Acid Ethyl Ester Research Articles

Effects of Cultivar Factors on Fermentation Characteristics and Volatile Organic Components of Strawberry Wine.

Strawberry wine production is a considerable approach to solve the problem of the Chinese concentrated harvesting period and the short shelf life of strawberries, but the appropriative strawberry cultivars for fermentation are still undecided. In this study, the strawberry juice and wines of four typical strawberry cultivars named Akihime (ZJ), Sweet Charlie (TCL), Snow White (BX), and Tongzhougongzhu (TZ) were thoroughly characterized for their physicochemical indicators, bioactive compounds, and volatile organic components (VOCs) to determine the optimal strawberry cultivars for winemaking. The results showed that there were significant differences in the total sugar content, pH, total acid, and other physicochemical indexes in the strawberry juice of different cultivars, which further affected the physicochemical indexes of fermented strawberry wine. Moreover, the content of polyphenols, total flavonoids, vitamin C, and color varied among the four strawberry cultivars. A total of 42 VOCs were detected in the strawberry juice and wines using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), and 3-methyl-1-butanol, linalool, trans-2-pinanol, hexanoic acid, and hexanoic acid ethyl ester were the differential VOCs to identify the strawberry wine samples of different cultivars. Overall, strawberry cultivar ZJ had a relatively high VOC and bioactive compound content, indicating that it is the most suitable cultivar for strawberry wine fermentation. In addition to determining the relatively superior fermentation characteristics of cultivar ZJ, the results may provide a theoretical basis for the raw material quality control and quality improvement of strawberry wine.

Electrochemical, thermodynamic and DFT studies of Fomitopsis pinicola as green corrosion inhibitor for carbon steel in sulfuric acid

In this work, the methanolic extract of Fomitopsis pinicola has been evaluated as a green corrosion inhibitor for the dissolution of 1018 carbon steel in 0.5 M sulfuric acid. For this, gravimetric tests and electrochemical methods such as potentiodynamic polarization curves, linear polarization resistance (LPR) and Electrochemical Impedance Spectroscopy (EIS) techniques were used. These tests were aided with Infrared and GC–MS analytical techniques. In addition to this, theoretical calculation with the use of the density functional theory (DFT) technique has been used to correlate the electronic extract properties and its inhibitory capacity. Weight loss results have shown an inhibitor efficiency of 85 % with the addition of 400 ppm. Thermodynamic parameters have shown that Fomitopsis pinicola extract is physically adsorbed onto the steel following a Langmuir adsorption isotherm. Potentiodynamic polarization curves showed that the extract behaves as a mixed type of corrosion inhibitor inducing the formation of a protective film onto the steel surface. In the presence of the Fomitopsis pinicola extract, a more resistive film obtained the highest polarization resistance value when 400 ppm of extract was used. In addition to this, as the concentration of the extract increased the charge transfer resistance and the double electrochemical layer capacitance decreased. GC–MS results indicated that main compounds contained in the Fomitopsis pinicola extract were Dehydrergosterol, Hydrazino-acetic acid ethyl ester, and Phthalic acid, di (2-propylpentyl) ester, whereas theoretical calculations showed that the highest EHOMO and lowest ELUMO values correspond to Dehydrergosterol and the Phthalic acid, which are the responsible for the extract inhibitory properties.

Microbial dynamics, chemical profile, and bioactive potential of diverse Egyptian marine environments from archaeological wood to soda lake

