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Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The content of ethyl lactate in baijiu is difficult to control owing to its high dependent on the brewing process. However, high levels of ethyl lactate can negatively affect the flavor of Baijiu and the after-effects of consumption. Therefore, analyzing the production mechanism of ethyl lactate and ensuring its appropriate concentration in different flavored baijiu holds significant guiding implications for both the production of distilleries and the healthy consumption of consumers. This article elaborates on the mechanism of ethyl lactate production from lactic acid and ethanol through esterification and chemical reactions in Baijiu, summarizes its effects on aroma production and taste enrichment, and sets standards for ethyl lactate content in different flavored Baijiu. Furthermore, this review discusses the measures utilized to control the content of ethyl lactate in Baijiu production, including raw materials, Jiuqu, lactic acid-degrading bacteria, microbial interactions, sealing methods, distillation equipment, distillation pressure, sequence, and aging process. It also analyzes the effects of lactate reduction measures on the quality, taste, and yield of baijiu, as well as the practical application of these measures in some Baijiu enterprises. The study proposes that future exploration and optimization of more efficient and environmentally friendly techniques of lactate reduction should focus on biotechnology, including genetic and metabolic engineering to provide reference for the further application of lactate reduction techniques in Baijiu brewing.

In the current trend of industrial manufacturing processes, an interest in utilization of industrial and agricultural wastes for producing green chemistry, eco-friendly product, has been increased. Therefore, this study aimed to produce ethyl lactate using solid-acid catalyst WO3/zeolite-A via esterification. Various analytical techniques, including XRF, BET, XPS, FTIR, NH3-IR, NH3-TPD, SEM-EDX, ICP-OES, XRD, TGA-DTA, and TEM, were employed to analyze the physical and chemical properties of zeolite-A and tungsten-supported on zeolite-A. The results revealed that after five reuse cycles, the lactic acid conversion rates were 20.1 % and 10.3 % for WO3/zeolite-A and Amberlyst-15, respectively. The spent WO3/zeolite-A exhibited a reduction in surface acid site, declining from 1,591.8 μmol/g in the first run to 690.1 μmol/g in the fifth run. The decline in efficiency was attributed to impurities blocking of active sites, structural alterations, and partial leaching of active species. XRD and FTIR analyses confirmed decreased crystallinity and structural changes in spent catalysts. TEM, SEM-EDS, and ICP-OES analyses showed the loss of active tungsten species and the deposition of reaction intermediates leading to a decrease in ethyl lactate yield (decreased from ca. 44 to 20 %). Despite structural changes affecting catalytic performance, WO3/zeolite-A demonstrated a good promising catalyst for ethyl lactate production over five successive cycles (with ca. 50 % decrease).

The application of a binary amphiphile/solvent blend composed of a natural surfactant (alkyl polyglucoside) and the green solvent ethyl lactate (EL) as an active component in the formulation of a new ecological detergent has improved the washing process conditions. Foaming properties of the detergent were optimal, with foam stability (R5) values of 76.17% and 78.61% for the best formulations. It is common practice to add substances that can regulate the pH to 9 to enhance the washing efficiency. This was reflected in the results of this study, where pH and the interaction between pH and surfactant type significantly influenced the percentage of residual fat. Currently, commercial detergents recommend a 1% dilution. However, studies have evaluated a 0.5% dilution. Therefore, it opted to evaluate new concentrations of 0.4% and 0.3%. Optimization of the factorial design resulted in dirt removal rates exceeding 91%, while the lowest percentage of residual fat (< 0.37%) was achieved at 25 °C, pH 9, and 0.3% detergent doses without lipase. Furthermore, illustrations of the surface morphology of the washed fibers demonstrated that the samples were not adversely affected by the formulated detergent or the washing process conditions. The alkyl polyglucoside/ethyl lactate binary blend was shown for the first time to exhibit strong interactions, possessing excellent residual fat and soil removal properties, suggesting its potential use in the formulation of green detergents for washing natural and synthetic textile fibers as a replacement for detergents based on ethoxylated fatty alcohols. [ABSTRACT FROM AUTHOR]

Ethyl lactate is the most abundant ester in semi-solid rice baijiu fermentation, affecting the flavor of baijiu to a great extent. The present study aimed to investigate the spatial distribution and formation contributor of ethyl lactate by removing the microorganisms and extracellular enzymes from the upper, middle, and lower fermentation broth during the later fermentation stage. The removal of suspended substances by centrifugation did not affect the ethyl lactate content in the top and middle fermentation broth containing free cells, enzymes, and starch particles. After day 5 of fermentation, only the lower fermentation broth containing granular cells attached to the starch could continue to accumulate lactic acid, thereby increasing the ethyl lactate content. The results showed that the chemical reactions were the main contributor to the increased ethyl lactate content at the anaphase of fermentation rather than enzymatic catalysis or microbial metabolism. Sequencing of granular cells revealed the main lactic acid producers at different fermentation stages. Lactobacillus helveticus showed the highest abundance of 94.45–95.40% on day 5, which decreased to 29.58–30.20% on day 15, while Lactobacillus acetotolerans showed the highest abundance of 47.93–49.72% at day 15. Additionally, the granular cells were recovered and used for supplementary inoculation in the next batch, which significantly increased the ethyl lactate content. This study provided a novel strategy for improving the ethyl lactate content in semi-solid baijiu fermentation. [Display omitted] • Esterification of cells and enzymes was studied in baijiu fermentation anaphase. • Ethyl lactate was mainly formed by chemical rather than biological reaction. • Lactic acid was mainly produced by granular cells attached to starch on the bottom. • Lactobacillus helveticus and L. acetotolerans were the major lactic acid producers. • Adding recovered granular cells in anaphase could much increase ethyl lactate. [ABSTRACT FROM AUTHOR]

Alternative solvents are being tested as green solvents to replace the traditional organic solvents used in both academy and industry. Some of these are already available, such as ethyl lactate, cyrene, limonene, glycerol, and others. This alternative explores eco-friendly processes for extracting secondary metabolites from nature, thus increasing the number of unconventional extraction methods with lower environmental impact over conventional methods. In this context, the Peruvian Ambrosia arborescens was our model while exploring a microwave-assisted extraction (MAE) approach over maceration. The objective of this study was to perform a phytochemical study including UHPLC-ESI-MS/MS and the antioxidant activity of Ambrosia arborescens, using sustainable strategies by mixing both microwaves and ethyl lactate as a green solvent. The results showed that ethyl lactate/MAE (15.07%) achieved a higher extraction yield than methanol/maceration (12.6%). In the case of the isolation of psilostachyin, it was similar to ethyl lactate (0.44%) when compared to methanol (0.40%). Regarding UHPLC-ESI-MS/MS studies, the results were similar. Twenty-eight compounds were identified in the ethyl lactate/MAE and methanol/maceration extracts, except for the tentative identification of two additional amino acids (peaks 4 and 6) in the MeOH extract. In relation to the antioxidant assay, the activity of the ethyl lactate extract was a little higher than the methanol extract in terms of ORAC (715.38 ± 3.2) and DPPH (263.04 ± 2.8). This study on A. arborescens demonstrated that the unconventional techniques, such as MAE related to ethyl lactate, could replace maceration/MeOH for the extraction and isolation of metabolites from diverse sources. This finding showed the potential of unconventional methods with green solvents to provide eco-friendly methods based on green chemistry. [ABSTRACT FROM AUTHOR]

