Acidic Products Research Articles

Synthesis of conductive polymeric nanoparticles with hyaluronic acid based bioactive stabilizers for biomedical applications

In recent years, the use of organic materials to infer conductivity in biomedical devices has received increasing attention. Typical inorganic semiconductors and conductors are rigid and expensive, usually require multiple processing steps and are unsuitable for biomedical applications. Electrochemically or chemically doped conjugated polymers help to overcome these problems due to their stability, low cost, light weight and excellent electrical and optical properties. The conducting polymer poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) is the material of choice for biomedical applications as it is water soluble, however, there are growing concerns around its stabilizer, PSS, due to its release of acidic products upon degradation in-vivo. Here, we report the successful synthesis of PEDOT nanoparticles using hyaluronic acid (HA) as a stabilizer via an oxidative miniemulsion polymerisation technique. This improves the bioactivity and hydrophilicity of nanoparticles. The effect of varying amounts of HA and different molar ratios of EDOT:TOS has been studied and their role in the conductive and morphological properties of final nanoparticles has been fully elucidated. Furthermore, bioactivity and biocompatibility of the nanoparticles are demonstrated for customizable in vivo applications. Nanoparticles were found to have a conductivity up to 10 times greater than pristine PEDOT:PSS with increased addition of oxidant. The proposed easy-to-manufacture approach, along with the highlighted superior properties, expands the potential of conductive polymers in future customizable biological applications such as tissue scaffolds, nerve conduits and cardiac patches and represents a real breakthrough from the current state of the art.

Torulaspora delbrueckii Phenotypic and Metabolic Profiling towards Its Biotechnological Exploitation.

Wine is a particularly complex beverage resulting from the combination of several factors, with yeasts being highlighted due to their fundamental role in its development. For many years, non-Saccharomyces yeasts were believed to be sources of spoilage and contamination, but this idea was challenged, and many of these yeasts are starting to be explored for their beneficial input to wine character. Among this group, Torulaspora delbrueckii is gaining relevance within the wine industry, owing to its low volatile acidity production, increased release of aromatic compounds and enhanced color intensity. In addition, this yeast was also attracting interest in other biotechnological areas, such as bread and beer fermentation. In this work, a set of 40 T. delbrueckii strains, of varied geographical and technological origins, was gathered in order to characterize the phenotypic behavior of this species, focusing on different parameters of biotechnological interest. The fermentative performance of the strains was also evaluated through individual fermentations in synthetic grape must with the isolates’ metabolic profile being assessed by HPLC. Data analysis revealed that T. delbrueckii growth is significantly affected by high temperature (37 °C) and ethanol concentrations (up to 18%), alongside 1.5 mM SO2, showing variable fermentative power and yields. Our computation models suggest that the technological origin of the strains seems to prevail over the geographical origin as regards the influence on yeast properties. The inter-strain variability and profile of the products through the fermentative processes reinforce the potential of T. delbrueckii from a biotechnological point of view.

Effect of doped functional bioceramic on in vitro degradation and histocompatibility of poly(l-lactide-trimethylene carbonate-glycolide) terpolymers

The effects of modified calcium carbonate whisker (CCW) and two modified mesoporous silica (SBA-15, MCM-41) bioceramic on the degradation behavior of pure poly(L-lactide-co-trimethylene carbonate-co-glycolide) (PLTG) terpolymer in PBS buffer solution were investigated. Compared with pure PLTG, the addition of inorganic particles can neutralize the acidic products produced during the degradation process and maintain the pH of the system. At the same time, the addition of inorganic particles improves the hydrophilicity of the composite and accelerates the initial degradation rate of the polymer matrix. However, with the prolongation of the degradation time, different inorganic particles show different degradation rate adjustment effects. Because of the barrier effect of the hexagonal phase structure of SBA-15 and MCM-41 mesoporous materials on the diffusion of water molecules and the compatibility with the PLTG matrix is better than that of solid CCW, the addition of mesoporous materials slows down the degradation of the PLTG matrix. The addition of CCW accelerated the autocatalytic degradation of PLTG. It can be seen that the in vitro degradation rate of composite materials can be regulated by adding different inorganic particles, which has important reference value for the artificial regulation of the degradation rate of composite materials. According to the H&E staining appearance, all samples present good histocompatibility. These results suggest that the terpolymer with 5 wt% mesoporous nanoparticles adding is promising for uses as fully biodegradable bone repair scaffold.

