Concentrations Of Ethyl Acetate Research Articles

Biofiltration of toluene in the presence of ethyl acetate or n-hexane: Performance and microbial community.

This study describes the operation of two independent parallel laboratory-scale biotrickling filters (BTFs) to degrade different types of binary volatile organic compound (VOC) mixtures. Comparison experiments were conducted to evaluate the effects of two typical VOCs, i.e., ethyl acetate (a hydrophilic VOC) and n-hexane (a hydrophobic VOC) on the removal performance of toluene (a moderately hydrophobic VOC) in BTFs ''A" and ''B", respectively. Experiments were carried out by stabilizing the toluene concentration at 1.64 g m-3 and varying the concentrations of gas-phase ethyl acetate (0.85-2.8 g m-3) and n-hexane (0.85-2.8 g m-3) at an empty bed residence time (EBRT) of 30 s. In the presence of ethyl acetate (850 ± 55 mg m-3), toluene exhibited the highest removal efficiency (95.4 ± 2.2%) in BTF "A". However, the removal rate of toluene varied from 48.1 ± 6.9% to 70.1 ± 6.8% when 850 ± 123 mg m-3 to 2800 ± 136 mg m-3 of n-hexane was introduced into BTF "B". The high-throughput sequencing data revealed that the genera Pseudomonas and Comamonadaceae_unclassified are the core microorganisms responsible for the degradation of toluene. The intensity of the inhibitory or synergistic effects on toluene removal was influenced by the type and concentration of the introduced VOC, as well as the number and activity of the genera Pseudomonas and Comamonadaceae_unclassified. It provides insights into the interaction between binary VOCs during biofiltration from a microscopic perspective.

Влияние винных и виноградных спиртов на качество напитков из виноградного сырья

Table grapes that have lost their marketable appearance are considered waste products. However, such grapes still possess some technological properties that make it possible to use them as a raw material for wine and grape spirits. This research featured the effect of the composition and technology of table grape alcohols on the volatile compounds and sensory profile 
 of grape beverages.
 The study involved six white and six red grape beverages. In the test samples, the fermentation process was stopped by adding wine spirits and grape spirits obtained by rectification of distillates from table grapes. In the control samples, the procedure involved rectified grain alcohol. The physicochemical parameters of drinks and spirits were defined by standard methods. The highly volatile compounds were determined by gas chromatography. The sensory assessment was conducted by panelists from the Winemaking Research Center of the North-Caucasian Federal Scientific Center of Horticulture, Viticulture, and Winemaking.
 In this study, the wine spirits and the grape spirits obtained from table grapes had no effect on the standard indicators, e.g., volatile acids and acetoin. However, they increased the mass concentrations of highly volatile compounds in the following manner: drinks with grain alcohol ˂ drinks with wine alcohol ˂ drinks with grape alcohol. The content of acetaldehyde increased by 10–14% while the contents of ethyl acetate, esters, and higher alcohols increased by 25–35, 4.5–8.5, and 15%, respectively. The furfural content increased by 0.4–1.4 mg/L in the samples with grape alcohol. The samples with white grape varieties acquired a more prominent floral-honey flavor whereas those with black grapes acquired hints of hazelnut and honey.
 As a result of the study, it was found that wine alcohol and grape alcohol moderately increased the content of volatile compounds in drinks and had a positive effect on their sensory perception, which proves the expediency of their use in beverage technology.

