Influence of Fermentation Beetroot Juice Process on the Physico-Chemical Properties of Spray Dried Powder

Picking vegetables is, along with salting and drying, one of the oldest ways to preserve food in the world. This is the process of decomposition of simple sugars into lactic acid with the participation of lactic bacteria. The aim of the study was to obtain powders from fermented red beet juice with the highest possible amount of lactic acid bacteria (LAB) and active ingredients. For the analysis, juices were squeezed from the vegetables and two types of fermentation were used: a spontaneous fermentation and a dedicated one. After inoculation, samples were taken for analysis on a daily basis. Extract, pH, total acidity, pigments, and color were measured. In addition, microbiological tests were also carried out. The juices from the fifth day of fermentation was also spray dried, to obtain fermented beetroot powder. Juices from 3–5th day were characterized by a high content of LAB and betanin, had also a low pH, which proves that the lactic fermentation is working properly. The exception was the juice from spontaneous fermentation. According to the observations, the fermentation process did not run properly, and further analysis is needed. The powders were stable; however, results obtained from the pigment content and the LAB content are not satisfactory and require further analysis.     

Application of mutually immiscible ionic liquids to the separation of aromatic and aliphatic hydrocarbons by liquid extraction: a preliminary approach

The recently discovered class of ionic liquids--mutually immiscible ionic liquids--are explored in this work for their first practical application: the separation of aromatic and aliphatic hydrocarbons by solvent extraction. For this preliminary approach, benzene and hexane were chosen as representatives of each group of hydrocarbons; the ionic liquids 1-ethyl-3-methylimidazolium bis( (trifluoromethyl)sulfonyl)amide and trihexyl(tetradecyl)phosphonium bis( (trifluoromethyl)sulfonyl)amide, which are both liquid at room temperature and hydrophobic, were selected as potential solvents. Liquid-liquid equilibrium experiments were carried out at 25 degrees C for the quaternary system formed by the two hydrocarbons and the two ionic liquids. Typical extraction parameters were calculated and analysed in order to evaluate the possibilities of the mutual immiscible ionic liquids in accomplishing the separation target. A comparison with the case of using just one of the ionic liquids was made.     

The Influence of Different Pretreatment Methods on Color and Pigment Change in Beetroot Products

Vegetable processing pomace contains valuable substances such as natural colors that can be reused as functional ingredients. Due to a large amount of water, they are an unstable material. The aim of our research was to assess how the pretreatment method (thermal or nonthermal) affects the properties of powders obtained from beet juice and pomace after the freeze-drying process. The raw material was steamed or sonicated for 10 or 15 min, and then squeezed into juice and pomace. Both squeezed products were freeze-dried. The content of dry substance; L*, a*, and b* color parameters; and the content of betalain pigments were analyzed. Pretreatments increased the proportion of red and yellow in the juices. Steam and ultrasound caused a significant reduction in parameter b* in the dried pomace. A significant increase in betanin in lyophilizates was observed after pretreatment with ultrasound and steam for 15 min. As a result of all experiments, dried juices and pomaces can also be used as a colorant source. However, there is higher potential with pomaces due to their additional internal substances as well as better storage properties. After a few hours, juice was sticky and not ready to use.     

Study on the Mechanism of Ionic Liquids Improving the Extraction Efficiency of Essential Oil Based on Experimental Optimization and Density Functional Theory: The Fennel (Foeniculi fructus) Essential Oil Case

In this work, microwave-assisted ionic liquids treatment, followed by hydro-distillation (MILT-HD), as an efficient extraction technology, was used to extract essential oil. The purpose for this was to use multivariate analysis (MVA) models to investigate the effects of potential critical process parameters on the extraction efficiency of essential oil, and explore the mechanism of ionic liquids (ILs). According to the design of experiment (DoE), under optimal process conditions, the extraction efficiency of essential oil was dramatically enhanced, and had low energy demands. Since little is known regarding those mechanisms, according to the non-covalent interaction analysis, the underlying mechanism for ILs improving extraction efficiency was explored based on the density functional theory (DFT). The results showed that ILs could form intense non-covalent bond interaction with cellulose. It helped destroy the network hydrogen bond structure of cellulose in plant cells and caused the essential oils in the cells to be more easily exposed to the extraction solution, thereby accelerating extraction efficiency. Based on this work, it is conducive to understand the MILT-HD process better and gain knowledge of the mechanism of ILs.     