Characterization and comparison of deposits in a coal-fired rotary kiln for iron ore fluxed pellets and acidic pellets productions

Compared to iron ore acidic pellet production, the deposit problem in kiln became more severe to produce iron ore fluxed pellets. This study characterized the deposit samples in a grate-kiln process for iron ore fluxed pellet production. The deposited samples were analyzed by chemical analysis, XRD, SEM-EDS, and thermodynamic software. The deposits contained mainly hematite particles embedded in bonding phases, mainly comprising silicates with different compositions. There was a significant change in the composition of bonding phases in deposits when the CaO content increased in the iron ore pellets. The bonding phases of deposits for fluxed pellets had higher CaO and Fe2O3 contents than acidic iron ore pellets. For the deposit samples from iron ore fluxed pellet production, the area of bonding phases in the phase diagram of CaO-Al2O3-SiO2-5wt%MgO moved to the higher CaO part, which had a lower liquid temperature. The change in the bonding phase caused a high proportion of formed liquid phases in the deposits, then led to severe deposit formation in the grate-kiln production plant.

A Novel Endo-Polygalacturonase from Penicillium oxalicum: Gene Cloning, Heterologous Expression and Its Use in Acidic Fruit Juice Extraction.

An endo-polygalacturonase (endo-PGase) exhibiting excellent performance during acidic fruit juice production would be highly attractive to the fruit juice industry. However, candidate endo-PGases for this purpose have rarely been reported. In this study, we expressed a gene from Penicillium oxalicum in Pichia pastoris. The recombinant enzyme PoxaEnPG28C had an optimal enzyme activity at pH 4.5 and 45°C and was stable at pH 3.0-6.5 and < 45°C. The enzyme had a specific activity of 4,377.65 ± 55.37 U/mg towards polygalacturonic acid, and the Km and Vmax values of PoxaEnPG28C were calculated as 1.64 g/l and 6127.45 U/mg, respectively. PoxaEnPG28C increased the light transmittance of orange, lemon, strawberry and hawthorn juice by 13.9 ± 0.3%, 29.4 ± 3.8%, 95.7 ± 10.2% and 79.8 ± 1.7%, respectively; it reduced the viscosity of the same juices by 25.7 ± 1.6%, 52.0 ± 4.5%, 48.2 ± 0.7% and 80.5 ± 2.3%, respectively, and it increased the yield of the juices by 24.5 ± 0.7%, 12.7 ± 2.2%, 48.5 ± 4.2% and 104.5 ± 6.4%, respectively. Thus, PoxaEnPG28C could be considered an excellent candidate enzyme for acidic fruit juice production. Remarkably, fruit juice production using hawthorn as an material was reported for the first time.

The structure of the kidneys and their intra- and extra-organ vascularization in poultry

