Tartaric Acid Research Articles

Impact of low molecular weight organic acids on heavy metal(loid) desorption in biochar-amended paddy soil.

Low molecular weight organic acids (LMWOAs) are important soil components and play a key role in regulating the geochemical behavior of heavy metal(loid)s. Biochar (BC) is a commonly used amendment that could change LMWOAs in soil. Here, four LMWOAs of oxalic acid (OA), tartaric acid (TA), malic acid (MA), and citric acid (CA) were evaluated for their roles in changing Cd and SB desorption behavior in contaminated soil with (S1-BC) or without BC (S1) produced from Paulownia biowaste. The results showed that OA, TA, MA, and CA reduced soil pH with rising concentrations, and biochar partially offset the pH reduction by LMWOAs. The LMWOAs reduced Cd desorption from the soil at low concentrations but increased Cd desorption at high concentrations, and CA was the most powerful in this regard. The LMWOAs had a similar effect on Sb desorption, and CA was the most effective species of LMWOAs. Adding BC to the soil affects Cd and Sb dynamics by reducing the Cd desorption but increasing Sb desorption from the soil and increasing the distribution coefficient (Kd) values of Cd but lowering the Kd values of Sb. This study helped understand the effects of LMWOAs on the geochemical behavior of Cd and Sb in the presence of biochar, as well as the potential risks of biochar amendment in enhancing Sb desorption from contaminated soil.

Influence of tartaric acid on the electron transfer between oxyanions and lepidocrocite

Iron oxide minerals control the environmental behavior of trace elements. However, the potential effects of electron transfer directions by iron oxides between organic acids and trace elements remain unclear. This study investigates the redox capacity of tartaric acid (TA) with chromate (Cr(Ⅵ)) or arsenate (As(V)) on lepidocrocite (Lep) from the perspective of electron transfer. The results demonstrated the configurations of TA (bidentate binuclear (BB)), As(V) (BB), and Cr(Ⅵ) (BB and protonated monodentate binuclear (HMB)) on Lep. Frontier molecular orbital calculations and X-ray photoelectron spectroscopy (XPS) binding energy shifts further indicated different electron transfer directions between TA and the oxyanions on Lep. The iron of Lep might act as electron acceptors when TA is adsorbed, whereas the iron and oxygen of Lep act as electron donors when As(V) is adsorbed. The iron of Lep might accept electrons from its oxygen and subsequently transfer these electrons to Cr(Ⅵ). Macroscopic validation experiments showed the reduction of Cr(VI), whereas no reduction of As(V). The XPS analysis showed a peak shift, with the possible formation of As–Fe–TA ternary complexes and electron transfer on Lep. These findings indicate that mineral interfacial electron transfer considerably influences the transport and transformation of oxyanions.

New tartrate and α-tocopherol based environmentally friendly plasticizers for improvement of the ductility of polylactic acid

This study focuses on developing environmentally friendly plasticized poly(lactide) (PLA) formulations using tartaric acid and α-tocopherol at 20 wt%. The extrusion and injection molding processes demonstrated the industrial applicability of these plasticizers. Mechanical tests revealed positive results for tartrate-based plasticizers, with elongation at break surpassing 220 %, while α-tocopherol succinate achieved 170 %. However, α-tocopherol acetate showed limited PLA plasticization. Field emission scanning electron microscopy confirmed plasticization in fractured surfaces. Thermal analysis indicated a reduction in PLA's glass transition temperature (Tg) from 60 °C to around 30 °C with these plasticizers, underscoring tartrates' exceptional efficiency. The cold crystallization temperature (Tcc) decreased for all plasticized samples due to enhanced chain mobility. Thermomechanical analysis revealed dimensional shrinkage, with dimethyl tartrate (DMT) causing less pronounced effects. Generally, tartrates yielded formulations with superior properties, attributed to their lower molecular weight compared to α-tocopherol-derived plasticizers. Notably, all plasticizers employed are an eco-friendly approach to improve PLA's processability and enhancing ductile properties.

