Acid Yield Research Articles

Products Distribution and Reaction Kinetics from Co-Pyrolysis of Pinewood and Polypropylene under Non-Catalytic and Catalytic Reaction Conditions

Abstract Co-pyrolysis technology offers vital pathways for efficient utilization of plastics and biomass resources to help reduce the environmental problems and energy resources issues. The pyrolysis characteristics of pinewood and polypropylene (PP) mixtures were analyzed using TGA. The results showed a decrease in first peak of the mixture with increase in PP in the mixture, while the second peak increased with an increase in PP in the mixture. The addition of a catalyst decreased the DTG peak heights. The reduction in the first peak with different catalysts was in the order: CaO/ZSM-5 >CaO >ZSM-5, while for the second peak showed: CaO >CaO/ZSM-5 >ZSM-5. The activation energy, calculated by Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), and Friedman models, revealed that ZSM-5 reduced the activation energy, whereas CaO/ZSM-5 increased the activation energy, as compared to no catalyst case. Increase of co-pyrolysis temperature reduced the yield of aldehydes, ketones, acids and esters, but increased the yield of hydrocarbons. The addition of CaO reduced the yield of ketones, phenols, esters, and acids, while it increased the yield of alcohols. The addition of ZSM-5 also decreased the yield of ketones, phenols, acids and hydrocarbons, but increased the yield of furans and alcohols. The addition of CaO/ZSM-5 specifically reduced the yield of aldehydes and alcohols. The results show the important role of the specific catalysts examined on the resulting products distribution for the same reaction condition.

Evaluating rice lipid content, yield, and quality in response to nitrogen application rate and planting density

To investigate the effects of nitrogen (N) application rate and planting density (D) on the contents of lipid and free fatty acid, fatty acid composition, yield and quality of rice grain, a field experiment was conducted using Koshihikari (japonica) as experimental material from 2021 to 2022 with three N levels (90, 150 and 210 kg ha-1, denoted as N1, N2 and N3, respectively) and three transplanting densities (19.0 × 104, 26.7 × 104 and 40.0 × 104 plants ha-1, denoted as D1, D2 and D3, respectively). The results showed that N application rate and planting density had highly significant impacts only on the contents of free fatty acid and saturated fatty acid, respectively. Increased N and planting density enhanced the contents of lipid (29.41 mg g-1) and free fatty acid (21.47%). The highest values were obtained under N3D3 increasing by 7.02% and 3.23 percentage points, respectively, compared to other treatments. No significant differences in lipid content were found among treatments, whereas free fatty acid exhibited significant differences. The unsaturated fatty acid content increased with increasing N but first decreased and then increased with increasing planting density, while saturated fatty acid content showed the opposite trend. Appropriate N level and planting density improved the relative chlorophyll content and net photosynthetic rate of rice flag leaves, as well as increased grain yield, effective panicle number and spikelete number per panicle, but decreased the seed setting rate. Under N2D2, the relative chlorophyll content and net photosynthetic rate remained relatively high throughout the grain filling stage, resulting in the highest grain yield, with increases of 43.87-47.03% compared to other treatments. A moderate N level improved the milling quality of rice, while increased planting density reduced it. However, both increased N and planting density reduced the appearance quality and cooking and eating quality of rice. Overall, the effects of increasing N application rate and planting density on enhancing rice lipid and free fatty acid contents were limited. A combination of 150 kg ha-1 N application rate and 26.7 × 104 plants ha-1 was recommended for achieving relatively higher yield, lipid content and better grain quality.

Development of an eco-fractionation process for Ricinodendron heudelotii oil to obtain α-eleostearic acid and β-eleostearic acid

