Molecular Characteristics and Antioxidant Activity of Spruce (Picea abies) Hemicelluloses Isolated by Catalytic Oxidative Delignification

Spruce (Piceaabies) wood hemicelluloses have been obtained by the noncatalytic and catalytic oxidative delignification in the acetic acid-water-hydrogen peroxide medium in a processing time of 3–4 h and temperatures of 90–100 °C. In the catalytic process, the H2SO4, MnSO4, TiO2, and (NH4)6Mo7O24 catalysts have been used. A polysaccharide yield of up to 11.7 wt% has been found. The hemicellulose composition and structure have been studied by a complex of physicochemical methods, including gas and gel permeation chromatography, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The galactose:mannose:glucose:arabinose:xylose monomeric units in a ratio of 5:3:2:1:1 have been identified in the hemicelluloses by gas chromatography. Using gel permeation chromatography, the weight average molar mass Mw of hemicelluloses has been found to attain 47,654 g/mol in noncatalytic delignification and up to 42,793 g/mol in catalytic delignification. Based on the same technique, a method for determining the α and k parameters of the Mark–Kuhn–Houwink equation for hemicelluloses has been developed; it has been established that these parameters change between 0.33–1.01 and 1.57–472.17, respectively, depending on the catalyst concentration and process temperature and time. Moreover, the FTIR spectra of the hemicellulose samples contain all the bands characteristic of heteropolysaccharides, specifically, 1069 cm−1 (C–O–C and C–O–H), 1738 cm−1 (ester C=O), 1375 cm−1 (–C–CH3), 1243 cm−1 (–C–O–), etc. It has been determined by the thermogravimetric analysis that the hemicelluloses isolated from spruce wood are resistant to heating to temperatures of up to ~100 °C and, upon further heating, start destructing at an increasing rate. The antioxidant activity of the hemicelluloses has been examined using the compounds simulating the 2,2-diphenyl-2-picrylhydrazyl free radicals.

Utilization Pemanfaatan Ekstrak Kulit Ubi Jalar Ungu Sebagai Pengganti Crystal Violet pada Pewarnaan Gram

Purple sweet potato has the high anthocyanin content. The anthocyanin content in purple sweet potato skin is higher than the anthocyanin in the tubers, namely 52.84-729.74 mg/100g while the tubers are 110.51 mg/100g. Natural dyes that have the potential to be extracted include anthocyanins. This research aimed to test anthocyanin dyes in purple sweet potato peel extract as the substitute for crystal violet in gram staining. The type of research used Quasi Experiments. This research was conducted in the Microbiology Laboratory of the Hasanuddin University Medical Faculty. In this research, extraction was carried out by using the solvent of Ethanol : Acetic Acid : Water (25: 1: 5). Furthermore, gram staining was carried out by using purple sweet potato peel extract using a concentration of 60%, 70%, 80%, 90%, 100% and crystal violet as positive control. The results of this research indicate that the staining used purple sweet potato peel extract concentrations of 60%, 70%, 80%, 90% in gram-positive Staphylococcus bacteria isolates showed poor bacterial staining results because the bacteria were not purple when compared to crystal violet dye. Where as at the concentration of 100% it showed good bacterial staining results because the bacteria was purple. Meanwhile, gram-negative e.coli bacteria isolates at the concentration of 60%, 70%, 80%, 90%, 100% showed good bacterial staining results because the bacteria were red. Suggestions for further research to do maceration longer.

Biodegradable Polymeric Membranes for Organic Solvent/Water Pervaporation Applications

Biodegradable polymers are a green alternative to apply as the base membrane materials in versatile processes. In this study, two dense membranes were made from biodegradable PGS (poly(glycerol sebacate)) and APS (poly(1,3-diamino-2-hydroxypropane-co-polyol sebacate)), respectively. The prepared membranes were characterized by FE-SEM, AFM, ATR-FTIR, TGA, DSC, water contact angle, and degree of swelling, in comparison with the PDMS (polydimethylpolysiloxane) membrane. In the pervaporation process for five organic solvent/water systems at 37 °C, both biodegradable membranes exhibited higher separation factors for ethanol/water and acetic acid/water separations, while the PDMS membrane attained better effectiveness in the other three systems. In particular, a positive relationship between the separation factor and the swelling ratio of organic solvent to water (DSo/DSw) was noticed. In spite of their biodegradability, the stability of both PGS and APS membranes was not deteriorated on ethanol/water pervaporation for one month. Furthermore, these two biodegradable membranes were applied in the pervaporation of simulated ABE (acetone-butanol-ethanol) fermentation solution, and the results were comparable with those reported in the literature.