Potential Antifungal of Merang Padi Extract (Oryza sativa) Against Fungal Growth

<div><table cellspacing="0" cellpadding="0" align="left"><tbody><tr><td align="left" valign="top"><p><em>Merang padi is a traditional medicine that comes from natural ingredients, namely plants. However, there has not been much research on the activity of rice straw extract (Oryza sativa) being explored and researched. The aim of this research was to determine the yield of extracts and the number of antifungal isolates in inhibiting fungal growth and their potential as antifungals against Candida albicans and Aspergillus fumigatus fungi. This research uses experimental research with a quantitative approach carried out through laboratory tests. The design used was a Completely Randomized Design (CRD) which was grouped into 6 treatment groups, namely 4 groups of rice straw extract and 2 control groups which were repeated for each treatment 4 times. The treatment group consisted of P1 with rice straw extract with a concentration of 20,000 ppm, P2 with rice straw extract with a concentration of 40,000 ppm, P3 with rice straw extract with a concentration of 60,000 ppm and P4 with rice straw extract with a concentration of 80,000 ppm. Meanwhile, the control group, namely P0 as a negative control, namely NaCl 0.9% and P5 as a positive control, namely Nystatin 100,000 IU. The research sample was rice straw from rice plants that had been identified and then weighed. Data analysis used one way ANOVA SPSS version 20. If there were differences then a further test was carried out, namely the Honest Significant Difference Test (BNJ) to see the differences between each treatment based on the coefficient of diversity (KK) value obtained at the 5% test level. The results of tests that have been carried out show that the n-hexane fraction of rice straw has no antifungal activity, while the ethyl acetate and n-butanol fractions have antifungal activity. The concentration of ethyl acetate in this study was greater than the other compounds.</em></p><p> </p></td></tr></tbody></table></div><p><strong><em>Keywords : Candida albicus, merang padi, mushrooms, oryza sativa</em></strong></p>

Microbial community dynamics and spatial distribution of flavor compound metabolism during solid-state fermentation of Baijiu enhanced by Wickerhamomyces anomalus

Biofortification of Baijiu fermentation process using exogenous functional strains can change the microbial community structure in the fermentation system, which in turn affects the flavor of Baijiu. In this study, we used a simulated solid-state fermentation of Baijiu to investigate the effects of the addition of Wickerhamomyces anomalus strain YM001 on the improvement of Baijiu flavor compounds and its mechanism. The results of microbial diversity analysis showed that Wickerhamomyces and Lactiplantibacillus were the dominant genera in the biofortified fermentation system. In addition, W. anomalus YM001 drove the change of bacteria with moisture and alcohol content, which will synthesise esters using ethanol and moisturet as substrates. The addition of W. anomalus YM001 increased the content of total esters in fermentation samples, especially ethyl acetate, and other compounds such as acetic acid and phenylethyl ester to some extent. W. anomalus YM001 altered the correlation between microorganisms and flavor compounds, with Latilactobacillus and Pediococcus showing a significant positive correlation with ethyl acetate and Weissella showing a significant negative correlation with ethyl caproate and ethanol. In addition, the metabolic properties of ethyl acetate, ethyl decanoate and phenethyl acetate were also altered. In summary, biofortification with W. anomalus YM001 altered the microbial community composition and the physicochemical properties of the fermented grains in the Baijiu brewing system, while elevating the contents of ethyl acetate, ethyl decanoate and phenyl acetate. These findings suggest that biofortification during Baijiu brewing improves Baijiu flavor and contributes to the overall quality of Baijiu.

An on-chip microarray platform for material-temperature optimization and gas discrimination

The demand for gases detection has promoted extensive research into gas sensors. Sensor arrays can be used as electronic olfaction units for complex gas detection and identification. However, the gas sensing properties are affected by various factors. The multi-dimensional nature of those interactions is crucial for creating a sensor array with diverse responses, but it is also challenging to fabricate an array considering all these parameters, particularly in miniaturization. In this paper, we present a framework that can take multiple factors into consideration and help to fabricate an optimal array for gas identification. 32 sensors including different MOS materials (SnO2, In2O3, WO3), morphologies (microsphere, nanoparticle, nanoflake), doped/loaded metals (Pd, Pt, Ce, Ru, Rb), and operational temperatures (250℃∼370℃) are discussed. A material-temperature-analyte-response database was then established by storing their response characteristics towards low ppm concentrations of ammonia, ethyl acetate, toluene, methanol, ethanol, and acetone. An optimized array was then constructed out of 10,518,300 possible combinations of materials and operational temperatures. Results showed improvements in discrimination ability and the optimized array integrated into the chip can provide vector signals with high selectivity, completely recognizing all the 6 target gases and even for their multi-component mixture after linear discriminant analysis transformation.

