RHEOLOGY OF CHICKPEA PROTEIN CONCENTRATE DISPERSIONS

Chickpea proteins are used as ingredients in comminuted sausage products and many oriental textured foods. Rheological behaviour of chickpea protein concentrate was studied using a controlled stress rheometer. The protein dispersion prepared with phosphate buffer at pH 7.0 presented non-Newtonian shear thinning behaviour and rheological data well fitted to the Sisko, Carreau and Cross models. The viscoelastic properties of the chickpea protein suspensions were estimated by measuring the storage and loss moduli in oscillatory frequency conditions (0.1-10 Hz) at 20°C. Moreover, thermally induced gelation of the chickpea proteins (16, 24 and 36%) was studied at pH 7.0 and 4.5 in the temperature range 50 to 100oC and salt concentration ranging from 0 to 1 M. Gelling behaviour was quantified by means of dynamic rheological measurements. Gels formation was preceded by the decrease of storage modulus and loss moduli, coupled with the increase of the phase angle (delta). The beginning of thermal gelation was influenced by protein concentration, pH and salt level. In all studied cases, storage modulus increased rapidly in the temperature range 70-90°C. All rheological parameters measured at 90°C were significantly higher at pH 4.5 compared to pH 7.0

Efficient Dehydration and Recovery of Ionic Liquid After Lignocellulosic Processing Using Pervaporation

Background: Biomass pretreatment using certain ionic liquids (ILs) is very efficient, generally producing a substrate that is amenable to saccharification with fermentable sugar yields approaching theoretical limits. Although promising, several challenges must be addressed before an IL pretreatment technology can become commercially viable. One of the most significant challenges is the affordable and scalable recovery and recycle of the IL itself. Pervaporation (PV) is a highly selective and scalable membrane separation process for quantitatively recovering volatile solutes or solvents directly from non-volatile solvents that could prove more versatile for IL dehydration. Results: We evaluated a commercially available PV system for IL dehydration and recycling as part of an integrated IL pretreatment process using 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) that has been proven to be very effective as a biomass pretreatment solvent. Separation factors as high as 1500 were observed. We demonstrate that \u3e 99.9 wt% [C2C1Im][OAc] can be recovered from aqueous solution (≤ 20 wt% IL) and recycled five times. A preliminary technoeconomic analysis validated the promising role of PV in improving overall biorefinery process economics, especially in the case where other IL recovery technologies might lead to significant losses. Conclusions: These findings establish the foundation for further development of PV as an effective method of recovering and recycling ILs using a commercially viable process technology

Frontiers of Ionic Liquids

Researchers around the globe are no strangers to the term “Ionic Liquids (ILs)”. With diverse applicability in chemistry, materials, chemical engineering, medicines, biochemistry to name a few, ILs are doing exactly what the researchers in the field predicted they will do, during the first international meeting devoted entirely to ILs research held on Greek grounds in Crete, back in April 2000: ILs are sustainable and decrease the environmental burden (e.g. reduce reliance on fossil fuel feedstock and replace them with renewable, increase energy efficiency, improved and/or new chemical and separation processes, etc.), while still being economically feasible in an industrial scale

THE EFFECT OF TRANSGLUTAMINASE ON THE RHEOLOGICAL PROPERTIES OF YOGURT

The aim of this study was to investigate the rheological characteristics of yogurts obtained from milk treated with transglutaminase prior to fermentation with Streptococus theromophilus and Lactobacillus delbrueckii subsp. Bulgaricus. A set of 36 experiments were carried out to test the influence of various enzyme concentrations ranging from 0 to 0.04%, different setting temperatures (35, 40 and 45 oC), and setting time (60, 90 and 120 min). The cross-linking of milk proteins influenced the post-acidification process as well as the stability of the yogurt samples. The enzymatic treatment of milk allowed avoiding the syneresis phenomena during yogurt storage at 4 oC; the water holding capacity during centrifugation was also improved. Concerning the rheological properties, the apparent viscosity of yogurt increased by increasing the enzyme concentration and the setting time for the entire tested domain of shear rates. The results indicate that transglutaminase catalyzed cross-linking is an effective tool for improving functional properties of yogurt

Frontiers of Ionic Liquids

Researchers around the globe are no strangers to the term “Ionic Liquids (ILs)”. With diverse applicability in chemistry, materials, chemical engineering, medicines, biochemistry to name a few, ILs are doing exactly what the researchers in the field predicted they will do, during the first international meeting devoted entirely to ILs research held on Greek grounds in Crete, back in April 2000: ILs are sustainable and decrease the environmental burden (e.g. reduce reliance on fossil fuel feedstock and replace them with renewable, increase energy efficiency, improved and/or new chemical and separation processes, etc.), while still being economically feasible in an industrial scale

ANTIMICROBIAL ACTIVITY OF EXTRACTS OF WILD GARLIC (Allium ursinum) FROM ROMANIAN SPONTANEOUS FLORA

Wild Romanian spontaneous garlic’s (Allium ursinum) antimicrobial activity was tested in order to establish the inhibition potential of growth of some microorganisms. As test microorganisms were used pure cultures of fungs (Aspergillus glaucus, Geotrichum candidum, Mucor mucedo, Saccharomyces cerevisiae) and bacteria (Bacillus subtilis) isolated from food microbiota. There were also, used microbial strains isolated from different pathological products: wound secretions (Staphylococcus aureus), throat swab (Streptococcus pyogenes), urine (Escherichia coli) and oral mucosa (Candida albicans). The antimicrobial potential of used extracts is highlighted depending on the type of the vegetal tissue (leaves, roots, bulbs) and the nature of the solvent used for extraction. Extracts used in these experiments are recommended to use in food industry to preserve the stability and to improve the organoleptic quality of products

Facile pulping of lignocellulosic biomass using choline acetate: Biomass; Pulping; Biopolymer recovery; Ionic liquids

International audienceTreating ground bagasse or Southern yellow pine in the biodegradable ionic liquid (IL), choline acetate ([Cho][OAc]), at 100 degrees C for 24 h led to dissolution of hemicellulose and lignin, while leaving the cellulose pulp undissolved, with a 54.3% (bagasse) or 34.3% (pine) reduction in lignin content. The IL solution of the dissolved biopolymers can be separated from the undissolved particles either by addition of water (20 wt% of IL) followed by filtration or by centrifugation. Hemicellulose (19.0 wt% of original bagasse, 10.2 wt% of original pine, containing 14-18 wt% lignin) and lignin (5.0 wt% of original bagasse, 6.0 wt% of original pine) could be subsequently precipitated. The pulp obtained from [Cho][OAc] treatment can be rapidly dissolved in 1-ethyl-3-methylimidazolium acetate (e. g., 17 h for raw bagasse vs. 7 h for pulp), and precipitated as cellulose-rich material (CRM) with a lower lignin content (e. g., 23.6% for raw bagasse vs. 10.6% for CRM)