Abstract The present article studies the transformations and fractionation of the reserve lipids of Ricinodendron heudelotii. The native triglycerides of this oil are composed mainly of conjugated polyunsaturated fatty acids, in particular α-eleostearic acid C18:3 n– 5 (9c, 11t, 13t) at 60%. This particular fatty acid of CLnA family exerts many activities potentially beneficial for health: anti-inflammatory, anti-leukemic, anti-microbial, anti-tumor, anti-ulcer and anti-diabetic. A process for transforming this acid into its isomers β-eleostearic acid and catalpic acid was explored with the aim of obtaining fractions enriched in β-eleostearic acid C18:3 n– 5 (9t, 11t, 13t). The β-eleostearic acid is a fatty acid of great interest because it is even more reactive and more efficient as antioxidant than α-eleostearic acid due to its higher trans content. Isomerization reaction of α-eleostearic acid in oil was carried out using artificial solar radiation treatment. The enrichment of concentrates in β-eleostearic acid was therefore tested using an eco-fractionation process. This process was carried out in two stages. The first step was the Candida rugosa lipase-catalyzed hydrolysis of triglycerides from native or isomerized Ricinodendron heudelotii oil. The second step was fractionation of the reaction medium obtained after hydrolysis. Triglyceride hydrolysis was complete, with a yield of free fatty acids of over 95% after 2 h of reaction. Treatment of the reaction media yielded 3 lipid concentrates with new chemical compositions of polyunsaturated fatty acids: a first concentrate, derived from hydrolysis of the native oil, composed of 60% α-eleostearic acid and 22% linoleic acid, and two other concentrates derived from fractionation of the hydrolysate of the oil isomerized by radiation. One was composed of 34% linoleic acid, 21% β-eleostearic acid, 11% α-eleostearic acid and 6% catalpic acid, and the last concentrate was composed of over 80% β-eleostearic acid. In addition to offering nutritional benefits similar to those of α-eleostearic acid, β-eleostearic acid also offers an interesting physical property: a very high melting point of 72 °C. Such a polyunsaturated fatty acid, which is solid at room temperature, could prove to be a raw material of choice, particularly in the world of food formulation, where manufacturers are looking for replacements with physical properties close to those of palm oil (the melting point of palmitic acid is 62 °C). Ricinodendron heudelotii oil has thus demonstrated its major role as a source of the triptych of α-eleostearic, β-eleostearic and linoleic fatty acids.

CRYSTALLIZATION TEMPERATURE AND SOLVENT COMPOSITION EFFECT FOR ENHANCEMENT OF UNSATURATED FATTY ACIDS FROM PALM OIL USING UREA COMPLEXATION

Mono and Poly Unsaturated Fatty Acids (MUFAs/PUFAs) are vital nutritional sources for infants, adults, and the elderly. The content of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) can be enhanced in vegetable oils or animal fats using a range of different techniques. The process of urea complexation is highly effective and efficient for concentrating monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) from vegetable oils. This study employed refined palm oil as the raw material that went through saponification and purification processes in order to generate fatty acids mixture. Subsequently, urea was introduced to create a complex chemical in the form of urea complexed fraction (UCF) and leaving the non-urea complexed fraction (NUCF). Gas chromatography was employed to analyze the fatty acid composition obtained from urea complexation. This study investigated the impact of different crystallization temperatures (-4°C, 8°C, 12°C, 22°C, and 30°C) and ethanol concentrations (ranging from 0% to 100%) on enhancing the unsaturated content and yield of fatty acids derived from palm oil. It also conducted predictive equations to determine the yield and fatty acids composition in the non-urea complexed fraction (NUCF) which are important for separation process design in chemical industries. The study revealed that increasing the crystallization temperature resulted in a larger yield in the liquid fraction (NUCF), but a lower concentration of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs).

Customising Sustainable Bio-Based Polyelectrolytes: Introduction of Charged and Hydrophobic Groups in Cellulose

Cellulose has been widely explored as a sustainable alternative to synthetic polymers in industrial applications, thanks to its advantageous properties. The introduction of chemical modifications on cellulose structure, focusing on cationic and hydrophobic modifications, can enhance its functionality and expand the range of applications. In the present work, cationization was carried out through a two-step process involving sodium periodate oxidation followed by a reaction with the Girard T reagent, yielding a degree of substitution for cationic groups (DScationic) between 0.3 and 1.8. Hydrophobic modification was achieved via esterification with fatty acids derived from commercial plant oils, using an enzyme-assisted, environmentally friendly method. Lipase-catalysed hydrolysis, optimised at 0.25% enzyme concentration and with a 1 h reaction time, produced an 84% yield of fatty acids, confirmed by FTIR and NMR analyses. The degree of substitution for hydrophobic groups (DShydrophobic) ranged from 0.09 to 0.66. The molecular weight (MW) of the modified cellulose derivatives varied from 1.8 to 141 kDa. This dual modification strategy enables the creation of cellulose-based polymers with controlled electrostatic and hydrophobic characteristics, customisable for specific industrial applications. Our approach presents a sustainable and flexible solution for developing cellulose derivatives tailored to diverse industrial needs.

