MODIFICATION TO MAKE SAGO FLOUR CLOSE TO THE EXTENDER OF UREA FORMALDEHYDE ADHESIVE PROPERTIES *)

Sejak  tahun  1970, baik jumlah   maupun  kapasitas  pabrik  kayu  lapis  di Indonesia   meningkat dengan  pesat.  Pada  tahun  1995, produksi  kayu  lapis Indonesia  mencapai  sekitar   13,6  juta  meter kubik.  Untuk  memeuuhi   produksi  sebesar  itu diimpor sekitar 240.930 ton  tepung   gandum. Dapat  diduga  bahwa  tepung  gandum  dapat  diganti  oleh  bahan  pati  lain seperti  tepung  sagu.  Tepung  sagu  seperti  tepung   gandum,    mengandung   kadar  pati  yang   tinggi.  Karena   itu  tepung sagu  berpoteusi   tinggi  untuk  mengganti   tepung   terigu  sebagai   bahan  ekstender   perekat   urea-formaldehida  (UF).  Tetapi   perbedaan   besar  molekul   dan  kandungan   bahan  kimia   lain  seperti  gluten   menyebahkan   sifat  fisiko-kimia  sagu  berbeda   dengan   terigu  bila digunakan  sebagai  bahan  ekstender   perekat   UF. Tepung  sagu  adalah  hasil  ekstrak  batang  pohon  sagu  (Metroxylon  sagus Roxb).   Pohon  sagu   terutama   tumbuh  di Indonesia   dan  Papua  Nugini.  Selain itu, dalam  jumlah kecil  juga tumbuh  di Malaysia,  Thailand  dan  Philipina. Dari  potensi  pohon  yang  tersedia  diperkirakan bahwa  setiap  tahun  di Indonesia   tersedia  sebanyak  3, 6 juta  ton tepung  sagu.  Bila  tidak dipanen  tepung  sagu  tersebut  akan  terbuang  bersama  pohon  yang  segera  mati  setelah  pembuahan. Dalam  penelitian ini sifat fisiko  kimia  tepung  sagu yang  dimodifikasi  diuji  dan diharapkanmemiliki  sifat  seperti   tepung   gandum  sebagai  bahan  ekstender   perekat  UF.   Tepung   sagu dimodifikasi  dengan  dua  cara  yaitu  dengan   penambahan   asam   klorida  (HCI)  dan   dengan fosforilasi   (campuran  mono -  dan  di-sodium  fosfat)   sampai  mencapai  padanan    sifat   bahan ekstender  perekat   UF  yang  lazim  digunakan

Antioxidant activity of fractions from Quercus sideroxyla bark and identifi cation of proanthocyanidins by HPLC-DAD and HPLC-MS

The most active phenolics in Quercus sideroxyla Humb. & Bonpl. residual bark were identified and evaluated following a chromatographic fractionation. Bark powder was defatted with hexane and crude extract (CE) was obtained by extraction with aqueous acetone (70%). A liquid partition with ethyl acetate was performed to produce an organic extract (OE), which was subsequently purified by column chromatography (Toyopearl HW-40F, methanol), and resulted in six methanolic fractions (MF1 to MF6) and an oligomeric fraction (OLF) eluted with acetone 67%. Extraction yields, total phenolic and flavanol contents were determined. The antioxidant activity of bark extracts was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), Trolox (6-hydroxy-2,5,7,8-tetramethyl-chroman-2-carboxylic-acid)-equivalent antioxidant capacity (TEAC), and ferric ion reducing antioxidant power (FRAP) assays. Their median effective concentration (EC₅₀) data and rate constants for DPPH radical scavenging were also estimated. Identification of major phenolics was carried out by high performance liquid chromatography with diode array detection (HPLC-DAD) and high performance liquid chromatography with electrospray ionization coupled to mass spectrometry (HPLC-ESI-MS) instruments. Bioactive gallic acid, catechin, epicatechin, gallocatechin, catechin gallate, dimeric procyanidins, galloylated dimeric proanthocyanidins, trimeric procyanidins, and tetrameric proanthocyanidins were detected and identified in Q. sideroxyla bark extracts. MF2 was the most active fraction containing gallocatechin as its major compound; MF5 and OLF contain galloylated procyanidins, which may explain their higher antiradical activity. OLF besides galloylated procyanidins has gallocatechin, which presumably contributes to its higher antiradical activity. Consequently, Q. sideroxyla bark could be a good source of therapeutic health products or nutraceutical ingredients that may exert a potential prevention or treatment action against diseases in biological systems.This is the publisher’s final pdf. The published article is copyrighted by Walter de Gruyter and can be found at: http://www.degruyter.com/view/j/hfsg.Keywords: proanthocyanidins, Quercus sideroxyla ., bark, antiradical activity, HPL

Biological screening of selected Pacific Northwest forest plants using the brine shrimp (Artemia salina) toxicity bioassay

The brine shrimp (Artemia salina) bioassay was used to screen 211 methanol extracts from 128 species of Pacific Northwest plants in search of general cytotoxic activity. Strong toxicity (LC₅₀ 1000 µg/ml). Our subsequent studies of conifer heartwoods with strong activity confirm the assay’s value for identifying new investigational leads for materials with insecticidal and fungicidal activity.Keywords: Artemia salina, Methanol extracts, Bioactivity, Brine shrimp lethalit