Development and Optimization of the Extrusion of Potato Peel–Based Biocomposite Films

ABSTRACTSide streams from the agricultural and food industries are considered an interesting alternative source for the production of packaging materials due to their composition. However, their use often involves complex and energy‐intensive extraction of individual components. Therefore, this study investigated the application of entire potato peels, without prior extraction, to produce extruded films. Potato peels (PP) and biobased polybutylene succinate adipate (BioPBS) at 1:0, 3:2, 1:1 and 2:3 ratios were used to produce pellets and films in a two‐stage extrusion process. The influence of PP concentration, the addition of maleic anhydride and tartaric acid as compatibilizers and the addition of carnauba wax on the film properties were characterized in terms of morphological, mechanical, physicochemical and thermal properties. Films with a high PP content (50%–100%) showed weak mechanical properties. However, increasing the BioPBS content to PP/PBS 2:3 resulted in a significant increase in tensile strength and elongation at break to 6.20 MPa and 38.09%, respectively, and significantly reduced the water vapour permeability of the film to 5.5 × 10−6 gm/m2 d Pa. The use of 1% maleic anhydride had no significant effect on tensile strength (6.23 MPa), but further increased the elasticity to 65.48%, with no additional effect on barrier properties. The addition of 0.5% tartaric acid showed a similar elongation at break (56.23%) while significantly increasing the tensile strength to 6.56 MPa. The incorporation of 5% carnauba wax increased the surface hydrophobicity of the films from 69.5° to 99.7°, but at the expense of a decrease in mechanical properties.

Quantification of arsenic in real samples using a spectrophotometric cloud point extraction of the formed ion pair with astrazon orange G

A novel cloud-point extraction (CPE) procedure for the determination of ultra-trace amounts of arsenic species in real samples, purchased from the local market by spectrophotometer was developed. Inorganic arsenic species analysis in water, beverages, and foods has become increasingly important in recent years, as arsenic species are considered carcinogenic and are assessed at significant levels in samples. The technique is established on a selective ternary complex of As(V) with astrazon orange G (AOG+) in the presence of tartaric acid and polyethylene glycol tertoctylphenyl ether (Triton X-114) at pH 4.0. The calibration curve developed within range 3.0–160 ng/mL with a correlation coefficient of 0.9988 for As(V) provided a preconcentration factor of 200 and a limit of detection (3S blank/m) of 0.88 ng/mL under optimum investigation conditions. The results of molar absorptivity and Sandell sensitivity are calculated and found to be 4.38 × 105 L/mol cm and 0.018 ng cm−2, respectively. The statistical treatment of data obtained from the proposed and GF-AAS procedures are compared in terms of Student’s t-tests and variance ratio F-tests has revealed no significant differences. The methodology has been effectively confirmed by assessing real samples and comparing it to the GF-AAS method statistically.

Carbon dots with tunable excitation-independent fluorescence and organelle-specific targeting via core graphitization and surface groups engineering

Single-emission fluorescence and non-specific cellular organelle-targeting limit the application of carbon dots (CDs) in bio-imaging. Here, we proposed an adjustable strategy for synthesis of four CDs: Tm1-, Tm2-, Tma-, and Tp-CDs. The synthetic scheme was designed with tartaric acid and m-/p-phenylenediamine as precursors and water/acetone as solvent through hydrothermal/solvothermal synthesis and (or) column chromatography isolation. The maximum productivity of the CDs was 56.2 % and the highest fluorescence quantum yield was 47.8 %. These CDs emitted excitation-independent blue, green, and yellow fluorescence, respectively. The red shift of CDs fluorescence was caused by increasing graphitized conjugated sp2 domain and graphitic nitrogen content of carbon core. The hydrophilicity/lipophilicity and protonation ability of CDs determined their cellular uptake, intracellular trafficking and subcellular targets, including endoplasmic reticulum, lysosomes and nucleus. These CDs have the potential application in fluorescence visualization of live bacteria and in the organelle-targeted imaging of living mammalian, fungal, and plant cells. The study provides novel insights into rational design of CDs with multi-color fluorescence and organelle-specific targeting in live cells.