Process Optimization for Production of Persimmon Wine with Lower Methanol.

Persimmon wine has various nutritional elements and high commercial potential. However, the high content of methanol, which is derived from the fruit's pectin, always hinders persimmon wine production. To reduce the methanol level in the wine, the effects of persimmon cultivar, starter, pectinase, and pretreatment methods were investigated via single-factor and orthogonal experiments. The persimmon cultivar 'MaoKui' was finally used throughout the study owing to its lowest pectin concentration (24.5 g/kg). The best treatment conditions against the persimmon pulp were pectinase (0.04 g/kg) at 30 °C for 4 h, then boiled at 115 °C for 15 min before fermentation started. The optimized fermentation conditions for wine production were pectinase (0.03 g/kg), 250 mg/kg starter (BO213 and SPARK with equal amounts), at 28 °C for 6 d. The obtained wine had 77.7 mg/L methanol and a 68.4% raw juice yield. The fruit wine had 111.4 mg/L methanol and a 90.6 sensory evaluation score. Forty-nine volatile aromas were identified. Ethyl acetate content was the highest, followed by 3-methyl-1-butanol, 2,3-butanediol, and lactate ethyl ester. The persimmon wine had a unique style with transparent color, elegant aroma, and pure taste.

Insight into the nucleation behavior of tiamulin hydrogen fumarate methanol solvate in methanol-ethyl acetate binary mixtures

To investigate the nucleation behavior of tiamulin hydrogen fumarate methanol solvate (THFMS), the solubility, induction time, and metastable zone width (MSZW) of THFMS in methanol-ethyl acetate binary mixtures were measured. The nucleation potential model, which is based on the classical nucleation theory and correlates the induction time and MSZW, has been employed to deal with the experimental data and estimate the interfacial energy and the critical nucleation potential. The estimated values determined from the nucleation potential model are in accordance with the experimental values. The interfacial energy and the critical nucleation potential of THFMS steadily decrease with the increasing saturation temperature, whereas those of THFMS initially decrease and subsequently increase as the ethyl acetate content increases. The results demonstrate that an increase in saturation temperature leads to enhanced nucleation favorability, while the difficulty of nucleation initially decreases and then increases with increasing ethyl acetate content. Furthermore, the critical nucleation parameters, including the critical Gibbs free energy, the critical nucleus size, and the critical number of molecules in a nucleus, exhibit the same trend in alterations regarding both saturation temperature and ethyl acetate content.

Effect of Fortified Inoculation with Indigenous Lactobacillus brevis on Solid-State Fermentation of Light-Flavor Baijiu.

Baijiu, one of the world's oldest distilled liquors, is widely consumed globally and has gained increasing popularity in East Asia. However, a comprehensive understanding of the underlying principles behind this traditional liquor product remains elusive. Currently, Baijiu is facing the industrial challenge of modernization and standardization, particularly in terms of food quality, safety, and sustainability. The current study selected a Lactobacillus brevis strain based on experiments conducted to assess its environmental tolerance, enzyme activity, and fermentation performance, and highlight its exceptional fermentation characteristics. The subsequent analysis focused on examining the effects of fortifying the fermentation process of L.brevis on key microbiotas, physicochemical parameters, and volatile profiles. The qPCR results revealed that the inoculated L. brevis strategically influenced the the composition of the dominant microbial communities by promoting mutual exclusion, ultimately leading to improved controllability of the fermentation process. Moreover, the metabolism of the inoculated L. brevis provided more compounds for the formation of flavor profiles during fermentation (the content of ethyl acetate was increased to 57.76 mg/kg), leading to a reduction in fermentation time (from 28 d to 21 d). These findings indicate promising potential for the application of the indigenous strain in Baijiu production.