Halophilic archaea are a unique group of microorganisms that thrive in high–salt environments, exhibiting remarkable adaptations to survive extreme conditions. Archaeological wood and El–Hamra Lake serve as a substrate for a diverse range of microorganisms, including archaea, although the exact role of archaea in archaeological wood biodeterioration remains unclear. The morphological and chemical characterizations of archaeological wood were evaluated using FTIR, SEM, and EDX. The degradation of polysaccharides was identified in Fourier transform infrared analysis (FTIR). The degradation of wood was observed through scanning electron microscopy (SEM). The energy dispersive X–ray spectroscopy (EDX) revealed the inclusion of minerals, such as calcium, silicon, iron, and sulfur, into archaeological wood structure during burial and subsequent interaction with the surrounding environment. Archaea may also be associated with detected silica in archaeological wood since several organosilicon compounds have been found in the crude extracts of archaeal cells. Archaeal species were isolated from water and sediment samples from various sites in El–Hamra Lake and identified as Natronococcus sp. strain WNHS2, Natrialba hulunbeirensisstrain WNHS14, Natrialba chahannaoensis strain WNHS9, and Natronococcus occultus strain WNHS5. Additionally, three archaeal isolates were obtained from archaeological wood samples and identified as Natrialba chahannaoensisstrain W15, Natrialba chahannaoensisstrain W22, and Natrialba chahannaoensisstrain W24. These archaeal isolates exhibited haloalkaliphilic characteristics since they could thrive in environments with high salinity and alkalinity. Crude extracts of archaeal cells were analyzed for the organic compounds using gas chromatography–mass spectrometry (GC–MS). A total of 59 compounds were identified, including free saturated and unsaturated fatty acids, saturated fatty acid esters, ethyl and methyl esters of unsaturated fatty acids, glycerides, phthalic acid esters, organosiloxane, terpene, alkane, alcohol, ketone, aldehyde, ester, ether, and aromatic compounds. Several organic compounds exhibited promising biological activities. FTIR spectroscopy revealed the presence of various functional groups, such as hydroxyl, carboxylate, siloxane, trimethylsilyl, and long acyl chains in the archaeal extracts. Furthermore, the archaeal extracts exhibited antioxidant effects. This study demonstrates the potential of archaeal extracts as a valuable source of bioactive compounds with pharmaceutical and biomedical applications.

The Role of Indigenous Yeasts in Shaping the Chemical and Sensory Profiles of Wine: Effects of Different Strains and Varieties.

The microbial terroir is an indispensable part of the terroir panorama, and can improve wine quality with special characteristics. In this study, eight autochthonous yeasts (Saccharomyces cerevisiae), selected in Huailai country, China, were trailed in small-scale and pilot fermentations for both white (Riesling and Sémillon) and red (Cabernet Sauvignon and Syrah) wines and evaluated by GC-MS analysis and the rate-all-that-apply (RATA) method. Compared to commercial yeast strains, the indigenous yeasts were able to produce higher concentrations of ethyl esters and fatty acid ethyl esters, and higher alcohol, resulting in higher odor activity values of fruity, floral attributes. Marked varietal effects were observed in the pilot fermentation, but yeast strains exerted a noticeable impact in modulating wine aroma and sensory profile. Overall, indigenous yeast could produce more preferred aroma compounds and sensory characteristics for both white and red wines, demonstrating the potential for improving wine quality and regional characteristics.

Effect of long-term ethanol consumption and a high-fat diet on mitochondrial respiration in rat pancreatic acinar cells and hepatocytes

Chronic alcohol consumption may cause pancreatitis and alcohol-related liver diseases. Both adaptation and damage of liver mitochondria in animals on chronic ethanol and high-fat diets were demonstrated. It is currently not clear if ethanol or its metabolites such as fatty acid ethyl esters can cause mitochondrial damage to the pancreas. The present study aimed to evaluate the effect of chronic ethanol administration in combination with a high-fat diet on mitochondrial respiration in both pancreatic acinar cells and hepatocytes of rats. Wistar male rats on a high-fat diet (35% calories) were administered ethanol (6 g/kg body weight) by oral gavage for 14 days. Pancreatic acini cells and hepatocytes were isolated with collagenase digestion. The respiration of isolated cells was studied with a Clark electrode. Ethanol administration to rats kept on a high-fat diet was followed by a rapid loss of animal weight during the first 5 days of the experiment and diminished secretory response of pancreatic acini to acetylcholine, however, no changes in acinar cells ultrastructure, basal, oligomycin-insensitive or FCCP-uncoupled respiration were found. Meanwhile ethanol caused a significant (~40%) increase in basal and maximal FCCP-uncoupled respiration rate of isolated hepatocytes. In conclusion, chronic ethanol administration to rats on a high-fat diet does not cause mitochondrial damage in the pancreas, while mitochondria of the liver adapt to ethanol by increasing respiration rate. Keywords: ethanol, hepatocytes, high fat diet, mitochondrial respiration, pancreatic acinar cells