Selective recovery of Cu from copper mold production waste by organic ligands

In the present study, organic acids - oxalic acid, citric acid, tartaric acid and siderophore Desferrioxamine B were evaluated for their efficiencies to selectively recover Cu from its mold production waste. XRD analysis showed that copper mold production waste mainly consisted of Fe and Cu. The complete dissolution of this waste in aqua regia and subsequent analysis via ICP-MS revealed metal contents of 355.3 mg/g Fe and 293.9 mg/g Cu. Among all the organic acids, citric acid had the highest leaching efficiency (58.5 %) for Fe while leaching <1 % of Cu. Whereas, the leaching of Cu and Fe was poor in oxalic acid medium and Cu leaching was also negligible in tartaric acid medium. Only Fe showed 11.2 % leaching efficiency at 2 mol/L tartaric acid. The step-by-step leaching of production waste with citric acid lead to 100 % leaching of Fe while leaving 93.1 % of Cu with a yield of >99 % in the solid residue in the 4th step. Further, the siderophore Desferrioxamine B could effectively leach Fe (91.2 %) while 21.4 % leaching of Cu in 30 days. The presence of Fe impedes the leaching of Cu from the waste as demonstrated by leaching and DFT calculations due to higher stability of Fe-citrate and Fe-desferrioxamine B complex compared to Cu-organic complexes. This recycling technique described herein is simple, reliable and environmentally friendly for recovery of Cu from copper mold production waste.

Eco-safe hot water dip alleviates antioxidant level and sensory quality of Indian jujube fruits

Indian jujube (Ber) is highly perishable climacteric fruit owing to high decay index limiting its marketability and demands interventions to prolong shelf life. Fungicides are normally used to control rot during postharvest storage, however, residues left necessitate eco-safe alternatives like hot water dipping. Mature, pre-climacteric jujubes were dipped in 45, 50 or 55 °C water for 8, 6 or 4 min, respectively and then stored at 5 °C for periodic quality evaluation. Dipping fruits in 55 °C water resulted in 32.69 and 35.27, 64.21 and 58.57, 30.41 and 30.42, 38.50 and 52.20 % lower weight loss, decay index, malondialdehyde (MDA) and electrolyte leakage, whereas 15.40 and 16.77, 19.51 and 20.48 % greater antioxidant activity and ascorbic acid respectively for Umran and Pakwhite compared to 25 °C water dip. The highest glucose, fructose, malic, citric, and tartaric acids were 23.44 ± 1.04 and 29.9 ± 0.95, 30.68 ± 1.72 and 41.17 ± 2.34 mg/100 g, 138.1 ± 6.45 and 112.97 ± 6.16, 57.49 ± 1.71 and 53.78 ± 1.90, 79.58 ± 5.1 and 65.3 ± 4.83 μg/100 g whereas lower sucrose 12.34 ± 0.94 and 16.33 ± 1.05 mg/100 g were respectively recorded in 55 °C water dipped Umran and Pakwhite fruits. High dip water temperature (55 °C) exhibited better quality with the lowest decay index and weight loss, greater membrane integrity, bioactives content and sensory acceptance scores. Hence, hot water dipping was shown to be an effective residue-free option to extend the marketable period of jujubes to capture distant markets.

Intermetallic particles distribution in 7010-T7451 and 7175-T6 aluminium alloys substrate impacts cathodic stability of silicate sealed anodic oxide film

Effect of silicate sealing on tartaric sulphuric acid anodized 7010-T7451 and 7175-T6 alloys with different distributions of intermetallics (IMPs) in aluminum substrates was studied. Surface characterisations evidenced similar morphology and chemical composition of the sealed layers on both substrates. Electrochemistry and time-lapse microscopy demonstrated the layer’s stability under anodic polarization and its localized pitting under cathodic polarization in NaCl electrolyte. No chemical or morphological modifications were detected outside of the pits. The number and size of the pits depended on the IMPs distribution in the alloy, buried under 6 µm thick oxide. A degradation mechanism explaining these observations was proposed.