The purpose of the study is to study the structural features of the kidneys and the sources of their vascularization in poultry. To study the structures of the kidneys, the method of conventional and fine dissection was used. In the manufacture of angiosteotopic preparations of the arterial system, self-hardening plastic of the acrylic series "Belakryl" was used. The objects of the study were the carcasses of chicken cross Hisex white, Peking duck and Italian goose at 160 days of age, in the amount of 9 pieces. Peking duck and Italian goose have cranial, middle, and caudal lobes in their kidneys, with the exception of chicken, which has an additional lobe. The relative mass of kidneys to body weight is 0.52% for chicken, 0.36% for Peking duck and 0.29% for Italian goose. The length of the kidneys from the length of the pelvis is 61.7% in the chicken, which is associated with a short trapezoid shape of the pelvic bone, in the Peking duck - 55.8% and in the Italian goose - 58.5%, which have long pelvic bones with their adaptation to the water image life. The kidneys maintain a constant osmotic pressure, chemical composition and active reaction of the blood by excreting excess salts and acidic products. The kidney parenchyma of the studied bird species consists of interstitial tissue, in which there are afferent renal arteries that produce urine and efferent ones that participate in the trophic function. The physiological functioning of the kidneys is associated with the work of the arterial system, which is involved in the excretory function. Arterial blood enters the kidneys through the cranial, middle, and caudal renal arteries. Within the kidney, the arteries branch into intralobular arteries. From which afferent arterioles depart, bringing blood to the vascular glomerulus. Efferent arterioles leave the vascular glomerulus, pass into the capillary and connect with the venous capillaries of the portal system of the kidneys.

Reactive oxygen species-degradable polythioketal urethane foam dressings to promote porcine skin wound repair.

Porous, resorbable biomaterials can serve as temporary scaffolds that support cell infiltration, tissue formation, and remodeling of nonhealing skin wounds. Synthetic biomaterials are less expensive to manufacture than biologic dressings and can achieve a broader range of physiochemical properties, but opportunities remain to tailor these materials for ideal host immune and regenerative responses. Polyesters are a well-established class of synthetic biomaterials; however, acidic degradation products released by their hydrolysis can cause poorly controlled autocatalytic degradation. Here, we systemically explored reactive oxygen species (ROS)-degradable polythioketal (PTK) urethane (UR) foams with varied hydrophilicity for skin wound healing. The most hydrophilic PTK-UR variant, with seven ethylene glycol (EG7) repeats flanking each side of a thioketal bond, exhibited the highest ROS reactivity and promoted optimal tissue infiltration, extracellular matrix (ECM) deposition, and reepithelialization in porcine skin wounds. EG7 induced lower foreign body response, greater recruitment of regenerative immune cell populations, and resolution of type 1 inflammation compared to more hydrophobic PTK-UR scaffolds. Porcine wounds treated with EG7 PTK-UR foams had greater ECM production, vascularization, and resolution of proinflammatory immune cells compared to polyester UR foam-based NovoSorb Biodegradable Temporizing Matrix (BTM)-treated wounds and greater early vascular perfusion and similar wound resurfacing relative to clinical gold standard Integra Bilayer Wound Matrix (BWM). In a porcine ischemic flap excisional wound model, EG7 PTK-UR treatment led to higher wound healing scores driven by lower inflammation and higher reepithelialization compared to NovoSorb BTM. PTK-UR foams warrant further investigation as synthetic biomaterials for wound healing applications.

High Entropy Alloy Electrocatalytic Electrode toward Alkaline Glycerol Valorization Coupling with Acidic Hydrogen Production.

Electrochemical glycerol oxidation reaction (GOR) is an attractive alternative anodic reaction to oxygen evolution reaction for a variety of electrolytic synthesis, thanks to the possibility of mass production of glycerol from biomass and the relative low thermodynamic potential of GOR. The development of high-activity cheap electrocatalysts toward GOR yet faces a daunting challenge. Herein, we experimentally prepare a new range of high entropy alloy (HEA) self-supported electrodes with uniform HEA nanoparticles grown on carbon cloth. The systematic electrochemical studies verify that the HEA-CoNiCuMnMo electrode exhibits attractive performance for GOR electrocatalysis with low overpotential and high selectivity toward formate products. The surface atomic configurations of HEA-CoNiCuMnMo are studied by a self-developed machine learning-based Monte Carlo simulation, which points out the catalytic active center to be Mo sites coordinated by Mn, Mo, and Ni. We further develop a hybrid alkali/acid flow electrolytic cell by pairing alkaline GOR with acidic hydrogen evolution reaction using the HEA-CoNiCuMnMo and the commercial RhIr/Ti as the anode and the cathode, respectively, which only requires an applied voltage of 0.55 V to reach an electrolytic current density of 10 mA cm-2 and maintains long-term electrolysis stability over 12 days continuous running at 50 mA cm-2 with Faraday efficiencies of over 99% for H2 in the cathode and 92% for formate production in the anode.

