scholarly journals Rekayasa Chitosan Sebagai Pengawet Dan Meningkatkan Kadar Protein Dalam Tahu [Technologi Engineering Chitosan As A Preservative And Elevated Levels Of A Protein On Tofu ]

2019 ◽  
Vol 5 (2) ◽  
pp. 145
Author(s):  
Crhisnawati Vega, Daniel Elkana, Oktavia Putri, Rikky Leonard, Sapto Andriyono

Abstract Chitosan is the potential to serve as a food preservative, because chitosan has polikation positively charged so that it can inhibit the growth of microbes and are able to bind to the compounds negatively charged such as protein, polysaccharides, nucleid acid, heavy methal and others. In addition, molecules of chitosan has an N capable of forming amino compound which is a component of protein and amine moieties on the H atoms which facilitates chitosan interact with water through hydrogen bonds. Know who manufactured this process at the time of processing is still done traditionality. So that power save know produced has a fairy low level of durability. This study used a randomized complete design methods, experimental design was used with tree treatment with five replicate. Treatment imposed in the research include ; treatment with the awarding of chitosan as much as 1%, granting of chitosan treatment B as much as 2%, granting of chitosan treatment C by as much as 3%. Form the results of our study, obtained a good treatment doses for food out of 3%. The doses may be extend save out to 5 days in the future at room temperature and increase the levels of protein know 0,5 – 1,5 %.

2019 ◽  
Author(s):  
Meifeng Wang ◽  
Liyin Zhang ◽  
Yiqun Li ◽  
Liuqun Gu

<p></p>Anomerization of glycosides were rarely performed under basic condition due to lack of efficiency. Here an imidazole promoted anomerization of β-D-glucose pentaacetate was developed; and reaction could proceed in both organic solvents and solid state at room temperature. Although mechanism is not yet clear, this unprecedent mild anomerization in solid state may open a new promising way for stereoseletive anomerization of broad glucosides and materials design in the future..


2021 ◽  
Author(s):  
Lifang Qi ◽  
Yao Le ◽  
Chao Wang ◽  
Rui Lei ◽  
Tian Wu

Self-assembling ultrathin active δ-MnO2 nanosheets and Mn3O4 octahedrons into hierarchical texture enhances room-temperature formaldehyde oxidation at a low-level of Pt.


2000 ◽  
Vol 66 (11) ◽  
pp. 4798-4802 ◽  
Author(s):  
Line Johnsen ◽  
Gunnar Fimland ◽  
Vincent Eijsink ◽  
Jon Nissen-Meyer

ABSTRACT Pediocin PA-1 is a food grade antimicrobial peptide that has been used as a food preservative. Upon storage at 4°C or room temperature, pediocin PA-1 looses activity, and there is a concomitant 16-Da increase in the molecular mass. It is shown that the loss of activity follows first-order kinetics and that the instability can be prevented by replacing the single methionine residue (Met31) in pediocin PA-1. Replacing Met by Ala, Ile, or Leu protected the peptide from oxidation and had only minor effects on bacteriocin activity (for most indicator strains 100% activity was maintained). Replacement of Met by Asp was highly deleterious for bacteriocin activity.


1975 ◽  
Vol 55 (2) ◽  
pp. 225-233 ◽  
Author(s):  
H. KODAMA ◽  
M. D. WEBBER

Two specimens of hydroxy aluminum phosphate interlayer materials in montmorillonite clay were prepared with 7.20 meq Al and 11.29 meq H3PO4/g clay and with 14.40 meq Al and 22.58 meq H3PO4/g clay, and the resulting complexes studied by chemical and mineralogical methods. Both interlayer materials were slightly positively charged and except for different water contents their chemical compositions were almost identical. They contained Al, PO4 and H2O and a minor amount of Ca and approximated hydrous AlPO4∙nH2O. The mole ratios of Al:Ca:PO4:OH were 1.00:0.08:0.92:0.24 and 1.00:0.05:0.91:0.24, respectively. The interlayer materials appeared to be loosely packed and distributed sparsely in interspaces of the montmorillonite. The degree of packing was greater for the preparation with the larger amount of interlayer material. The materials increased the montmorillonite basal spacing to 23.3 Å under air-dry condition (30–40% relative humidity) but did not affect the lateral dimensions. The basal spacing varied somewhat with relative humidity at room temperature and decreased markedly as water was driven off by heating. Heat treatments between room temperature and 300 C sharply reduced the d001 spacings to 16.7 Å which persisted up to 700 C. It is postulated that the large basal spacings occur because the hydrated interlayer materials have a framework structure with tunnels along the c-axis. This being so, changes in the spacings with different humidities might result from the movement of water molecules among interstitial spaces existing around and between the loosely distributed molecules of interlayer material. The 16.7 Å spacing for the dehydrated phase corresponds to the sum of 7.0 Å, the edge dimension of an orthorhombic anhydrous AlPO4 and 9.7 Å, the silicate layer thickness.


