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Complex agroforestry systems that mimic local forest structure, so-called ‘analogs’, are assumed to be of specific value to rural people as well as the environment. The objective of this study was to document and evaluate the utilization of plant resources by Philippine lowland farmers to identify native species suitable for integration in such a system. The interviewed farmers maintain a comprehensive ethnobotanical knowledge. They reported using 122 plant species for 77 purposes. Eighty species have medicinal value, 35 provide food, and 32 serve other uses. About 64% of the identified species are Philippine natives. The life form composition of these species is dominated by trees but also includes herbs, lianas, and graminoids, thus providing the structural elements required in analog systems. Nevertheless, only a few of the species seem to be promising for cultivation. Many of them are ubiquitous in the vicinity of villages. Some species are also not much appreciated but act as staple food only during food shortage. Even though several of the species have proven market value, such as rattan (e.g. Calamus merrillii), or are reputed medicines, such as ‘Philippine ginseng’ (Sarcandra glabra), no cultivation could be observed. This shows that usefulness in itself cannot be the only criterion to promote species but that it requires a careful analysis of the marketability of the respective species. In this context we suggest the following three species that are of proven medicinal value for in-depth study: the liana Tinospora crispa (Menispermaceae), the tree Picrasma javanica (Simaroubaceae), and the herb Sarcandra glabra (Chloranthaceae). They represent three different life form strategies and would thus fit well in vertically structured agroforestry systems.  相似文献   
23.
Cryopreservation of selected genotypes of European chestnut and cork oak was carried out in two laboratories in a project involving conservation of field collections. Plant material was selected on the basis of disease resistance (chestnut), growth habit, phytosanitary performance and cork quality (cork oak). The cryopreservation technique comprised of vitrification of shoot apices isolated from in vitro stock shoot cultures (chestnut) and somatic embryos (cork oak). Forty-three out of 46 chestnut genotypes assayed survived the freezing process, but only 63% recovered their capacity to produce new shoots. After completion of multiplication and rooting steps, the surviving shoots produced plants that were morphologically identical to those derived from non-supercooled material. All 51 cork oak genotypes withstood freezing and were able to produce new somatic embryos through a process of secondary embryogenesis. Multiplication and germination of the recovered embryos enabled production of plants that were morphologically identical to those derived from non-supercooled material. In light of the results obtained, long-term cryopreservation of these species is feasible, thereby ensuring conservation of valuable genotypes during field evaluation.  相似文献   
24.
The laurel forest of Anaga is the most emblematic community of the Canarian Archipelago. Restoration programs are being developed to increase laurel forest area on the island of Tenerife. Structural and spatial characteristics determine many aspects of the community, including regeneration patterns, disturbance level, stand history. In spite of the importance of this information for restoration, few quantitative studies have been conducted on laurel forest dynamics. We analyzed two stands of the Anaga laurel forest of different aspect. The main difference between the two sites was the wind exposure, one leeward and the other windward. Regeneration, spatial distribution of regeneration, tree species composition, asexual regeneration and environmental parameters were analyzed in three 50 × 50 m plots at each site. Both sites differ in important aspects such as species richness, species composition, asexual regeneration and dead tree composition, while they are not different in basal area, density, density of regeneration and density of dead trees. Both sites have had similar management in the last century. Asexual regeneration is able to maintain the present species composition, while sexual regeneration is able to offer future changes in the canopy composition. Regeneration strategies and the effect of some environmental characteristics should be considered in restoration programs.  相似文献   
25.
Hydrolysates obtained by autohydrolysis-posthydrolysis of corncobs were detoxified with charcoal, concentrated, supplemented with nutrients, and fermented with Debaryomyces hansenii. After biomass removal, the fermented media contained 0.1137 kg of nonvolatile components (NVC)/kg of liquor, which corresponded mainly to xylitol (0.6249 kg/kg of NVC) but also to minor amounts of inorganic components (measured as ashes), proteins, nonfermented sugars (xylose and arabinose), uronic acids, arabitol, and other nonvolatile components (ONVC). The media were subjected to further processing (sequential stages of adsorption, concentration, ethanol precipitation, concentration, and crystallization) to obtain food-grade xylitol. Adsorption experiments were carried out at various solid-to-liquor ratios. Under selected conditions (1 kg of charcoal/15 kg of liquors), the xylitol content increased to 0.6873 kg/kg of NVC, and almost total decoloration was achieved. The resulting liquor was concentrated by evaporation to increase its NVC content to 0.4032 kg/kg of liquor (corresponding to a xylitol concentration of 0.280 kg/kg of liquor), and ethanol was added to precipitate a part of the NVC (mainly proteins, but also uronic acids, ashes, and other nonvolatile compounds). Refined liquors (containing 0.7303 kg of xylitol/kg of NVC) were concentrated again, and ethanol was added (to reach 40-60% volume of the stream) to allow crystallization at -10 or -5 degrees C. Under selected conditions, 43.7% of xylitol contained in the initial fermentation broth was recovered in well-formed, homogeneous crystals, in which xylitol accounted for 98.9% of the total oven-dry weight. Material balances are presented for the whole processing scheme considered in this work.  相似文献   
26.