The development of effective and stable non‐precious catalysts for hydrogenation of ester to diols remains a challenge. Herein, the catalytic hydrogenation of ethyl lactate (EL) to 1,2‐propanediol (1,2‐PDO) with supported Co catalysts derived from layered double hydroxides (LDHs) is investigated. Catalytic tests reveal that LDH‐derived Co catalysts exhibit the best catalytic performance with 98 % of EL conversion and >99 % of 1,2‐PDO selectivity at mild conditions, compared with other Co catalysts (supported on Al2O3, and TiO2) and LDH‐derived Cu catalysts. Due to the strong interaction among Co and Al matrix, the main composition is metallic Co0 and CoO after reduction at 600 °C. Besides, the catalyst shows good recyclability in the liquid phase hydrogenation. The superior catalytic performance can be attributed to the synergistic effect between Co0 and CoO, in which H2 molecule is activated on Co0 and EL is strongly adsorbed on CoO via hydroxyl groups. [ABSTRACT FROM AUTHOR]

Copyright of China Surfactant Detergent & Cosmetics (2097-2806) is the property of China Surfactant Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ethyl lactate was produced with corn stover as a carbon source by a cascade bioprocess without adding any enzymes. Immobilized Aspergillus niger and Saccharomyces cerevisiae was co-cultivated in a modified gas lift bioreactor. Cellulase from Aspergillus niger was 8.05 U/mL in the gas lift bioreactor. The fermentation broth was transferred into an anaerobic fermenter, in which the immobilized Saccharomyces cerevisiae and Lactobacillus rhamnosus was cultivated. The maximum esterase activities were over 5005 U/mL and the ethyl lactate yield was over 8.76 g/L during five repeated batches. Without adding any cellulase and esterase, ethyl lactate production was achieved during five repeated batches by the cascade of the aerobic process and the anaerobic process with the lignocellulose as a carbon source. [ABSTRACT FROM AUTHOR]

Carotenoids are ubiquitous and versatile isoprenoid compounds. The intake of foods rich in these pigments is often associated with health benefits, attributable to the provitamin A activity of some of them and different mechanisms. The importance of carotenoids and their derivatives for the production of foods and health-promotion through the diet is beyond doubt. In the new circular economy paradigm, the recovery of carotenoids in the biorefinery process is highly desirable, for which greener processes and solvents are being advocated for, considering the many studies being conducted at the laboratory scale. This review summarizes information on different extraction technologies (ultrasound, microwaves, pulsed electric fields, pressurized liquid extraction, sub- and supercritical fluid extraction, and enzyme-assisted extraction) and green solvents (ethyl lactate, 2-methyltetrahydrofuran, natural deep eutectic solvents, and ionic liquids), which are potential substitutes for more toxic and less environmentally friendly solvents. Additionally, it discusses the results of the latest studies on the sustainable green extraction of carotenoids. The conclusions drawn from the review indicate that while laboratory results are often promising, the scalability to real industrial scenarios poses a significant challenge. Furthermore, incorporating life cycle assessment analyses is crucial for a comprehensive evaluation of the sustainability of innovative extraction processes compared to industry-standard methods. [ABSTRACT FROM AUTHOR]

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Alternative solvents are being tested as green solvents to replace the traditional organic solvents used in both academy and industry. Some of these are already available, such as ethyl lactate, cyrene, limonene, glycerol, and others. This alternative explores eco-friendly processes for extracting secondary metabolites from nature, thus increasing the number of unconventional extraction methods with lower environmental impact over conventional methods. In this context, the Peruvian Ambrosia arborescens was our model while exploring a microwave-assisted extraction (MAE) approach over maceration. The objective of this study was to perform a phytochemical study including UHPLC-ESI-MS/MS and the antioxidant activity of Ambrosia arborescens, using sustainable strategies by mixing both microwaves and ethyl lactate as a green solvent. The results showed that ethyl lactate/MAE (15.07%) achieved a higher extraction yield than methanol/maceration (12.6%). In the case of the isolation of psilostachyin, it was similar to ethyl lactate (0.44%) when compared to methanol (0.40%). Regarding UHPLC-ESI-MS/MS studies, the results were similar. Twenty-eight compounds were identified in the ethyl lactate/MAE and methanol/maceration extracts, except for the tentative identification of two additional amino acids (peaks 4 and 6) in the MeOH extract. In relation to the antioxidant assay, the activity of the ethyl lactate extract was a little higher than the methanol extract in terms of ORAC (715.38 ± 3.2) and DPPH (263.04 ± 2.8). This study on A. arborescens demonstrated that the unconventional techniques, such as MAE related to ethyl lactate, could replace maceration/MeOH for the extraction and isolation of metabolites from diverse sources. This finding showed the potential of unconventional methods with green solvents to provide eco-friendly methods based on green chemistry.

Commercial koji has been increasingly used in Chinese Baijiu brewing; however, there are only few studies comparing different koji and their relationship with key components of Chinese Baijiu such as ethyl acetate, ethyl lactate, and higher alcohols. Here, we studied six commercially available koji and showed that the microbial communities in the individual koji varied in composition, with Rhizopus, Aspergillus, and Bacillus primarily associated with starch hydrolysis and Saccharomyces mainly associated with alcohol production. In the brewing processes using the six koji, Saccharomyces was undoubtedly the most abundant fungus and Weissella, Bacillus, and Acinetobacter were the predominant bacterial groups. The levels of ethyl acetate, ethyl lactate, and higher alcohols in all brewing processes using the koji exhibited rapid increase in the early stages of fermentation, which stabilized in the later stages, followed by substantial increase after distillation. The results of metagenomic and redundancy analyses of samples taken during the brewing processes indicated that Saccharomyces from the koji was closely related to the production of ethyl acetate, ethyl lactate, and higher alcohols. This study provides a basis for the quality improvement and application of commercial koji.

Carotenoids are ubiquitous and versatile isoprenoid compounds. The intake of foods rich in these pigments is often associated with health benefits, attributable to the provitamin A activity of some of them and different mechanisms. The importance of carotenoids and their derivatives for the production of foods and health-promotion through the diet is beyond doubt. In the new circular economy paradigm, the recovery of carotenoids in the biorefinery process is highly desirable, for which greener processes and solvents are being advocated for, considering the many studies being conducted at the laboratory scale. This review summarizes information on different extraction technologies (ultrasound, microwaves, pulsed electric fields, pressurized liquid extraction, sub- and supercritical fluid extraction, and enzyme-assisted extraction) and green solvents (ethyl lactate, 2-methyltetrahydrofuran, natural deep eutectic solvents, and ionic liquids), which are potential substitutes for more toxic and less environmentally friendly solvents. Additionally, it discusses the results of the latest studies on the sustainable green extraction of carotenoids. The conclusions drawn from the review indicate that while laboratory results are often promising, the scalability to real industrial scenarios poses a significant challenge. Furthermore, incorporating life cycle assessment analyses is crucial for a comprehensive evaluation of the sustainability of innovative extraction processes compared to industry-standard methods.

