Changes to the chemical and microbiological characteristics of Leucaena leucocephala seeds during tempeh fermentation in Pacitan, East Java

Lamtoro tempeh is a traditional Indonesian fermented food made from lamtoro (Leucaena leucocephala). In Pacitan, it is usually fermented using usar (a traditional tempeh inoculum made from senggani leaves). The fermentation process takes 42 hrs and during this period, there are changes in the chemical and microbiological characteristics of the lamtoro seeds. To study these changes, samples were collected and tested for chemical characteristics (water content, ash content, dissolved protein, pH, and total acid titration) and microbiological characteristics (the number of fungi, yeast, and lactic acid bacteria) every 6 hrs during the 42 hrs fermentation. During fermentation, the water content increased significantly in the initial 6 hrs of fermentation and then tended to stabilize until the 42-hour. The ash content increased, while the dissolved protein content increased from the 0-hour to the 36-hour of fermentation but dropped at the 42-hour. The pH level of the lamtoro tempeh decreased from 0-hour until 30-hour and then increased until the end of the fermentation period. However, the level of total acid titration increased during the lamtoro tempeh fermentation. The growth of fungi, yeast and lactic acid bacteria initially declined but then gradually increased until the end of fermentation (42-hour). The fermentation time was found to affect both the number of microbes and the chemical characteristics of the lamtoro tempeh from the Pacitan area.

A Simple and Accurate Approach for Determining the VFA Concentration in Anaerobic Digestion Liquors, Relying on Two Titration Points and an External Inorganic Carbon Analysis

A new analytic approach is presented for determining the total volatile fatty acids (VFAT) concentration in anaerobic digesters. The approach relies on external determination of the inorganic carbon concentration (CT) in the analyzed solution, along with two strong-acid titration points. The CT concentration can be determined by either a direct analysis (e.g., by using a TOC device) or by estimating it from the recorded partial pressure of CO2(g) in the biogas (often a routine analysis in anaerobic digesters). The titration is carried out to pH 5.25 and then to pH 4.25. The two titration results are plugged into an alkalinity-mass-based equation and then the two terms are subtracted from each other to yield an equation in which VFAT is the sole unknown (since CT is known and the effect of the total orthophosphate and ammonia concentrations is shown to be small at this pH range). The development of the algorithm and its verification on four anaerobic reactor liquors is presented, on both the raw water and on acetic acid-spiked samples. The results show the method to be both accurate (up to 2.5% of the expected value for VFAT/Alkalinity >0.2) and repetitive when the total orthophosphate and ammonia concentrations are known, and fairly accurate (±5% for VFAT >5 mM) when these are completely neglected. PHREEQC-assisted computation of CT from the knowledge of the partial pressure of CO2(g) in the biogas (and pH, EC and temperature in the liquor) resulted in a very good estimation of the CT value (±3%), indicating that this technique is adequate for the purpose of determining VFAT for alarming operators in case of process deterioration and imminent failure.

Deconvolution of intermixed redox processes in Ni-based cation-disordered Li-excess cathodes

Capacity deconvolution of intermixed high-valent Ni redox and oxygen redox through 18O labelling, acid titration, and mass spectrometry.

Flower Extracts of Cage Plants (Canavalia virosa) as an Indicator of Acid Base

Cage plants (Canavalia virosa) are classified as nuts. This study aims to prove the flowers of the cage plants as acid-base indicators and determine the type of acid-base titration that is suitable for indicators of cage plants. The flowers of the cage plants were macerated with ethanol. Extras were tested as indicators in acid-base solutions, buffer solutions, and compared with phenolphthalein and methyl orange for acid-base titration, namely: strong acid with a strong base, a weak acid with a strong base, and weak base with strong acid. The results obtained in this study, namely: flower extracts of cage plants in strong red acid, in weak acid pink, in strong green bases, and weak bases in light green. In a buffer solution of pH 1 to pH 11, the flower extract of the cage plants gives 4 color groups, namely: a buffer solution with pH 1 colored red, pH 3 colored pink, pH 5 to pH 9 being light green, and pH 11 being dark blue. Cage plant flower extract can be used as an indicator of acid-base, cage plant flower extract can be used on strong-base strong acid titration, strong weak-acid base, and weak-strong base acid titration.