&lt;strong&gt;Comparison between carbonated and fruit-based soft drinks effect on calcium release from enamel surface of extracted permanent teeth&lt;/strong&gt;

Introduction: People widely consume soft drinks due to their easy accessibility and delightful taste, without realising the impact on the tooth surface. Enamel dissolves easily due to acidic products that contact acid, a chemical demineralisation process (dental erosion). This study aimed to analyse the comparison between carbonated and fruit-based soft drinks effect on calcium release from enamel surface of extracted permanent teeth. Methods: In-vitro study with a time-series design was conducted on the population of extracted premolars taken from a private dental clinic and orthodontics clinic of the Faculty of Dentistry Universitas Sumatera Utara, Medan. The sample was obtained using the pairwise difference hypothesis test formula. The samples were 24 pieces divided into two treatment groups by immersing in carbonated drinks and fruit-based soft drinks for 5 to 60 minutes. The statistical test used was the independent t-test and generalised linear model-repeated measures (GLM-RM). Results: The calcium level after immersion in the carbonated drink at the fifth minute was 0.476±0.397 mg/L, then increased significantly at the sixtieth minute to 3.058±0.811 mg/L (p=0.001). In the fruit-based soft drinks immersion group, the dissolved calcium at the fifth minute was 0.671±0.208 mg/L, then increased significantly to 2.258±1.351 mg/L (p-value=0.028). Neither carbonated drinks nor fruit-based soft drinks showed a significant effect on the levels of dissolved calcium (p-value=0.135). Conclusion: In the fifth minutes of immersion, fruit-based soft drinks caused higher calcium release level compared to carbonated soft drinks. In contrast, in the sixtieth-minutes of immersion, the calcium release is found to be higher in the carbonated soft drinks group.

Biochemical, microbiological and technological characteristics of type II sourdoughs produced with lactic acid bacteria single-strains

The interplay between biochemical characteristics and the generation of volatile compounds in 11 type II sourdough fermented by single strains of lactic acid bacteria (LAB) was studied. Samples were collected at 0, 6, 9, 12, 15, 18 and 24h for analyses of microbial growth, pH, titratable acidity and CO2 production. During the first 12h, the LABs entered the stationary phase, and the formation of organic and carboxyl acids, alcohols, and esters were observed. Although acidity is an important characteristic of sourdough, in this work increasing the acetic acid content decreased yeast growth and the CO2 retention capacity of the doughs. The main carbohydrate consumed by autochthonous yeast was influenced by the LAB added (homo-or heterofermentative), as observed by correlation analysis. Maltose and glucose showed a strong and negative correlation with the yeast cell density in the dough fermented by homo and heterofermentative LAB, respectively. Moreover, LAB had an important effect on the aromatic profile, being the alcohols, aldehydes, alkanes, organics acids and esters mainly groups characterized. Altogether, 100 different volatile compounds were identified; however, each dough had a different volatile profile. This study shows, for the first time, the influence of a single strain of LAB on the characteristics of type II sourdough.

Characterizing a novel hyposialylated erythropoietin by intact glycoprotein and glycan analysis

