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.

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.

The consequences of humidity exchanges between food and environment are always very important for the preservation of microbiological and sensorial quality of the product. For a realistic shelf-life evaluation of sensitive food-products is therefore essential to know exactly the water vapour transmission rate (WVTR) through the packaging material. The measurement of this important diffusional property is commonly performed without regard of the exchange direction and in conditions very far from those of reality: extremes temperature and humidity combinations as 38 deg C and 90% of RU. Thus, it was considered useful and interesting to verify if the permeability phenomenon could be affected by the direction of flow and by the contact of dry or moist product. To such purpose, measures of water vapour permeability were realized using PET and OPP pouches, filled with water or calcium chloride. The results achieved excluded the influence of the contact of dry or wet substances with the pouches walls and of the flow direction on the determination of the WVTR for the materials and the conditions examined | Le conseguenze di uno scambio di umidita' tra alimento ed ambiente risultano sempre molto importanti per la conservazione della qualita' biologica ed organolettica del prodotto. Per una reale valutazione della conservabilita' dei prodotti alimentari sensibili all'umidita' e' quindi essenziale conoscere la velocita' di trasmissione al vapore acqueo (WVTR) attraverso il materiale di confezionamento. I metodi convenzionali di misura di questa importante proprieta' diffusionale sono solitamente riferiti a condizioni lontane da quelle reali sia per le combinazioni temperatura-umidita' relativa in cui si effettuano le determinazioni (38 gradi C e 90% di UR), sia per quanto riguarda le modalita' in cui il fenomeno di permeazione avviene. Non si tiene infatti in considerazione ne' la direzione di flusso del vapore d'acqua, ne' che nel caso reale il prodotto (umido o secco) si puo' trovare a diretto contatto con il materiale. Si e' cosi' ritenuto importante poter verificare se il fenomeno di permeabilita' fosse influenzato da queste condizioni e dalla direzione del flusso. A tal fine si sono effettuate misure di permeabilita' impiegando buste realizzate con PET ed OPP, riempite con acqua o cloruro di calcio. I risultati ottenuti hanno escluso l'influenza del contatto e della direzione di flusso sulla determinazione della WVTR per i materiali e le condizioni considerate

The limiting effects of food and water on juvenile growth rates in the lizard Anolis aeneus were investigated in the field (Grenada, West Indies) and laboratory. Growth rates of lizards in the field were unrelated to their snout—vent lengths, but both prey biomass and rainfall had significant effects on juvenile growth rates. Laboratory experiments indicated that water had a primary limiting effect on growth; even when food supplies were superabundant, growth rates were low when drinking water was curtailed. Laboratory and field experiments suggest that limited water availability reduces growth rates for most (67%) of the dry season, whereas food levels are sufficiently low to limit growth during the weeks of the dry season when rainfall is sufficient for growth. During the wet season there is no evidence of water scarcity, food levels are high and average growth rates are 85% of the maximal rates observed under optimal conditions in the laboratory.

BACKGROUND: Quantification of spray deposition on a target crop is of vital importance to optimize pesticide application. In traditional determinations of spray deposition, a large amount of organic solvent is used to extract pesticides from the target crops. In this study, a water‐soluble food dye of Allura Red was developed as a tracer to determine pesticide spray deposition on a rice target crop. RESULTS: The addition of Allura Red does not obviously alter the physicochemical properties of pesticides (viscosity, density and surface tension) and droplet spectra. An ultra‐performance liquid chromatography (UPLC) analytical method was developed and validated to determine the deposition amount of Allura Red on rice plants. Method accuracy and precision for Allura Red were found to be satisfactory with recoveries of 96.07% to 107.48%. To validate the method, comparative deposition analyses were carried out using representative systematic and non‐systematic pesticides (nitenpyram and chlorothalonil) under the same spraying scenarios using a Potter spray tower. Allura Red and pesticides showed comparable deposition under the same application conditions with ratios from 0.98 to 1.21. A field trial using an unmanned aerial vehicle sprayer further indicated that the deposition rates for Allura Red and nitenpyram on rice seedling were 13.04% and 11.07%, with corresponding relative standard deviation values (n = 5) of 16.39% and 18.79%. CONCLUSION: A laboratory test and field trial confirmed that the developed method of using Allura Red as a tracer for spray deposition assessment is feasible and practicable. © 2019 Society of Chemical Industry