Se usó aguas de desecho de la industria de la masa y la tortilla (aguas de nixtamal o nejayote) para crecer rotíferos de agua dulce, Brachionus calycijlorus. El nejayote sin dilución no permitió el desarrollo del rotífero. Sin embargo, cuando se diluyó, B. calycijlorus aprovechó la materia orgánica. El agua de desecho por sí misma (sin alimento algal adicional) fue comparable al agua con densidades del alga Chlorella de 2 X 106 células m¡-I. Concentraciones de nejayote por encima del 8% no permitieron el crecimiento poblacional. Sin embargo, la presencia de alga permitió el desarrollo del rotífero a concentraciones de 8% y 16%. Nuestros hallazgos indican que el nejayote puedo ser utilizado de manera efectiva para la producción de rotíferos a gran escala para la acuacultura. | Se usó aguas de desecho de la industria de la masa y la tortilla (aguas de nixtamal o nejayote) para crecer rotíferos de agua dulce, Brachionus calycijlorus. El nejayote sin dilución no permitió el desarrollo del rotífero. Sin embargo, cuando se diluyó, B. calycijlorus aprovechó la materia orgánica. El agua de desecho por sí misma (sin alimento algal adicional) fue comparable al agua con densidades del alga Chlorella de 2 X 106 células m¡-I. Concentraciones de nejayote por encima del 8% no permitieron el crecimiento poblacional. Sin embargo, la presencia de alga permitió el desarrollo del rotífero a concentraciones de 8% y 16%. Nuestros hallazgos indican que el nejayote puedo ser utilizado de manera efectiva para la producción de rotíferos a gran escala para la acuacultura.

The problem of the wall slip in steady-state flow measurements of oil-in-water (o/w) food emulsions has been investigated for different sensor system geometries and surface profiles. Experimental results demonstrated that slip effects are strongly dependent on the type of emulsion studied. This may be related to the emulsion microstructure. Thus, for instance, a highly structured gel-like continuous phase dampens wall slip effects, as opposed to emulsions in which creaming appears as a mechanism of instability, because of the formation of particulate flocs. The occurrence of wall slip is more clearly observed if the flow curves are obtained from stress sweep experiments. Although the recovery of the steady-state viscosity of a presheared sample is generally complete (similar values at low and high shear rates), the appearance of slip effects may be favoured by emulsion preshearing.

The aims of the investigations were to estimate the biomass and the production of the macrozoobenthos and to know their season dynamics. Investigations were supported by Fishery's Foundation. Sediment chemical analysis showed that the macrozoobenthos biomass was determined by the quantity of the phosporus. Chironomid larvae formed the 70-90 per cent of benthos biomass in Keszthely basin.

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 objective of the study reported here was to investigate three factors that may affect the amounts of water consumed and urine excreted by a rat in the metabolism cage: water dilution, housing, and food. Young F344/N rats (eight per group) were used for all experiments. Food was withheld from rats before each 16-h urine collection, then rats were transferred into a metabolism cage. For trial A (water dilution), urine was collected from rats supplied with dyed water (0.05%,vol/vol). This was repeated three times over a 2-week period. Dye in water or urine was quantified, using a spectrophotometer. For trial B (housing), rats were individually housed in wire cages for 3 weeks before the first urine collection. Then they were group housed in the solid-bottom cage (four per cage). After 2 weeks of acclimation, urine collection was repeated. For trial C (food), one group of rats was provided with food, the other was not, during urine collection. About 8% of urine samples of small volume (less than or equal to 3 ml) from trial A were contaminated with drinking water up to 13% of volume. The average urine volume associated with individual housing was approximately twice as large as that associated with group housing. When food was provided during urine collection, rats consumed similar amounts of water but excreted significantly smaller amounts of urine than did rats without food. It was concluded that water dilution of a urine sample from a sipper bottle is relatively small; rats individually housed in wire caging before urine collection can consumed and excrete a larger quantity of water, compared with rats group housed in solid-bottom cages: and highly variable urine volumes are, in part, associated with lack of access to food during urine collection.

Resumes des communications des 3 ateliers du Colloque de l'Academie d'Agriculture de France - EDF. Accueil et introduction: - Allocution d'ouverture (Merillon, R.) - Les enjeux de la gestion de l'eau dans l'industrie alimentaire (Bruder, M.) - Implications d'EDF dans le programme Bretagne Environnement Plus (Delamarre, P.). Atelier 1: Production d'eau: - Valorisation d'eau de riviere par techniques membranaires (microfiltration, osmose inverse) (Henneron, G., Bossard, P.) - Elimination des nitrates de l'eau potable par electrodialyse (Largeteau, D.). Atelier 2: Traitement et valorisation des effluents: - Valorisation d'effluents de confiserie par concentration mecanique de vapeur (CMV) (Dupenloup, F.) - Concentration et valorisation d'effluents de cuisson de viandes (Landry, B.) . Atelier 3: Stations d'epuration: - Reacteur biologique a membranes et traitements des boues en laiterie (Fuchs, C.) - Reacteur bilogique a membrabnes et traitement des boues en charcuterie-salaisons (Dupont, B.). Allocution de cloture: L'eau et les effluents dans l'industrie alimentaire (Meriaux, S.)

Waste water from Mexico's largest food processing industrial sector (based on maize, nejayote water) was used for growing Brachionus calyciflorus isolated from Lake Chapultepec in the Federal District of Mexico (D.F.). Nejayote water was collected from Colonia Providencia, D.F. Experiments were conducted at 25°C in 25 ml capacity vials with 20 ml of medium into which we introduced B. calyciflorus at an initial density of 1 ind ml-1. The experimental design consisted a total of 33 test vessels (2 food combinations X 5 densities X 3 replicates = 30 plus 3 replicates as controls that contained only algae). Experiments were terminated after day 16. Waste water in original concentration did nt rotifes. However, when diluted to 5 oncentrations (ranging from 2% to 32% and pH adjusted to 7.0), rotifer density increased with increasing concentration of waste water. Green algae (at constant density of 2 X 10 6 cells-1 of Chlorella) in combination with waste water resulted in a higher abundance of rotifers only at higher concentration (above 8 %) of waste water. The maximum peak density of rotifers (238-50 ind ml -1) was obtained at 16% dilution of waste water nd with addition of Chlorella. The rate of population increase per day ® (mean-SD) varied from 0.355-0.059 to 0.457-0.048 depending on food combination and concetration.<br>Se usó aguas de desecho de la industria de la masa y la tortilla (aguas de nixtamal o nejayote) para crecer rotíferos de agua dulce, Brachionus calyciflorus. El nejayote sin dilución no permitió el desarrollo del rotífero. Sin embargo, cuando se diluyó, B. calyciflorus aprovechó la materia orgánica. El agua de desecho por sí misma (sin alimento algal adicional) fue comparable al agua con densidades del alga Chlorella de 2 X 10(6) células ml-1. Concentraciones de nejayote por encima del 8% no permitieron el crecimiento poblacional. Sin embargo, la presencia de alga permitió el desarrollo del rotífero a concentraciones de 8% y 16%. Nuestros hallazgos indican que el nejayote puedo ser utilizado de manera efectiva para la producción de rotíferos a gran escala para la acuacultura.