NeuroEPO plus is a recently developed recombinant human erythropoietin (rhEPO) without erythropoietic activity and shorter plasma half-life due to its low sialic acid content. This novel rhEPO product is under investigation as therapeutic protein in the treatment of neurodegenerative diseases owing to its neuroprotective and neurodegenerative properties. In this study, an in-depth characterization of NeuroEPO plus N-glycans was performed by a glycan isotope [12C6]/[13C6] coded aniline labeling strategy followed by capillary zwitterionic hydrophilic interaction liquid chromatography-mass spectrometry (CapZIC-HILIC-MS). A superior amount of low sialylated glycans and less branched structures were detected in NeuroEPO plus compare to other commercial rhEPOs. At the intact glycoprotein level, NeuroEPO plus glycoforms were separated by capillary zone electrophoresis with ultraviolet detection (CE-UV), optimizing the composition and pH of the separation electrolyte. Moreover, an isoelectric focusing polyacrylamide gel electrophoresis (IEF-PAGE) method was also optimized for the simultaneous analysis of this basic rhEPO and conventional acidic rhEPO products. The proposed glycomic and intact glycoprotein methods provide a robust and reliable analytical platform for NeuroEPO plus characterization and for its future implementation as biopharmaceutical in neurodegenerative diseases.

Characterization of degradation products of carrageenan by LC-QTOF/MS with a hypothetical database

Carrageenan (CGN) belongs to the sulfated polysaccharides family that is commonly used in the food industry. For oligosaccharide analysis, a liquid chromatography quadrupole time-of-flight/mass spectrometry strategy was developed using a hypothetical database. There are 2100 structures in the developed hypothetical κ-CGN database. To eliminate false-positive results, three approaches were used, including size exclusion chromatography with mass spectrometry, which differentiates the loss of sulfated groups caused by the hydrolysis process or the ionization process.Profiling of acidic hydrolysis products of κ-CGN was found that after 12 h of HCl cultivation, the κ-CGN was hydrolyzed to oligosaccharides lower than the degree of polymerization 10, breaking the α-1,3-glycoside linkage and producing even-numbered oligosaccharides. Another finding was that the pH at which acidic hydrolysis is terminated affects the generation of even and odd oligosaccharides. Peeling reaction occurs at the reduction end 4-linked-3,6-anhydrous-d-galactose when adjusted to alkaline conditions, thus generating odd oligosaccharides.

Reactivity passivation of red phosphorus with thin plasma-deposited carbon coating

Red phosphorus, when exposed to humid environments in air, breaks down into toxic phosphine gas and acidic phosphorus species, presenting a challenge for many applications, such as flame retardants or pyrotechnic obscurants. We have developed and characterized a method of plasma-deposited carbon to form a nanometer-thick, chemically stable carbon layer on red phosphorus particles to suppress phosphine and acidic phosphorus production. Using a combination of XPS surface analysis and a novel IR headspace analysis method, we developed and quantified an understanding of the reaction of red phosphorus with water vapor and the suppression of decomposition products using plasma-deposited carbon coatings. Phosphine production, quantified by IR, was accompanied by the formation of surface POx species produced as the particles react with water vapor. Increasing plasma deposition time increased thickness and uniformity of graphitic carbon coating, corresponding to a marked decrease in phosphine generation and formation of surface POx species.

Assessment of structural modification and time-dependent behavior of poly (lactic acid) based composites upon hydrolytic degradation

Structural modification of starch/PLA composites caused by hydrolysis was evaluated at different temperatures. Water uptake of starch/PLA composites showed a time-dependent behavior which did not follow the Fickian behavior well. Molecular weight also showed a time dependence, especially at 50 °C. Combining water uptake and molecular weight change together, the entrapment of acidic products in the bulk could increase the hydrophilicity of materials and catalyze the hydrolysis. The chain scission occurred at the C = O in the PLA chains according to the FTIR results. The presence of starch may induce the hydrolysis to take place at the interface between starch and PLA matrix. In addition, starch may slow down the hydrolysis rate slightly without influencing the hydrolysis degree. This research should provide valuable information for designing green materials to be applied in water-present conditions.