Rapid Determination of Five Residual Solvents in Ursodeoxycholic Acid Raw Materials

The chromatographic conditions were optimized using headspace gas chromatography, and a simple and rapid method was established for the simultaneous determination of five residual solvents in ursodeoxycholic acid raw materials. The corresponding quality standards were revised. The research results demonstrate that by utilizing a capillary column with a stationary phase consisting of 5% phenyl-95% dimethylpolysiloxane (HP-5, 30 m × 0.32 mm, film thickness 1.0 µm) and a flame ionization detector in conjunction with a headspace injection system and a programmed temperature ramping method, satisfactory analytical results can be achieved. The specific operating conditions are as follows: an initial column temperature of 45 °C, followed by a column temperature increase at a rate of 5 °C per minute up to 60 °C, then a further increase at a rate of 10 °C per minute up to 100 °C, and finally a rapid increase at a rate of 40 °C per minute up to 200 °C, where it is held for 10 min. Nitrogen is employed as the carrier gas at a flow rate of 1 mL/min with a split ratio of 14:1. The headspace vial temperature is maintained at 100 °C, with a sample equilibration time of 45 min. The concentration of methanol ranged from 0.06 mg/mL to 0.3 mg/mL, and the concentrations of acetone, tert-butanol, ethyl acetate, and triethylamine showed a good linear relationship with the peak area within the range of 0.1 mg/mL to 0.5 mg/mL (r = 0.999); The quantitation limits for methanol, acetone, tert-butanol, ethyl acetate, and triethylamine were 4.2, 0.9, 1.5, 1, and 0.1 μg/mL, respectively, with detection limits of 1.2, 0.25, 0.025, 0.3, and 0.025 μg/mL, respectively. The recovery rates of each solvent ranged from 92.9% to 106.0%, with RSD% (n = 9) less than 3.8%; the method exhibited good repeatability, with RSD% (n = 6) less than 2.5%. Furthermore, the robustness is good. The established method is simple, accurate, specific, and highly sensitive, and can be used for the simultaneous and rapid determination of five residual solvents in ursodeoxycholic acid raw materials.

Determination of Anti-oxidant Activity of Ethanol, Ethyl acetate, Hexane, and Aqueous Extracts of Sri Lankan Traditional Poly-herbal Formula Nāgarādi Panchakaya

Natural products are the good source of natural antioxidants. Nāgarādi panchakaya is a well-known poly-herbal formula prescribed specially for upper respiratory tract diseases by Sri Lankan Ayurveda medical practitioners. The name implies that it contains five herbal ingredients including Inguru (Zingiber officinale), Devadāra (Cedrus deodara), Kottammalli (Coriandrum sativum), Ela batu (Solanum indicum) and Katuwelbatu (Solanum xanthocarpum). This research study was aimed to determine the antioxidant activity of Nāgarādi panchakaya, extracted with different solvents (ethanol, ethyl acetate, n-hexane and water). Antioxidant activity was evaluated by using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay method and the Ferric Reducing Antioxidant Power (FRAP) assay. In vitro antioxidant free radicals scavenging capacities of different concentrations of ethanol, ethyl acetate, n-hexane and water extracts, of Nāgarādi panchakaya were evaluated. The percentage of inhibition and IC50 were calculated. IC50 (μg/mL) of water, ethanol, ethyl acetate, n-hexane and Ascorbic Acid were found to be 179.89±1.25 µg /mL, 248.09±1.74 µg /mL, 169.43± 0.98µg /mL, 189.56±2.23 µg /mL, and 01.18±0.98 µg /mL respectively in DPPH radical scavenging assay. In FRAP assay the reducing power for the different extracts varied in following order: water > ethanol > ethyl acetate > n-hexane. The total Phenolic content of water, ethanol, ethyl acetate and n-hexane extracts were 1.73±0.51 mg GAE/g, 2.59±0.67 mg GAE/g, 3.67±0.81 mg GAE/g and 1.57±0.09 mg GAE/g respectively. The results can be concluded that Ethanol & water extracts exhibit high antioxidant activity possibly due to the presence of high phenolic content than the other extracts.