Enhanced mass transfer during solid–liquid extraction of gamma-irradiated red beetroot

The exposure to gamma-irradiation pretreatment increases cell wall permeabilization, resulting in loss of turgor pressure, which led to the increase of extractability of betanin from red beetroot. The degree of extraction of betanin was investigated using gamma irradiation as a pretreatment prior to the solid–liquid extraction process and compared with control beetroot samples. The beetroot subjected to different doses of gamma irradiation (2.5, 5.0, 7.5, 10.0 kGy) and control was dipped in an acetic acid medium (1% v/v) to extract the betanin. The diffusion coefficients for betanin as well as ionic component were estimated considering Fickian diffusion. The results indicated an increase in the diffusion coefficient of betanin (0.302×10⁻⁹–0.463×10⁻⁹ m²/s) and ionic component (0.248×10⁻⁹–0.453×10⁻⁹ m²/s) as the dose rate increased (from 2.5 to 10.0 kGy). The degradation constant was found to increase (0.050–0.079 min⁻¹) with an increase gamma-irradiation doses (2.5–10.0 kGy), indicating lower stability of the betanin as compared to control sample at 65 °C.     

Präbetanin,ein Schwefelsäure-halbester des Betanins. Ein Beitrag zur Kenntnis der Betacyane

Prebetanin, a minor companion of betanin in the red beet, was isolated and found to be the 6′-sulfuric acid half-ester of betanin. The arguments are based on elemental analyses, partial hydrolysis and methanolysis, and on comparison of the NMR-spectra of prebetanin and betanin, and of their derivatives.     

Recent progress of task‐specific ionic liquids in chiral resolution and extraction of biological samples and metal ions

Ionic liquids have been functionalized for modern applications. The functional ionic liquids are also called task‐specific ionic liquids. Various task‐specific ionic liquids with certain groups have been constructed and exploited widely in the field of separation. To take advantage of their properties in separation science, task‐specific ionic liquids are generally used in techniques such as liquid–liquid extraction, solid‐phase extraction, gas chromatography, high‐performance liquid chromatography, and capillary electrophoresis. This review mainly covers original research papers published in the last five years, and we will focus on task‐specific ionic liquids as the chiral selectors in chiral resolution and as extractant or sensor for biological samples and metal ion purification.     

Application of ionic liquids based microwave-assisted simultaneous extraction of carnosic acid, rosmarinic acid and essential oil from Rosmarinus officinalis

An ionic liquid based microwave-assisted simultaneous extraction and distillation (ILMSED) method has been developed for the effective extraction of carnosic acid (CA), rosmarinic acid (RA) and essential oil (EO) from Rosmarinus officinalis. A series of 1-alkyl-3-methylimidazolium ionic liquids differing in composition of anion and cation were evaluated for extraction yield in this work. The results obtained indicated that the anions and cations of ionic liquids had influences on the extraction of CA and RA, 1.0M 1-octyl-3-methylimidazolium bromide ([C8mim]Br) solution was selected as solvent. In addition, the ILMSED procedures for the three target ingredients were optimized and compared with other conventional extraction techniques. ILMSED gave the best result due to the highest extraction yield within the shortest extraction time for CA and RA. The novel process developed offered advantages in term of yield and selectivity of EO and shorter isolation time (20 min in comparison of 4h of hydrodistillation), and provides a more valuable EO (with high amount of oxygenated compounds). The microstructures and chemical structures of rosemary samples before and after extraction were also investigated. Moreover, the proposed method was validated by the stability, repeatability and recovery experiments. The results indicated that the developed ILMSED method provided a good alternative for the both extraction of non-volatile compounds (CA and RA) and EO from rosemary as well as other herbs.     