Direct conversion of fructose to levulinic acid in water medium catalyzed by a reusable perfluorosulfonic acid Aquivion® resin

In this work, we reported an environmental-benign and cost-effective route for the direct conversion of fructose to levulinic acid. A commercial perfluorosulfonic acid resin in a pellet form, that is, Aquivion® P98, was shown as a water-tolerant and reusable solid acid catalyst. The influence of catalyst dosage, reaction temperature and reaction time on the dehydration of fructose was systematically investigated. It was disclosed that fructose was initially dehydrated to 5-hydroxymethylfurfural as the intermediate and it was subsequently hydrolyzed to produce levulinic acid and formic acid over the Brønsted acidic sites provided by Aquivion® P98. Under the optimum reaction conditions, 96% yield to levulinic acid at 100% conversion of fructose was obtained in water at 120 °C after 12 h. Productivity of levulinic acid reached 3.2 mol mol−1H+, an outstanding value reported in literature to date. The Aquivion® P98 catalyst can be regenerated through a simple ion-exchange method, and a stable yield of levulinic acid was maintained after six consecutive reuses. The controlled experiments proved that the acidic products, i.e., formic acid and levulinic acid, allowed working as homogeneous catalysts to accelerate the dehydration of fructose and the subsequent hydrolysis of 5-hydroxymethylfurfural.

Prenylated (iso)flavonoids as antifungal agents against the food spoiler Zygosaccharomyces parabailii

Species belonging to the Zygosaccharomyces bailii sensu lato clade are some of the most troublesome spoilage yeasts of acidic food products, primarily due to their resistance towards synthetic food preservatives, like weak organic acids. Therefore alternative, powerful and more natural antifungal agents are needed. Herein, prenylated isoflavonoids, present mainly in the Leguminosae family, were investigated for their antifungal properties (including potency and mode of action) against a Z. bailii food isolate, its interspecies hybrid, Z. parabailii. The mono-prenylated isoflavonoids, wighteone and glabridin were the most active, with minimum fungicidal concentrations (MFC) of 12.5 μg/mL (37 μM) and 25 μg/mL (77 μM), respectively, at pH 4.0, rendering them over 20 times (on weight basis) more potent than sorbic acid (MFC 550 μg/mL, 4.5 mM). The two active mono-prenylated isoflavonoids induced killing within 15 min, suggesting potential membrane activity. Membrane permeabilization by these molecules was confirmed by propidium iodide uptake and TEM imaging. Membrane permeabilization was accompanied with leakage of intracellular material. Molecular properties such as the electrostatic energy potential and the hydrophobic integy moment were correlated to activity through a binary classification quantitative structure-activity relationship (QSAR) model. Altogether, mono-prenylated isoflavonoids can serve as highly potent, novel and natural antifungal against Z. parabailii acting by severely compromising the membrane integrity.

Effect of photodegradation on fungal colonization on wood during initial stage of brown-rot decay

Abstract Photodegradation and decay may happen simultaneously on wood under many exposure conditions. The aim of this study was to explore the effect of photodegradation on fungal colonization during initial stage of brown-rot decay of wood. For this purpose, southern pine (Pinus spp.) wood was exposed to accelerated UV weathering for different durations, and then decayed by a brown-rot fungus (Gloeophyllum trabeum). The changes in wood microstructure, chemical composition, surface color, crystallinity, fungal colonization pathways, and photodegradation products after weathering and decay were evaluated and characterized. The results showed that both weathering and decay led to obvious color change on wood surface. The photodegradation of wood resulted in the formation of cracking in cell wall, thus creating new voids. The photodegradation products, which mainly consisted of phenols, diterpenoid acids, and other lignin derived compounds, appeared in the cell lumen. During the initial stage of brown-rot decay, fungal hyphae invaded into wood through inherent voids such as ray cells, axial tracheids, and pits, and completed the initial colonization after 20 days. After photodegradation, hyphae could also invade wood from the new voids, and the acidic photodegradation products promoted the non-enzymatic degradation process of brown-rot. However, lignin derived compounds seemed to inhibit the further activity of decay fungi.