Study of Controlled Migration of Cadmium and Lead Into Foods From Plastic Utensils for Children

Lead is a highly neurotoxic chemical element known for reducing intelligence quotient (IQ) and promoting antisocial behavior in children and adolescents, while cadmium is a carcinogenic bioaccumulative element. Contaminated foods and beverages are the most common routes of exposure. The objective of this study was to determine Cd and Pb concentrations in colored plastic utensils for use by children and to measure the specific migration of these elements into beverages and foods. Pb and Cd concentrations were determined using a handheld XRF. Specific migration tests were conducted using the simulant solutions. Migration levels were determined by ICP-MS and migration tests for Pb were also performed on actual samples GF-AAS determination. Utensils (n=87) were purchased for containing Cd and/or Pb concentrations above permitted limits. The mean of Pb and Cd were 1110 and 338 ppm respectively. For specific migration assays, Pb levels were 187, 13 and 380 times above the permitted limit for acetic acid, water and orange juice, respectively. Cd levels 50 and 2.4 times above the permitted limit for acetic acid and water, respectively. The districts where the utensils were purchased were grouped according to their Social Vulnerability Index and compared using ANOVA. Results revealed a group difference in mean Pb levels for low versus medium/high social vulnerability (p = 0.006). The findings corroborate the initial hypothesis that these utensils constitute a major source of exposure to PTEs such as Cd and Pb.

Qualitative Protein Hydrolyzed from Nerita undata in supralittoral rocks and mezolittoral zone of Hasa Cape using TLC

Gastropods are the sources of protein for coastal communities in the Maluku islands. We conducted analysis quantitative and qualitative of protein in Nerita undata meat from Hasa Cape in Saparua Island. The percentage of protein was analyzed by the Kjeldahl method. Qualitative analysis began with breaking peptide bonds in protein to amino acid components by sulphuric acid and barium hydroxide hydrolyzed. We identified amino acid compounds by using thin-layer chromatography (TLC) in butanol-acetic acid-water (8:1:1, v/v) as eluent. The result showed that N. undata meat contains 11.15% of protein and twelve amino acid compounds. There are seven essential amino acids in N. undata meat from supralittoral rocks and mezolittoral zone of Hasa cape is a source of quality protein. Thus, this species can be considered as a source of high-quality protein.

Determination of Triterpenoids and Phenolic Acids from Sanguisorba officinalis L. by HPLC-ELSD and Its Application

A novel analytical method involving high-performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD) was developed for simultaneous determination of 11 phenolic acids and 12 triterpenes in Sanguisorba officinalis L. Chromatographic separation was conducted with gradient elution mode by using a DiamonsilTM C18 column (250 mm × 4.6 mm, 5 μm) with the mobile phase of 0.1% acetic acid water (A) and methanol (B). The drift tube temperature of ELSD was set at 70 °C and the nitrogen cumulative flow rate was 1.6 L/min. The method was fully validated to be linear over a wide concentration range (R2 ≥ 0.9991). The precisions (RSD) were less than 3.0% and the recoveries were between 97.7% and 101.4% for all compounds. The results indicated that this method is accurate and effective for the determination of 23 functional components in Sanguisorba officinalis L. and could also be successfully applied to study the influence of processing method on those functional components in Sanguisorba officinalis L.

Vapor-liquid Equilibrium in the Ternary Systems Acetic Acid + Water + (Xylose or Glucose)

Hydrolysates of lignocellulosic biomass are aqueous solutions containing, among others, sugars andacetic acid. They are concentrated by evaporation. Only little is known on the influence of the sugars onthe volatility of the low-molecular-weight components in those mixtures. Therefore, in the present workthe isobaric vapor-liquid equilibrium of the systems (acetic acid (AA) þ water (W) þ xylose (X)) and(acetic acid (AA) þ water (W) þ glucose (G)) was studied at 20.0 kPa in a thin film evaporator. The resultsshow that the volatility of acetic acid is increased by the sugars and that xylose and glucose have asimilar influence. The vapor-liquid equilibrium data were correlated using the NRTL model for describingthe liquid phase non-ideality and taking the dimerization of acetic acid in the vapor phase into account.