Food supplements based on antioxidants and vitamins are often prescribed to correct inefficiencies in the human diet and delay diseases such as premature aging and alopecia (temporary or permanent hair loss), given the free radical scavenging activity of these biomolecules. By reducing the concentration of reactive oxygen species (ROS), which promote abnormal hair follicle cycling and morphology, follicle inflammation and oxidative stress are reduced, minimising the effects of these health issues. Gallic acid (GA), which is significantly present in gallnuts and in pomegranate root bark, and ferulic acid (FA), commonly found in brown rice and coffee seeds, are very important antioxidants for the preservation of hair colour, strength and growth. In this work, these two secondary phenolic metabolites were successfully extracted in the Aqueous Two-Phase Systems (ATPS) {ethyl lactate (1) + trisodium citrate (2) + water (3)} and {ethyl lactate (1) + tripotassium citrate (2) + water (3)} at 298.15 K and 0.1 MPa, moving towards the application of these ternary systems in extracting antioxidants from biowaste and their a posteriori processing as food supplements for hair fortification. The studied ATPS provided biocompatible and sustainable media for the extraction of gallic acid and ferulic acid, yielding low mass losses (<3%) and contributing to an eco-friendlier production of therapeutics. The most promising results were obtained for ferulic acid, which attained maximum partition coefficients (K) of 15 ± 5 and (3 ± 2) · 101 and maximum extraction efficiencies (E) of (92.7 ± 0.4)% and (96.7 ± 0.4)% for the longest tie-lines (TLL = 69.68 and 77.66 m%) in {ethyl lactate (1) + trisodium citrate (2) + water (3)} and {ethyl lactate (1) + tripotassium citrate (2) + water (3)}, respectively. Moreover, the effect of pH on the UV-Vis absorbance spectra was studied for all the biomolecules to minimise errors in solute quantification. Both GA and FA were found to be stable at the used extractive conditions. [ABSTRACT FROM AUTHOR]

Accurate temperature tracking for fast heating/cooling and regulation during the batch pretreatment of lignocellulosic biomass (LCB) is required to guarantee high product yield and quality repeatability. However, yield discrepancies are frequently found in the pretreatment literature in which temperature trajectory or heating sources details are seldom reported. Innacurate temperature control may be one of the reasons for these discrepancies. This paper proposes a tracking-regulation-tracking temperature control system for batch pretreatments of LCB heated by an electrical jacket heater. The accuracy of the control system in tracking the temperature set-point trajectory is measured with the weighted integral of the absolute error IAE ¯ . The controlled process performance was measured with the percentage difference between the experimental lignin recovery percentage and the value calculated with a steady-state mathematical model using the average temperature of the isothermal reaction period. The system was tested in an ethyl lactate-based 190 ∘ C, 1 L batch organosolv pretreatment with a maximum heating rate of 8.6 ∘ C/min and a mean cooling rate of -2.4 ∘ C/min. The process performance was 2.8% for an IAE ¯ of 1044 ∘ C/min thus confirming the efficacy of the proposed control system. [ABSTRACT FROM AUTHOR]

Spark ignition engines are one of the main technologies in the transport sector. The improvement and optimization of the fuels used to empower these engines are of vital importance, both for economic and environmental reasons. In particular, one of the main issues of spark ignition engines is the knock phenomenon; new formulations of fuels are being studied in order to overcome this problem. In this study, a possible innovative anti-knock, octane booster additive is considered: ethyl lactate. This molecule is almost unknown in combustion literature, as it has been used only as green solvent and food additive. The first experimental results under combustion conditions are presented, together with a kinetic mechanism. Two set-ups have been employed: a rapid compression machine, to measure ignition delay times, and an innovative spherical bomb, OPTIPRIME, to obtain laminar flame speeds. The results are encouraging for the expected application and the mechanism shows good performance. Ignition delay times at all conditions are well predicted by the mechanism and, when compared to ethanol, they are longer, implying a greater anti-knock capability. A rate of production analysis has been performed, where the unimolecular reaction leading to ethylene and lactic acid has been proved to be quite important at high temperatures and lean conditions. For laminar flame speeds, the agreement between model and experiments is good, with some discrepancies at lean conditions and high pressures. Compared to ethanol, at rich and stoichiometric conditions ethyl lactate flame speeds are slightly slower except at lean conditions, indicating that under some conditions this molecule could provide better performances than ethanol as an octane booster additive. [ABSTRACT FROM AUTHOR]

Designing and synthesizing bio-based catalysts for the catalytic conversion of biomass to high-value chemicals is a green and promising route in the field of sustainable chemistry. Herein, V x O y /NC_ P catalyst was synthesized by a simple impregnation-pyrolysis method using green and cheap bio-chitin or chitosan as the N-doped carbon (NC) precursor and was applied to the aerobic oxidation of ethyl lactate (EL) to ethyl pyruvate (EP). These catalysts were characterized by XRD, N 2 adsorption-desorption, SEM, TEM, XPS, and H 2 -TPR. When chitin was used as the NC precursor (V x O y /NC_chitin), the catalyst activity was significantly higher than that of chitosan as the NC precursor (V x O y /NC_chitosan). Correlation between catalytic performance and characterization results showed that the high surface area, abundant pyridinic-N, and low valence vanadium species (V3+ and V4+) played an important role in catalyst activity. A 97.3 % EL conversion with 97.8 % EP selectivity was obtained over V x O y /NC_chitin at 120 °C for 2 h, and no significant deactivation after five cycles. Moreover, this catalyst also showed a high activity in the selective oxidation of other alcohols to their corresponding aldehydes. [Display omitted] • V x O y /NC_ P (P denotes NC precursor) catalysts were prepared by a convenient impregnation-pyrolysis method. • The highest activity was achieved when chitin was used as the NC precursor. • A 97.8 % EP selectivity with 97.3 % EL conversion was obtained over V x O y /NC_chitin catalyst. • The presence of abundant pyridine-type N and low valence vanadium species was the key to high catalytic performance. [ABSTRACT FROM AUTHOR]