Effects of salt and rice flour concentration on microbial diversity and the quality of sour meat, a Chinese traditional meat

This study investigated the effects of salt (3 % and 6 %, m/m) and rice flour (10 % and 20 %, m/m) addition in sour meat, a traditional Chinese fermented meat. It was found that salt has greater effect than rice flour addition in spontaneous fermentation. Low-salt groups had lower pH and higher titratable total acid. In the low-salt groups, the dominant genera were Lactobacillus and Lactococcus, whereas Staphylococcus, Weissella, and Tetragenococcus were dominant in the high-salt groups. Higher total free amino acids and essential amino acids, organic acids, hexanoic acid ethyl ester and octanoic acid ethyl ester were found in the low-salt groups. The RDA analysis revealed that Lactococcus was closely related to product quality, with the S3F10 (3 % salt and 10 % rice flour) group outperforming the others in the sensory evaluation. Therefore, 3 % salt and 10 % rice flour were considered more appropriate for the production of healthy and tasty fermented sour meats.

Hydrogen Storage Studies of Nanocomposites Derived From O‐Ethyl‐S‐((5‐Methoxy‐1H‐Benzo[d]Imidazol‐2‐Yl)Carbonothioate (OESMBIC) With ZnO and TiO2 Nanoparticles

ABSTRACT5‐Methoxy‐2‐mercaptobenzamidazole was used to synthesize O‐ethyl‐S‐(5‐methoxy‐1H‐benzo[d]imidazol‐2‐yl) carbonothioate (OESMBIC) by the reaction with chloroacetic acid ethyl ester in a KOH solution. The reaction product (OESMBIC) was characterized using Fourier transform infrared (FTIR), melting point, and 1H‐NMR. The characteristic results prove the formation of the target compound with high purity. Furthermore, the work includes the synthesis of ZnO and TiO2 nanoparticles via chemical methods in the high alkalinity solution. These nanoparticles were used to synthesize two novel nanocomposites named OESMBIC‐ZnO and OESMBIC‐TiO2. The synthesized nanocomposites were characterized by FTIR, SEM, EDX, TEM, and XRD. The results prove that the prepared titanium oxide as nanotubes with diameters ranging between 20 and 35 nm decorated with OESMBIC. The results prove that ZnO in OESMBIC‐ZnO was found as nanorods with different lengths and diameters of 40–65 nm decorated with OESMBIC molecules. The as‐prepared compounds; OESMBIC, OESMBIC‐ZnO, and OESMBIC‐TiO2 were used for the hydrogen storage application using the VTI method. The results prove that the addition of ZnO and TiO2 nanoparticles enhanced the storage ability of OESMBIC as the OESMBIC gave only 0.50 wt% at an equilibrium pressure of 40 bar, while it reached 2.40 and 4.37 wt% at equilibrium pressures of 60 and 75 bar for OESMBIC‐ZnO and OESMBIC‐TiO2, respectively.

