Ice VI freezing of meat: supercooling and ultrastructural studies

While "classical" freezing (to ice I) is disruptive to the microstructure of meat, freezing to ice VI has been found to preserve it. Ice VI freeze-substitution microscopy showed no traces of structural alteration on muscle fibres compared with the extensive damage caused by ice I freezing. The different signs of the freezing volume changes associated with these two ice phases is the most likely explanation for the above effects. Ice VI exists only at high pressure (632.4-2216 MPa) but can be formed and kept at room temperature. It was found that its nucleation requires a higher degree of supercooling than ice I freezing does, both for pure water and meat. Monitoring of the freezing process (by temperature and/or pressure measurements) is, thus, essential. The possible applications of ice VI freezing for food and other biological materials and the nucleation behaviour of this ice phase are discussed.     

Chickpeas—Composition,Nutritional Value,Health Benefits,Application to Bread and Snacks: A Review

Chickpea is grain legumes grown mainly in areas with temperate and semiarid climate. It is characterized by a high content of protein, fat, vitamins, fiber, and a lower content of carbohydrates than flour of wheat. Chickpeas may contain antinutritional compounds that can impair utilization of the nutrients by people. Heat treatment is an effective method to increase the amount of protein available for intestinal digestibility. Adding chickpeas to a foodstuff can increase their nutritional value and reduce the acrylamide content. Acrylamide is an antinutritional substance present in foods, such as bread, snacks, and chips. Chickpea flour and protein may be new way to a reduce the content of acrylamide in products of this type. The addition of chickpea flour affects the sensory and textural properties.     

Conversion of Lower Hydrocarbons in the Presence of Carbon Dioxide: The Theoretic Analysis and Catalytic Tests over Active Carbon Supported Vanadium Oxide

The results of thermodynamic analysis of methane oxidative coupling and dehydrogenation of C₂–C₄ hydrocarbons in the presence of carbon dioxide were compared to the corresponding results in an inert gas atmosphere. Moreover, conversion of alkanes in some undesirable side reactions, such as decomposition of alkanes to the synthesis gas or to carbon oxide and water, as well as the gasification of coke by carbon dioxide in the Boudouard reaction, were investigated. Finally, the results of the theoretical calculations were compared with the experimental data obtained over VO_x/C_act catalyst. The results are discussed in relation to the acid–base properties of the catalyst surface and the atomic charge on the hydrogen most susceptible to abstraction (i.e., the weakest C–H bond in hydrocarbons). Thus, the changes of the catalytic performance in the presence and absence of carbon dioxide are explained.     

Adenosine and 2′‐Deoxyadenosine Modified with Boron Cluster Pharmacophores as New Classes of Human Blood Platelet Function Modulators

Novel types of adenosine and 2′‐deoxyadenosine derivatives containing boron clusters at positions C2′, N6, or C8 were synthesized. The effect of these modified compounds on platelet function was studied. Modification of adenosine at the C2′ position with a para‐carborane cluster (C₂B₁₀H₁₁) results in efficient inhibition of platelet function, including aggregation, protein secretion, and P‐selectin expression induced by thrombin or ADP. These preliminary findings and the new chemistry proposed form the basis for the development of a new class of adenosine analogues that modulate human blood platelet activities.     

Application of glycidol in synthesis of oligoetherols with perhydro‐1,3,5‐triazine ring

A new method of preparation of oligoetherols containing perhydro‐1,3,5‐triazine rings from isocyanuric acid and an excess of glycidol, alkylene carbonates, or oxiranes is presented. The course of reaction was studied at various molar ratios of glycidol to isocyanuric acid. The structure of the products was established, and some physical properties were measured. The oligoetherols were demonstrated to be useful substrates for polyurethane foams of enhanced thermal stability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The Release of Ferulic Acid and Feruloylated Oligosaccharides During Wort and Beer Production