Superlubricity between steel/diamond-like carbon (DLC) film could be achieved at vacuum or nitrogen condition, but it would be failed at ambient conditions. In this work, the macroscale superlubricity was achieved at ambient conditions by introducing ethyl lactate into ethylene glycol as lubricant additive for the friction pairs of silicon-doped diamond-like carbon (Si-DLC)/steel. Stable friction coefficient (μ = 0.002) and wear rate of friction pairs with the introduction of ethyl lactate could be respectively reduced by 99 % and 35 %. The characterization tests and density functional theory (DFT) calculation both demonstrated that the partial ethyl lactate was hydrolyzed into lactic acid due to the catalysis effect of steel surfaces. The molecular dynamics (MD) simulation result showed that the lactic acid molecules could be chemically adsorbed on the surfaces of friction pairs, forming a tribofilm through hydrogen bond with ethylene glycol molecules, which led to a significant reduction in the friction coefficient. This work presents a novel approach to achieve superlubricity on Si-DLC film with liquid, providing a great support for industrial application of superlubricity on DLC film. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The temperature factors, and the ethyl lactate (EL) addition significantly influence the results for. V ϕ °. • Benzethonium chloride molecules exhibit spontaneous aggregation at the interface of polar-nonpolar systems. • A Bayesian two-factor approach with uninformative priors helped to rigorously stablish the existence of significant differences in the acoustic and volumetric parameters. Surface active agents (SAAs) are versatile molecules that possess the ability to serve as multifunctional ingredients in a wide range of consumer products across various industrial sectors. These molecules can act as wetting and dispersion agents, emulsifiers, foaming and anti-foaming agents, lubricants, and more. The objective of this study was to evaluate the effect of temperature, and ethyl lactate concentration on micelle formation in systems containing benzethonium chloride (BC) and N-lauroyl sarcosine sodium salt (NLSS). The experimental measurements were conducted at three equidistant temperatures i.e., 298.15 K to 318.15 K and pressure, P=0.1 MPa. Several volumetric as well as compressibility parameters including apparent molar properties (V ϕ , K ϕ , S ), partial molar properties (V ϕ ° , K ϕ , S °), transport properties (Δ tr V ϕ ° , Δ tr K ϕ , S °) , hydration number, etc. have been evaluated. A Bayesian two-factor design with uninformative priors was used to analyze the values of V ϕ ° , and K ϕ , S °. It was possible to determine that the temperature factors, and the ethyl lactate (EL) addition significantly influence the results for V ϕ ° while for K ϕ , S ° it is not appreciable at 5 and 10 % in EL concentration when BC and NLSS systems is compared. The simulations of the micellization process show the impact of temperature, particularly in the presence of ethyl lactate, is evident in the structural and dynamic changes observed in the micelles. Specifically, as the temperature rises from 298.15 K to 318.15 K, the self-assembly process becomes more spontaneous and accelerated, leading to larger and more spherical micelles. These alterations in micelle size, shape, and orientation enhance their capacity to effectively solubilize hydrophobic substances. The computational simulations demonstrated that BC molecules exhibit spontaneous aggregation at the interface of polar-nonpolar systems, resulting in the formation of a monolayer. In this monolayer, the heads of the molecules are oriented towards the polar phase, while the hydrophobic tails are in the nonpolar phase. Similarly, the NLSS system exhibits a continuous and gradual process of self-organization over a period of 120 ns, where NLSS molecules naturally come together to create a single layer arrangement at the zigzag-shaped boundary. [ABSTRACT FROM AUTHOR]

The growing human population, together with the inefficient use of natural resources, has been dramatically increasing the production of food waste, which poses serious economic, environmental, and social problems. Being so, it is necessary to increase the efficiency of food consumption so as to reduce its waste and to convert the remaining residues into societal benefits. Since this biowaste is rich in polyphenols and vitamins, it could become the feedstock for the production of important value-added compounds for the pharmaceutical (e.g., food supplements) and cosmetic (e.g., creams and shampoos) industries. In this work, partition studies of one polyphenol (epicatechin) and two B-complex vitamins (cyanocobalamin and nicotinic acid) were performed in biodegradable Aqueous Two-Phase Systems (ATPS) based on ethyl lactate and on organic salts (disodium tartrate, tripotassium citrate, and trisodium citrate) at 298.15 K and 0.1 MPa. The largest partition coefficient (K) and extraction efficiency (E) were obtained for vitamin B12 ( K = 78.56 , E = 97.5 % ) for the longest tie line TLL = 77.66 % in the ATPS {ethyl lactate (1) + tripotassium citrate (2) + water (3)}. All the extractions were obtained with low biomolecule mass losses in quantification (<5%) and after a thorough study of pH influence in the UV–Vis absorbance spectra. [ABSTRACT FROM AUTHOR]

Salvia rosmarinus (Lamiaceae), previously known as Rosmarinus officinalis, is a plant cultivated worldwide, native to the Mediterranean region. Its leaves are traditionally used for cooking. This species possesses numerous biological activities, including antioxidant, antimicrobial, anticancer, anti-inflammatory, and hepatoprotective properties. These biological properties are due to the presence of phenolic compounds, including rosmarinic acid and phenolic diterpenoids, such as carnosic acid and carnosol. In this study, we investigated the chemical composition of a green extract obtained by maceration with ethyl lactate for the first time. Seventy-five compounds were tentatively identified by UHPLC–ESI–MS/MS, including six organic acids, six cinnamic acid derivatives, five fatty acids, eighteen flavonoids, and thirty-eight terpenoids. Thus, abietane-type diterpenoids from the ethyl lactate extract were the predominant diterpenoids in the Chilean S. rosmarinus species, in contrast to the Chinese species, in which labdane and isopimarane-type diterpenoids were found for the first time. Finally, our study confirms that the extraction of S. rosmarinus with green ethyl lactate as a solvent is efficient and sustainable for the identification of flavonoids, phenols, and terpenoids from leaves. [ABSTRACT FROM AUTHOR]

A scalable procedure with minimum energy requirements, MSAT (Medium Scale Ambient Temperature), in combination with solvents generally recognized as safe (GRAS), has been optimized to obtain polyphenolic extracts from white grape (Vitis vinifera) marc. The solvents considered were propylene glycol (Pg), ethanol (Et), and ethyl lactate (Lc), as well as their respective hydro-organic mixtures. In a first approach, the operating parameters were optimized through a response surface matrix: extraction solvent volume (range 10–150 mL), marc mass (range 20–200 g) and marc/dispersant mass ratio (range 0.5–2 g⋅g–1), using the total polyphenol content (TPC) and the antioxidant activity (AA) of the extracts as response parameters. The highest TPC (5,918 mgGAE⋅L–1) and AA (44 mmolTE⋅L–1) values were obtained using 200 g marc and 100 mL solvent. Regarding the type of solvent, a better response was reached with Lc > Et > Pg > H2O obtaining a polyphenol concentration of 252 mg⋅L–1 for the hydro-organic isovolumetric ratio of ethyl lactate. In addition, the stability of the extracts was studied for 62 days. The effect of factors such as temperature, light exposure, and oxidative reactivity was evaluated. The bioactivity indices showed no changes with the storage conditions of the extracts in the first month of analysis, after which 75% of the antioxidant activity as the concentration of the polyphenolic profile (204 mg⋅L–1) remains. The absence of reactive oxygen and the cooling of the extract (4°C) were the most determining factors (p < 0.05) in modulating the stability of the total polyphenolic profile.