Potential authentication of re-esterified triacylglycerol-type omega-3 oils using multivariate analysis of lipid profiles

This study aimed to authenticate re-esterified triacylglycerol (rTG)-type omega-3 oils prone to adulteration with fatty acid ethyl ester (FAEE)-type oils via hierarchical cluster analysis (HCA) and principal component analysis (PCA) of their lipid profiles. A total of 104 rTG-type omega-3 oil samples, consisting of seven authentic (two commercial and five laboratory-made), 60 adulterated, and 37 unauthenticated commercial samples, were analyzed for their acylglycerol, FAEE, and total EPA/DHA contents. Type 1 authentic samples contained higher triacylglycerols (TG) (63.0–86.3 wt%), lower diacylglycerols (DG) (8.1–31.5 wt%), and no FAEE compared to type 2 authentic samples (36.9–62.1 wt% TG, 9.4–36.9 wt% DG, and 14.9–27.3 wt% FAEE). HCA and PCA differentiated authentic samples from adulterated samples, although type 2 samples were closer to adulterated samples. Both analyses showed that 30/37 commercial samples exhibited higher similarity in lipid profiles to authentic samples than to adulterated samples, indicating their potential for authentication.

Exploring the Volatile Profile of Vanilla planifolia after Fermentation at Low Temperature with Bacillus Isolates.

Vanilla planifolia is grown as a high-value orchid spice for its odor and savor attributes that increase due to the curing process associated with microbial colonization. This tends to influence the aromatic properties of vanilla. Hence, 11 Bacillus sp. strains were isolated from V. planifolia and identified with 16S rRNA gene sequencing. The liquid culture (1 mL of 107 CFU mL-1) of selected Bacillus vallismortis NR_104873.1:11-1518, Bacillus velezensis ZN-S10, and Bacillus tropicus KhEp-2 effectively fermented green-blanched vanilla pods kept at 10 °C during the sweating stage. GC-MS analysis showed that the methanol extract of non-coated, and B. vallismortis treated vanilla detected three (3) volatile compounds, whereas seven (7) components were obtained in B. tropicus and B. velezensis treatment. 4H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl was found in B. velezensis ZN-S10, B. tropicus KhEp-2, and B. vallismortis while it was not present in the control samples. This ketone compound suggested a Maillard reaction resulting in brown-increased aroma pods. Linoleic acid and Hexadecanoic acid ethyl esters were detected only in ZN-S10 strain-coated vanilla. A novel 3-Deoxy-d-mannoic lactone was detected only in B. vallismortis-treated vanilla characterized as a new compound in V. planifolia which suggested that the new compound can be altered with the coating of bacteria in vanilla during fermentation. Thus, the Bacillus strains improved the volatile profile and exhibited a new aroma and flavor profile of vanilla owing to bacteria fermentation during the curing process.

Evaluation of volatile and bioactive compounds of ethanol leaf extracts of Justicia secunda using GC-MS and GC-FID analysis.

The study evaluated the volatile and bioactive constituents of ethanol extracts of Justicia secunda using gas chromatography-mass spectrometry (GC-MS) for volatile composition while bioactive compound were assessed using gas chromatography flame ionization detector (GC-FID). The leaf extracts were prepared by being collected, air-dried, macerated in 96% ethanol, filtered and concentrated at 450C. The result obtained revealed the presences of bioactive compound such as flavonoid that include: Spartein (28.10 µg/ml), Ruti (15.6 µg/ml), Oxalate (12.70 µg/ml), Naringin (12.4 µg/ml), Steroids (11.7 µg/ml), Epinedrine (11.10 µg/ml), Cardiac glycoside (10.10 µg/ml), Flavonone (10.10 µg/ml), Ribalinidine (9.30 µg/ml), Anthocyanin (7.70%), Flavone (7.30 µg/ml), Sapogenin (7.30µg/ml), Proanthocyanin (6.90 µg/ml),Resveratol (6.70µg/ml), Epicatechin (5.70 µg/ml), Phytate (5.70µg/ml), Kaempferol (3.90 µg/ml),Catechin (2.00 µg/ml), Tannin (2.00 µg/ml). The GC-MS Screening of the plant’s extract identified eighty-two (82) bioactive compounds, which include Ethyl palmitate (5.54%), 2,4-Di-tert-butylphenol (4.04%),9,17-Octadecadienal, (4.05%), Linoleic acid ethyl ester (4.05%), 9,12-Octadecadienoic acid, ethyl ester (4.00%), Decane, 2-methyl (3.82%), Hexadecane (3.82%), Heptadecane, 2,6-dimethyl (3.26%), N-(3-methylButyl) acetamide (3.02%), Sulfurous acid, butyl octyl ester (3.25%), Hexane,1-(hexyloxy)-5-(3.06%) as the major bioactive compounds. The result of the GC-MS analysis showed that the ethanol extract of Justicia secunda contains many pharmacologically important bioactive compounds such as antioxidant, anti-inflammatory, anti-microbial, anti-diabetic anti-cancer effects. Traditionally, Justicia species are used in the treatment of inflammation, rheumatism, arthritis gastrointestinal diseases, anaemia and respiratory tract infection. The proximate analysis of the ethanol extract of the leaves revealed notable levels of various components, where carbohydrates were found to be the highest, followed by moisture content, protein, fats, fiber, and ash content, respectively.

