Summary (En)

Having enough clean drinking water is a top priority during any emergency! A normally active person needs at least two quarts of water each day. However, needs vary depending on the weather and an individual’s age and health status. When clean water is not available, we need to purify all water before using it for drinking, preparing food, or personal hygiene. Many methods for purifying water are available, but none (by itself) is perfect. Often, a combination of more than one methods works best. This document is FCS9195, one of a series of the Department of Family, Youth and Community Sciences, Florida Cooperative Extension Service, IFAS, University of Florida, Gainesville FL 32611. First published: May 2003.

This first background paper from the CGIAR Water for Food Program seeks to identify research needs to increase crop water productivity, such that food security can be ensured and farmers’ livelihoods enhanced without increasing water diverted for agriculture.The paper proposes a number of priority topics for research on crop water management in the challenge Program on Water and Food, which will be amended during the development of the Program. These studies are grouped into four categories of research issues: effective development of genotypes to accelerate improvement of crop water productivitynew opportunities and technologies for integrated crop and natural resources management at field and farm levelopportunities for enhancing water productivity at regional and agro-ecological systemsinstitutional arrangements at the farming-systems level, which promote farmers’ adoption of technologies that enhance water productivityThe paper concludes that whilst there are challenges to be met at each of the levels considered there are hopeful signs that the goals of the program are achievable.

The analysis of water by near infrared spectroscopy (NIRS) was the first successful application of this rapid technology which has been developed over the past 30 years into a routine method for many agricultural commodities and food constituents. Nowadays, NIRS technology offers many advantages because its rapidity allows more frequent measurements at all stages from purchase of raw materials and ingredients to the control of the finished products. NIRS-methods are well suited to in-line use. Nevertheless the two dominant and broad peaks, near to 1440 and 1930 nm in nearly every NIR spectrum due to water, are responsible for some typical complications in this analysis. Effects of hydrogen bonding and sample temperature are found to affect the reliability of NIRS results.

Having enough clean drinking water is a top priority during any emergency! A normally active person needs at least two quarts of water each day. However, needs vary depending on the weather and an individual’s age and health status. When clean water is not available, we need to purify all water before using it for drinking, preparing food, or personal hygiene. Many methods for purifying water are available, but none (by itself) is perfect. Often, a combination of more than one methods works best. This document is FCS9195, one of a series of the Department of Family, Youth and Community Sciences, Florida Cooperative Extension Service, IFAS, University of Florida, Gainesville FL 32611. First published: May 2003.

Having enough clean drinking water is a top priority during any emergency! A normally active person needs at least two quarts of water each day. However, needs vary depending on the weather and an individual’s age and health status. When clean water is not available, we need to purify all water before using it for drinking, preparing food, or personal hygiene. Many methods for purifying water are available, but none (by itself) is perfect. Often, a combination of more than one methods works best. This document is FCS9195, one of a series of the Department of Family, Youth and Community Sciences, Florida Cooperative Extension Service, IFAS, University of Florida, Gainesville FL 32611. First published: May 2003.

The structured food systems (i.e. cellular tissues) are dissipative structures whose functionality mainly concerns their properties (physico-chemical properties, chemical and biochemical reactions), external interactions with surroundings (interactions with micro-organisms, heat and mass transport pathway) and especially, their interactions with consumers (nutritional value, quality, taste and flavour, texture, appearance: size, shape, colour). Dehydration or rehydration processes concern heat and mass transport phenomena (water, solutes) coupled with micro and macrostructure changes both producing important effects on food functionality. Control of these changes is the major concern in food product development. This control must be applied not only to the changes in physico-chemical properties but also to those related with consumers' issues. Food matrixengineering is a branch of food engineering which aims to apply the knowledge of the food matrixcomposition, structure and properties to promote and control adequate changes which can improve some sensorial and/or functional properties in the food. These changes, which are caused by some basic operations, are related to the phenomena of heat and mass transfer, vaporization-condensation, internal gas or liquid release, structure deformation-relaxation and phase transitions in matrixcomponents, and are usually coupled throughout the operation's progress. The final product may be a new product with improved composition and sensorial properties and/or more stability. All these concepts are discussed in this paper using several examples related to the application of combined food dehydration techniques.