Improvements in the manufacture of benzoic acid obtained by catalytic oxidation of toluene

This study investigates improvements in benzoic acid production through the catalytic oxidation of toluene with cobalt octoate. The oxidation process, which occurs under controlled conditions with temperatures ranging from 130 °C to 165 °C, typically results in a conversion rate of 50% toluene with a selectivity of 80% over benzoic acid. However, various by-products such as benzyl alcohol, benzaldehyde, and benzyl benzoate are also formed, which reduces the overall yield. The work identifies methods to minimize these byproducts, particularly benzyl benzoate, which forms in the distillation column. One strategy investigated involved using additives to inhibit the esterification reaction that produces benzyl benzoate, aiming to improve the selectivity of the oxidation process. Experimental results show that maintaining reaction temperatures between 135 °C and 145 °C in combination with using sodium benzoate as an additive effectively reduces the formation of benzyl benzoate and increases the yield of benzoic acid. Furthermore, increasing the O2/toluene ratio increases the oxidation efficiency.

Electrochemical carboxylation: Green synthesis of atrolactic acid using boron-doped diamond electrodes

Electrochemical CO2 fixation is vital for sustainability in the chemical industry, yet the selective synthesis of multi-carbon products remains challenging. Organic electrosynthesis offers promise by enabling precise control over reaction conditions and facilitating novel reactivity patterns. One such technique, electrochemical carboxylation, involves coupling CO2 with organic molecules to produce carboxylic acids. Specifically, electro-carboxylation of acetophenone yields atrolactic acid, a valuable precursor for nonsteroidal anti-inflammatory drugs, providing a greener alternative to traditional production methods. This study focuses on the synthesis and characterization of boron-doped diamond (BDD) films using the microwave plasma-assisted chemical vapor deposition (MP-CVD) method and synthesized BDD electrodes were then used for the electrolytic carboxylation of acetophenone. Various analytical techniques, including X-ray diffraction (XRD), Raman spectroscopy, and laser microscopy, etc. were employed to characterize the BDD films. Various BDD films synthesized for different durations were utilized in the electrolytic carboxylation of acetophenone, with the highest yield of atrolactic acid (25 %) achieved using a BDD film synthesized over 6 h. Also, the effect of BDD surface modification i.e. oxygen and hydrogen terminated BDD on the synthesis of atrolactic acid was studied. Additionally, different electrolytes were employed in the synthesis process of atrolactic acid. A comparative study between Pt and BDD electrodes for the electrolytic carboxylation of acetophenone was conducted, and a mechanism for the formation of atrolactic acid was proposed.

13 C-MFA helps to identify metabolic bottlenecks for improving malic acid production in Myceliophthora thermophila

BackgroundMyceliophthora thermophila has been engineered as a significant cell factory for malic acid production, yet strategies to further enhance production remain unclear and lack rational guidance. 13C-MFA (13C metabolic flux analysis) offers a means to analyze cellular metabolic mechanisms and pinpoint critical nodes for improving product synthesis. Here, we employed 13C-MFA to investigate the metabolic flux distribution of a high-malic acid-producing strain of M. thermophila and attempted to decipher the crucial bottlenecks in the metabolic pathways.ResultsCompared with the wild-type strain, the high-Malic acid-producing strain M. thermophila JG207 exhibited greater glucose uptake and carbon dioxide evolution rates but lower oxygen uptake rates and biomass yields. Consistent with these phenotypes, the 13C-MFA results showed that JG207 displayed elevated flux through the EMP pathway and downstream TCA cycle, along with reduced oxidative phosphorylation flux, thereby providing more precursors and NADH for malic acid synthesis. Furthermore, based on the 13C-MFA results, we conducted oxygen-limited culture and nicotinamide nucleotide transhydrogenase (NNT) gene knockout experiments to increase the cytoplasmic NADH level, both of which were shown to be beneficial for malic acid accumulation.ConclusionsThis work elucidates and validates the key node for achieving high malic acid production in M. thermophila. We propose effective fermentation strategies and genetic modifications for enhancing malic acid production. These findings offer valuable guidance for the rational design of future cell factories aimed at improving malic acid yields.