Novel simultaneous analysis of 18 types of glycosaminoglycan-derived disaccharides using 4-aminobenzoic acid ethyl ester derivatization by HPLC with fluorescence detection.

Glycosaminoglycans (GAGs), including hyaluronic acid (HA), chondroitin sulfate (CS)/dermatan sulfate (DS), heparan sulfate (HS)/heparin (HP), and keratan sulfate (KS), play pivotal roles in living organisms. Generally, GAGs are analyzed after enzymatic digestion into unsaturated or saturated disaccharides. Due to high structural similarity between disaccharides, however, separation during analysis is challenging. Additionally, little is known about the structures of GAGs and their functional relationships. Elucidating the function of GAGs requires highly sensitive quantitative analytical methods. We developed a method for the simultaneous analysis of 18 types of disaccharides derived from HA (1 type), CS/DS (7 types), HS/HP (8 types), and KS (2 types) potentially detectable in analyses of human urine. The simple method involves HPLC separation with fluorescence detection following derivatization of GAG-derived disaccharides using 4-aminobenzoic acid ethyl ester (ABEE) as a pre-labeling agent and 2-picoline borane as a reductant. The ABEE derivatization reaction can be performed under aqueous conditions, and excess derivatization reagents can be easily, rapidly, and safely removed. This method enables highly sensitive simultaneous analysis of the 18 abovementioned types of GAG-derived disaccharides using HPLC with fluorescence detection in small amounts of urine (1mL) in a single run. The versatile method described here could be applied to the analysis of GAGs in other biological samples.

Discovery of cycloheptapeptides phakefusins A−E from the marine sponge Phakellia fusca based on molecular networking

Guided by a probe-based molecular networking strategy, five undescribed cycloheptapeptides, phakefusins A−E (1−5), were isolated from the marine sponge Phakellia fusca. Compounds 1 and 2 contain the nonproteinogenic amino acid residues of dioxindolyalanine (Dioia) and β-3-oxindolylalanine (Oia), respectively. Compound 3 possesses a unique methionine sulfoxide, whereas compound 5 includes a glutamic acid ethyl ester unit. Their structures were elucidated through NMR spectroscopy, HR-MS/MS analysis, and the advanced Marfey's method. By synthesizing the (S, S/R)-Oia standard through tryptophan oxidation, we determined the configuration of this amino acid in compound 2 using the advanced Marfey's method. These cycloheptapeptides were evaluated for their antitumor, antibacterial, and antioxidant activities. Compound 1 showed moderate cytotoxicity against MCF-7 and PC9 cells, with IC50 values of 6.8 and 9.6 μM, respectively, while compounds 2−5 demonstrated potential antioxidant effects by upregulating HO-1, NQO1, and SOD2 levels, as well as inducing Nrf2 activation.

