Characterisation and functional properties of proteins of some Indian chickpea (Cicer arietinum) cultivars

BACKGROUND: Chickpea (Cicer arietinum L.) proteins have received attention during recent years owing to their higher biological values and better functional ingredients than oilseed proteins. In this study the composition, fractionation, electrophoretic behaviour and functional properties of five chickpea protein concentrates were determined. RESULTS: The chickpea proteins contained 15.9–54.8 g kg^?1 albumin, 48.9–154.1 g kg^?1 globulin, 39.2–76.5 g kg^?1 glutelin and traces of prolamin. Electrophoresis of the various fractions revealed that albumin and globulin were made up of sub‐units of different molecular weights ranging from 7 to 96 kDa. Water and oil absorption of the protein concentrates varied from 1.15 to 2.75 g g^?1 and from 2.60 to 5.65 g g^?1 respectively. Foaming capacity and foam stability of the protein concentrates were good and improved with the addition of salt (10 g L^?1 NaCl) or sugar (100 g L^?1 sucrose) at both isoelectric and neutral pH. Emulsifying capacity and emulsion stability of the protein concentrates were good and excellent respectively. CONCLUSION: Protein concentrates prepared from chickpeas have potential use in food formulations owing to their good emulsifying/foaming and water/oil‐binding capacities. Copyright © 2008 Society of Chemical Industry     

Supercritical fluid fractionation of fatty acid ethyl esters from butteroil

Countercurrent supercritical fractionation of the fatty acid ethyl esters from butteroil has been investigated. The main objective of the present study was to obtain extracts rich in short- and medium-chain fatty acid ethyl esters. To that end, transesterification of the original butteroil was used to transform the triacylglycerols into the corresponding fatty acid ethyl esters. Then, several supercritical fluid extractions were carried out at pressures ranging from 8.9 to 18.6 MPa and at 2 different temperatures (48 and 60°C). The flow ratio of CO₂ to butteroil was 15. Composition and yield of short- and medium-chain fatty acid ethyl esters was evaluated at different extraction conditions. Extracts containing ∼70% short- and medium-chain fatty acid ethyl esters were obtained at 101 bar and 60°C, and can be used as starting material for the production of highly valuable functional lipids.     

Studies of the comonomer distributions in low density polyethylenes using temperature rising elution fractionation and stepwise crystallization by DSC

The comonomer distributions of commercial linear low density polyethylenes (LLDPE) and linear very low density polyethylenes (VLDPE) produced with traditional high activity Ziegler–Natta (Z–N) catalysts were characterized by temperature rising elution fractionation (TREF). In order to develop faster characterization methods the polymers were also characterized using a segregation fractionation technique (SFT) based on a stepwise crystallization by differential scanning calorimetry (DSC). Comparative studies of SFT and TREF demonstrated that SFT provides an alternative tool for the relative qualitative analysis of the chemical composition distribution (CCD) and the technique is useful to characterize the heterogeneity in comonomer unit distribution. Lamellar thickness distributions can be calculated from the DSC endo-therms by applying the Thomson–Gibbs equation. The SFT technique was also applied to commercial single-site (metaliocene) LLDPE and VLDPE polymers. In spite of their more homogeneous structure compared with the Z–N copolymers, which contain many active sites, these single site copolymers also gave thermograms resolved into several peaks.     

Fractionation of oligomers of linear alphaolefins in a molecular evaporator

Oligomers of higher alphaolefins, mainly of 1-decene and 1-octene have important applications as synthetic lubricating oils or their components. The results of fractionation of polydecene, polyoctene, and polybutene oils in a wiped-film molecular evaporator, for the purpose of preparing narrow distillate cuts, are presented in the paper. Characteristics and properties of the fractions obtained are shown, and the possibilities for this distillation method in the fractionation of polyolefin oils discussed.     

Contribution of triglycerides from cocoa butter to the physical properties of milkfat fractions

Milkfat was separated into major chainlength fractions by solid-phase extraction. The effect on thermal behavior and texture of replacing both saturated and monounsaturated long-chain triglycerides from milkfat by long-chain monounsaturated triglycerides with an unsaturated fatty acid in thesn-2 position is reported. Increasing proportions of cocoa butter were added to fractions of short-to medium-chain triglycerides (C₂₂−C₄₄) and medium- to long-chain triglycerides (C₃₆−C₄₈) isolated from milkfat. Thermal behavior and texture of the mixtures were measured. Results indicated that long-chain monounsaturated triglycerides from cocoa butter enhanced co-crystallization and co-operative melting and did not induce polymorphic transitions upon crystallization and melting of the fractions. At 4°C, they acted as texture builder if present in proportions of more than 30%, whereas below this level, they acted as texture softeners. The effect of the long-chain monounsaturated triglycerides on the texture of fractions that melt at low temperature could not be predicted from the proportion of solid fat at that temperature. Presented at the 1995 AOCS Annual Meeting & Expo, San Antonio, Texas, May 1995.     

