP. The in situ rumen incubation study revealed that moist heating decreased (P &lt; 0.05) RDP and increased (P &lt; 0.05) RUP and its intestinal digestibility. The molecular spectroscopy study revealed that moist heating altered protein molecular structures. Except PA and lag time, dry heating did not significantly alter any of the CNCPS CP subfraction, in situ ruminal CP degradation parameters, intestinal digestibility of RUP, and protein molecular structures. The correlation analysis showed that the heat-induced changes in protein secondary structures, α-helix-to-β-sheet ratio, were positively correlated (P &lt; 0.05) with the contents PA (r = 0.90), PB1 (r = 0.89), RDP (r = 0.72) and intestinal digestibility (r = 0.91) of RUP, and negatively correlated (P &lt; 0.05) with PB2 (r = –0.90), PB3 (r = –0.85) and RUP (–0.87). These results showed that compared with dry heating, moist heating significantly changed protein subfractions, rumen degradability and intestinal digestibility, and these changes were strongly associated with changes in protein molecular structures.

Moist and dry heating-induced changes in protein molecular structure, protein subfractions, and nutrient profiles in camelina seeds

The objectives of the present study were to investigate the nutritive value of camelina seeds (Camelina sativa L. Crantz) in ruminant nutrition and to use molecular spectroscopy as a novel technique to quantify the heat-induced changes in protein molecular structures in relation to protein digestive behavior in the rumen and intestine of dairy cattle. In this study, camelina seeds were used as a model for feed protein. The seeds were kept as raw (control) or heated in an autoclave (moist heating) or in an air-draft oven (dry heating) at 120°C for 60 min. The parameters evaluated were (1) chemical profiles, (2) Cornell Net Protein and Carbohydrate System protein subfractions, (3) nutrient digestibilities and estimated energy values, (4) in situ rumen degradation and intestinal digestibility, and (5) protein molecular structures. Compared with raw seeds, moist heating markedly decreased (52.73 to 20.41%) the content of soluble protein and increased (2.00 to 9.01%) the content of neutral detergent insoluble protein in total crude protein (CP). Subsequently, the rapidly degradable Cornell Net Protein and Carbohydrate System CP fraction markedly decreased (45.06 to 16.69% CP), with a concomitant increase in the intermediately degradable (45.28 to 74.02% CP) and slowly degradable (1.13 to 8.02% CP) fractions, demonstrating a decrease in overall protein degradability in the rumen. The in situ rumen incubation study revealed that moist heating decreased (75.45 to 57.92%) rumen-degradable protein and increased (43.90 to 82.95%) intestinal digestibility of rumen-undegradable protein. The molecular spectroscopy study revealed that moist heating increased the amide I-to-amide II ratio and decreased α-helix and α-helix-to-β-sheet ratio. In contrast, dry heating did not significantly change CP solubility, rumen degradability, intestinal digestibility, and protein molecular structures compared with the raw seeds. Our results indicated that, compared with dry heating, moist heating markedly changed protein chemical profiles, protein subfractions, rumen protein degradability, and intestinal digestibility, which were associated with changes in protein molecular structures (amide I-to-amid II ratio and α-helix-to-β-sheet ratio). Moist heating improved the nutritive value and utilization of protein in camelina seeds compared with dry heating.

Studies on Brassica carinata Seed. 1. Protein Molecular Structure in Relation to Protein Nutritive Values and Metabolic Characteristics