Comparison of Formaldehyde Measurements by HANTZSCH, CRDS and DOAS instruments in the SAPHIR Chamber

<p>Three instruments using different measurement techniques were used to measure formaldehyde (HCHO) concentrations during experiments in the atmopshere simulation chamber SAPHIR at the Forschungszentrum Juelich. An AL4021 instrument by Aero Laser GmbH uses the wet-chemical Hantzsch reaction for efficient gas stripping, chemical conversion and fluorescence measurement. An internal permeation gas source provides daily calibrations characterized by sulfuric acid titration. A G2307 analyzer by PICARRO INC. uses Cavity Ring-Down Spectroscopy (CRDS) technique to determine concentrations of HCHO, water and methane. A high-resolution laser differential optical absorption spectroscopy (DOAS) instrument provided HCHO measurements along the central chamber axis using an optical multiple reflection cell. The measurements were conducted from June to December 2019 in experiments when ambient air was flowed through the chamber and also in photochemical experiments in synthetic air with mixtures of different reactants, water vapour, nitrogen oxides, and ozone concentrations. Results demonstrate the importance for a linear base line interpolation between zero measurements for the Hantzsch instrument. In addition, a strong water dependence of the baseline of CRDS measurements was found. After correction for the baselines, the correlation analysis of measurements demonstrate good agreement (R > 0.98) between the instruments.</p>

PENGARUH KONSENTRASI SUKROSA SEBAGAI CRYOPROTECTANT TERHADAP KARAKTERISTIK SIFAT KIMIA YOGHURT SINBIOTIK KERING BEKU

ABSTRAKYoghurt sinbiotik merupakan susu fermentasi oleh Bakteri Asam Lakat (BAL) spesies Lactobacillus bulgaricus dan Streptococcus thermophillus, dan Lactobacillus plantarum Dad 13 sebagai probiotik dengan penambahan ubi jalar ungu sebagai prebotik. Yoghurt sinbiotik diproses dengan pengeringan beku. Pada proses pengeringan beku ditambahkan Cryoprotectant untuk mencegah kerusakan membran sel bakteri pada yoghurt. Cryoprotectant berfungsi sebagai pelindung sel bakteri asam laktat selama pembekuan. Tujuan penelitian adalah mengetahui pengaruh konsentrasi Cryoprotectant sukrosa terhadap sifat kimia yoghurt sinbiotik kering beku. Penelitian ini menggunakan Rancangan Acak Lengkap dengan satu variasi yaitu konsentrasi Croprotectant (0%, 2,5%, 5%, 7,5%). Data yang diperoleh dianalisis statistic menggunakan Analysis Of Variance (ANOVA) dengan tingkat signifikan 5% dan jika terdapat perbedaan yang nyata antar perlakuan maka dilanjutkan dengan uji Duncan’s Multiple Range Test (DMRT). Parameter pengamatan yang digunakan untuk menganalisis yoghurt sinbiotik kering beku meliputi kadar air, kadar abu, total asam titrasi, dan pH. Hasil penelitian menunjukkan bahwa konsentrasi Cryoprotectant tidak berpengaruh nyata terhadap kadar air, dan pH yoghurt sinbiotik kering beku, namun berpengaruh nyata terhadap kadar abu dan total asam titrasi. Pengaruh konsentrasi sukrosa sebagai Cryoprotectant diperoleh hasil terbaik pada konsentrasi 5% mempunyai kadar air 5,633%, kadar abu 4,900%, total asam titrasi 8,8167%, dan pH 3.867.ABSTRACTSynbiotic yogurt is fermented milk by Lactic Acid Bacteria (LAB) species Lactobacillus bulgaricus and Streptococcus thermophillus, and Lactobacillus plantarum Dad 13 as probiotics with the addition of purple sweet potatoes as prebotics. Synbiotic yogurt is processed by freeze drying. In the freeze drying process Cryoprotectant is added to prevent damage to bacterial cell membranes in yogurt. Cryoprotectant functions as a protective cell for lactic acid bacteria during freezing. The purpose of this study was to determine the effect of sucrose cryoprotectant concentrations on the chemical properties of freeze dried sinbiotic yogurt. This study uses a Completely Randomized Design with one variation, namely the concentration of Croprotectant (0%, 2.5%, 5%, 7.5%). The data obtained were statistically analyzed using Analysis Of Variance (ANOVA) with a significant level of 5% and if there were significant differences between treatments then continued with the Duncan's Multiple Range Test (DMRT). Observation parameters used to analyze freeze dried synbiotic yogurt include water content, total titration acid, ash content, and pH. The results showed that the concentration of Cryoprotectant had no significant effect on water content, and the pH of freeze dried synbiotic yogurt, but had a significant effect on ash content and total acid titration. Effect of sucrose concentration as Cryoprotectant obtained the best results at a concentration of 5% having a moisture content of 5.633%, ash content of 4.900%, total acid titration of 8.8167%, and pH of 3,867.Keywords: Synbiotic Yogurt, Purple Sweet Potato, Cryoprotectant