[Display omitted] • A novel coordination compound (VTC) with well-defined crystalline framework has been designed and synthesized. • A sustainable protocol for the liquid-phase selective aerobic oxidation of ethyl lactate has explored with the as-synthesized complex. • Homogeneous and heterogeneous selective oxidation of ethyl lactate can be regulated by VTC. • The cleavage of weak C-Cl bond in VTC exposes the more V-based active sites. As a green and sustainable alternative for producing ethyl pyruvate (EP), the selective aerobic oxidation of ethyl lactate (EL) is still facing issues such as low catalytic efficiency, harsh reaction conditions and catalyst instability. Herein, a novel crystalline vanadium-based coordination compound (VTC=VPTPYCl 2 (H 2 O), PTPY = 4′-phenyl-2,2′:6′,2′'-terpyridine) has been designed and synthesized. A highly efficient homogeneous catalytic system (VTC-400-O 2 -CH 3 CN, 400 represents the activation temperature) and a recyclable heterogeneous system (VTC-500-O 2 -CH 3 CN) for the liquid-phase conversion of EL to EP are developed using molecular oxygen as oxidant through activating VTC at different temperature. In VTC-400-O 2 -CH 3 CN system, EL can be completely converted within 4 h, and the yield of EP is 77.8 %, which outperforms the state-of-art reported catalytic system. Meanwhile, the heterogeneous VTC-500 catalyst can also promote the full conversion of EL within 4 h, and its activity remains basically unchanged after being used for 10 times. Structural characterization reveals that the soluble VTC breaks the weak coordination V-Cl bonds at a lower activation temperature of 400 ° C to expose more vanadium-based catalytic sites, but the framework of ligand remains intact. However, the organic derived carbon skeleton at higher temperature of 500 ° C can effectively confine the V-based active species and prevent the dissolution of the catalyst, which impels the transition of the homogeneous to heterogeneous catalytic system. [ABSTRACT FROM AUTHOR]

Incorporating fillers into the polymer matrix and coating it with a hydrophobic polymer can enhance the properties of biodegradable starch-based materials, aiming to replace conventional fuel-based plastics. This study assesses the impact of both polymer coating and solvent type on the physical, chemical, morphological, and mechanical properties of cassava starch-rice husk ash foams. The designed foams were coated with four different polymer solutions using the conventional solvent, chloroform, and the sustainable alternative solvent, ethyl lactate, through a dip coating method: poly(lactic acid) in chloroform (PLA C), poly(lactic acid) in ethyl lactate (PLA-L), poly(butylene adipate- co -terephthalate) in chloroform (PBAT-C), and poly(butylene adipate-co-terephthalate) in ethyl lactate (PBAT-L). Results indicate that the morphology, chemical structure, density, and thickness of the foams were not significantly affected by the polymer coating. However, all coatings improved water resistance, with PLA-C providing the most expressive reduction (90 %) compared to the uncoated foam. In terms of mechanical properties, both PLA-C and PBAT-C coatings increased the maximum rupture stress by 36 % and 20 %, respectively, and Young's modulus by 45 % and 40 %, respectively, compared to the uncoated foams. Based on the findings presented in this work, PLA-chloroform was identified as the most effective polymer-solvent pairing to achieve robust barrier properties in the biodegradable composite material based on cassava starch and rice husk ashes. Additionally, the PLA-L results suggest that the environmentally friendly solvent, ethyl lactate, could replace chloroform while still enhancing the mechanical properties and water resistance of the biodegradable starch-ash foams. • Polymer coatings can effectively enhance the water resistance of starch-based foams. • PLA is better than PBAT to improve mechanical resistance of starch-based foams. • The solvent impacts the properties of coated foams using dip coating method. • Ethyl lactate can replace chloroform in PLA and PBAT dissolution. • High temperature changes the characteristics of starch-based foams. [ABSTRACT FROM AUTHOR]

Under the direction of triethylamine and diisopropylamine, the VAPO molecular sieves with two topological configurations were synthesized and used as catalysts for the oxidation of ethyl lactate to ethyl pyruvate. [Display omitted] The presence of the template agent within the pore or cage during the synthesis process of the molecular sieve plays a crucial role in the formation of its porous structure. Using triethylamine and diisopropylamine as structure-guiding agents, VAPO molecular sieve with AFI and AEL topologies were synthesized by hydrothermal method. The physical and chemical properties of hierarchical VAPO-5 and VAPO-11 molecular sieves were characterized by XRD, SEM, N 2 -adsorption desorption, UV–Vis, XPS, NH 3 -TPD and Py-IR, etc. It was verified that V isomorphically displaced the P-site of the molecular sieve in pentavalent form, and more acid sites were obtained on the surface of VAPO-5 molecular sieve. This is closely related to the performance of the catalytic oxidation of ethyl lactate to ethyl pyruvate. The activity evaluation showed that the VAPO-5 molecular sieve outperformed the VAPO-11 molecular sieve in terms of catalytic performance. The theoretical study on the reaction mechanism showed that the rate-determining step energy barriers of the catalytic oxidation of EL to EP were 118.7 kJ/mol and 150.18 kJ/mol, respectively. They were consistent with the apparent activation energies of 98.92 kJ/mol and 119.24 kJ/mol obtained by kinetic experiments. The conjecture of the reaction mechanism was confirmed in which the VAPO molecular sieve adsorbs H 2 O 2 molecules and produces surface reactive oxygen species, thus promoting the catalytic oxidation of EL to EP. [ABSTRACT FROM AUTHOR]

• Highly selective synthesis of ethyl pyruvate was realized in liquid-phase. • The conversion of ethyl lactate to ethyl pyruvate using O2 as oxidant was realized under 90 oC temperature. • The yield of ethyl pyruvate reached up to 92.6 % when ethyl lactate was fully converted. • The optimized SBA-15/Zn(10)/Ni(15) catalyst owned high surface area (630.01 m2 g −1) and enhanced charge separation efficiency. • SBA-15/Zn(10)/Ni(15) serves as recyclable heterogeneous catalyst without compromising the activity. The solid-state catalyst-mediated oxidation of alkyl lactate produced from biomass to alkyl pyruvate is an intriguing approach to manufacture valuable resources compounds. In this study, several types of SBA-15/Zn/Ni catalysts containing different nickel loadings have been developed and used in a molecular oxygen environment to oxidize ethyl lactate (EL) compound to ethyl pyruvate (EP). The aforementioned catalyst was comprehensively characterised by employing XRD, ICP, FTIR, N 2 physisorption, NH 3 -TPD, HR-SEM and HR-TEM. As more of nickel was loaded onto the Ni/Zn/SBA-15 catalyst, the EL conversion improved, but the selectivity of EP consistently exceeded greater than 95 %, regardless of the 15 % nickel loading. Assuming maximum conditions for the reaction (90 °C, 2 h in O 2) over the Ni/Zn/SBA-15 catalyst, the selectivity of 99.5 % for EP and a conversion of 97.7 % for EL were achieved. A selectivity of 99.5 % for EP and a conversion of 97.7 % for EL were achieved. The catalytic combination of SBA-15 and Zn/Ni exhibited a significant reducing capacity due to the significant connection between both of them, as demonstrated by the NH 3 -TPD data. [Display omitted] [ABSTRACT FROM AUTHOR]