The recovery of tartaric acid (TA) from distilled vinification lees coming from the white and red winemaking technology was optimized using response surface methodology and Statistica 5.0 software. The sequential treatment of dissolving TA and further calcium tartrate (CaT) precipitation could be used to recover up to 92.4% of the initial TA when distilled white lees were used. The residual lees were employed as economic nutrients for lactic acid production by Lactobacillus pentosus CECT-4023 using hemicellulosic vine shoot hydrolysates as carbon source. Distilled lees after TA extraction used as nutrients provided values of lactic acid (18.4-18.9 g/L), global volumetric productivities (0.82-0.84 g/L.h), and product yields (0.69-0.70 g/g) similar to those achieved when using the general medium for Lactobacilli (18.6 g/L, 1.11 g/L.h, and 0.62 g/g, respectively) or lees without TA extraction (16.4-17.2 g/L, 0.96-1.21 g/L.h, and 0.61-0.66 g/g, respectively). This technology not only avoids pollutant disposal but also represents a commercial source of tartaric acid and economic nutrients for biotechnological processes.  相似文献   
27.
Urea is an important precursor in the formation of ethyl carbamate, a known carcinogen in alcoholic beverages. Ethyl carbamate has recently been detected at high concentrations in sugar cane distilled spirits, but little is known about the concentration of urea in these beverages. The objectives of this study were to validate methodology for the determination of urea in sugar cane distilled spirits, to determine the levels in 68 samples from different regions within the state of Minas Gerais, Brazil, and to examine the relationship between the concentrations of urea and ethyl carbamate. The method, based on the reaction of urea with 1-phenyl-1,2-propanodione-2-oxime and spectrophotometric quantification at 540 nm, provided linear response from 0.5 to 15.0 mg/L. No purification of the sample was required. The limits of detection and quantification were 0.1 and 0.5 mg/L, respectively. Urea was detected in 69% of the samples at levels varying from 0.50 to 5.10 mg/L. There was no significant difference on the levels of urea in samples from different regions of the state. No significant correlation between the levels of urea and ethyl carbamate was observed for the samples analyzed.  相似文献   
28.
In this study, the hypothesis that food-derived opioid peptides besides β-casomorphin 7 might modulate the production of mucin via a direct action on epithelial goblet cells was investigated in HT29-MTX cells used as a model of human colonic epithelium. Seven milk whey or casein peptides, a human milk peptide, and a wheat gluten-derived peptide with proved or probable ability to bind μ- or δ-opioid receptors were tested on the cell culture. Significantly increased secretion of mucins was found after exposure to six of the assayed peptides, besides the previously described β-casomorphin 7, as measured by an enzyme-linked lectin assay (ELLA). Human β-casomorphin 5 and α-lactorphin were selected to study the expression of mucin 5AC gene (MUC5AC), the HT29-MTX major secreted mucin gene. α-Lactorphin showed increased expression of MUC5AC from 4 to 24 h (up to 1.6-fold over basal level expression), although differences were statistically different only after 24 h of exposure. However, this increased expression of MUC5AC did not reach significance after cell treatment with human β-casomorphin 5. In conclusion, six food-derived peptides have been identifed with described or probable opioid activity that induce mucin secretion in HT29-MTX cells. Concretely, α-lactorphin is able to up-regulate the expression of the major secreted mucin gene encoded by these cells.  相似文献   
29.
This paper reports a systematic approach to the development of a method that combines continuous solid-phase extraction and gas chromatography-mass spectrometry for the simultaneous determination of 20 pharmacologically active substances including antibacterials (chloramphenicol, florfenicol, pyrimethamine, thiamphenicol), nonsteroideal anti-inflammatories (diclofenac, flunixin, ibuprofen, ketoprofen, naproxen, mefenamic acid, niflumic acid, phenylbutazone), antiseptic (triclosan), antiepileptic (carbamazepine), lipid regulator (clofibric acid), β-blockers (metoprolol, propranolol), and hormones (17α-ethinylestradiol, estrone, 17β-estradiol) in milk samples. The sample preparation procedure involves deproteination of the milk, followed by sample enrichment and cleanup by continuous solid-phase extraction. The proposed method provides a linear response over the range of 0.6-5000 ng/kg and features limits of detection from 0.2 to 1.2 ng/kg depending on the particular analyte. The method was successfully applied to the determination of pharmacologically active substance residues in food samples including whole, raw, half-skim, skim, and powdered milk from different sources (cow, goat, and human breast).  相似文献   
30.
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