Effect of fatty acid composition on the volatile compounds of pasteurized milk during low-temperature storage

The change in milk fat during storage greatly influences its flavor. This study investigates the effect of fatty acid composition on milk flavor by analyzing volatile compounds in pasteurized whole milk (PWM) and pasteurized skim milk (PSM) during storage at 4 °C. 33 types of volatile compounds were detected and the content of ketones was highest, followed by esters and aldehydes. Based on variable importance in projection and relative odor activity value, 2-hexenal dimer, acetic acid ethyl ester dimer, acetic acid ethyl ester, and butanal were identified as the key differential volatile compounds. These compounds were found in higher concentrations in PWM than in PSM, indicating a close relationship with the changes in the fatty acid composition of milk fat. Among 11 fatty acids detected in PWM, the content of saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) decreased by 0.69 % and 49.1 %, respectively, while the content of monounsaturated fatty acids increased by 46.8 % during 15 days storage, which suggests that the oxidation of SFA and PUFA contributed more to the volatile compound formation. Correlation analysis between fatty acid composition and volatile compounds found that fatty acid C18:2 and C16:0 were strongly associated for 2-hexenal, acetic acid ethyl ester, and butanal. These fatty acids were mainly derived from neutral lipids or phospholipids. These findings provide a new perspective for the formation pathway of milk flavor.

Analysis of lipophilic fingerprints of edible wild rhubarb (Rheum ribes L.) using GC-MS combined with chemometrics

Rhubarb (Rheum ribes L.) is used globally as both a food supplement and a vegetable. The lipophilic fingerprints of wild rhubarb of Turkiye origin were investigated by gas chromatography-mass spectrometry (GC-MS) combined with chemometrics, including hierarchical cluster analysis (HCA) and principal component analysis (PCA). GC-MS results identified a total of 72 lipophi6lic compounds, including fatty acids, fatty acid esters, simple hydrocarbons and other organics, in all parts of the plant. PCA and HCA analyses revealed intraspecific lipophilic component variation among six wild rhubarb populations, as well as significant variation among lipophilic fingerprints in leaves, fruits, flowers, and roots. Among the compounds, palmitic acid, α-linolenic acid, ethyl palmitate, ethyl oleate, linoleic acid ethyl ester and n-tetracosane were important for the overall lipophilic fingerprints of all parts of the rhubarb. These findings highlight the potential of using HCA and PCA analysis in combination with GC-MS fingerprints as an effective analytical approach.

Antioxidant properties, antidiabetic activity, and GC-MS phytochemical analysis of wheat-based bread fortified with celosia argentea seed flour

Pseudocereals like Celosia argentea seed have been indicated to have numerous therapeutic and prophylactic potentials that are yet to be incorporated into food materials. This study evaluated the antioxidant properties, antidiabetic potential, and phytochemicals of wheat-based bread fortified with Celosia argentea seed flour. Bread samples were produced using standard methods, fortifying refined and whole wheat with 5 and 10% Celosia argentea seed flour. The antioxidant properties and α-amylase inhibition of bread samples were determined using standard methods. The phytochemicals present in the methanolic extracts of bread samples were identified with Gas Chromatography-Mass Spectrometry (GCMS). Statistical significance was tested at α0.05. The result of the antioxidant properties for bread samples were Total flavonoid content (0.61-0.85 mg/g), Total Phenolic Content (1.1-1.31 mgGAE/g), total antioxidant capacity (1.19-3.34 mgGAE/g), Ferric reducing antioxidant power (0.13-0.54 mg/g) and DPPH (42.58-49.75%). The IC50 values obtained for Celosia argentea seed substituted wheat bread ranged between 58.20 and 171.05 μg/mL. The antioxidant properties and α-amylase inhibition showed a significant (p<0.05) increase as the percentage of inclusion of Celosiae argentea seed increased. Bioactive compounds detected in bread samples produced by the fortification of wheat flour (whole and refined) with Celosia argentea seed flour include 9,12-Octadecadienoic acid methyl ester; Docosanoic acid, methyl ester; E,E,Z-1,3,12-Nonadecatriene-5,14-diol; Linoleic acid ethyl ester; and Squalene. The predominant health benefits of phytochemicals detected in bread samples fortified with C. argentea seed were anti-inflammatory potentials, antioxidant protection, and reduction of lipid peroxidation. Including Celosia argentea seed impacted the antioxidant and antidiabetic potential of bread samples.