Ferulic (FA) and gallic (GA) acids stand as crucial antioxidants in the cosmetics, food and pharmaceutical industries, playing a key role in the prevention of diabetes, cancer and cardiovascular diseases. The extraction of these antioxidants from by-products of the food industry, such as sweet corn residues, contributes to a more circular economy, reducing the environmental footprint associated with their extraction processes. In this work, these phenolic compounds were successfully extracted in the Aqueous Two-Phase Systems (ATPSs) {Ethyl lactate (1) + Potassium Sodium Tartrate or Disodium Succinate (2) + Water (3)} at 298.2 K and 0.1 MPa. In general, the ATPSs achieved partition coefficients (K) larger than unity, indicating a preference towards the top phase (ethyl lactate-rich), hinting a successful extraction of the phenolic compounds. Moreover, larger tie-lines generally led to higher partition coefficients and extraction efficiencies (E), promoting solute migration to the top phase. The most promising results referred to the partition of ferulic acid in Potassium Sodium Tartrate, with K = 12 ± 3 and E = 93.3 ± 0.4 % for the longest tie-line (TLL = 70.73 % in mass). Finally, tie-line compositions were effectively described using a generalised version of the electrolyte non-random two-liquid (eNRTL) model for double salts, presenting low standard deviations (σ x) from experimental data while considering the non-randomness factor (α i j) equal to 0.2 (σ x < 8.47 · 10 − 3) and 0.3 (σ x < 4.78 · 10 − 3). [Display omitted] [ABSTRACT FROM AUTHOR]

The recovery of bioactive compounds from agro-industry-derived by-products sustains circular economy principles by encouraging maximized recycling and minimized waste. Tomato processing by-products are abundant in carotenoids, which have several health-promoting properties, and their reintegration into functional food products represents a major interest for scientists and manufacturers. In the present study, carotenoids were recovered from tomato processing by-products based on the principles of green chemistry by using generally recognized as safe (GRAS) solvents, freeze-drying as pretreatment, and ultrasound in the recovery procedure. Spectrophotometric measurements and HPLC were used to identify and quantify total and individual carotenoids from the extracts. The highest values for lycopene (1324.89 µg/g dw) were obtained when ethyl lactate was applied as a solvent, followed by ethyl acetate with slightly smaller differences (1313.54 µg/g dw). The extracts obtained from freeze-dried samples presented significantly lower amounts of lycopene, indicating that carotenoids are highly susceptible to degradation during lyophilization. Flaxseed, grape seed, and hempseed oils were enriched with carotenoids and their rheological measurements showed favorable viscoelastic properties, especially hempseed and flaxseed oil, with viscosity under 50 mPa·s. Considering the results and the economic perspective of carotenoid recovery from tomato processing by-products, ethyl acetate is suitable, sustainable, and environmentally friendly for carotenoid extraction. [ABSTRACT FROM AUTHOR]

Ethyl lactate could be fully photocatalysed to ethyl pyruvate with 88.4% yield using O 2 as oxidant under room temperature. [Display omitted] • Photocatalytic conversion of ethyl lactate to ethyl pyruvate using O 2 as oxidant was realized under room temperature. • The yield of ethyl pyruvate reached up to 88.4% when ethyl lactate was fully converted. • Singlet oxygen acting as the direct major active species for the oxidation over the ZnIn sulfides. • The optimized ZnIn sulfides catalyst owned high surface area (215.7 m2 g−1) and enhanced charge separation efficiency. Selective oxidation of ethyl lactate (EL) with molecular oxygen as oxidant is an alternative route to produce ethyl pyruvate (EP). However, to obtain pyruvate with high yield under mild conditions remains challenging due to the troublesome over oxidation issue. Here, a highly efficient photocatalytic strategy was firstly developed to obtain EP at room temperature. ZnIn sulfides (ZIS) with different Zn/In ratios were synthesized as the catalysts. Under the irradiation of visible light, 100% EL conversion with 88.4% EP yield could be obtained. The optimized ZIS catalyst shows the highest surface area (215.7 m2 g−1) as well as much higher separation and transport efficiency of the electron-hole pairs. Combining radical trapping experiments with characterization results, a reaction mechanism was proposed. The mild reaction conditions with efficient generation of singlet oxygen contribute the high yield of EP. Kinetic isotope experiments indicate that the cleavage of C(OH)−H bond probably was involved in the rate determining step. [ABSTRACT FROM AUTHOR]

[Display omitted] • The reaction kinetics were performed with ion exchange resins as catalysts. • Developed RD modeling was validated by pilot-scale RD experiment. • Developing a low-cost and energy-efficient RD process through excess lactic acid. • A reduction of 52.25% for TAC and 4.63% for the gas emissions. • Providing guidance for the green technology development of EL production. Bio-ethyl lactate (EL), an alternative green solvent to the traditional petroleum-based solvent, has a distinct advantage in the chemical industry. However, to solve the problem of high energy consumption and low yield in the production of EL is the premise of large-scale production and application. This work proposes an economical and energy-efficient reactive distillation (RD) process through excess lactic acid (LA). As the primary data of RD process design, the kinetics of esterification reaction between LA and EL were investigated using the ion exchange resins KRD001 catalyst. Besides, the developed RD model has been validated utilizing five pilot-scale RD experimental data for process design. Furthermore, the proposed process is optimized with the objective of the minimum heat duty per kilogram product (HDP) of EL, taking into account energy consumption, reaction conversion, economic and environmental impacts. The proposed process has obvious economic and environmental advantages, which can cause a reduction of 52.25% for the total annual cost per kilogram product (T A C K) of EL and 4.63% for the gas emissions compared with the excess ethanol (EtOH) process. This provides guidance and reference for the green technology development and production of EL. [ABSTRACT FROM AUTHOR]

Food supplements based on antioxidants and vitamins are often prescribed to correct inefficiencies in the human diet and delay diseases such as premature aging and alopecia (temporary or permanent hair loss), given the free radical scavenging activity of these biomolecules. By reducing the concentration of reactive oxygen species (ROS), which promote abnormal hair follicle cycling and morphology, follicle inflammation and oxidative stress are reduced, minimising the effects of these health issues. Gallic acid (GA), which is significantly present in gallnuts and in pomegranate root bark, and ferulic acid (FA), commonly found in brown rice and coffee seeds, are very important antioxidants for the preservation of hair colour, strength and growth. In this work, these two secondary phenolic metabolites were successfully extracted in the Aqueous Two-Phase Systems (ATPS) {ethyl lactate (1) + trisodium citrate (2) + water (3)} and {ethyl lactate (1) + tripotassium citrate (2) + water (3)} at 298.15 K and 0.1 MPa, moving towards the application of these ternary systems in extracting antioxidants from biowaste and their a posteriori processing as food supplements for hair fortification. The studied ATPS provided biocompatible and sustainable media for the extraction of gallic acid and ferulic acid, yielding low mass losses (K) of 15 ± 5 and (3 ± 2) · 101 and maximum extraction efficiencies (E) of (92.7 ± 0.4)% and (96.7 ± 0.4)% for the longest tie-lines (TLL = 69.68 and 77.66 m%) in {ethyl lactate (1) + trisodium citrate (2) + water (3)} and {ethyl lactate (1) + tripotassium citrate (2) + water (3)}, respectively. Moreover, the effect of pH on the UV-Vis absorbance spectra was studied for all the biomolecules to minimise errors in solute quantification. Both GA and FA were found to be stable at the used extractive conditions.