Effect of enzyme-assisted fermentation on quality, safety, and microbial community of black soldier fly larvae (Hermetia illucens L.) as a novel protein source

Considering the significance and scarcity of quality protein, this study aims to obtain a novel safe protein source through fermenting the black soldier fly larvae (BSFL). Lactobacillus crispatus M1027 and Pichia kudriavzevii DHX19 were added as starters together with neutral protease for enzymolysis during fermentation. The results showed that the low pH value (from 6.60 to 3.99), generated by lactic acid accumulation, created an environment where the pathogen could hardly grow. During fermentation, the flavor compound ethyl acetate content reached up to 406.55 mg/L, and the melanization was effectively inhibited by the starters. The increase of trichloroacetic acid-soluble protein content (from 8.73 % to 17.96 %) contributed to improving the absorbability of product by animals after feeding. Notably, the contents of detrimental substances, including total volatile basic nitrogen and histamine, were both below specified limits after fermentation. Simultaneously, the malonic dialdehyde content remained stable during fermentation. Relative abundance of Lactobacillus and Pichia gradually increased and finally dominated in the culture during fermentation, accompanied by pathogens decline below detection limit (1.0 Log cfu/g). Moreover, there was a close relationship between the dynamics of physicochemical indices and microbial succession. Overall, our studies explored a new process to ferment the BSFL paste which would improve the quality and safety of fermented BSFL paste. This research provided theoretical support for fermented insect as a novel protein source.

Investigation into spatial profile of microbial community dynamics and flavor metabolites during the bioaugmented solid-state fermentation of Baijiu

Biofortification of Baijiu fermentation using exogenous functional strains can change the microbial community structure of the fermentation ecosystem and flavor metabolism, which can impact Baijiu flavor. In this work, a high ethyl hexanoate-producing Saccharomyces cerevisiae Y285 strain was added for biofortification to investigate microbial communities' succession and flavor compounds throughout the fermentation of strong-flavor Baijiu. The microbial community composition of the fermentation samples was analyzed using the Illumina MiSeq platform, and the results showed that Pediococcus, Lactobacillus, Weissella and Saccharomyces were the dominant genera. A total of 111 flavor compounds, consisting of esters (50), alcohols (14), acids (3), aldehydes (9), phenols (9), pyrazines (3), ketones (8), and others (15), were detected in all samples, and the content of total esters of the fortified Daqu increased dramatically. Among them, the content of ethyl acetate decreased while that of ethyl hexanoate increased significantly, and the content of other compounds such as ethyl palmitate, ethanol, phenethyl alcohol and tetramethylpyrazine also increased. Redundancy analysis and Spearman's correlation analysis revealed that Saccharomyces, Pediococcus, Lactobacillus, and Weissella were significantly positively correlated with esters and alcohols. To summarize, biofortification with S. cerevisiae during Baijiu fermentation modifies microbial community composition, as well as the content of ethyl hexanoate in Baijiu, and induces changes in the content of other flavor compounds. These findings imply that modifying the microorganisms throughout the Baijiu fermentation process can alter the flavor of Baijiu and further enhance it.

Fingerprint Analysis of Volatile Flavor Compounds in Crassostrea gigas of Different Ploidy and Gender under High-Temperature Incubation.