Variation in the Aroma Composition of Jasmine Tea with Storage Duration.

This study investigated the changes in the aroma of jasmine tea during storage. Solid-phase micro-extraction (SPME)-gas chromatography (GC)-mass spectrometry (MS) and stir bar sorptive extraction (SBSE)-GC-MS were combined to detect all volatile compounds. GC-olfactometry (GC-O), odor activity value (OAV), and p-value were employed to analyze and identify the key aroma compounds in six jasmine tea samples stored for different durations. Nine key aroma compounds were discovered, namely (Z)-3-hexen-1-yl acetate, methyl anthranilate, methyl salicylate, trans-β-ionone, linalool, geraniol, (Z)-4-heptenal, benzoic acid methyl ester, and benzoic acid ethyl ester. The importance of these compounds was confirmed through the aroma addition experiment. Correlation analysis showed that (Z)-4-heptenal might be the main reason for the increase in the stale aroma of jasmine tea. Through sensory evaluation and specific experimental analysis, it can be concluded that jasmine tea had the best aroma after 3 years of storage, and too long a storage time may cause the overall aroma of the tea to weaken and produce an undesirable odor. The findings can provide a reference for the change in aroma during the storage of jasmine tea and provide the best storage time (3 years) in terms of jasmine tea aroma.

On the evaluation of surface tension of biodiesel

Over time, with the increase in population and the subsequent increase in energy consumption and also due to the non-renewability of fossil fuels, the study of alternative fuels has increased. One of these fuels is biodiesel, which is a suitable alternative to fossil fuels such as diesel and received much attention from researchers today. For this reason, measuring the physical properties of biodiesel is of great importance. Due to the high cost and time-consuming nature of laboratory methods, numerical methods are used to estimate material properties. The novelty of this research was the use of two white box models, including Group method of data handling (GMDH) and Gene expression programming (GEP), which work on the basis of artificial intelligence. By using these models, two simple mathematical equations with high accuracy were presented to predict the surface tension of biodiesel. These models can be used at different temperatures and molecular weights. To do modeling, 78 laboratory data available in the literature were gathered and the data were randomly divided into two groups, train and test, in a ratio of 80 and 20. The input parameters include mass fraction of fatty acid ethyl esters and temperature (T), and esters are divided into three groups according to their molecular weight: less than 200 (Mw1), between 200 and 300 (Mw2), and greater than 300 (Mw3). The statistical error parameters were calculated for the two models developed in this research and after comparing the results, it was found that the GMDH model estimates the surface tension of biodiesel with a higher accuracy. The average absolute relative error for GMDH and GEP models was reported as 0.97 and 1.89, respectively. Also, other statistical error parameters of GMDH such as RMSE, SD, and R2 for the GMDH model were obtained as 0.444, 0.000233, and 0.9233, respectively. Moreover, sensitivity analysis showed that temperature has the highest impact on the surface tension of biodiesel, which is also an inverse effect. Finally, suspicious laboratory and outlier data points were identified using the Leverage technique. According to this analysis, only five data points were identified as outliers and suspicious laboratory data.

Fermentation Performances and Aroma Contributions of Selected Non-Saccharomyces Yeasts for Cherry Wine Production.