Transcriptomic and metabolomic analysis of prebiotics utilization by Bifidobacterium animalis.

In this study, the utilization mechanism of oligosaccharides by Bifidobacterium was investigated through the transcriptome sequencing and non-targeted metabolomics technology of Bifidobacterium animalis cultured with fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS). The results showed that FOS affected the synthesis of adenosine triphosphate binding transporters (ABC transporters) by increasing the expression levels of msmE, msmG, and gluA. Similarly, GOS improved aminoacyl-tRNA synthases by upregulating the expression of tRNA-Ala, tRNA-Pro, and tRNA-Met. Bifidobacterium animalis cultured with FOS and GOS produced different metabolites, such as histamine, tartaric acid, and norepinephrine, with the functions of inhibiting inflammation, alleviating depression and diseases related to brain and nervous system and maintaining body health. Furthermore, the transcriptome and metabolome analysis results revealed that FOS and GOS promoted the growth and metabolism of Bifidobacterium animalis by regulating the related pathways of carbohydrate, energy, and amino acid metabolism. Overall, the experimental results provided significant insights into the prebiotic effects of FOS and GOS.

Solution Combustion Synthesised Cu‐CeO2 Catalysts For CO2 Hydrogenation to Methanol‐ the Effect of the Fuel

AbstractThe tunability of structural properties such as oxygen vacancies, Cu surface composition, reducibility of CuO, and basicity by solution combustion synthesised (SCS) Cu‐CeO2 catalysts was investigated. Five different fuels, viz. urea (U), tartaric acid (TA), citric acid (CA), ethylene glycol (EG) and oxalyl dihydrazide (ODH), were employed in the synthesis of the catalysts. Raman spectroscopy, O2‐TPD and XPS revealed that the urea synthesised catalyst had the highest concentration of oxygen vacancies, the amount of which was controlled by the fuel used. The oxygen vacancies were the catalytic sites for CO2 adsorption and promoted electron donation to Cu at the Cu‐CeO2 junction, thus improving H2 adsorption and spillover, which was beneficial for methanol synthesis. The better catalytic performance of the urea synthesised Cu‐CeO2 catalyst with a methanol STY of 163 gCH3OH kg−1cat h−1 compared to the other solution combustion synthesis fuels, was attributable to higher oxygen vacancies, more facile Cu reduction, larger Cu surface area and higher Cu surface composition. Based on the absence of the Cu+ species capable of directing the methanol synthesis reaction through the CO intermediate based on XPS data, we surmised that the formate route was the preferred pathway for the studied Cu‐CeO2 catalysts.

Facile preparation of fluorescent tartaric acid-modified polymer dots for Fe3+ detection

Herein, fluorescent polymer dots (T-PDs) with excellent properties were synthesized through a facile magnetic stirring method using carboxymethyl cellulose derivative (CMC-NH2) and tartaric acid (TA). The synthesized T-PDs exhibit a nanoscale structure, excellent stability and good fluorescence behavior with a fluorescence quantum yield of 12.5 %. Moreover, the T-PDs can be selected for the design of sensors for detecting Fe3+ via the internal filtration effect (IFE) through a fluorescence quenching process. A good linear equation can be fitted between (F0-F/F0) and the amount of Fe3+ from 0 to 600 μM (R2 = 0.998) and the detection limit (LOD) for Fe3+ was determined to be 0.74 μM (3σ/slope). Additionally, the as-prepared sensing platform can be utilized for detecting Fe3+ in real samples, which indicates its great potential for application in sensing. Interestingly, the fluorescence of the quenched system can be partially recovered by the addition L-cysteine. Thus, a fluorescent “ON-OFF-ON” switch can be designed, and a resettable and multireadout logic gate operation can be realized.