In this study, diploid, triploid, and tetraploid Crassostrea gigas samples were subjected to gas chromatography and ion mobility (GC-IMS) to identify and analyze volatile compounds and flavor fingerprints under conditions of high-temperature incubation. The GC-IMS technology identified a total of 54 volatile components in C. gigas. The contents of 1-octen-3-ol, butyl pentanoate, p-methyl anisole, and 2-methyl-2-hepten-6-one in male oysters were significantly higher than in females, while the contents of phenylacetaldehyde, benzaldehyde, 2-ethyl-3-methylpyrazine, 2-ethylfuran, and 2,4-hexadienal in female oysters were significantly higher than in males. The contents of non-3-en-2-one-M and 1-pentanol in diploids were significantly higher than in triploids and tetraploids, while the content of 2,4-hexadienal in tetraploids was significantly higher than in diploids and tetraploids. The contents of ethyl acetate, ethyl-2-butenoate, and butanal in tetraploids were significantly higher than those in diploids and triploids. The results of a principal components analysis showed that different samples were relatively independently clustered, allowing the ability to distinguish different oyster samples. The chemical fingerprints of volatile compounds of C. gigas with different ploidy and gender under high-temperature incubation were established, and the volatile substance contours of C. gigas were visualized. The results provide a reference for distinguishing the ploidy and gender of C. gigas under conditions of high-temperature incubation.

Self-assembly of MOFs-like materials by Zn2+ and histidine functionalized graphene quantum dots for the efficient removal of VOCs simulants

Volatile organic compounds (VOCs) in the field of printing and packaging, have caused great harm to the environment. Therefore, the removal of volatile organic compounds (VOCs) is a hot topic, and metal-organic frameworks (MOFs) and graphene quantum dots (GQDs) have been applied in this field. However, improving the removal efficiency of different VOCs by using the two kinds of materials is still a great challenge. Herein, ZIF-8 like materials of Zn-His-GQDs were prepared by assembling Zn2+ and histidine functionalized GQDs (His-GQDs) in this work. The morphologies, structure and adsorption performances of Zn-His-GQDs were investigated. These results showed that mesoporous Zn-His-GQDs with a specific surface area of 63.3 m2·g−1 had similar structure to ZIF-8. When the content of Zn-His-GQDs was 200 mg, the equilibrium adsorption capacity for toluene solution of 500 mg·L−1 and ethyl acetate solution of 1600 mg·L−1 was 350 mg·L−1 and 669.44 mg·L−1, respectively. Due to channel filling, cation-π interaction, π-π interaction, hydrogen bond and high surface energy, Zn-His-GQDs exhibited a relative high removal efficiency for high concentration of toluene and ethyl acetate. The removal rate of Zn-His-GQDs on toluene and ethyl acetate after five cycles remained 59.80 % and 36.75 %, respectively. Moreover, this kind of MOFs like materials maintained stable structure during the adsorption in different pH solutions. Therefore, as-prepared Zn-His-GQDs with excellent adsorption performances for typical VOCs simulants in this work have potential application in the treatment of VOCs in the field of printing and packaging.

Prediction of cosolvent effect on solvation free energies and analysis of intermolecular forces of tizanidine hydrochloride in ethyl acetate + methanol / ethanol mixtures

The solubility of small molecule drug in solvents can be dramatically affected by addition of a suitable cosolvent, which makes the screening of the best-suited cosolvent an important task for the purification and preparation. The present work aims to improve the fundamental understanding of tizanidine hydrochloride (TIZ HC) solvation by cosolvent. Solubility experimental data from TIZ HCl in mixtures of ethyl acetate + alcohols were obtained at different temperatures with the method of isothermal equilibrium. In the system of ethyl acetate + methanol, the solubility data increased firstly and then decreased with an increase in ethyl acetate content, however, the strictly monotonic decreasing of solubility in ethyl acetate + ethanol mixtures was observed. The solubility correlation fitting was performed with the Jouyban-Acree model and CNIBS/R-K model. The solvent effect analysis indicates that the hydrogen bond acidity, the polarity / polarizability and the cohesive forces of the solvent have a greater influence on the solubility, which was further validated by the local quantitative molecular surface analysis results of electrostatic potential (ESP). The dissolution process of TIZ HCl in systems with different solvent compositions was analyzed in the form of preferential solvation parameters, it was found that methanol is the preferred solvent in the solvation shell of TIZ HCl in methanol-rich and ethyl acetate-rich mixtures but the ethanol is preferred in intermediate compositions and ethyl acetate-rich mixtures. Moreover, the types of intermolecular solute–solvent interactions were discussed on the basis of the structural characteristics of TIZ HCl. The solvation free energy is a key parameter describing solvent effects, which is extremely important for understanding solution chemistry. For this part, with the aid of density functional theory (DFT) and molecular dynamics (MD) simulations, it was found that the cosolvent effect is consistent with the prediction trend of solvation free energy of TIZ HCl in each systems. The effect of the cavity formed by the solvent molecules and dipole moment of solute was calculated accordingly by the solvation model based on density (SMD) for explaining the former behavior.