This study evaluates the fermentation performances of non-Saccharomyces strains in fermenting cherry must from Italian cherries unsuitable for selling and not intended to be consumed fresh, and their effects on the chemical composition of the resulting wine. Fermentation trials in 100 and 500 mL of must were carried out to select 21 strains belonging to 11 non-Saccharomyces species. Cherry wines obtained by six select strains were chemically analyzed for fixed and volatile compounds. Quantitative data were statistically analyzed by agglomerative hierarchical clustering, partial least squared discriminant analysis, and principal component analysis. Wines revealed significant differences in their composition. Lactic acid and phenylethyl acetate levels were very high in wines produced by Lachancea and Hanseniaspora, respectively. Compared to S. cerevisiae wine, non-Saccharomyces wines had a lower content of fatty acid ethyl esters 4-vinyl guaiacol and 4-vinyl phenol. The multivariate analysis discriminated between wines, demonstrating the different contributions of each strain to aroma components. Specifically, all wines from non-Saccharomyces strains were kept strictly separate from the control wine. This study provided comprehensive characterization traits for non-conventional strains that enhance the aroma complexity of cherry-based wine. The use of these yeasts in cherry wine production appears promising. Further investigation is required to ascertain their suitability for larger-scale fermentation.

Fast On-Site Electroanalysis of Eicosapentaenoic Acid Ethyl Ester in the Liver and Meat of Stingray Using a Stochastic Miniplatform Based on a 3D Stochastic Microsensor

Eicosapentaenoic acid ethyl ester has an important role in metabolism and it is also an important antithrombotic agent. Its concentration in the liver and meat of the stingray is essential when one would like to use the extracts containing the eicosapentaenoic acid ethyl ester from stingray as biopharmaceutical products. A miniplatform having as detection tool a 3D stochastic microsensor was designed and used for the assay of eicosapentaenoic acid ethyl ester from stingray liver and meat. Natural monocrystalline diamond paste was modified with a solution of heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin to obtain the modified diamond paste used in the 3D stochastic microsensor. A wide working concentration range (5.0 × 10−15 – 5.0 × 10−8) and a very low limit of quantitation (5.0 × 10−15) were attained. The proposed miniplatform was successfully used for the assay of eicosapentaenoic acid ethyl ester from stingray liver and meat with recoveries higher than 99.90%, and % RSD values lower than 0.05 (N = 10).

A multi reaction kinetic model to describe the enzymatic transesterification reaction of jatropha oil using a fermented solid containing lipases

The advancement of more precise tools for sustainable process design in enzymatic biodiesel synthesis from renewable sources is crucial. Kinetics of solvent-free transesterification reactions were conducted across a temperature spectrum from 30 °C to 60 °C, utilizing Jatropha curcas oil (TG) and ethanol as substrates, alongside a fermented solid by Rhizopus homothallicus as the biocatalyst. The dynamics of chemical species concentrations were monitored through High-performance Thin-Layer Chromatography. Maximum productivities were achieved at 35 °C and 60 °C for biodiesel (293.24 and 299.02 g kg biocat−1 h−1, respectively), at 40 °C for diglycerides (1018.36 g kg biocat−1 h−1), and at 35 °C for monoglycerides (560.75 g kg biocat−1 h−1). Maximum yields were determined at 30 °C for fatty acid ethyl esters (0.56 g gTG−1), and at 40 °C for diglycerides (0.53 g gTG−1) and monoglycerides (0.30 g gTG−1). Based on the experimental findings, a kinetic model was formulated encompassing three reversible transesterification reactions. Individual reactions were structured following classical biochemical kinetics, inclusive of ethanol inhibition. Model fitting was executed through non-linear multivariable regression techniques, with the minimum of the average coefficient of variation of the residuals (ACVR) serving as the objective function. The resulting fit of the kinetic model to the experimental data proved satisfactory, with an ACVR of less than 5 % across all instances. Notably, the maximum biodiesel productivity, obtained in this work, represented the highest value, compared to other related studies, using a fermented solid as a biocatalyst.