1980 ◽  
Vol 58 (9) ◽  
pp. 867-874 ◽  
Author(s):  
Osvald Knop ◽  
Wolfgang J. Westerhaus ◽  
Michael Falk

Available evidence suggests that (1) the stretching frequencies of highly-bent hydrogen bonds decrease with increasing temperature, regardless of whether the bonds are static or dynamic in character, to a single acceptor or to several competing acceptors; and (2) departures from symmetric trifurcation (or bifurcation) toward asymmetric situations lower the stretching frequency. In further support of these criteria isotopic probe ion spectra between 10 K and room temperature have been obtained for taurine and for trigonal (NH4)2MF6 (M = Si, Ge, Sn, Ti). Evidence of a low-temperature transition at 100(10) K in trigonal (NH4)2SnF6 is presented, and existence of the previously reported transition at 38.6 K in trigonal (NH4)2SiF6 is confirmed. Symmetry changes associated with these transitions are discussed.


2015 ◽  
Vol 71 (11) ◽  
pp. 1384-1387
Author(s):  
Marwen Chouri ◽  
Habib Boughzala

The title compound bis(1,4-diazoniabicyclo[2.2.2]octane) di-μ-chlorido-bis[tetrachloridobismuthate(III)] dihydrate, (C6H14N2)2[Bi2Cl10]·2H2O, was obtained by slow evaporation at room temperature of a hydrochloric aqueous solution (pH = 1) containing bismuth(III) nitrate and 1,4-diazabicyclo[2.2.2]octane (DABCO) in a 1:2 molar ratio. The structure displays a two-dimensional arrangement parallel to (100) of isolated [Bi2Cl10]4−bioctahedra (site symmetry -1) separated by layers of organic 1,4-diazoniabicyclo[2.2.2]octane dications [(DABCOH2)2+] and water molecules. O—H...Cl, N—H...O and N—H...Cl hydrogen bonds lead to additional cohesion of the structure.


1968 ◽  
Vol 23 (5) ◽  
pp. 708-715 ◽  
Author(s):  
V. Hohler ◽  
H. D. Lutz

The IR-spectrum of gypsum (CaSO4·2 H2O) in the frequency range from 10 000 to 1200 cm-1 has been investigated with polarized light at room temperature. Between 3700 and 1200 cm-1, the measurements confirm the data of HASS and SUTHERLAND and as well as those of SCHAAK derived from IR and reflection measurements. The IR-spectrum shows a great number of bands, most of which can be assigned to combination and fundamental vibrations in terms of normal vibrations of the water molecules and the sulfate ions. The influence of the lattice vibrations is briefly discussed. The existence of hydrogen bonds between the water molecules and the sulfate ions gives rise to combinations of fundamental vibrations of both complexes.


2018 ◽  
Vol 29 (39) ◽  
pp. 395603 ◽  
Author(s):  
Dilek Duranoğlu ◽  
Deniz Uzunoglu ◽  
Banu Mansuroglu ◽  
Tulin Arasoglu ◽  
Serap Derman

Author(s):  
Emil Drápela

Urban geoheritage is a phenomenon that is present in almost every city, but so far, only some cities use it as a tourist product. In May and June 2019, in order to create an urban geoheritage trail in Liberec, it was mapped in the wider city centre. Considering the vastness of the area, mapping was carried out by volunteers who were interested in the topic of popularization of geology but did not have the expertise of geological knowledge. This lack of expertise may seem to be a significant limiting factor, but in fact, it is a positive thing, as the knowledge of the mapping volunteer is at a similar (low) level to the future user of the educational trail. Thus, in the evaluation of geosites, the expert-layman barrier is eliminated and the benefit is the feedback of the future user. However, participatory research has its own specifics, which must be adapted to the methodology used. First, it is to ensure the homogeneity of the data that is collected by a large number of volunteers and which can be influenced by subjective influences. Furthermore, it is their professional value and practical application. Finally, yet importantly, the technical parameters of data that will be further processed in GIS. This paper describes the research methodology used and summarizes the experience with the use of participatory research for the purpose of mapping urban geoheritage in Liberec.


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