Rice-flavor baijiu is a traditional Chinese liquor. The flavor profile and volatiles presentedwith orwithout the solid-state saccharification (SSS)were investigated to reveal the effects of SSS process on the quality of rice-flavor baijiu. The liquor prepared with SSS had a sweet flavor. It contained significantly higher contents of β-phenylethyl alcohol, β-phenylethyl acetate, and ethyl lactate with odor active value of >1. The liquor prepared without SSS had a cheese-like flavor. It was confirmed that the cheese-like flavor derived frombutanoic acidwas only detected in the liquor prepared without SSS. SSS facilitated the biosynthesis of β-phenylethyl alcohol and ethyl lactate by supplying a large amount of phenylalanine and lactic acid at the initial stage of fermentation, and it prevented contamination. These results indicated that the SSS process contributed to produce the characteristic flavor compounds of rice-flavor baijiu. Practical Application: Solid-state saccharification (SSS) process of rice-flavor baijiu contributes not only in brewing, but also in the production of the characteristic flavor compounds and the repression of the off-flavor derived from the contamination. Therefore, SSS is a critical process to control the flavor of riceflavor baijiu. [ABSTRACT FROM AUTHOR]

The growing human population, together with the inefficient use of natural resources, has been dramatically increasing the production of food waste, which poses serious economic, environmental, and social problems. Being so, it is necessary to increase the efficiency of food consumption so as to reduce its waste and to convert the remaining residues into societal benefits. Since this biowaste is rich in polyphenols and vitamins, it could become the feedstock for the production of important value-added compounds for the pharmaceutical (e.g., food supplements) and cosmetic (e.g., creams and shampoos) industries. In this work, partition studies of one polyphenol (epicatechin) and two B-complex vitamins (cyanocobalamin and nicotinic acid) were performed in biodegradable Aqueous Two-Phase Systems (ATPS) based on ethyl lactate and on organic salts (disodium tartrate, tripotassium citrate, and trisodium citrate) at 298.15 K and 0.1 MPa. The largest partition coefficient (K) and extraction efficiency (E) were obtained for vitamin B12 (K=78.56, E=97.5%) for the longest tie line TLL=77.66% in the ATPS {ethyl lactate (1) + tripotassium citrate (2) + water (3)}. All the extractions were obtained with low biomolecule mass losses in quantification (

Salvia rosmarinus (Lamiaceae), previously known as Rosmarinus officinalis, is a plant cultivated worldwide, native to the Mediterranean region. Its leaves are traditionally used for cooking. This species possesses numerous biological activities, including antioxidant, antimicrobial, anticancer, anti-inflammatory, and hepatoprotective properties. These biological properties are due to the presence of phenolic compounds, including rosmarinic acid and phenolic diterpenoids, such as carnosic acid and carnosol. In this study, we investigated the chemical composition of a green extract obtained by maceration with ethyl lactate for the first time. Seventy-five compounds were tentatively identified by UHPLC–ESI–MS/MS, including six organic acids, six cinnamic acid derivatives, five fatty acids, eighteen flavonoids, and thirty-eight terpenoids. Thus, abietane-type diterpenoids from the ethyl lactate extract were the predominant diterpenoids in the Chilean S. rosmarinus species, in contrast to the Chinese species, in which labdane and isopimarane-type diterpenoids were found for the first time. Finally, our study confirms that the extraction of S. rosmarinus with green ethyl lactate as a solvent is efficient and sustainable for the identification of flavonoids, phenols, and terpenoids from leaves.

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• Experimental densities and viscosities for binary mixtures were measured. • PC-SAFT model was applied to calculate the density of components in mixtures. • Governing molecular interactions were discussed. In the current paper, the aim is to investigate the characteristics and relationships of liquid mixtures containing ethyl lactate and 1-Alkanols (C4–C7), which include 1-butanol, 1-pentanol, 1-hexanol, and 1-heptanol. To accomplish this, excess molar volumes and the deviation in viscosity were determined by utilizing experimental density and viscosity measurements at different temperatures and a pressure of 0.1 MPa. Our findings revealed that for solutions containing ethyl lactate and 1-butanol or 1-pentanol, positive values were observed when the mole fractions were higher in alcohols and lower in lactate. However, as the mole fractions shifted towards higher levels of lactate, the excess molar volumes became negative. On the contrary, when examining binary solutions of ethyl lactate with 1-hexanol and 1-heptanol, positive values for the excess molar volumes were found. The PC-SAFT model was used to simulate the density of pure fluids and liquid mixtures, resulting in a maximum deviation of 1.17 % for ethyl lactate and 1-hexanol solutions. Our analysis revealed that PC-SAFT is capable of accurately predicting and correlating the density of both pure liquids and solutions. [ABSTRACT FROM AUTHOR]

Transition-metal silicates are recognized as effective solid acid catalysts to produce value-added compounds from bio-based platform chemicals. One crucial feature in such catalytic transformations is the isomorphic substitution of transition metal into the tetrahedral coordination environment of SiO 2 matrices. This substitution generates the acidic sites which represent the catalytically active sites. Herein, the preparation of hafnium-doped mesoporous SiO 2 (hafnosilicates) is disclosed, and these materials are explored as catalysts for the efficient conversion of dihydroxyacetone (DHA) to ethyl lactate (EL). The one-step catalyst preparation is based on the aerosol-assisted sol-gel (AASG) process and leads to spherical mesoporous silicates with a homogeneous insertion of isolated Hf – as single sites into the SiO 2 matrix, as indicated by XPS. These sites display high Lewis acidity (as evidenced by Pyridine-IR) and this translates into good catalytic performance. Moreover, pH adjustment via the controlled addition of triethanolamine before the aerosol process is shown as a practical way to improve the textural properties, the degree of Hf insertion into the SiO 2 matrix (Lewis acidity), and therefore the catalytic activity. Under optimized reaction conditions (5 mL of 0.4 M DHA, 140 °C, 6 h, 200 mg of catalyst), complete conversion of DHA to EL was observed with a yield higher than 45%. [Display omitted] • Mesoporous hafnosilicate catalysts prepared in one step via an aerosol-assisted sol-gel process. • pH adjustment strategy greatly enhanced the degree of Hf insertion resulting in higher Lewis acidity. • Ethyl lactate yield was greatly improved by the amount of Lewis acidity in the hafnosilicates. • Hafnosilicates can be reused in several cycles with high stability and no leaching of active sites. [ABSTRACT FROM AUTHOR]

• Sustainable aqueous biphasic systems composed of sugar-based DESs and ethyl lactate were developed. • Influence of monosaccharide/disaccharide-based DES as soluting-out agents on ABS formation was studied. • The effective excluded volume value was used to characterized soluting-out ability of sugar-based DES. • The effect of the nature of the coexisting phase on biomolecules partition was investigated. In recent years, the use of green solvents with efficient extraction techniques has gained considerable interest in the research community. This study proposed a novel aqueous biphasic system (ABS) consisting of a hydrophilic sugar-based deep eutectic solvent (DES) and biodegradable ethyl lactate (EL). To understand the phase behaviour of sugar-based DES-EL ABS, at 298.15 K and at an atmospheric pressure, the phase diagrams were determined, and the effects of the structure of different saccharides such as HBDs on the phase separation were discussed. By fitting the effective excluded volume theory (EEV) model to phase diagram data, the ability of the monosaccharide/disaccharide-based DES to induce phase separation was determined. Furthermore, the tie-line length (TLL) was measured and analysed for the stability of DES in both phases at equilibrium. Finally, extraction experiments of such systems for five target biomolecules (eugenol, vanillin, vanillic acid, gallic acid and rutin) were conducted. The results indicated that the hydrophilic/hydrophobic nature of biomolecules preferentially drives their partitioning behaviour. Eugenol, vanillin, and vanillic acid preferentially migrated to the more hydrophobic EL-rich phase, whereas gallic acid and rutin entered the hydrophilic DES-rich phase. A combination of factors such as pH, viscosity and TLL of the system can also affect the separation efficiency. The results of the extraction experiments confirmed the good feasibility of the proposed system for biomolecular extraction applications. [ABSTRACT FROM AUTHOR]