Impact of microorganisms on key processes of organic acid metabolism during the occurrence and disappearance of paocai pellicle.

In vegetable fermentation, pellicle is a common quality deterioration phenomenon. This study investigates the characteristics of glucose, organic acids, amino acids, and biogenic amines during the pellicle occurrence and disappearance of paocai. The results revealed a slight increase in pH of the fermentation system after pellicle occurred, and glucose was the main carbohydrate that microbial activity primary relied on. The microorganisms responsible for pellicle formation consumed organic acids in brine, but the lactic acid in paocai gradually increased and exceeded 25mg/g. The appearance of pellicle caused a decrease in total free amino acids from 200.390mg/100g to 172.079 when pellicle occurred, whereas its impact on biogenic amines was not apparent. Through Kyoto Encyclopedia of Genes and Genomes pathway enrichment of metagenomics sequencing data, screening, and sorting of the key enzymes involved in organic acid metabolism, it was observed that the composition and species of the key microorganisms capable of metabolizing organic acids were more abundant before the appearance of pellicle. When pellicle occurred, lactic acid may be metabolized by Lactobacillus plantarum; in contrast, Lactobacillus and Pichia were associated with citric acid metabolism, and Lactobacillus, Pichia, Saccharomycodes, and Kazachstania were linked to malic acid metabolism. Moreover, Prevotella, Kazachstania, Lactobacillus, Vibrio, and Siphonobacter were implicated in succinic acid metabolism. Additionally, the production of tartaric acid and oxalic acid in paocai and brine resulted from abiotic effects. This knowledge offers a theoretical basis for precise control of paocai fermentation process. PRACTICAL APPLICATION: Our study revealed the specific situation of the metabolites produced by the microorganisms during the pollution and recovery process of pellicle in paocai fermentation, especially the effect of pellicle on the key process of organic acid metabolism. These research results provided theoretical basis for precise control of paocai fermentation.

Porous-anodic-alumina-templated Ta-Nb-alloy/oxide coatings via the magnetron-sputtering/anodizing as novel 3D nanostructured electrodes for energy-storage applications

The Ta-52 at.%Nb thin alloy films were magnetron sputter-deposited over a low-aspect-ratio nanoporous anodic-alumina template formed in 0.05 M tartaric acid solution at 250 V and modified by the pore-widening technique to enlarge the pores up to ∼500 nm. The alloy coated the pores evenly, thus forming a 3D continuous conducting nanofilm on the template. Partially anodizing the templated alloy in a borate buffer solution of pH 7.5 generated a compact amorphous mixed-oxide anodic film thickening proportionally to the applied voltage. It was revealed that the oxide on the Ta-52 at.%Nb alloy grows with a slower migration of Ta5+ ions relative to Nb5+ ions, resulting in mixing Ta2O5 and Nb2O5 in the film depth and forming a few-nm-thick Nb2O5 outmost layer. The unique migration of Ta4+, Ta3+, Nb4+, and Nb3+ ions is assumed accountable for forming corresponding suboxides in the 3D anodic film in contrast to a flat Ta-52 at.%Nb alloy film used as a reference. The 3D anodic films behave as an n-type semiconductor with a low donor density Nd = ∼2 × 1018 cm−3, appropriate for dielectric applications. An unusual two-layered structure with a sharp electrical interface revealed in the 3D oxide films anodized to 30–130 V, comprising a low-resistivity layer superimposed on the high-resistivity layer, is explained by an immobile negative space charge in the outer film part. The air-annealing at moderate temperatures releases the space charge and transforms the two layers into a high-resistivity single layer having substantially improved dielectric properties and thermostable (up to 250 °C) capacitance of 1.2 μF cm−2 achieved for the film anodized to practical 50 V. The 3D films having up to 4.5 times enlarged effective surface area can be utilized as novel metal/oxide nanostructured electrodes for electrolytic microcapacitors suitable for classical electronic circuits and energy-storage applications.