Current Advances in the Roles of Doped Bioactive Metal in Biodegradable Polymer Composite Scaffolds for Bone Repair: A Mini Review

The election of bone tissue engineering scaffolds material is mainly based on the bionics of natural bones. Although the content of trace elements in bone is low, the lack of them affects the growth and metabolism of bones, thus increasing the risk of orthopedic diseases caused by the deterioration of bone quality. Therefore, inspired by trace elements in natural bone, biodegradable polymer composite scaffolds doped with bioactive metals such as Mg, Zn, Sr, Fe, Cu, Mn, Co, Li, Ag, Nb, and V have attracted more attention. Herein, the role of bioactive metals doping in biodegradable polymer matrix is mainly reviewed, including improving hydrophilicity, preventing aseptic inflammation caused by acidic degradation products, imparting antibacterial activity, improving mechanical properties, and promoting vascularization of polymer scaffolds. Then, the reasons and solutions for interfacial bonding and cytotoxicity caused by doping bioactive metals are focused on.

Tuning the reactivity of Al–Ni by fine coating of halogen-containing energetic composites

In this paper, various core-shell structured Al–Ni@ECs composites have been prepared by a spray-drying technique. The involved ECs refer to the energetic composites (ECs) of ammonium perchlorate/nitrocellulose (AP/NC, NA) and polyvinylidene fluoride/hexanitrohexaazaisowurtzitane (PVDF/CL-20, PC). Two Al–Ni mixtures were prepared at atomic ratios of 1:1 and 1:3 and named as Al/Ni and Al/3Ni, respectively. The thermal reactivity and combustion behaviors of Al–Ni@ECs composites have been comprehensively investigated. Results showed that the reactivity and combustion performance of Al–Ni could be enhanced by introducing both NA and PC energetic composites. Among which the Al/Ni@NA composite exhibited higher reactivity and improved combustion performance. The measured flame propagation rate (v = 20.6 mm/s), average combustion wave temperature (Tmax = 1567.0 °C) and maximum temperature rise rate (γt = 1633.6 °C/s) of Al/Ni@NA are higher than that of the Al/Ni (v = 15.8 mm/s, Tmax = 858.0 °C, and γt = 143.5 °C/s). The enhancement in combustion properties could be due to presence of the acidic gaseous products from ECs, which could etch the Al2O3 shell on the surface of Al particles, and make the inner active Al to be easier transported, so that an intimate and faster intermetallic reaction between Al and Ni would be realized. Furthermore, the morphologies and chemical compositions of the condensed combustion products (CCPs) of Al–Ni@ECs composites were found to be different depending on the types of ECs. The compositions of CCPs are dominated with the Al–Ni intermetallics, combining with a trace amount of Al5O6N and Al2O3.

​Optimization of Fermentation Factors for Vinegar Preparation from Sugarcane Jaggery using Response Surface Methodology

Background: Vinegar, an acidic functional fermentation product and known for its diverse health benefits was developed using liquid jaggery. A study was conducted to standardize the method of vinegar production from liquid jaggery using two different sugarcane varieties viz., CoH160 and Co89003. Methods: The submerged fermentation of liquid jaggery was carried out using yeast Saccharomyces cerevisiae and vinegar was produced using Acetobacter aceti. For the computation analysis of an optimized solution, a central composite rotatable design was applied which constituted three variables temperature (°C), inoculum concentration (%) and incubation time (days) and its influence on acetic acid percent as an important response was studied using Response Surface Methodology. Overall, twenty experimental trials were conducted as well as assessed on the vinegar quality indexes. Result: Vinegar prepared with 7.5 per cent inoculum concentration, incubated for a fermentation period of 12.5 days at 28.5°C was selected due to maximum acetic acid concentration achieved ( greater than 3.5% (w/v). The optimized vinegar contained total soluble solids (4.55-4.75 °Brix), reducing sugar (0.26-0.29%), total sugars (2.7-2.8%), titratable acidity (4.72-5.10%), pH (4.28-4.52), ascorbic acid (17.64-19.97%), alcohol content (0.68-0.79%), acetic acid (3.52-3.83%) and total phenols (36.69-38.22 mg/100 ml). The liquid jaggery vinegar had a bright yellow- brown color, cane flavor and vinegar aroma. It was found organoleptically acceptable.