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Water for food and ecosystems in the Baviaanskloof Mega Reserve : land and water resources assessment in the Baviaanskloof, Eastern Cape Province, South Africa
2008
Jansen, H.C.
Water for food and ecosystems in the Baviaanskloof Mega Reserve : land and water resources assessment in the Baviaanskloof, Eastern Cape Province, South Africa
2008
Jansen, H.C.
Modeling Vadose Zone Processes during Land Application of Food-Processing Waste Water in California's Central Valley Полный текст
2008
Miller, Gretchen R. | Rubin, Yoram | Mayer, K Ulrich | Benito, Pascual H.
Land application of food-processing waste water occurs throughout California's Central Valley and may be degrading local ground water quality, primarily by increasing salinity and nitrogen levels. Natural attenuation is considered a treatment strategy for the waste, which often contains elevated levels of easily degradable organic carbon. Several key biogeochemical processes in the vadose zone alter the characteristics of the waste water before it reaches the ground water table, including microbial degradation, crop nutrient uptake, mineral precipitation, and ion exchange. This study used a process-based, multi-component reactive flow and transport model (MIN3P) to numerically simulate waste water migration in the vadose zone and to estimate its attenuation capacity. To address the high variability in site conditions and waste–stream characteristics, four food-processing industries were coupled with three site scenarios to simulate a range of land application outcomes. The simulations estimated that typically between 30 and 150% of the salt loading to the land surface reaches the ground water, resulting in dissolved solids concentrations up to sixteen times larger than the 500 mg L⁻¹ water quality objective. Site conditions, namely the ratio of hydraulic conductivity to the application rate, strongly influenced the amount of nitrate reaching the ground water, which ranged from zero to nine times the total loading applied. Rock–water interaction and nitrification explain salt and nitrate concentrations that exceed the levels present in the waste water. While source control remains the only method to prevent ground water degradation from saline wastes, proper site selection and waste application methods can reduce the risk of ground water degradation from nitrogen compounds.
Показать больше [+] Меньше [-]Effects of withholding food and/or water supply on the quality of meat from rex rabbits Полный текст
2008
XIONG, GUO-YUAN | XU, XING-LIAN | ZHU, XIU-BAI | ZHOU, GUANG-HONG | SHI, SHUAI
The effects of withholding food and/or water supply on the quality of meat from rex rabbits were investigated. Thirty-two rabbits were maintained under four different conditions: food and water respectively withheld 16-18 h and 6-8 h before slaughter (group 1); food withheld for 16-18 h, but water available ad libitum (group 2); food available ad libitum, but water withheld for 6-8 h (group 3); food and water available ad libitum (group 4). The pH₂₄ h (pH of meat at 24 h postmortem) increased following fasting. Withholding food or water decreased the lightness (L*-value) of meat after storage for 24 h. Group 2 had the highest redness value (a*-value). Drip loss, ripe meat ratio and tenderness were more affected by withholding water than by withholding food. Water content and intramuscular fat content were not affected by the treatment conditions (P < 0.05). Group 2 had the lowest drip loss and Warner-Bratzler shear force value, and the highest ripe meat ratio. Therefore, the best-quality rabbit meat can be obtained by withholding food for 16-18 h before slaughter, but allowing access to water ad libitum. Rabbit meat has become increasingly popular because of its high nutritional value. However, relatively little is known about the factors that affect the quality of rabbit meat, as especially few investigations have considered the effects of pre-slaughter conditions on rabbit meat quality. We were interested in knowing the effects of withholding food and/or water on rabbit meat quality, and have done some research in this field. We found that the best-quality rabbit meat can be obtained by withholding food for 16-18 h before slaughter, but allowing access to water ad libitum. This finding could be a reference value for rabbit meat production.