Abstract Background Green organic solvents such as lactate esters have broad industrial applications and favorable environmental profiles. Thus, manufacturing and use of these biodegradable solvents from renewable feedstocks help benefit the environment. However, to date, the direct microbial biosynthesis of lactate esters from fermentable sugars has not yet been demonstrated. Results In this study, we present a microbial conversion platform for direct biosynthesis of lactate esters from fermentable sugars. First, we designed a pyruvate-to-lactate ester module, consisting of a lactate dehydrogenase (ldhA) to convert pyruvate to lactate, a propionate CoA-transferase (pct) to convert lactate to lactyl-CoA, and an alcohol acyltransferase (AAT) to condense lactyl-CoA and alcohol(s) to make lactate ester(s). By generating a library of five pyruvate-to-lactate ester modules with divergent AATs, we screened for the best module(s) capable of producing a wide range of linear, branched, and aromatic lactate esters with an external alcohol supply. By co-introducing a pyruvate-to-lactate ester module and an alcohol (i.e., ethanol, isobutanol) module into a modular Escherichia coli (chassis) cell, we demonstrated for the first time the microbial biosynthesis of ethyl and isobutyl lactate esters directly from glucose. In an attempt to enhance ethyl lactate production as a proof-of-study, we re-modularized the pathway into (1) the upstream module to generate the ethanol and lactate precursors and (2) the downstream module to generate lactyl-CoA and condense it with ethanol to produce the target ethyl lactate. By manipulating the metabolic fluxes of the upstream and downstream modules through plasmid copy numbers, promoters, ribosome binding sites, and environmental perturbation, we were able to probe and alleviate the metabolic bottlenecks by improving ethyl lactate production by 4.96-fold. We found that AAT is the most rate-limiting step in biosynthesis of lactate esters likely due to its low activity and specificity toward the non-natural substrate lactyl-CoA and alcohols. Conclusions We have successfully established the biosynthesis pathway of lactate esters from fermentable sugars and demonstrated for the first time the direct fermentative production of lactate esters from glucose using an E. coli modular cell. This study defines a cornerstone for the microbial production of lactate esters as green solvents from renewable resources with novel industrial applications.

Density, sound velocity and refractive index of ethyl lactate + butyronitrile mixtures were measured at five temperatures from 283.15 to 323.15 K. Excess molar volumes, partial molar volumes, thermal expansion coefficients, isentropic compressibility and molar refraction values were calculated. The sigmoid behaviour of the excess volume curve is discussed. [ABSTRACT FROM AUTHOR]

The recovery of bioactive compounds from agro-industry-derived by-products sustains circular economy principles by encouraging maximized recycling and minimized waste. Tomato processing by-products are abundant in carotenoids, which have several health-promoting properties, and their reintegration into functional food products represents a major interest for scientists and manufacturers. In the present study, carotenoids were recovered from tomato processing by-products based on the principles of green chemistry by using generally recognized as safe (GRAS) solvents, freeze-drying as pretreatment, and ultrasound in the recovery procedure. Spectrophotometric measurements and HPLC were used to identify and quantify total and individual carotenoids from the extracts. The highest values for lycopene (1324.89 µg/g dw) were obtained when ethyl lactate was applied as a solvent, followed by ethyl acetate with slightly smaller differences (1313.54 µg/g dw). The extracts obtained from freeze-dried samples presented significantly lower amounts of lycopene, indicating that carotenoids are highly susceptible to degradation during lyophilization. Flaxseed, grape seed, and hempseed oils were enriched with carotenoids and their rheological measurements showed favorable viscoelastic properties, especially hempseed and flaxseed oil, with viscosity under 50 mPa·s. Considering the results and the economic perspective of carotenoid recovery from tomato processing by-products, ethyl acetate is suitable, sustainable, and environmentally friendly for carotenoid extraction.

A comprehensive study of the properties and reactivity of ethyl(S)‐lactate has been conducted. The conformational landscape, the enthalpy of formation of the ground state, ΔfH∘−(0K)=−600.2±2.2 kJ mol−1, the thermochemistry (entropy, specific heat, enthalpy function), adiabatic ionization energy, and the single bond dissociation energies are also mapped out. Unimolecular elimination reactions leading to water and ethyl acrylate or ethene and lactic acid proceed with barriers in excess of 250 kJ mol−1—with the latter always dominant. The chemical kinetics of the abstraction of H‐atoms from primary, secondary, tertiary, and alcoholic sites by the radicals H• and CH3• are calculated as well as the kinetics of addition reactions to the carbonyl bond. [ABSTRACT FROM AUTHOR]

Experimental viscosity data were obtained for ethyl lactate + acetonitrile mixtures at five temperatures. Viscosity deviations and activation parameters of viscous flow have been calculated. Values obtained suggest that the inter and intramolecular hydrogen bonds of ethyl lactate are affected by the electron pair in the nitrogen atom of acetonitrile. The obtained data have been correlated through several approaches proposed in the literature, namely, the Grunberg – Nissan, the Katti – Chaudri, the Teja – Rice, and the Herráez approaches of, for dynamic viscosities. [ABSTRACT FROM AUTHOR]

In this study, direct conversion of rice straw to ethyl lactate (EL) was evaluated in acidic conditions with ethanol as reaction medium. The devised Lewis acid catalyst system (SnCl2/SnCl4) and, Lewis/Brønsted acid catalyst system (SnCl2/ZSM-5) played vital role in the selective production of EL. The yield of EL was optimized up to 21.8% with SnCl2/SnCl4 followed by 20.0% with SnCl2/ZSM-5 at 220 °C in sub-critical ethanol (100%) for reaction time of 4 h. On contrarily, the SnCl2/γ-Al2O3 catalyst system was less effective in improving the EL yield (17.1%). As Brønsted acid, the catalytic activity of heterogeneous catalyst ZSM-5 and homogeneous catalyst H2SO4 was compared by using these catalysts along with SnCl2 loading. Due to catalytic stability, ZSM-5/SnCl2 with 3:1 mass ratio has proved to be slightly more influential than H2SO4 in enhancing Lewis acidity of SnCl2. Overall both Lewis and Brønsted acid systems are significantly active in selective production of EL. On the basis of catalytic activity, it can be incurred that the Brønsted acid sites mainly facilitated the degradation of holocellulose into monosaccharides and respective dehydration reactions. Strong Lewis acid sites, on the other hand, catalyzed C–C bond cleavage and rearrangement reactions during isomerization, retro-aldol and finally esterification reactions. [ABSTRACT FROM AUTHOR]