Food processing systematically aims at meeting the needs of consumers who are looking for total high quality and perfect food safety. As the various thermal and non-thermal food preservation technologies often affect the natural properties in terms of sensation, flavor, texture, etc., instant controlled pressure drop (DIC) has been conceived as a relevant, innovative process in this field. DIC uses high saturated steam pressure and short duration to provide a new way to expand biological matrices, improve drying, decontaminate, and extract biologically active compounds, among other attributes. Therefore, this review focuses on describing the applications of DIC technology on a wide range of products such as foods and by-products that have been processed both in the laboratory and on an industrial scale. The application of DIC has shown the possibility of a significant leap in quality improvement and cost reduction in the food industry. DIC reduces the drying time of fruits and vegetables, and improves the extraction of essential oils, vegetable oils, and antioxidant components. It also provides strong decontamination, eliminates vegetative microorganisms and spores, and reduces non-nutritional and allergenic components. Over the past 33 years, this technology has continued to expand its food applications and improve its characteristics on an industrial scale. But there are still many food unit operations that can be taken to the next level with DIC. 相似文献
The synthesis of new oxazolidinylthiazolidines bicycles, oxygen analogues of bisthiazolidines, also known as metallo-β-lactamase inhibitors is described. The reaction of β-aminoalcohols and 2,5-dihydroxy-1,4-dithiane led to oxazolidinylthiazolidines and/or dithioazabicycles as the main products. The distribution pattern depends mainly on the aminoalcohol substituents. In a one-pot reaction, four new bonds are formed in good yields and with high atom efficiency. When the oxazolidinylthiazolidines are formed, two stereogenic centres are generated with high enantiospecificity. The reaction mechanism is discussed based on crystallographic data and interconversion studies. Two oxazolidinylthiazolidines were evaluated as inhibitors of the potent lactamase NDM-1 and compound 4f displayed competitive inhibition with Ki = 1.6 ± 0.6 μM. 相似文献
Heterogeneous photocatalytic oxidation of contaminants present in wastewater produced by a textile industry was carried out. The samples were withdrawn from the plant before and after a traditional biological treatment. The effluents were named A and A' (before the biological treatment), B and B' (after the biological treatment). Polycrystalline TiO2 (Degussa P25) was used as the catalyst in a batch photoreactor with immersed lamp. An almost complete decolorization was observed after about 0.5 divided by 1 hours for both kinds of effluents, but the decrease of the total organic carbon (TOC) concentration occurred more slowly. The influence of some chemical oxidants, i.e. ozone, hydrogen peroxide and peroxydisulfate on the photo-oxidation rate was also investigated. After addition of H2O2 or S2O8(2-) TOC decreased more quickly only for B and B'. The runs performed by using O3 as bubbling gas showed a mineralization rate higher than that observed in the presence of O2. 相似文献
The Re(IV) complex [ReCl4(mal)]2-, in the form of two slightly different salts, (AsPh4)1.5(HNEt3)0.5[ReCl4(mal)] (1a) and (AsPh4)(HNEt3)[ReCl4(mal)] (1b), and the Re(IV)-Cu(II) bimetallic complexes [ReCl4(mu-mal)Cu(phen)2].CH3CN (2), [ReCl4(mu-mal)Cu(bpy)2] (3), and [ReCl4(mu-mal)Cu(terpy)] (4) (mal=malonate dianion, AsPh4=tetraphenylarsonium cation, HNEt3=triethylammonium cation, phen=1,10-phenanthroline, bpy=2,2'-bipyridine and terpy=2,2':6',2' '-terpyridine) have been synthesized and the structures of 1a, 1b, 2, and 3 determined by single-crystal X-ray diffraction. The structures of 1a and 1b are made up of discrete [ReCl4(mal)]2- anions and AsPh4+ and HNEt3+ cations, held