不同离子液体双水相萃取钯

为实现贵金属钯的绿色、高效萃取,本文使用有“绿色溶剂”之称的离子液体与磷酸钾形成的双水相体系,不加入其它萃取剂对钯(Ⅱ)进行萃取,并采用浊点法对所研究的6种咪唑类离子液体的双结线和系线进行测定。 结果表明,基于氯离子和溴离子的离子液体成相能力和萃取率无显著差异。 阳离子上支链的疏水性是影响咪唑类离子液体成相能力的关键因素之一。 与不含官能团的离子液体相比,支链上嵌入氨基和腈基的离子液体,成相能力较低,但萃取率分别提高了11.57%和34.26%。 当含腈基的离子液体浓度和磷酸钾浓度分别为5.00%和39.55%时,离子液体双水相体系对钯(Ⅱ)的萃取率可达到100%。 本文的研究成果为设计/选择可利用其双水相体系高效萃取钯(Ⅱ)的离子液体提供了理论基础和数据支持。     

超临界流体萃取分离离子液体与有机物及其相平衡的研究

离子液体具有一些优良的物理和化学性质,非常有希望成为传统有机溶剂的替代溶剂.但是如何从过程物流中分离和回收离子液体将是其工业化应用的一个很大挑战.蒸馏、液液萃取和超临界萃取是目前已知的三个可行的方法.其中超临界萃取可应用于离子液体与挥发的或相对不挥发的有机物的分离,而且不存在相间交叉污染.本文从二元体系相平衡、三元体系相平衡、模型化研究和萃取实验结果方面介绍了超临界萃取方法的最新研究进展,在此基础上提出了用超临界丙烷替代超临界二氧化碳作为萃取溶剂的新思路,并探讨了该领域今后的研究方向和工业化前景.     

Application of ionic liquids based enzyme-assisted extraction of chlorogenic acid from Eucommia ulmoides leaves

A new approach for ionic liquid based enzyme-assisted extraction (ILEAE) of chlorogenic acid (CGA) from Eucommia ulmoides is presented in which enzyme pretreatment was used in ionic liquids aqueous media to enhance extraction yield. For this purpose, the solubility of CGA and the activity of cellulase were investigated in eight 1-alkyl-3-methylimidazolium ionic liquids. Cellulase in 0.5 M [C6mim]Br aqueous solution was found to provide better performance in extraction. The factors of ILEAE procedures including extraction time, extraction phase pH, extraction temperatures and enzyme concentrations were investigated. Moreover, the novel developed approach offered advantages in term of yield and efficiency compared with other conventional extraction techniques. Scanning electronic microscopy of plant samples indicated that cellulase treated cell wall in ionic liquid solution was subjected to extract, which led to more efficient extraction by reducing mass transfer barrier. The proposed ILEAE method would develope a continuous process for enzyme-assisted extraction including enzyme incubation and solvent extraction process. In this research, we propose a novel view for enzyme-assisted extraction of plant active component, besides concentrating on enzyme facilitated cell wall degradation, focusing on improvement of bad permeability of ionic liquids solutions.     

Determination of triazine herbicides in juice samples by microwave‐assisted ionic liquid/ionic liquid dispersive liquid–liquid microextraction coupled with high‐performance liquid chromatography

A novel microextraction method, termed microwave‐assisted ionic liquid/ionic liquid dispersive liquid–liquid microextraction, has been developed for the rapid enrichment and analysis of triazine herbicides in fruit juice samples by high‐performance liquid chromatography. Instead of using hazardous organic solvents, two kinds of ionic liquids, a hydrophobic ionic liquid (1‐hexyl‐3‐methylimidazolium hexafluorophosphate) and a hydrophilic ionic liquid (1‐butyl‐3‐methylimidazolium tetrafluoroborate), were used as the extraction solvent and dispersion agent, respectively, in this method. The extraction procedure was induced by the formation of cloudy solution, which was composed of fine drops of 1‐hexyl‐3‐methylimidazolium hexafluorophosphate dispersed entirely into sample solution with the help of 1‐butyl‐3‐methylimidazolium tetrafluoroborate. In addition, an ion‐pairing agent (NH₄PF₆) was introduced to improve recoveries of the ionic liquid phase. Several experimental parameters that might affect the extraction efficiency were investigated. Under the optimum experimental conditions, the linearity for determining the analytes was in the range of 5.00–250.00 μg/L, with the correlation coefficients of 0.9982–0.9997. The practical application of this effective and green method is demonstrated by the successful analysis of triazine herbicides in four juice samples, with satisfactory recoveries (76.7–105.7%) and relative standard deviations (lower than 6.6%). In general, this method is fast, effective, and robust to determine triazine herbicides in juice samples.     