Fast Atom Bombardment Mass Spectrometry of Condensed Tannin Sulfonate Derivatives

Condensed tannin sulfonate derivatives were studied by fast atom bombardment mass spectrometry (FAB-MS) to assess the feasibility of using this technique for determining molecular weight and structural information about these compounds. Both positive- and negative-ion spectra provided useful data with regard to molecular weight, cation species present, and presence of the sulfonate moiety. Additional structural information was provided in the spectra of the dimer sulfonates by fragment ions resulting from retro-Diels Alder fission and cleavage of the interflavanoid bond. Overall, negative-ion spectra proved to be superior to positive-ion spectra because of less interference from matrix ions. FAB-MS holds promise as a technique for analyzing condensed tannin sulfonates yet to be isolated and will help facilitate development of new adhesives made with these compounds

Ability of natural extracts to limit mold growth on Douglas-fir sapwood

The ability of selected plant extracts from wood and foliage to inhibit mold regrowth on fungal colonized wood was evaluated on Douglas-fir sapwood. Most foliage extracts produced some inhibition of Graphium or Trichoderma species, but isolations of other fungi increased following treatment. Five out of eight wood extracts produced 50% reductions in isolations, and those from Alaska cedar, western juniper, and incense cedar produced at least 80% reductions. The results indicate that wood extracts may be useful for reducing the incidence of mold on wood products, but none of the materials evaluated completely inhibited the test fungi. These extracts may provide a useful value-added application for by-products of lumber production from these species.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by North Carolina State University, Department of Wood and Paper Science. The published article can be found at: http://www.ncsu.edu/bioresources/.Keywords: Trichoderma spp., Douglas-fir sapwood, Penicillium spp. leaf extracts, Graphium spp., Mold, Xylem extracts, Aspergillus spp

VARIACIÓN DEL CONTENIDO DE TANINOS EN PLANTAS DEL MONTE GALLEGO

Los taninos son compuestos fenólicos de importancia en las relaciones herbívoroplanta, ya que pueden reducir la digestibilidad de la vegetación y actuar como sustancias repelentes debido a su característico sabor astringente y a veces toxicidad. En muchas ocasiones, pueden formar complejos insolubles con las proteínas que son excretados a través de las heces, de este modo disminuyendo la cantidad de proteína digestible en el alimento. Se estudió la variación estacional del contenido de taninos en plantas del monte gallego que forman parte de la dieta de cérvidos (ciervo, corzo) y del ganado doméstico. Los taninos estuvieron ausentes en grupos de plantas consideradas altamente palatables. Es el caso de las pertenecientes al grupo de las leguminosas, gramíneas, hiedra {Hederá helix), acebo {Ilex aquifolium) y sanguino {Frángula alnus). Las ericáceas, ya citadas por otros autores como de baja preferencia en las dietas, así como la zarza {Rubus sp.), presentaron taninos. La capacidad de los taninos para formar complejos insolubles con las proteínas fue mayor en los períodos de mayor actividad vegetativa. Se discute la importancia que la variación en el contenido de taninos en las plantas puede tener en el manejo de los ecosistemas forestales con presencia de ramoneadores y herbívoro

Research observation: Hydrolyzable and condensed tannins in plants of northwest Spain forests

Tannins are secondary metabolites that may influence feeding by mammals on plants. We analyzed hydrolyzable and condensed tannins in 30 plant species consumed by livestock and deer, as a preliminary attempt to study their possible implications on browsing and grazing in forest ecosystems. Heathers (Ericaceae) and plants of the Rose (Rosaceae) family had tannins, while forbs, grasses and shrubs other than the heathers did not show astringency properties. We found the highest tannin content of all the species in Rubus sp., with the highest value around 180 mg TAE/g dry weight in spring. Potentilla erecta, Alnus glutinosa and Quercus robur were next with 57 to 44 mg TAE/g dw. Total tannins in heathers ranged from 22 to 36 mg TAE/g dw. Levels of condensed tannins were higher than hydrolyzable for most of the species. Only Betula alba, Calluna vulgaris, Pteridium aquilinum and Vaccinium myrtillus had 100% hydrolyzable tannins. Tannin content of the species changed seasonally with highest values during the growing season, corresponding to late winter or early spring, depending on the species.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

AN INTEGRATED APPROACH USING Bacillus subtilis B26 AND ESSENTIAL OILS TO LIMIT FUNGAL DISCOLORATION OF WOOD

Bacillus subtilis and essential oils have been explored separately for their ability to limit colonization by wood stain and mold fungi, but neither approach has been completely effective. One alternative strategy would be to combine the bacterial biocontrol with one or more natural products extracts. In this report, the ability of combinations of B. subtilis B26 and 20 essential oils to limit fungal stain was explored on Douglas-fir sapwood wafers under controlled laboratory conditions. A number of extracts markedly improved the anti-fungal activity of B. subtilis B26, including 0.25% myrtlewood oil, 0.5% orange oil, 0.5% lime oil, and 1% Leyland cypress needles oil, which yielded improvements by 2 to 8 times. However, none of the combinations completely protected the wood from fungal attack. The results illustrate the difficulties associated with controlling the diverse array of organisms that can colonize freshly cut wood

Biologically Important Eremophilane Sesquiterpenes from Alaska Cedar Heartwood Essential Oil and Their Semi-Synthetic Derivatives

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