Optimisation of coumaric acid production from aromatic amino acids in Kluyveromyces marxianus

Yeasts are attractive hosts for the production of heterologous products due to their genetic tractability and relative ease of growth. While the baker’s yeast Saccharomyces cerevisiae is a powerful workhorse of the biotechnology industry, the species has metabolic limitations and it is critical that we develop alternative platforms that will facilitate the development of bioprocesses that rely on sustainable feedstocks. In this study, we used synthetic biology tools to construct coumaric acid–producing strains of Kluyveromyces marxianus, a yeast whose physiological traits render it attractive for biotechnology applications. Coumaric acid is a building block in the synthesis of many different families of aromatics and is a key precursor for the synthesis of complect phenylpropanoid molecules, including many flavours and aromas. The starting point for this work was a K. marxianus chassis strain that has increased flux towards the synthesis of tyrosine and phenylalanine, the aromatic amino acids that can serve as starting points for coumaric acid synthesis. Following principles of synthetic biology, a modular approach was taken to identify the best solution to different metabolic possibilities and these were then combined in different ways. For the first step, it was established that the route from phenylalanine was superior to that from tyrosine and the combined overexpression of PlPAL, AtC4H and AtCPR1 delivered the highest yield of coumaric acid. Next, it was established that while Pdc5 and Aro10 both had phenylpyruvate decarboxylase activity, inactivation of ARO10 was sufficient to prevent flux loss in the pathway. Since phenylalanine is the starting point, efforts were made to improve efficiency of its production. It was found that glutamate was a preferred nitrogen source for coumaric acid production, and this knowledge was used to engineer a strain that overexpressed S. cerevisiae GDH1 and delivered higher yields of coumaric acid. Ultimately, this strategy led to the development of strains that has yields of up to 48mg coumaric acid /g glucose. Strains were evaluated in bioreactors to investigate the effects of different process parameters. These analyses indicated that engineered strains face some redox balance challenges and further work will be required overcome these to develop strains that can perform well under industrial conditions.

Recycling copper wire waste into active Cu-based catalysts for value-added chemicals production via CO2 electrochemical reduction

The CO2 electroreduction reaction (CO2RR) is a method for producing value-added compounds from CO2. This study aimed to use copper from wiring waste to create Cu-based catalysts on Vulcan XC-72R carbon for converting CO2 into valuable chemicals. Copper nanopowder with an average crystallite size of 27 nm derived from the wiring waste solution was utilized as the starting material for mono and bimetallic catalysts preparation. During the bimetallic PdCu/C catalyst synthesis, a galvanic displacement reaction between Pd and Cu occurred, resulting in the formation of PdCu alloy and a reduction in the copper crystallite size. The inclusion of Pd on Cu/C in CO2RR decreased the onset potentials for C1 and C2 chemical production. The yields of methanol, formic acid, and formaldehyde products were generally increased as the Pd:Cu ratio increased. The 1:2-PdCu/C exhibited the smallest crystallite size and an onset potential of less than −1.0 V, resulting in the highest Faradaic efficiency of the products. This catalyst converted CO2 into formic acid (FE = 71.5 %) at a potential of −0.8 V and methanol (FE = 65.4 %) at −0.5 V. The catalyst’s stability was demonstrated for more than 6000 s at current densities of approximately 2 mA mg-1catalyst.

