Rapid p-Nitroaniline Test for Assessing Microbial Quality of Refrigerated Meat

The p-nitroaniline test, a rapid method to estimate microbial quality of refrigerated meat, was applied to many retail meat samples from several animal species to confirm its applicability. This method allows determination of psychotroph levels between 10⁴ and 10⁸ CFU/cm² in about 2.5 hr. A good correlation was found (r = 0.88, p < 0.001) between this method and the standard plate count technique. Because of the yellow color of the p-nitroaniline released during reaction, bacterial loads higher than 10^s CFU/cm² develop a color intense enough to be detected visually.     

EFFECTS OF FEED DIETS ON DIGESTIVE PROTEASES FROM THE HEPATOPANCREAS OF WHITE SHRIMP (Penaeus vannamei)

Protease activities in the hepatopancreas extract (HP) from white shrimp (Penaeus vannamei) fed one of seven test diets for 30 days were evaluated by several methods. The test diet contained 85% of a reference ration for shrimp and 15% of either anchovy meal, tuna waste meal, deboned white fish meal, langostilla meal, soybean meal, and two menhaden meals as a protein replacer. One of the menhaden fish meals tested (B) had the lowest quality as a shrimp feed based on amino acid analysis. SDS-PAGE zymograms of HP from each of the seven diet groups showed similar proteins activity patterns with casein as substrate. The degree of hydrolysis of casein, measured by pH-stat, was also the same for HP from the seven diet groups (P > 0.05). However, total protease activity measured by azocasein hydrolysis (units/g HP) was higher for the diet group fed the test ration containing tuna waste as a replacer (P > 0.05). Trypsin and chymotrypsin activities measured with synthetic substrates (units/mg protein; units/g HP) from animals reared on the diet with menhaden meal B replacer were greater than in the other diet groups (P < 0.05). This study shows that a relatively small amount (15%) of a specific protein replacer in white shrimp rations can influence the protease activity of shrimp HP. Given that digestive proteases such as trypsin can leach into the muscle of postharvest shrimp and thereby cause softening of the meat, the impact of the rearing diet on postharvest shelf-life should be considered along with the standard measures of feed quality that are used by the fish farmer, i.e. animal growth and heatlh.     

A Pictorial Query Language for Geographic Features in an Object-Oriented Environment

In this paper, a visual algebra and the relative pictorial query language (PQL) for geographic information systems (GIS) are proposed and discussed. The base data structure of the object oriented model for geographical data is defined and the symbolic features used in the PQL are described. The algebra operators are formally defined, besides their properties and applicability. The use of the symbolic features to express the queries is illustrated, as well as the possible pictorial operations are considered. The used interface is part of the Scenario GIS, developed using an object-oriented environment. This PQL makes easier the formulation of a complex query and simplifies user approach to the system, maintaining a strong expressive power. Finally, an example of query and its pictorial composition on the screen is shown.     

Kinetic Energy Calculations for Non-Newtonian Fluids in Circular Tubes

Expressions to calculate the kinetic energy of Herschel-Bulkley fluids flowing in circular tubes are presented. The influence of yield stress, consistency coefficient and flow behavior index are investigated. An equation - based on theoretical considerations - for determining kinetic energy from a kinetic energy correction factor is developed. Solutions are given in a graphical format to facilitate kinetic energy calculations.     

THE USE OF OZONATION TO REDUCE THE POTENTIAL FOR FORMING TRIHALOMETHANE COMPOUNDS IN CHLORINATING RESORCINOL,PHLOROGLUCINOL AND 1,3 CYCLOHEXANEDIONE

This study concerns the ozonation of Resorcinol, Phloroglucinol and 1,3 Cyclohexanedione in the presence of bromide ion in a bubble column, prior to chlorination. Preozonation in aqueous solutions reduces the potential for forming chlorinated trihalomethane compounds. At organic concentrations greater than 10^?4?M a short ozonation time increases the potential for forming trihalo compounds. At longer ozonation times the reverse is true. Finally the influence of mass transfer and chemical reaction on the ozone absorption rate have been evaluated following the film theory.     

INFLUENCE OF DRYING ON THE STORAGE ABILITY OF RICE BRAN

It is known that the rate of formation of free fatty acids in rice bran is dependant on the history of temperature and moisture content experienced by the bran since its formation. A mathematical model is already available to predict the rate of formation of free fatty acids in rice bran for heat treatment conditions. This paper attempts to apply the model for storage conditions in order to predict the storage ability of rice bran which has undergone varying drying conditions. Experimental results already available were found to be in agreement with the predicted theoretical values based on the model.     

Characterisation and evolution of grape polyphenol profiles of Vitis vinifera L. cv. Tannat during ripening and vinification

Background and Aims: Changes in different polyphenol families during grape ripening and vinification were determined in Tannat grapes. This was done to establish a polyphenol profile for Tannat grapes during ripening and for young wines. Methods and Results: We demonstrated, by high‐performance liquid chromatography with diode array detection and mass spectrometry (HPLC‐DAD‐MS) analysis, that the content of flavan‐3‐ols in Tannat seeds was higher than that reported for a large number of other grape varieties analysed. Forty per cent of the total flavan‐3‐ols in seeds were galloylated compounds, whereas the flavan‐3‐ol profile in skins was characterised by the absence of galloylated forms. Prodelphinidins in skins ranged between 30 and 35% with very low values for epigallocatechin. Epicatechin gallate was not detected in Tannat wine and galloylated forms represented a low percentage of total flavan‐3‐ols. Tannat grapes had very high concentrations of anthocyanins in skins with levels increasing during ripening. Eleven phenolic acids were identified in Tannat grape skins and wines, but only gallic and protocatechuic acids were found in the seeds. Conclusions: Tannat wines were shown to have one of the highest levels of phenolic compounds reported for vinifera grape varieties. The profiles for different polyphenol families present in Tannat grapes (skins and seeds) and wines were determined. Significance of the Study: The results presented will help to better understand the phenolic winemaking potential of this variety and its functional properties within food chemistry.     

WT-1 mRNA expression is modulated by nitric oxide availability and Hsp70 interaction after neonatal unilateral ureteral

Wilms tumor gene 1 (wt-1), a key regulator of mesenchymal-epithelial transformation, is downregulated during congenital obstructive nephropathy, leading to apoptosis. There is a functional interaction between WT-1 and inducible nitric oxide synthase (iNOS). In this regard, we reported that after neonatal unilateral ureteral obstruction, rosuvastatin prevents apoptosis through an increase in nitric oxide bioavailability, which in turn is linked to higher Hsp70 expression. Hence, the goal of this study was to determine whether a nitric oxide/Hsp70 interaction is involved in changes in WT-1 mRNA expression after ureteral obstruction. Neonatal rats submitted to experimental ureteral obstruction were treated with either vehicle or rosuvastatin for 14 days. Decreased nitric oxide and iNOS/Hsp70 expression associated with WT-1 low expression was shown in obstructed kidneys. Apoptosis was induced and it was associated with an increased Bax/BcL2 ratio. Conversely, iNOS/Hsp70 upregulation and an increased WT-1 mRNA expression, without an apoptotic response, were observed in the cortex of obstructed kidneys of rosuvastatin-treated rats. Nitric oxide also modulated Hsp70 and WT-1 mRNA expression in MDCK cells. Finally, in vivo experiments with nitric oxide modulators support our hypothesis that WT-1 mRNA expression is associated with nitric oxide level. Results suggest that rosuvastatin may modulate WT-1 mRNA expression through renal nitric oxide bioavailability, preventing neonatal obstruction-induced apoptosis associated with Hsp70 interaction.