A Novel Mechanism for the Extraction of Metals from Water to Ionic Liquids

We present a novel mechanism for the extraction of metals from aqueous phases to room-temperature ionic liquids (ILs) by use of a high-temperature salt as an extraction agent. The mechanism capitalizes on the fact that charged metal complexes are soluble in ILs; this allows for extraction of charged complexes rather than the neutral species, which are formed by conventional approaches. The use of a well-chosen extraction agent also suppresses the competing ion-exchange mechanism, thus preventing degradation of the ionic liquid. The approach permits the use of excess extractant to drive the recovery of metals in high yield. This work presents both a thermodynamic framework for understanding the approach and experimental verification of the process in a range of different ILs. The method has great potential value in the recovery of metals, water purification and nuclear materials processing.     

Screening of ionic liquids for extraction of flavonoids from heather

Room temperature ionic liquids are novel solvents with the specific properties that makes them of interest for application for extraction for a wide range of compounds. In this work extraction efficiency of flavonoids from heather flowers using ionic liquids based on imidazolium cation were evaluated and compared with organic solvents. It was found that the anion of ionic liquid significantly influence the extraction yields. Flavonoid content as well as antioxidant activity based on radical scavenging on 1,1-diphenul-2-pirylhydrazyl radicals and cupric reducing antioxidant capacity increased in the order: [Bmim]PF₆ < [Bmim]BF₄ < [Bmim]Cl. The obtained extraction yield using [Bmim]Cl were higher than reported for 60% ethanol and ethyl acetate under similar conditions, thus, may be helpful for better utilization of heather flowers as the potential pharmaceutical and nutraceutical ingredients.     

Functional amino acid ionic liquids as solvent and selector in chiral extraction

Amino acid ionic liquids (AAILs) have received great attention due to their potentials in catalysis and separations. In this work, functional AAILs were used as solvent and selector in chiral liquid–liquid extraction for the first time. The AAILs have shown distinct enantioselectivity in amino acid extraction. Using these functional AAILs as acceptor phase and ethylacetate as donor phase, more L-enantiomer of amino acid was extracted into the ionic liquid phase than that of D-enantiomer. The influencing factors, including AAILs structure, copper ion concentration, organic phase and amino acid concentration, were investigated. We found that the enantioselective enrichment of racemic amino acids was achieved through a chiral ligand-exchange mechanism. The enantioselectivity of single-step extraction was up to enantiomeric excess value of 50.6%. Moreover, the functional AAILs were found to be efficient extraction solvents for amino acids. The logarithm of distribution coefficient for L-Phe was in the range of 3.4–3.6 in the ionic liquid–ethylacetate two-phase system. This liquid–liquid extraction approach may extend the application of ionic liquids in chiral separations.     

有机-无机杂化聚离子液体材料制备及其对染料吸附性能的评价

以烯丙基三乙氧基硅烷与1-乙烯基-3-辛基咪唑溴盐离子液体为单体通过自由基聚合及溶胶-凝胶制备了有机-无机杂化聚离子液体材料。通过红外光谱和扫描电镜对所制备的杂化聚离子液体材料进行了表征,并考察了其对柠檬黄、日落黄、苋菜红以及诱惑红等常见染料的吸附性能。研究结果表明:所制备的聚离子液体材料对日落黄和诱惑红具有优异的吸附性能,其吸附容量分别为29.20和86.17 mg/g;当吸附时间为5 min时,该材料对诱惑红和日落黄的吸附分别达到平衡时吸附量的87.5%和72.8%,显示了较快的吸附速率。     

Development of ultrasound-assisted emulsification microextraction for the determination of seven pesticides in apple juice by gas chromatography–mass spectrometry