together by electrostatic forces and hydrogen bonds. The Re(IV) atom is surrounded by four chloride anions and a bidentate malonate group, in a distorted octahedral environment. The structure of 2 consist of neutral dinuclear units [ReCl4(mu-mal)Cu(phen)2], with the metal ions united through a bridge carboxilato. The environment of Re(IV) is nearly identical to that in the mononuclear complex, and Cu(II) is five coordinate, being surrounded by four nitrogen atoms of two bidentate phen ligands and one oxygen atom of the malonato ligand. In 3, there are also dinuclear units, [ReCl4(mu-mal)Cu(bpy)2], but the Cu(II) ions complete a distorted octahedral coordination by binding with the free malonato oxygen atom of a neighbor unit, resulting in an infinite chain. The magnetic properties of 1-4 were also investigated in the temperature range 2.0-300 K. The magnetic behavior of 1a and 1b is as expected for a Re(IV) complex with a large value of the zero-field splitting (2D ca. 110 cm(-1)). For the bimetallic complexes, the magnetic coupling between Re(IV) and Cu(II) is antiferromagnetic in 2 (J=-0.39 cm(-1)), ferromagnetic in 4 (J=+1.51 cm(-1)), and nearly negligible in 3 (J=-0.09 cm(-1)). 相似文献
Structural and magnetic studies are presented for the perovskite type Sr1−xLaxCo0.5Fe0.5O3−δ (0?x?0.5) materials annealed under moderately high-oxygen pressures of ∼200 atm. A detailed analysis of the room temperature neutron time-of-flight diffraction data reveals that the crystal structure of the sample SrCo0.5Fe0.5O2.89(1), previously described as vacancy-disordered cubic, is similar to the formerly reported, oxygen-vacancy ordered Sr8Fe8O23 compound, i.e. Sr8Co4Fe4O23 is tetragonal with the I4/mmm symmetry. With an increase of the La content the studied materials become nearly oxygen stoichiometric and a lowering of the crystal symmetry is observed from cubic (x=0.1 and 0.2) to tetragonal I4/mcm (x=0.3 and 0.4), and finally to monoclinic I12/c1 (x=0.5). Low-temperature structural and magnetic measurements show a ferromagnetic ordering with the maximum Curie temperature near 290 K at x=0.2. 相似文献
A new hybrid material has been prepared by intercalating the supramolecular cationic complex [μ-meso-tetra(4-pyridyl)porphyrinatecobalt(II) tetrakis[bis(bipyridine)(chlorido)ruthenium(II)], referred to as [CoTPyP{Ru(bipy)2Cl}4]4+ into a Cameroonian smectite clay (from Bagba hill, denoted Ba). The intercalated material (named CoTPyPRu(bipy)2–Ba) was used to modify glassy carbon electrodes (GCE), which were successfully applied to the simultaneous determination of acetaminophen (AC) and tyrosine (Tyr). The CoTPyPRu(bipy)2–Ba material was characterized by UV/Vis absorption spectroscopy, X-ray diffractometry and FT-IR spectroscopy. The intercalation of [CoTPyP{Ru(bipy)2Cl}4]4+ into the Ba interlayer endowed large surface area to the material. Electrodes modified with CoTPyPRu(bipy)2–Ba display good compatibility and stability, high selectivity and sensitivity, even with real samples. Working at pH?7.0, AC was oxidized at +0.42 V and Tyr at 0.72 V (vs Ag/AgCl). Linear calibration plots for AC and Tyr were obtained in the 1 to 50 μM and 1 to 24 μM range, with detection limits of 0.1 μM and 0.5 μM, respectively. The modified electrode was successfully applied to the determination of tyrosine in urine, and of acetaminophen in a pharmaceutical product.
Graphical Abstract Flask 1: Porphyrin solution. (a) Respective spectrum. Flask 2: Same porphyrin solution, after clay addition. (b): Spectrum obtained with a suspension of clay-porphyrin. (c): Spectrum of flask 2 supernatant. A cationic tetra-ruthenated cobalt porphyrin was intercalated into natural Cameroon smectite clay. Further, a sensitive electrochemical sensor was developed by depositing the prepared nanohybrid clay porphyrin onto glassy carbon electrode as thin film. This new modified electrode presented a very favorable response for simultaneous determination of acetaminophen and tyrosine.