The objectives of this study were to investigate (1) the protein chemical profile, (2) the protein subfractions partitioned by the Cornell Net Carbohydrate and Protein System (CNCPS), (3) the rumen crude protein (CP) degradation kinetics, (4) the protein supply predicted by the DVE/OEB system, (5) the protein structural features using a Fourier transform infrared (FTIR) spectroscopic technique with attenuated total reflectance (ATR), and (6) the correlations between protein intrinsic structural features and nutritional profiles in three strains of Brassica carinata in yellow and brown seed coats, with comparison to canola seed as a reference. The results showed that carinata seed strains were different in both nutritional values and IR absorbance within the protein spectral region (ca. 1720-1482 cm(-1)). The comparison between yellow and brown B. carinata seeds indicated that the former was lower in acid detergent insoluble crude protein (ADICP; P = 0.002) and undegradable protein fraction (PC; P = 0.002) and greater in the degradable (D) fraction (P = 0.004) and true absorbed protein in the small intestine (DVE; P = 0.02) as well as feed milk value (FMV; P = 0.02) than the latter. The brown canola seed (Brassica napus L.) was also not in full accordance with B. carinata seed on these parameters. The FTIR studies showed significant differences in protein amide II peak height, amide I peak area, and β-sheet height among different B. carinata strains. However, multivariate spectral analyses indicated a similarity in protein structural makeup in these four kinds of oilseed. The not very strong correlations shown in this study implied that the limited sample size and narrow range in biological and spectral variation might be responses for the weak relationships between chemical profile and mid-IR spectral data. Further studies using sufficient samples with wide and diverse range in nutritional properties are needed to illustrate the actual relationship between spectroscopic data and nutritional profiles in oilseeds.

Molecular basis of protein structure in combined feeds (hulless barley with bioethanol coproduct of wheat dried distillers grains with solubles) in relation to protein rumen degradation kinetics and intestinal availability in dairy cattle

The objectives of this study were to reveal protein molecular structure in relation to rumen degradation kinetics and intestinal availability in combined feeds of hulless barley with bioethanol coproduct [pure wheat dried distillers grains with solubles (DDGS)] at 5 different ratios (100:0, 75:25, 50:50, 25:75, and 0:100) in dairy cattle. The parameters assessed included 1) protein chemical profiles, 2) protein subfractions partitioned by the Cornell Net Carbohydrate and Protein System, 3) in situ protein degradation kinetics, 4) truly absorbed protein supply in the small intestine (DVE), metabolizable protein characteristics and degraded protein balance (OEB), 5) protein molecular structure spectral profiles, and 6) correlation between protein molecular structure and protein nutrient profiles and metabolic characteristics. We found that 1) with increasing inclusion of wheat DDGS in feed combinations, protein chemical compositions of crude protein (CP), neutral detergent-insoluble CP, acid detergent-insoluble CP, and nonprotein N were increased, whereas soluble CP was decreased linearly; CP subfractions A, B3, and C were increased linearly, but CP subfractions B1 and B2 were decreased; truly digestible CP increased but total digestible nutrients at 1× maintenance decreased linearly; protein degradation rate was decreased without affecting potentially soluble, potentially degradable, and potentially undegradable fractions, and both rumen-degradable protein and rumen-undegradable protein were increased; by using the DVE/OEB system, the DVE and OEB values were increased from 98 to 226g/kg of dry matter and −1 to 105g/kg of dry matter, respectively; 2) by using the molecular spectroscopy technique, the spectral differences in protein molecular structure were detected among the feed combinations; in the original combined feeds, amide I and II peak area and ratio of amide I to II were increased linearly; although no difference existed in α-helix and β-sheet height among the combinations, the ratio of α-helix to β-sheet height was changed quadratically; 3) in the in situ 48-h residue samples, amide I and amide II peak area intensities were increased linearly and the ratio of amide I to II peak area was decreased linearly from 4.28 to 2.63; α-helix and β-sheet height of rumen residues were similar among 5 feed combinations; and 4) the ratio of α-helix to β-sheet height in original feed combinations was strongly correlation with protein chemical and nutrient profiles, but the ratio of amide I to II area had no significant correlation with all items that were tested; no correlation was found between the ratio of α-helix to β-sheet height of the in situ rumen residues and protein chemical and nutrient profiles. In conclusion, by integration of hulless barley with bioethanol coproduct of wheat DDGS, feed quality in combined feeds was improved and more optimized. Adding wheat DDGS increased linearly CP, truly digestible CP, rumen-degradable protein, rumen-undegradable protein, DVE, and OEB values in combined feeds. The molecular spectral differences of protein molecular structures (amide I and II area intensities, the ratio of amide I to amide II, and the ratio of α-helix to β-sheet height among feed combinations) were detected among the combinations. This may partially explain the biological differences in protein chemical profiles and protein utilization and availability in dairy cattle. In the original combined feeds, protein α-helix-to-β-sheet ratio had significant correlations with protein chemical and nutrient profiles, but in in situ 48-h residue samples, protein amide I-to-II ratio had significant correlations with protein chemical and nutrient profiles. This study may provide an insight into how to more efficiently use hulless barley grain (high energy and high degradation rate) and wheat DDGS (high metabolizable protein and low degradation rate) in beef and dairy production systems.