Green and feasible fabrication of loose nanofiltration membrane with high efficiency for fractionation of dye/NaCl mixture by taking advantage of membrane fouling

Loose nanofiltration membrane emerges as required recently, since it is hard for conventional nanofiltration membrane to fractionate mixture of dyes and salts in textile wastewater treatment. However, the polymeric membranes unavoidably suffer from membrane fouling, which was caused by the adsorption of organic pollutants (like dyes). Normally, the dye fouling layer will shrink membrane pore size, thus resulting in flux decline and rejection increase. It is thought that membrane fouling may be a double-edged sword and can be an advantage if properly utilized. Thereby, loose nanofiltration membranes were constructed here by a green yet effective method to fractionate dyes/salt mixture by taking advantage of membrane fouling without using poisonous ingredients. A commercially available polyacrylonitrile (PAN) ultrafiltration membrane with high permeability was chosen as the substrate, and dyes were used to contaminate PAN substrate and formed a stable barrier layer when adsorption of dyes reached dynamic equilibrium. The resultant PAN-direct red 80 (DR80) composite membranes displayed superior permeability (~128.4 L m⁻² h⁻¹) and high rejection (~99.9%) to DR80 solutions at 0.4 MPa. Moreover, PAN-DR80 membranes allowed fast fractionation of dyes/sodium chloride (NaCl) mixture, which maintained a negligible dye loss and a low NaCl rejection (~12.4%) with high flux of 113.6 L m⁻² h⁻¹ at 0.4 MPa. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47438.     

Wide range humidity sensors printed on biocomposite films of cellulose nanofibril and poly(ethylene glycol)

Cellulose nanofibril (CNF) films were prepared from side streams generated by the sugarcane industry, that is, bagasse. Two fractionation processes were utilized for comparison purposes: (1) soda and (2) hot water and soda pretreatments. 2,2,6,6-Tetramethylpiperidinyl-1-oxyl-mediated oxidation was applied to facilitate the nanofibrillation of the bagasse fibers. Poly(ethylene glycol) (PEG) was chosen as plasticizer to improve the ductility of CNF films. The neat CNF and biocomposite films (CNF and 40% PEG) were used for fabrication of self-standing humidity sensors. CNF-based humidity sensors exhibited high change of impedance, within four orders of magnitude, in response to relative humidity (RH) from 20 to 90%. The use of plasticizer had an impact on sensor kinetics. While the biocomposite film sensors showed slightly longer response time, the recovery time of these plasticized sensors was two times shorter in comparison to sensors without PEG. This study demonstrated that agroindustrial side streams can form the basis for high-end applications such as humidity sensors, with potential for, for example, packaging and wound dressing applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47920.     

Removal of inorganic constituents from pine barks and switchgrass

The ash content of biomass has some negative impacts on the efficient utilization of biomass for the production of value-added products. In this paper, the techniques of ash removal from Mountain Pine Beetle (MPB) killed pine bark and switchgrass were examined systematically. Size fractionation was found to be effective for ash removal not only for the heterogeneous switchgrass but also for the homogeneous pine bark. Inorganic constituents of untreated samples and treated samples showed that leaching by water and four dilute acid solutions was effective in removing most of ash from both biomass samples. The inorganic element distributions in ash of pine bark samples before and after the acid leaching showed that substantial reductions were achieved in different main elements, Al (66%), Ca (90%), Fe (66%), K (92%), Mg (98%), Na (100%) and S (25%). For switchgrass, most of the element concentrations were reduced by water leaching because of its high content of water-soluble metals in the ash. For the purpose of practical applications of the two types of biomass, especially the underutilized pine barks, different leaching methods should be evaluated to identify the most suitable method for the removal of inorganic constituents.     

气体分馏装置脱丙烷塔的流程模拟

以某石化公司300kt/a气体分馏装置中脱丙烷塔为研究对象,运用流程模拟软件PRO/Ⅱ进行稳态模拟,使脱丙烷塔在产品质量符合要求的条件下,塔的操作参数最佳,塔的能耗值达到最小.综合考虑各关键影响因素,采用流程模拟软件PRO/Ⅱ的灵敏度分析方法,对该塔进行模拟分析,并对分析的结果进行总结和讨论.