Показать больше [+] Меньше [-]Determination of Suitable Water Salinity and Live Food in The Rearing of Eel (Anguilla bicolor) Fry Полный текст
2008
. Sutrisno
This study was conducted to determine suitable water salinity and live food in the rearing of eel, Anguilla bicolor fry. Eel fry in weight of 0.15±0.008 g/tail were reared at controlled tank at density of 2 fish liter-1 for 42 days. Experiment was devided into two steps. In the first step of experiment, eel fry were reared at different water salinity, i.e., 0; 5; 10 and 15 ppt. Fish were fed on Tubifex at satiation. The best result from the first experiment was then used in the second step of study to examine proper live food for eel fry. Fish were fed on live food (Tubifex, Artemia, or Spirulina) at 10% body weight. Survival rate, specific growth rate and food conversion ratio were observed. The result of experiment showed that survival rate of eel fry reared in water salinity of 5 ppt (100%), 10 (96%) and 15 ppt (97%) was higher (p
Показать больше [+] Меньше [-]Food wrapping by females of the European Beewolf, Philanthus triangulum, retards water loss of larval provisions Полный текст
2008
HERZNER, GUDRUN | STROHM, ERHARD
Females of the European beewolf, Philanthus triangulum F. (Hymenoptera, Crabronidae), embalm the provisions of their larvae, paralyzed honeybees, with a secretion from a postpharyngeal gland prior to oviposition. This food wrapping is known to delay fungus infestation of the prey. In the present study, the hypothesis that the food wrapping has an additional function, namely the prevention of prey desiccation, is tested. Water loss of paralyzed but unembalmed honeybees and embalmed honeybees is measured and the composition and quantity of their cuticular hydrocarbons analyzed by coupled gas chromatography-mass spectrometry. Water loss is significantly lower in embalmed compared with unembalmed bees. This might have important advantages for the larvae under the warm and dry conditions that prevail in some brood cells. The embalming by beewolf females increases the total amount of hydrocarbons on the surface of the bees by almost ten-fold. Moreover, the proportion of unsaturated and short-chained hydrocarbons is significantly increased. Unsaturated and short-chain hydrocarbons are usually less effective against water loss, so the increased protection against water loss appears to be mediated mainly by the thickness of the hydrocarbon layer.
Показать больше [+] Меньше [-]The bactericidal effect of electrolyzed water on fresh food as influenced by rinsing methods and treatment times
2008
Kamitani, Y.(Kagoshima Univ. (Japan). Faculty of Agriculture) | Hiejima, H. | Morita, K. | Yagi, F.
Strong acidic electrolyzed water (SAcEW) is generated by using a diaphragm type electrolytic cell and adding a small amount of salt solution to the tap water. The acidity of this water causes chloride ions, as the major factor in sterilization process, to form hypochlorous acid. Therefore, it is said that the sterilization time with SAcEW is shorter than with sodium hypochlorite generally used for food sterilization. After being registered as a food additive (2002) in Japan, SAcEW began to be used for washing food in food processing facilities in order to improve the food sterilization level. In this research, the possibility of an enhanced sterilization effect of SAcEW generated by a water electrolyzer was evaluated by adding physical washing methods (ultrasonic, stream overflow, bubbling) and pre-washing with strong alkaline electrolyzed water (SAlEW) which is generated at the same time. As a result, the combination with pre-washing with SAlEW was found to be less effective than washing with SAcEW only when comparing the same washing time. As for the supplementation of physical washing methods, the stream type was found most effective. In addition, comparison between the sodium hypochlorite treatments (200 mg/L, soaked for 5 minutes) recommended by the Japanese Ministry of Health, Labor and Welfare for raw food materials and the SAcEW treatment for 10-30 seconds suggested equivalent sterilization effects on raw food materials.
Показать больше [+] Меньше [-]Learning from bright spots to enhance food security and to combat degradation of water and land resources Полный текст
2008
Penning de Vries, F. | Acquay, H. | Molden, David | Scherr, S. | Valentin, C. | Cofie, Olufunke
Green and blue water accounting in the Ganges and Nile basins: Implications for food and agricultural policy
2008
Sulser, Timothy B. | Ringler, Claudia | Zhu, T. | Msangi, Siwa | Bryan, Elizabeth | Rosegrant, Mark W.
Learning from bright spots to enhance food security and to combat degradation of water and land resources
2008
Penning de Vries, Frits W.T. | Acquay, H. | David, S. | Scherr, Sara J. | Valentin, Christian | Cofie, Olufunke O.