Headspace versus direct injection for the quantitation of methanol, ethyl acetate, and fusel oils in distilled spirits by gas chromatography – Flame ionization detection

Distilled spirits can be very complex in their sensory or organoleptic compounds. Of significant interest is determination of the concentration of methanol, ethyl acetate, and fusel oils, which include n-propanol, isobutanol, n-butanol, active amyl (2-methyl-1-butanol) and isoamyl (3-methyl-1-butanol) alcohols. Here, we describe a validated method for the analysis of these analytes using a headspace (HS) sampling unit coupled with a gas chromatograph fitted with a flame ionization detector (GC/FID) for profiling these analytes in distilled spirits (n = 26) obtained from local retailers. HS results were compared to the direct injection (DI) GC/FID protocol made available by the US Alcohol and Tobacco Tax and Trade Bureau (TTB), method SSD:TM:200 via correlation and Bland-Altman difference plots to demonstrate that HS-GC/FID is a valid alternative to the direct injection protocols described elsewhere.•A method for the analysis of methanol, ethyl acetate, and fusel oils via headspace sampling coupled to a gas chromatograph fitted with a flame ionization detector (HS-GC/FID) is described.•Samples required no pre-treatment beyond diluting 1 mL of distilled spirit in 4 mL water containing table salt, which resulted in a method with minimal inlet or column maintenance, little sample prepration, and a rapid run time with retention times under 7 min.•Validation by comparing to established protocols using direct injection made available by the US Federal Tax and Trade Bureau (TTB).

Antioxidant Activities of Different Solvent Extracts of Moringa oleifera Seeds Using DPPH Assay

Moringa oleifera (Moringaceae) which grows in the tropical and subtropical regions of the world, has long unani system of medicine with ayurvedic history. The seeds are known to possess high medicinal properties. This study aimed to determine the antioxidant activity of M. oleifera seeds, extracted with different solvents (methanol, ethyl acetate and n-hexane) using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. This research was carried out using different concentrations of methanol, ethyl acetate, and n-hexane extracts, (5, 10, 15, 20, 25, 30 mg/mL). Vitamin C was also used as standard antioxidant control. The percentage of inhibition and IC50 were measured. The results showed that the DPPH free radicals were scavenged by all seed extracts in a concentration dependent manner. Moreover, the IC50 values for DPPH radicals with methanol, ethyl acetate and n-hexane extract of the M. oleifera seeds were found to be 30.77, 44.77 and 45.04 mg/mL, respectively. Interestingly, the IC50 value of all the extracts revealed very active antioxidant activity but lower than the standard vitamin C due to their IC50 values < 50 mg/mL. The order of activity for all the assay was methanol > ethyl acetate > n-hexane. The results suggested that methanol extract of M. oleifera seeds has the most active antioxidant activity.

