Se han revisado diversos metodos de determinacion de la actividad del agua. Los metodos pueden dividirse en aquellos que requieren el uso de instrumentos comunes de laboratorio y en aquellos que necesitan para su determinacion aparatos especiales. La principal ventaja de los que necesitan aparatos especiales es que la actividad del agua puede determinarse mas rapidamente

En esta Monografia se trata el tema de la utilizacion del cloro y sus compuestos como medio de alcanzar los requisitos sanitarios que deben cumplir las aguas utilizadas en la industria alimentaria. Se explica la terminologia empleada en cloracion asi como la quimica del cloro en el agua y su comportamiento en funcion de Ph y temperatura. Se ejemplifican distintos sistemas de cloracion y finalmente se hace referencia a un posible programa de control de la cloracion en planta y a metodos analiticos para la evaluacion del cloro activo.

Quantifying the interactions of the food-energy-water (FEW) nexus is crucial to support new policies for the conjunctive management of the three resources. Currently, our understanding of FEW systems in metropolitan regions is limited. Here, we quantify and model FEW interactions in the metropolitan area of Phoenix, Arizona, using the Water Evaluation and Planning (WEAP) platform. In this region, the FEW nexus has changed over the last thirty years due to a dramatic population growth and a sharp decline of cultivated land. We first thoroughly test the ability of WEAP to simulate water allocation to the municipal, agricultural, industrial, power plant, and Indian sectors against historical (1985–2009) data. We then apply WEAP under possible future (2010–2069) scenarios of water and energy demand and supply, as well as food production. We find that, if the current decreasing trend of agricultural water demand continues in the future, groundwater use will diminish by ~23% and this would likely result in aquifer safe-yield and reduce the energy demand for water. If agricultural activities decrease at a lower rate or a multidecadal drought occurs, additional (from 7% to 33%) water from energy-intensive sources will be needed. This will compromise the ability to reach safe-yield and increase energy demand for water up to 15%. In contrast, increasing the fraction of energy produced by solar power plants will likely guarantee safe-yield and reduce energy demand of 2%. This last solution, based on an expanded renewable portfolio and current trends of municipal and agricultural water demand, is also projected to have the most sustainable impacts on the three resources. Our analytical approach to model FEW interconnectivities quantitatively supports stakeholder engagement and could be transferable to other metropolitan regions.

En esta Monografia se trata el tema de la utilizacion del cloro y sus compuestos como medio de alcanzar los requisitos sanitarios que deben cumplir las aguas utilizadas en la industria alimentaria. Se explica la terminologia empleada en cloracion asi como la quimica del cloro en el agua y su comportamiento en funcion de Ph y temperatura. Se ejemplifican distintos sistemas de cloracion y finalmente se hace referencia a un posible programa de control de la cloracion en planta y a metodos analiticos para la evaluacion del cloro activo.

Green cleaner and disinfectant can provide a better environment and they can reduce cleaning cost by eliminating the cost of harsh cleaning chemicals, minimizing cleaning chemicals storage space, reducing cost for wastewater treatment and reducing logistics cost for chemical supply. This study explored the personal view of Small and Medium Enterprises (SMEs) top to bottom workers towards the challenges during cleaning and disinfection process and their readiness in accepting a green cleaner and disinfectant. In this work, the advantages and disadvantages of electrolyzed water (EW) as green cleaner and disinfectant were discussed. A lab-scale batch ion-exchange membrane electrolysis unit was used to produce acidic electrolyzed water (AcEW) and alkaline electrolyzed water (AlEW). The stability of AcEW and AlEW was also studied based on its physical changes (pH, oxidative-reduction potential (ORP), chlorine content and hydrogen peroxide content) in 7 days of storage, whereby measurements were taken daily. The pH maintained for both AcEW and AlEW during the 7 days of storage. The ORP maintained at plateau for the first 5 days of AcEW storage. After 5 days, AcEW showed a decreasing trend. While ORP for AlEW increases drastically between day 1 and 2. Then, the ORP reaches a plateau after three days. The amount of free chlorine, total chlorine and hydrogen peroxide content was 10 mg/L, respectively, on the day of production. However, all the properties decreased gradually and there were no chlorine and hydrogen peroxide detected on the 7th day. The results from this study can be used as a guideline to store the EW and to understand the stability of the EW, which can benefit the SME food manufacturers.

Although maximum stability of natural products has been tied to minimum total moisture, research in the last 25 years has defined a narrow optimum water activity range for many natural foods. Water activity has a closer relationship to the chemical, physical, and biological properties of foods than moisture content; it may have a direct effect on chemical and enzymatic reactions and on microorganism proliferation. Fairly narrow water activity ranges may cause changes in texture, color, flavor, aroma, stability, and acceptability of both processed and raw food products. Most applied work in this field has been pioneered by "water activists" who have used their own tools and methods. Preparation of moisture sorption isotherms will be facilitated by development of automatic, precise, rapid, and convenient techniques to determine water activity and absolute moisture content.

Japan's Specifications and Standards for Food Additives, 7th Edition (JSFA-VII) does not set limits for total contents of water-soluble chlorides and water-soluble sulfates (water-soluble inorganic salts) in food color aluminum lakes (FC-Als). However, the regulatory limit is 2% in JECFA and CFR. We used column switching suppressor-type ion chromatography (CSS-IC) for determination of anions. The total contents of water-soluble inorganic salts in FC-Als (112 qualified samples) were determined using the modified CSS-IC from fiscal year 1998 to fiscal year 2003. Total contents of water-soluble inorganic salts in four samples exceeded 2%. From an international point of view, it is desirable that the total content of water-soluble inorganic salts in FC-A1 should again be regulated in Japan.

Se han revisado diversos metodos de determinacion de la actividad del agua. Los metodos pueden dividirse en aquellos que requieren el uso de instrumentos comunes de laboratorio y en aquellos que necesitan para su determinacion aparatos especiales. La principal ventaja de los que necesitan aparatos especiales es que la actividad del agua puede determinarse mas rapidamente.