Preparation of SiO2 nanotubes and nanoparticles in the presence of L-tartaric acid by sol-gel method and their electrochemical performance for Li-ion batteries

Recently, SiO2 has attracted increasing attention as an anode material for lithium-ion batteries (LIBs) owing to its low cost and high theoretical specific capacity. However, its inherent poor conductivity limits its practical application. To address this issue, nanostructured material design is considered an effective solution. Herein, based on the traditional ammonium tartrate template-directed sol-gel method, we use low-cost and easily available L-tartaric acid in place of D, L-tartaric acid to prepare high-yield silica nanotubes (SNTs) with a thin wall (ca. 50 nm), small diameter (ca. 150 nm), rough surface and open ends, as well as tiny spongy-like silica nanoparticles (SNPs) by adjusting the feeding amount and feeding mode of NH4OH solution. The electrochemical characterization results suggest that the SNTs show better cyclability and rate performance than the SNPs, which maintain a reversible capacity of 741.3 mAh g−1 after 500 cycles at a current density of 0.4 A g−1 and deliver a high rate capacity of 819.4 mAh g−1 at a high current rate of 2 A g−1. The excellent electrochemical performance suggests that hollow one-dimensional hollow nanotubes are more efficient in improving the electrochemical performance of SiO2 than zero-dimensional nanoparticles, and SNTs with thin tube walls and rough surfaces are demonstrated to be fascinating and promising anode materials for LIBs.

Formulation Development and Evaluation of Effervescent Granules of Rizatriptan Benzoate

The present study describes the formulation and development of rizatriptan benzoate (RZB) effervescent granules and compares its dissolution rate against the conventional rizatriptan benzoate tablets. Earlier, placebo-effervescent granules were prepared to optimize the concentration of citric acid, NaHCO3 and tartaric acid and its effect on CO2 content and effervescence time. Effervescent granules were prepared by direct sifting and blending of ingredients. Rizatriptan effervescent granules were prepared by the addition of RZB in the above-optimized placebo granule formula and evaluated for various physicochemical parameters. Later, the effervescent RZB granules were compared with the marketed RZB tablets for the dissolution rate. It was observed that RZB effervescent granules have the fastest dissolution rate compared with marketed RZB tablets. The optimized RZB effervescent granule formulation is quite superior to that of RZB conventional tablets to relieve the patients from migraine and the possible associated hyperacidity it.

Strategies to mitigate acrylamide development in bakery products: Effect of asparagine content in flour and tartaric acid addition in biscuit formulation

This paper explores strategies to mitigate acrylamide formation in bakery goods, with a focus on using tartaric acid as an acid neutralizer in biscuit recipes. Initial analyses involved screening the asparagine content in various flours, aiming to encompass a wide range of samples, including those that presented substantial challenges. Subsequently, experimental biscuits were produced with various treatments (tartaric acid addition, steam release during baking, and both steam/acid). Results showed a correlation between asparagine content in flours and acrylamide formation. Tartaric acid was remarkably effective, achieving a 57%–87% reduction in acrylamide production. Colorimetric measurements assessment demonstrated that tartaric acid treatment reduced browning, while the aw (<0.15) was not affected even using steam during cooking. Sensory analysis indicated slight sour taste in acid-treated biscuits, but overall acceptability remained high. Texture analysis revealed improved friability, crucial for preventing oral mucosal lesion, especially in children's products. PCA highlighted the impact of treatments on variables like acrylamide content, color, water activity, and sensory attributes. The study suggests that using tartaric acid as a neutralizing agent is a solid strategy to mitigate acrylamide without compromising sensory qualities in biscuits. Further research will include exploring other acids, optimal dosage, and variations in flour composition.

Chemical Characterization of Sauvignon Blanc Wines from Three Cold-Climate-Growing Areas of Chile.