Simple enzymatic depolymerization process based on rapid ball milling pretreatment for high-crystalline polyethylene terephthalate fibers

The high crystallinity (30 %–50 %) of discarded polyester textile waste limits the industrialization of its clean enzymatic depolymerization. In this study, a simple process based on ball milling pretreatment was developed to achieve effective enzymatic hydrolysis of high-crystalline polyester fiber. Ball milling was selected for its short, mild, and chemical-free process, which achieved a remarkable 23.8-fold (60.9 %) increase in terephthalic acid (TPA) yield from waste polyethylene terephthalate (PET) degradation, along with high TPA purity in the released soluble compounds. Just 30 min of ball milling at room temperature induced polyester amorphization, resulting in polyester with 12 % lower crystallinity compared with untreated polyester (51 %), while simultaneously increasing the surface roughness of polyester, thereby enhancing the efficiency of enzymatic hydrolysis. The simple process for effective enzymatic-depolymerization of waste polyester fiber developed in this study has potential industrial applications

Microbial approach towards anode biofilm engineering enhances extracellular electron transfer for bioenergy production

Applying microbial electrolysis cells (MEC) is a biological approach to enhance the growth of high amounts of electroactive biofilm for extracellular electron transfer. The electroactive biofilm degrades the organics by oxidizing them at the anode and producing electrical energy. Addition of waste-activated sludge (WAS) with fat grease oil (FOG) produces an optimal reactor environment for microbial growth to enhance the exchange of electrons between cells via microbial electrolysis. The present work aimed to investigate the microbial approach to increase the extracellular electron transfer (EET) in microbial electrolysis cells. Results revealed that metabolites in electroactive microbes (EAM) grow viable cells that initiate high EET at anode sites. At optimum WAS with FOG addition, volatile fatty acid and current generation yield production was 2.94 ± 0.19 g/L and 17.91 ± 7.23 mA, accompanied by COD removal efficiency of 89.5 ± 14.4%, respectively. This study introduces a novel approach to anode biofilm engineering that significantly enhances extracellular electron transfer, offering a fresh perspective on bioenergy production. Our approach, which demonstrates that anodic biofilm enhances intercellular electron transfer, increases NADH-NAD ratio, and increases metabolite yield-fluxes, has the potential to revolutionize bio-electricity production. Results indicated that the electrolysis highlights MEC performance in power generation of 788 mV with 200 mL of anode volume of active viable cells by utilizing WAS with 11% FOG. The achievements of this study provide critical parameters for the anode biofilm engineering, demonstrating how growth cell volume, intercellular electron transfer, and increases in NADH-NAD ratio are evidence of an increase in the EET, compelling evidence for the resilience treatment and efficient current production. These findings are significant in advancing our understanding of bioenergy production.

Study on the influence characteristics of multi-working condition parameters on membrane electrode type CO2 electrolyzer

The electrochemical conversion of carbon dioxide (CO2) into basic chemicals or carbon-based fuels is a promising new strategy for carbon resource utilization. Within this domain, solid-electrolyte CO2 electrolyzer demonstrate significant potential for the continuous production of pure formic acid solutions. This study, leveraging a 4 cm2 visualization electrolyzer, explores the impact of three working condition parameters on performance: working voltage, gas flow rate, and the intermediate chamber water flow rate. It compares the variations in current density, formic acid concentration, and the distribution of liquid water on the cathode side under different working conditions. The results indicate that the working voltage, current density, and formic acid yield are all positively correlated; overly low gas flow rates can lead to CO2 deficiency and diminished electrolyzer performance; concentration control of the formic acid solution is effectively achieved by adjusting the intermediate chamber water flow rate; and during the electrolyzer reaction process, almost all of the liquid water is positioned at the bends downstream of the cathode flow channel.

Revealing the dynamic changes of metabolites and molecular mechanisms of chlorogenic acid accumulation during the leaf development of Vaccinium dunalianum based on multi-omic analyses.

Vaccinium dunalianum, a medicinal plant, is utilized for Quezui Tea production from its leaf buds and young leaves. Despite prior research on V. dunalianum revealing several medicinal compounds, the comprehensive variations in metabolites during its growth and development, along with the molecular mechanisms underlying high chlorogenic acid (CGA) yield, remain unclear. Through a joint analysis of transcriptomics and proteomics, our study first identified 15 key structural genes and 3 transcription factors influencing CGA biosynthesis in V. dunalianum, offering new evidence to understand its regulatory network. Furthermore, non-targeted metabolomics analysis provides the first extensive report on the metabolic profile of V. dunalianum, furnishing a valuable dataset for deeper exploration of its nutritional and medicinal value, and the development of a quality evaluation system for its product Quezui Tea. This study offers the most comprehensive molecular information on V. dunalianum, marking a significant step toward understanding and enhancing the plant's potential for medicinal and nutritional applications. Additionally, this study also reveals V. dunalianum holds promise as a natural antioxidant source for functional foods, providing data support for network pharmacology.

