Modeling and Simulation of Food Products in Superchilling Technology

The food superchilling process is of increasing importance because of its benefit in achieving food quality and extending shelf life of food products. The rate of the superchilling process is critical to the products’ quality and to the productivity of the process, and therefore the superchilling dynamics are of extreme importance. The objective of this work was to develop a one-dimensional implicit finite difference numerical model for predicting partial freezing time necessary to achieve an optimal degree of superchilling in foods and to validate the model experimentally. The evaluation of degree of superchilling was determined using finite slab and measured by using a calorimetry method. There is a good level of agreement between numerical simulation and laboratory experimental results.     

Scavenging Capacity of Marine Carotenoids against Reactive Oxygen and Nitrogen Species in a Membrane-Mimicking System

Carotenoid intake has been associated with the decrease of the incidence of some chronic diseases by minimizing the in vivo oxidative damages induced by reactive oxygen (ROS) and nitrogen species (RNS). The carotenoids are well-known singlet oxygen quenchers; however, their capacity to scavenge other reactive species, such as peroxyl radical (ROO^•), hydroxyl radical (HO^•), hypochlorous acid (HOCl) and anion peroxynitrite (ONOO⁻), still needs to be more extensively studied, especially using membrane-mimicking systems, such as liposomes. Moreover, the identification of carotenoids possessing high antioxidant capacity can lead to new alternatives of drugs or nutritional supplements for prophylaxis or therapy of pathological conditions related to oxidative damages, such as cardiovascular diseases. The capacity to scavenge ROO^•, HO^•, HOCl and ONOO⁻ of seven carotenoids found in marine organisms was determined in liposomes based on the fluorescence loss of a fluorescent lipid (C₁₁-BODIPY^581/591) due to its oxidation by these reactive species. The carotenoid-bearing hydroxyl groups were generally more potent ROS scavengers than the carotenes, whilst β-carotene was the most efficient ONOO⁻ scavenger. The role of astaxanthin as an antioxidant should be highlighted, since it was a more potent scavenger of ROO^•, HOCl and ONOO⁻ than α-tocopherol.     

Evaluation of the Nutritional Quality of the Grain Protein of New Amaranths Varieties

Plant Foods for Human Nutrition - The efforts for promoting the consumption of food of plant origin are increasingly growing. The amaranth grain is an important vegetable protein source, superior...     

ULTRASONOGRAPHIC DIAGNOSIS OF PORTOSYSTEMIC SHUNTING IN DOGS AND CATS

The value of ultrasonography was evaluated in 85 dogs and 17 cats presented with a clinically suspected portosystemic shunt (PSS). A PSS was confirmed in 50 dogs and nine cats (single congenital extrahepatic in 42, single congenital intrahepatic in 11, and multiple acquired in six). Six dogs and one cat had hepatic microvascular dysplasia, and 29 dogs and seven cats had a normal portal system. Ultrasonography was 92% sensitive, 98% specific, and had positive and negative predictive values of 98% and 89%, respectively, in identifying PSS, with an overall accuracy of 95%. When a PSS was identified with ultrasonography, extrahepatic, intrahepatic, and multiple acquired PSS could be correctly differentiated in 53/54 patients (98%). The combination of a small liver, large kidneys, and uroliths had positive and negative predictive values of 100% and 51% for the presence of a congenital PSS in dogs. The portal vein/aorta (PV/Ao) and portal vein/caudal vena cava (PV/ CVC) ratios were smaller in animals with extrahepatic PSSs compared with animals with microvascular dysplasia, intrahepatic PSSs and those without portal venous anomalies (P<0.001). All dogs and cats with a PV/Ao ratio of < or = 0.65 had an extrahepatic PSS or idiopathic noncirrhotic portal hypertension. Dogs and cats with PV/Ao and PV/CVC ratios of > or = 0.8 and > or = 0.75, respectively, did not have an extrahepatic PSS. Reduced or reversed portal flow was seen in four of four patients with multiple acquired PSSs secondary to portal hypertension. The presence of turbulence in the caudal vena cava of dogs had positive and negative predictive values of 91% and 84%, respectively, for the presence of any PSS terminating into that vein.     

Essential oil of Lippia alba in the diet of Macrobrachium rosenbergii: Effects on antioxidant enzymes and growth parameters

The juveniles of Macrobrachium rosenbergii (0.060 ± 0.004 g and 2.018 ± 0.071 cm) were fed during 60 days with diets containing different doses of Lippia alba essential oil (EOLA) (0.0—control, 1.0, or 2.0 ml EOLA/kg diet; in triplicate, with 20 prawns/replicate). After the experimental period, were verified the survival, growth parameters and the antioxidant enzymes, lipid peroxidation and Na/K‐ATPase activities in hepatopancreas and gills, respectively, of the animals. There were no significant differences on survival, growth parameters and gill Na/K‐ATPase activity. However, glutathione peroxidase and glutathione‐S‐transferase activities were lower in hepatopancreas of prawns fed with 1.0 ml EOLA/kg diet compared to the control. Moreover, the activity of the enzyme superoxide dismutase was higher in hepatopancreas of prawns that received 2.0 ml EOLA/kg diet compared to those fed with 1.0 ml EOLA/kg diet. Although the addition of both EOLA doses has not improved the survival and growth parameters of M. rosenbergii, these doses contributed to decrease lipid peroxidation. Additionally, the dose of 2.0 ml EOLA/kg diet contributed for increasing the antioxidant enzymes activities in the hepatopancreas, improving antioxidant status, and therefore, it can be recommended as diet supplementation for M. rosenbergii.     

Influence of temperature on growth,feed consumption and chemical composition in the muscle of Pacu Piaractus mesopotamicus

The zootechnical performance of fish can be influenced by temperature through the induction of metabolic changes that are likely to affect growth and body composition. Thus, the objectives of this study were: (a) to examine the influence of five different temperatures (18, 21, 24, 27 and 30°C) on growth performance and metabolic parameters and (b) to evaluate the relationship of the protein efficiency ratio (PER) with the fillet proximate composition of Pacu juveniles. Growth and feed consumption (FC) were positively correlated with temperature (R² = .95), while PER and FC were negatively correlated with temperature (R² = .89). For the fillet composition, ethereal extract increased, and moisture decreased with the temperature. Protein content was lowest at 18 and 30°C and highest at 21, 24 and 27°C. The robust adjusted curve between PER and fillet protein content in relation to temperature showed the best result at 21°C. The obtained results indicate that Pacu juveniles reared between 21 and 27°C showed better protein efficiency with regard to FC, and this effect reflected better meat quality.