Screening ester-producing yeasts to fortify the brewing of rice-flavor Baijiu for enhanced aromas

ABSTRACTTo enhance the aromas in Guangdong rice-flavor Baijiu, ester-producing yeast was selected to fortify Baijiu brewing. Among eight kinds of ester-producing yeasts selected, Saccharomyces cerevisiae CM15 (CM15) that showed both the stronger ability to utilize substrates to produce esters and the excellent tolerance to industrially relevant stress factors was chosen. When CM15 was synergistically fermented with six kinds of Kojis from distilleries of rice-flavor liquor in Guangdong, the enhanced total esters had happened to the liquors brewing with the fortified four kinds of Kojis, especially with Koji F. When Koji F was fortified with CM15, the resultant Baijiu showed a higher esters proportion and a lower higher alcohol ratio than that of Baijiu brewed only with Koji F, with the content of ethyl acetate and ethyl lactate increasing by 25% and 214%, respectively. This study suggested that CM15 can be used as a functional microorganism to fortify Baijiu brewing, which might also be suitable for other traditional fermented foods.

Insights into the volatile flavor and quality profiles of loquat (Eriobotrya japonica Lindl.) during shelf-life via HS-GC-IMS, E-nose, and E-tongue

Loquat fruits are among the most popular Chinese fruits because of their unique taste and aroma. The quality profiles of these fruits during 18 days of shelf-life at 20 °C were elucidated by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), E-nose, and E-tongue. During shelf-life period, the properties and variations of 43 (20 aldehydes, 7 esters, 6 ketones, 1 alcohol, and 1 furan) volatile flavored compounds were determined by GC-IMS, which showed that the contents of methyl 3-methyl butanoate, ethyl acetate, and dimethyl ketone gradually decrease with prolonged shelf-life time, while (E)-2-heptenal, heptanal, (E)-2-pentenal, 1-penten-3-one 3-pentanone and 2-pentylfuran increase. The PCA based on the signal intensity of GC-IMS and E-nose, revealed that loquat fruits are well distinguished at different shelf-life times. The taste profile alternates as the storage time increases, along with higher pH, and lower amounts of total soluble solids, vitamin C, and total phenolics. The visual plots of GC-IMS, E-nose, and E-tongue had good consistency, and they characterized the aroma characteristics of loquat fruits well during different shelf-life periods. The findings of this research provide a useful understanding of the flavors of loquat fruits during their prolonged shelf-life, and a potential research basis for advancements in the loquat industry.

Selection of Salt-Tolerance and Ester-Producing Mutant Saccharomyces cerevisiae to Improve Flavour Formation of Soy Sauce during Co-Fermentation with Torulopsis globosa.

Soy sauce, as a traditional seasoning, is widely favoured by Chinese and other Asian people for its unique colour, smell, and taste. In this study, a salt-tolerance Saccharomyces cerevisiae strain HF-130 was obtained via three rounds of ARTP (Atmospheric and Room Temperature Plasma) mutagenesis and high-salt based screening. The ethanol production of mutant HF-130 was increased by 98.8% in very high gravity fermentation. Furthermore, ATF1 gene was overexpressed in strain HF-130, generating ester-producing strain HF-130-ATF1. The ethyl acetate concentration of strain HF-130-ATF1 was increased by 130% compared to the strain HF-130. Finally, the soy sauce fermentation performance of Torulopsis globosa and HF-130-ATF1 was compared with T. globosa, HF-130, HF-130-ATF1, and Torulopsis and HF-130. Results showed ethyl acetate and isoamyl acetate concentrations in co-fermentation of T. globosa and HF-130-ATF1 were increased by 2.8-fold and 3.3-fold, respectively. In addition, the concentrations of ethyl propionate, ethyl caprylate, phenylethyl acetate, ethyl caprate, isobutyl acetate, isoamyl alcohol, phenylethyl alcohol, and phenylacetaldehyde were also improved. Notably, other three important flavour components, trimethylsilyl decyl ester, 2-methylbutanol, and octanoic acid were also detected in the co-fermentation of T. globosa and HF-130-ATF1, but not detected in the control strain T. globosa. This work is of great significance for improving the traditional soy sauce fermentation mode, and thus improving the flavour formation of soy sauce.