Levulinic Acid Production from Artichoke Leaves (Cynara Scolymus L.) by Catalytic Hydrothermal Reaction

In addition to examining the highest yield production of Levulinic acid (LA) from artichoke leaves by the subcritical catalytic hydrothermal decomposition, the studies were carried out on also increasing the production yields of 5-Hydroxymethylfurfural (HMF), Acetic and Formic acid from this biomass. In order to obtain the most suitable reaction conditions, the effect of different reaction conditions, including different temperature, reaction time, pH and catalyst types, on the decomposition of artichoke leaves and product yields were investigated. The subcritical thermal decomposition studies of artichoke leaves were carried out in an autoclave system at temperatures (120°C, 140°C, 160°C, and 180°C) for reaction times of 10, 20, 30, 40, and 50 min in the presence of H2SO4, HNO3, and HCL catalysts with different pH values; these reactions were realized also without adding a catalyst. As a result of the detailed research, it was seen that the most suitable experimental conditions for the production of LA with the highest yield from artichoke leaves could be achieved by adding sulfuric acid with a pH of 0.5 at a reaction temperature of 180°C and a reaction time of 50 min. The investigations were continued till achieving the highest product yields. After carrying out the experiments stated above, the optimal yields of the products produced from the artichoke biomass by the reactions were found as 209.39 g/kg biomass for LA, 117.40 g/kg biomass for formic acid, 72.27 g/kg biomass for acetic acid, and 39.04 g/kg biomass for 5-HMF.

Segatella clades adopt distinct roles within a single individual’s gut

Segatella is a prevalent genus within individuals’ gut microbiomes worldwide, especially in non-Western populations. Although metagenomic assembly and genome isolation have shed light on its genetic diversity, the lack of available isolates from this genus has resulted in a limited understanding of how members’ genetic diversity translates into phenotypic diversity. Within the confines of a single gut microbiome, we have isolated 63 strains from diverse lineages of Segatella. We performed comparative analyses that exposed differences in cellular morphologies, preferences in polysaccharide utilization, yield of short-chain fatty acids, and antibiotic resistance across isolates. We further show that exposure to Segatella isolates either evokes strong or muted transcriptional responses in human intestinal epithelial cells. Our study exposes large phenotypic differences within related Segatella isolates, extending this to host-microbe interactions.

Microstructural Modification and Sorption Capacity of Green Coffee Beans.

To enhance the pore structure of green coffee beans (GCB) and detect the sorption capacity and extraction characteristics of flavor compounds before roasting, this study employed several methods: hot air drying (HD), freeze-drying (FD), 3-levels short-time heating with puffing (SH1P, SH2P, and SH3P), and 3-levels microwave with puffing (MW45P, MW60P, and MW75P). These methods were applied to GCBs pre-soaked in water for different times. The effects of these treatments on color change, porosity, microstructure, citric acid sorption capacity, and caffeine and chlorogenic acid extraction yield were investigated. Results indicated that, except for GCBs treated with SH1P, SH2P, SH3P, and MW75P, all other modified GCBs showed minimal color change. GCBs treated with MW60P exhibited favorable pore structures. MW60P treatments significantly improved the extraction yield of caffeine and chlorogenic acid. Furthermore, the increased porosity and improved pore size distribution of GCB after MW60P resulted in a significant increase in the sorption of citric acid onto modified GCB. The rate of the sorption reaction followed the pseudo-first-order kinetics. In conclusion, MW60P are effective treatments for enhancing the microstructure of GCB, improving sorption capacity, and improving the extraction yield of flavor compounds.