Amylopectin internal molecular structure in relation to physical properties of sweetpotato starch

Unit chain length distributions of amylopectins and their φ,β-limit dextrins (reflecting amylopectin internal part) from 11 Chinese sweetpotato genotypes were characterized by high performance anion-exchange chromatography after debranching, and were related to the thermal and pasting properties of granular starches. The weight-based unit chain length profiles of whole amylopectin and their internal parts both had three distinguishable major groups with approximate range of DP 6–36, 37–68, and >69 for amylopectins and DP 3–25, 26–55, and >55 for φ,β-limit dextrins. Among different genotypes, two different patterns of B fp (fingerprint B-chains, DP 3–7) were observed for φ,β-limit dextrins, whereas A fp (fingerprint A-chains, DP 6–8) for whole amylopectins were consistent. Reconstruction of amylopectins from their φ,β-limit dextrins revealed that B-chains with internal DP > 20 possessed an external chain length corresponding to the average value DP 12.8. Wide genetic variations were recorded among structural parameters, of which several concerning the amylopectin internal part were highly correlated to the thermal and pasting parameters of sweetpotato starches, and suggested that the internal part of amylopectin is critical to the physical behavior of granular starch.

Plant‐based food and feed protein structure changes induced by gene‐transformation, heating and bio‐ethanol processing: A synchrotron‐based molecular structure and nutrition research program

Unlike traditional "wet" analytical methods which during processing for analysis often result in destruction or alteration of the intrinsic protein structures, advanced synchrotron radiation-based Fourier transform infrared microspectroscopy has been developed as a rapid and nondestructive and bioanalytical technique. This cutting-edge synchrotron-based bioanalytical technology, taking advantages of synchrotron light brightness (million times brighter than sun), is capable of exploring the molecular chemistry or structure of a biological tissue without destruction inherent structures at ultra-spatial resolutions. In this article, a novel approach is introduced to show the potential of the advanced synchrotron-based analytical technology, which can be used to study plant-based food or feed protein molecular structure in relation to nutrient utilization and availability. Recent progress was reported on using synchrotron-based bioanalytical technique synchrotron radiation-based Fourier transform infrared microspectroscopy and diffused reflectance infrared Fourier transform spectroscopy to detect the effects of gene-transformation (Application 1), autoclaving (Application 2), and bio-ethanol processing (Application 3) on plant-based food and feed protein structure changes on a molecular basis. The synchrotron-based technology provides a new approach for plant-based protein structure research at ultra-spatial resolutions at cellular and molecular levels.

The Coordination Chemistry of Azulene: A Comprehensive DFT Investigation

DFT calculations with full geometry optimization have been carried out on a series of real and hypothetical compounds of the type LnMAz, MAz2, LnM2Az, and M2Az2 (Az = azulene). The analysis of their electronic and molecular structures in relation to their electron counts allows a comprehensive rationalization of the bonding within this very large family of compounds. A very rich coordination chemistry of azulene is apparent, even much richer than one could determine from the avalaible experimental data. The reason for this diversity comes in part from the marked dissymmetry of azulene, which is made up of two fused rings of very different sizes. It comes also in large part from the very large electronic and structural flexibility of azulene (in contrast to its isomer naphthalene), which is able to adapt to the electronic demand of the metal(s). Any of the fused C5 and C7 rings of azulene can be coordinated in various hapticities and symmetries, depending on the nature of the MLn moiety (or moieties) they ...

