خيارات البحث
النتائج 41 - 50 من 6,038
Water activity in food
1979
Anagnostopoulos, G.
One of the oldest methods of food preservation is the reduction of water content in foods. Sun and fire drying, salting of animal flesh, and sugaring of fruit in prehistoric times simulated natural drying processes such as fruit drying on trees. Foods with a high water content, such as milk, meat, fruits, and vegetables, undergo rapid microbial deterioration. The concept of water activity (a-w) gives information about the availability to microbial growth and the stability of food. It is expressed in terms of vapor pressure generated by an aqueous system relative to that of pure water at the same temperature. Growth and survival of food spoilage organisms (bacteria, yeasts and molds) are a function of water activity and other environmental factors including temperature, pH, oxygen, and carbon dioxide concentration, and the presence of preservatives.
اظهر المزيد [+] اقل [-]Water activity and food
1978
Troller, John A. | Christian, J. H. B.
Land, water, and food
1955
Addison, Herbert
Water, food, and irrigation النص الكامل
2023
Hoogesteger, Jaime | Suhardiman, Diana | Veldwisch, Gert Jan | Hidalgo-Bastidas, Juan Pablo | Boelens, Rutgerd
Irrigated agriculture plays a central role in global food production as it provides resilience to rainfall variability, increased productivity and production security. However, it has also gone hand in hand with serious socio-environmental challenges. Large-scale irrigated agricultural production, which depends on both surface and groundwater resources, has encountered several technical and managerial challenges. It has led to widespread environmental deterioration through drying and polluting rivers, lakes, wetlands, and aquifers. At the same time, irrigated agricultural production has been increasingly commodified, specialized and globalized through large commercial farming enterprises, contract farming and international agro-export chains. This has led to widespread processes of land and water accumulation and related socio-environmental inequities in many regions of the world. In contraposition to this tendency peasant irrigated production plays a key role in producing for local and regional fresh food markets. In this context, we explore a few innovative and promising grassroots initiatives that spring from peasant agriculture. These are agro-ecology, farmer-led irrigation development and peri-urban agriculture, all initiatives that rest on the creation of local food production and marketing networks. Finally, this book chapter closes by setting out critical questions about policies and the political implications of food consumption patterns.
اظهر المزيد [+] اقل [-]Water-energy-food nexus
2017
"Water, energy and food are key resources to sustain life, and are fundamental to national, regional, and global economies. These three resources are interlinked in multiple ways, and the term 'nexus' captures the interconnections. The nexus has been discussed, debated, researched, and advocated widely but the focus is often on the pairings of 'water-energy' or 'water-food' or 'energy-food'. To really benefit from the nexus approach in terms of resource use efficiency, it is essential to understand, operationalize, and practice the nexus of all three resources. As demand for these resources increases worldwide, using them sustainably is a critical concern for scientists, citizens, governments, and policymakers. Water-Energy-Food Nexus: Principles and Practices is a valuable resource for students, research scholars, and professionals in academic institutions with strong interests in interdisciplinary research involving geography, earth science, environmental science, environmental management, sustainability science, international development, and ecological economics. The volume will also be useful for professionals, practitioners and consultants in NGOs, government, and international agencies"--Back cover.
اظهر المزيد [+] اقل [-]Water-food-energy nexus النص الكامل
2014
Bird, Jeremy | Dodds, F. | McCornick, Peter | Shah, Tushaar
Food and water security
2008
Aswathanarayana, U.
Growing food in water النص الكامل
2000
Technical Centre for Agricultural and Rural Cooperation
Growing food in little space is a challenge being faced daily by families in crowded areas. Hydroponics, the art of growing plants with no soil in water with added nutrients, is one solution but it has faced opposition from urban planners and scientists who stress that its complexity is beyond the normal woman or man. As the article on urban agriculture in Spore 81 urged, 'The scientist, whether based in a laboratory or a local community group, who develops a popular and transferable method of hydroponics will be remembered far into the next millennium for a significant contribution to food security.' Is Home Hydroponic Gardens the answer to the prayer? It could well be, with its rugged hard-cover full of careful and detailed texts and superb step-by-step coloured illustrations explaining how to use simplified hydroponics, requiring no mechanical devices. It gives methods and construction techniques for building hydroponic gardens on waste lots in towns, in backyards, on rooftops, with details of experiences in Zimbabwe, Senegal and Colombia. There are precise and proven recipes for the production of home-made organic nutrient mixes, as well as explanations of how plants take their nutrients and grow. This is real popular science at work, with dietary advice and recipes following the section on the daily chores of plant care and harvesting the dozens of suggested fruits, herbs, spices and salad, root and table vegetables. With a little bit of effort, a family with a hydroponic garden will not only end up healthier and wealthier, but also much better informed about how plants grow, and thus able to encourage the neighbours to take the hydroponic route too. Home Hydroponic Gardens. P Bradley & C Marulanda. Global Hydroponic Network. 2000. 240 pp.US$ 34.95 E 40.95 Contact GHN for price of mail, or details of distributors in Zimbabwe, Europe, Asia and Latin America GHN PO Box 151 Corvallis, Oregon 97339, USA Email: [email protected] | Home Hydroponic Gardens. P Bradley & C Marulanda. Global Hydroponic Network. 2000. 240 pp.US$ 34.95 E 40.95 Contact GHN for price of mail, or details of distributors in Zimbabwe, Europe, Asia and Latin America GHN PO Box 151 Corvallis, Oregon 9
اظهر المزيد [+] اقل [-]Water and food quality
1989
Hardman, T.M. (ed.)