Α simple, relatively rapid, sensitive and cost-effective method based on ultrasound-assisted emulsification microextraction (USAEME) followed by gas chromatography coupled with mass spectrometry has been developed for the determination of seven endocrine disruptor pesticides (chlorpyrifos, deltamethrin, dimethoate, fenitrothion, malathion, pendimethalin and procymidone) in apple juice. This approach is based on the emulsification of organic extraction solvent in a diluted apple juice sample by ultrasound radiation and further separation of both liquids phases by centrifugation. The influence of the different parameters affecting the procedure (extraction solvent, extraction solvent volume, ultrasound time, centrifugation time, ionic strength and pH) was evaluated in order to optimise the efficiency of the extraction process. Target analytes were extracted from a 0.5 g apple juice sample that was diluted by 10 times with aqueous buffer solution (pH 7). The optimised USAEME procedure used 100 μL of chloroform as extraction solvent, 8 min of ultrasound extraction, ionic strength (2.5% w/v) and 7.5 min of centrifugation at 3800 rpm. The optimised method presented recoveries between 70 and 113% for the target analytes. Acceptable linearity for all target analytes was recorded with correlation coefficients (r) higher than 0.992. The limits of quantification were found between 1.1 and 4.6 μg kg^?1 ensuring compliance with the maximum residue limits established by the European Commission. The proposed method was applied for the determination of the endocrine disruptor pesticides in apple samples proving its suitability to the Commission Implementing Regulation (EU) no. 400/2014.     

Thermodynamic studies of partitioning behavior of cytochrome c in ionic liquid-based aqueous two-phase system

The ionic liquid/aqueous two-phase extraction systems (ATPSs) based on imidazolium ionic liquids were used to extract cytochrome c. Effects of the alkyl chain length of the ionic liquid cations, concentration of potassium citrate, temperature and pH on the extraction efficiency have been investigated. The thermodynamic parameters (ΔG(T)°, ΔH(T)° and ΔS(T)°) associated with Cyt-c partitioning in aqueous two phase systems were determined. Thermodynamic studies indicated that the partitioning of Cyt-c was driven by both hydrophobic and electrostatic interactions in the extraction process. Under the optimum conditions, experiment results showed that 94% of the cytochrome c could be extracted into the ionic liquid-rich phase in a one-step extraction. The structural characterization of Cyt-c in the IL ATPS was investigated by UV-vis and circular dichroism (CD) spectra. The results demonstrated that no direct bonding interaction observed between ionic liquid and cytochrome c, while the native properties of the cytochrome c were not altered. Compared with traditional liquid-liquid extractions based on toxic organic solvents, ionic liquid/aqueous two phase extraction offers clear advantages due to no use of volatile organic solvent and low consumption of imidazolium ionic liquids.     

Determination of sudan dyes in red wine and fruit juice using ionic liquid-based liquid-liquid microextraction and high-performance liquid chromatography

The liquid-liquid microextraction (LLME) was developed for extracting sudan dyes from red wine and fruit juice. Room temperature ionic liquid was used as the extraction solvent. The target analytes were determined by high-performance liquid chromatography. The extraction parameters were optimized. The optimal conditions are as follows: volume of [C(6)MIM][PF(6)] 50 μL; the extraction time 10 min; pH value of the sample solution 7.0; NaCl concentration in sample solution 5%. The extraction recoveries for the analytes in red wine and fruit samples are 86.79-108.28 and 68.54-85.66%, whereas RSDs are 1.42-5.12 and 1.43-6.19%, respectively. The limits of detection and quantification were 0.428 and 1.426 ng/mL for sudan I, 0.938 and 3.127 ng/mL for sudan II, 1.334 and 4.445 ng/mL for sudan III, 1.454 and 4.846 ng/mL for sudan IV, respectively. Compared with conventional liquid-liquid extraction (CLLE) and ultrasonic extraction (UE), when LLME was applied, the sample amount was less (LLME: 4 mL; CLLE: 10 mL; UE: 10 mL), the extraction time was shorter (LLME: 15 min; CLLE: 110 min; UE: 50 min) and the extraction solvent amount was less (LLME: 0.05 mL IL; CLLE: 15 mL hexane; UE: 20 mL hexane). The proposed method offers a simple, rapid and efficient sample preparation for determining sudan dyes in red wine and fruit juice samples.