Ferulic acid, a very attractive natural antioxidant is present in beer in free form, but the main form is the bound form as feruloylated oligosaccharides. Previous research showed that feruloylated oligosaccharides more effectively inhibited lipid and Low Density Lipoprotein oxidation than free ferulic acid. The aim of the present study was to evaluate free and bound ferulic acid concentrations throughout the brewing process in experimental mashes (worts, beers during fermentation, maturation and storage), and to conduct a comparison in commercial beers. Another aim of the study was to investigate methods to increase levels of bound ferulic acid in beer due to the potential health benefits. Specifically, the influence of commercial enzyme preparations on both forms of ferulic acid contents was studied. Five commercial enzyme preparations during mashing were examined: Celluclast, Shearzyme, Viscozyme, Cereflo and Ultraflo. In all experimental beers, the concentrations of esterified ferulic acid were 4–6 fold higher than the corresponding free ferulic acid contents, depending on the enzyme preparation used. Ferulic acid contents in the ester form in experimental beers were in the range of 748.4 mg/hL to 1244.3 mg/hL, whereas the contents of free ferulic acid were in the range of 134.6 mg/hL to 275.2 mg/hL. Comparison of free and bound ferulic acid contents in experimental beers, produced using enzyme preparations and commercial beers found in a local market, showed that concentrations of bound ferulic acid in experimental beers were significantly higher than in commercial beers, whereas concentrations of free ferulic acid in experimental and commercial beers were comparable.     

Indole compounds in fruiting bodies of some edible Basidiomycota species

The contents of nonhallucinogenic indole compounds were determined in methanol extracts from fruiting bodies of four common edible European species of higher fungi representing the most popular taxon Basidiomycota: Agaricus bisporus (J.E. Lange), Cantharellus cibarius Fr., Lactarius deliciosus (L. Fr.) S.F. Gray and Leccinum rufum (Schaef.) Kreisel. Amongst eleven compounds under analysis, 6–7 metabolites, distinct in different species, were identified in the extracts of fruiting bodies. Serotonin and melatonin were the only common compounds to all species. The contents of the analyzed compounds were diverse, ranging from 0.01 to almost 40 mg/100 g d.w. The contents of tryptophan, 5-hydroxytryptophan, tryptamine and melatonin were low (below 1.40 mg/100 g d.w.). Noteworthy, the serotonin contents were very high in all species under study and amounted to 5.21, 29.61, 18.42 and 31.71 mg/100 g d.w., respectively. Moreover, the fruiting bodies of these species contained indoleacetic acid (max. 2.04 mg/100 g d.w.) and tryptophan degradation products: kynureine sulfate (max. 39.20 mg/100 g d.w.) and kynurenic acid (6.21 mg/100 g d.w.).     

Changes in the stress field in the elastohydrodynamic contact zone due to some operating factors and their possible role in the rolling contact fatigue of cylindrical surfaces

A theoretical analysis has been carried out of changes in the stress field in the elastohydrodynamic contact zone of cylindrical surfaces due to operating variables. Their possible role in rolling contact fatigue has been assessed by accelerated rolling contact fatigue tests. The results show that changes of the elastohydrodynamic pressure distribution in the contact zone associated with increase of the viscosity-velocity parameter induce considerable changes in the stress field in the contact zone. The poor correlation of rolling contact fatigue life with material effects according to elastohydrodynamic theory and the considerable changes in rolling contact fatigue life due to lubrication effects suggests that the explanation lies outside elastohydrodynamic theory and possibly in the theory of asperity lubrication.     

Meso and macroscopic considerations about damage accumulation processes

Meso (effect of grain size) and macroscopic (effect of sample dimension) considerations about damage accumulation processes are discussed. Although both factors may significantly influence damage accumulation kinetics, they are not taken into account in most of currently used models. The role of meso and macroscopic factors may be explained in the framework of a recently developed model of damage accumulation (Multi-Step Damage Accumulation - MSDA), which assumes that the damage build-up can be regarded as a sequence of structural transformations triggered by the destabilization of the current structure of a crystal induced by radiation damage.     

Proton beam induced luminescence of silicon dioxide implanted with silicon

Light emission from a silicon dioxide layer enriched with silicon has been studied. Samples used had structures made on thermally oxidized silicon substrate wafers. Excess silicon atoms were introduced into a 250-nm-thick silicon dioxide layer via implantation of 60 keV Si⁺ ions up to a fluence of 2 × 10¹⁷ cm⁻². A 15-nm-thick Au layer was used as a top semitransparent electrode. Continuous blue light emission was observed under DC polarization of the structure at 8-12 MV/cm. The blue light emission from the structures was also observed in an ionoluminescence experiment, in which the light emission was caused by irradiation with a H₂⁺ ion beam of energy between 22 and 100 keV. In the case of H₂⁺, on entering the material the ions dissociated into two protons, each carrying on average half of the incident ion energy. The spectra of the emitted light and the dependence of ionoluminescence on proton energy were analyzed and the results were correlated with the concentration profile of implanted silicon atoms.