Impact of freeze drying on the properties of palmitic acid extracted from Plantain stalk waste

The challenge of effectively preserving and concentrating palmitic acid from plantain stalk waste is compounded by the loss and degradation of the compound during traditional drying and extraction methods, which may lead to reduced yield and altered properties of the extracted palmitic acid. This study was aimed at evaluating the impact of the freeze-drying process on the properties of palmitic acid extracted from plantain stalk waste. The study involved preparing plantain stalks, applying freeze-drying or non-freeze-drying methods, extracting palmitic acid, and characterizing the samples using GC-MS, FTIR, XRD, EDX, and SEM. The GC-MS analysis revealed that freeze-drying significantly increased the concentration of palmitic acid compared to non-freeze-drying, as indicated by the higher peak area and height. FTIR spectra demonstrated that freeze-drying better preserved the structural integrity of palmitic acid, while XRD analysis showed enhanced crystalline structure and increased crystallite size in the freeze-dried sample. Additionally, EDX showed that freeze-drying increased the carbon content and decreased the oxygen content of the material, while SEM analyses indicated that freeze-drying resulted in a more porous and irregular surface compared to the denser, smoother structure of the non-freeze-dried sample. The mass, energy, and cost analysis revealed that freeze-drying resulted in a higher yield of palmitic acid compared to non-freeze-drying methods, which, despite being more cost-effective and requiring less energy, demonstrated a notable trade-off in extraction efficiency. The study showed that freeze-drying significantly improved the preservation, concentration, and structural integrity of palmitic acid extracted from plantain stalk waste compared to the non-freeze-drying method.

EFFECT OF ULTRASOUND ON THE EXTRACTION OF HYDROXYCINNAMIC ACIDS FROM DANDELION ROOTS

Introduction. Ultrasonic extraction is widely used to accelerate the extraction of biologically active substances (BAS). Given the presence of free and bound moisture in medicinal plant raw materials (MPRM), it is rational to assume a positive effect of ultrasound on the MPRM itself in order to increase the yield of BAS. The aim of the work is to study the effect of ultrasonic pre-treatment of dandelion roots on the yield of hydroxycinnamic acids (HCA) from them and to substantiate the feasibility of pre-treatment this MPRM to obtain tinctures. Material and methods. The object of the study was dandelion roots. The mass fraction and composition of HCA were determined by the spectro-photometric method according to the reaction with Arnov's reagent and by high-performance liquid chromatography using standard samples, respec-tively. Results. Preliminary ultrasound exposure of dandelion roots significantly increases the yield of HCA. The maximum content was determined when MPRM with a layer thickness of 2-4 cm and a particle size of 500 μm or less were exposed to ultrasound for 45 min with a frequency of 31 kHz. The highest amount of HCA in tinctures was determined when they were obtained by fourteen-day maceration and subsequent ultrasound extraction for 15 min using 50% ethanol in a volume of 50 ml per 1 g of MPRM with a particle size of 500 μm or less. Defatting, ultrasonic, thermal pre-treatment and their combination enrich dandelion tinctures with HCA; the greatest enrichment of tinctures with this group of BAS was observed with ultrasonic treatment and thermal treatment followed by defatting. Conclusions. The parameters of preliminary ultrasonic pre-treatment and technological parameters for obtaining tinctures of dandelion roots were ex-perimentally determined. It is recommended to use preliminary pre-treatment of raw materials as one of the stages of the technology for obtaining tinctures, ensuring an increase in the yield of HCA.

Hexanoic acid production from anaerobic fermentation of Chinese cabbage waste with exogenous lactic acid as electron donor

The lack of electron donors is one of the key factors hindering hexanoic acid production from anaerobic fermentation. In this study, three different types of lactic acids were supplemented as exogenous electron donors to the anaerobic fermentation system of Chinese cabbage waste (CCW). The yields of hexanoic acid in the reactors supplemented with CCW lactic acid pre-fermentation broth (PFB), lactic acid diluent (LAD) and chemical lactic acid (LA) were 6996.8 mg COD/L, 4534.8 mg COD/L and 6777.1 mg COD/L, respectively. Compared with the reactor supplemented with LA, the electron efficiency of hexanoic acid in reactor supplemented with PFB increased by 188 %. Supplementing PFB shifted the microbial communities towards a direction favorable to hydrolysis and chain elongation, thereby facilitating the synthesis of hexanoic acid.