The influence of the geographical location on the chemical composition of commercial Sauvignon Blanc wines was investigated. The assay was carried out on Sauvignon Blanc wines from three cold-climate valleys in Central Chile, Casablanca, Leyda, and San Antonio. The analyses revealed clear variations in some chemical parameters, especially in titratable acidity, which was higher in the geographical areas closest to the Pacific Ocean, such as the Leyda and San Antonio valleys. Regarding the composition of low-molecular-weight phenolic compounds, 17 compounds were found, and the results show that the Casablanca valley exhibits a greater abundance of monomeric flavanols, such as (+)-catechin, whereas the Leyda valley shows a higher abundance in flavonols and phenolic acids esterified with tartaric acid. Concerning the aromatic compound profile, the wines from the Casablanca valley showed a greater abundance of esters, C13 norisoprenoids, and some terpenes. The PLS-DA analysis revealed some differences, especially between wines from Casablanca and Leyda, demonstrating that the difference in the chemical composition of the wines was influenced by the geographical area.

Improving Sweet Bread Properties with Diacetyl Tartaric Acid Ester of Monoglyceride (DATEM)

Diacetyl Tartaric Acid Ester of Monoglyceride (DATEM) has been used in bread making to improve its dough and final product properties. The efficiency of DATEM in bread with the presence of sugar is yet to be studied. Therefore, this study aims to examine the effects of DATEM addition on sweet bread properties, i.e., its water content, loaf volume expansion, porosity and organoleptic properties. Completely Randomized Design (CRD) was employed with 5 treatments and 4 replications. The variables were the addition of DATEM, i.e., 0%, 0.15%, 0.3%, 0.45%, 0.6% (w/w) of the total flour. The data were analyzed using Analysis of Variance (ANOVA) with the significance level of 5%. The study showed that DATEM significantly impacts the physical and organoleptic properties of sweet bread. As DATEM concentration increases, so does moisture content, porosity, and loaf volume. Consequently, the texture becomes softer, and fewer crumbs are produced. Overall, DATEM enhances sweet bread properties, with 0.6% concentration yielding the best results. Sweet bread with 0.6% DATEM exhibited 34.05% moisture content, 76.86% loaf volume expansion, and 3.38 mm porosity.

Dynamic changes in aromas and precursors of edible fungi juice: mixed lactic acid bacteria fermentation enhances flavor characteristics.

Lactic acid bacteria (LAB) fermentation technology has been increasingly used in the deep processing of edible fungi. However, the flavor profiles of edible fungi products after mixed LAB fermentation have received less attention and how aromas changes during the mixed LAB fermentation are still open questions. In the present study, fermented Hericium erinaceus and Tremella fuciformis compound juice (FHTJ) was prepared by mixed LAB strains. We aimed to systematically monitor the dynamic changes of aromas and precursors throughout the fermentation process and a data-driven association network analysis was used to tentatively illustrate the mechanisms of formation between aromas and their precursors. Mixed LAB fermentation could enrich the aroma profile of FHTJ, reducing the unpleasant flavors such as nonanal and 1-octen-3-ol, as well as increasing the floral flavors such as ethyl acetate and α-pinene. Partial least squares-discriminant analysis and relative odor activity values revealed that 11 volatile chemicals were recognized as aroma-active markers. Volcano plot analysis showed that 3-octen-2-one (green flavor) was the key aroma-active marker in each stage, which was down-regulated in fermentation stages I, II and IV, whereas it was up-regulated in stage III. 3-Octen-2-one was significantly negatively correlated with organic acids, particularly pyruvate (r2 = -0.89). Ethyl caprylate (floral flavor) was up-regulated in the late fermentation stage, and showed a negative correlation with sugar alcohols and a positive correlation with organic acids, especially tartaric acid (r2 = 0.96). The present study demonstrates the beneficial effect of mixed LAB fermentation on flavor characteristics, providing guidance for fermented edible fungi juice flavor quality monitoring and control. © 2024 Society of Chemical Industry.