Dietary protection against free radicals: a case for multiple testing to establish structure-activity relationships for antioxidant potential of anthocyanic plant species.

DNA damage by reactive species is associated with susceptibility to chronic human degenerative disorders. Anthocyanins are naturally occurring antioxidants, that may prevent or reverse such damage. There is considerable interest in anthocyanic food plants as good dietary sources, with the potential for reducing susceptibility to chronic disease. While structure-activity relationships have provided guidelines on molecular structure in relation to free hydroxyl-radical scavenging, this may not cover the situation in food plants where the anthocyanins are part of a complex mixture, and may be part of complex structures, including anthocyanic vacuolar inclusions (AVIs). Additionally, new analytical methods have revealed new structures in previously-studied materials. We have compared the antioxidant activities of extracts from six anthocyanin-rich edible plants (red cabbage, red lettuce, blueberries, pansies, purple sweetpotato skin, purple sweetpotato flesh and Maori potato flesh) using three chemical assays (DPPH, TRAP and ORAC), and the in vitro Comet assay. Extracts from the flowering plant, lisianthus, were used for comparison. The extracts showed differential effects in the chemical assays, suggesting that closely related structures have different affinities to scavenge different reactive species. Integration of anthocyanins to an AVI led to more sustained radical scavenging activity as compared with the free anthocyanin. All but the red lettuce extract could reduce endogenous DNA damage in HT-29 colon cancer cells. However, while extracts from purple sweetpotato skin and flesh, Maori potato and pansies, protected cells against subsequent challenge by hydrogen peroxide at 0°C, red cabbage extracts were pro-oxidant, while other extracts had no effect. When the peroxide challenge was at 37°C, all of the extracts appeared pro-oxidant. Maori potato extract, consistently the weakest antioxidant in all the chemical assays, was more effective in the Comet assays. These results highlight the dangers of generalising to potential health benefits, based solely on identification of high anthocyanic content in plants, results of a single antioxidant assay and traditional approaches to structure activity relationships. Subsequent studies might usefully consider complex mixtures and a battery of assays.

Ultrasonic studies of the crystallization behavior of two palm fats O/W emulsions and its modification

Based on the difference between the speed of sound in solids and liquids, an ultrasonic velocity technique was employed to monitor the phase transition, nucleation and crystal growth of two palm oils dispersed as oil-in-water (O/W) emulsions. The O/W emulsions of palm mid-fraction (PMF) and palm kernel oil (PKO) crystallized at 12 and 0 °C, respectively. The degree of supercooling of PMF emulsion was 18 °C, while that of PKO emulsion was 28 °C. The effects of different hydrophobic emulsifier additives on the interfacial heterogeneous nucleation, induced at the oil/water interface of emulsion droplets, and crystal growth were studied by monitoring the sound velocity ( V) during isothermal crystallization. Sucrose oligoesters (SOEs) having stearic (S-170) and palmitic (P-170) fatty acid chains accelerated nucleation, yet SOEs having short chains such as lauric (L-170) showed no effect in the two fats. A polyglycerine ester (DAS-750) had a lesser and different effect on the nucleation of PKO compared to PMF. Moreover, the crystal growth was retarded in the two oils at different degrees by the addition of S-170. Solubility measurements indicated that the solubility degree of DAS-750 was more than that of S-170. In addition, the solubility of DAS-750 was higher in PKO than in PMF. The effects of the additives were thus discussed in terms of their molecular structure in relation to the oil phase composition.

Laboratory gas phase spectroscopy of carbon molecular structures in relation to diffuse interstellar bands

An experiment suitable for studying the carbon molecular structures which are the candidates for carriers of the diffuse interstellar bands (DIBs) in astrophysical spectra has been developed in the plasma-chemistry laboratory of the Masaryk University in Brno. The experimental arrangement including an apparatus for detecting the gas phase spectra of monopolar high-frequency discharge is described. The preliminary results involving a search for the ultraviolet, visible, and near-infrared well pronounced features of the carbon molecular structures are discussed.