Effects of Whitening Agents and Frozen Storage on the Quality of Sardine (Sardina pilchardus) Surimi: Physicochemical and Mechanical Properties

This work is focused on the effect of using whitening agents (WA) during a process followed by frozen storage (4 months at ?18°C) on the whiteness, quality parameters, and mechanical properties of sardine surimi. The whiteness of surimi exhibited a significant improvement when whitening agents (calcium carbonate and peroxide hydrogen) were used (48.75 to 60.24). Dynamic rheological measurement showed that storage moduli, G′, was considerably higher than loss moduli, G″, for both surimi with WA and control; however, the highest viscoelastic moduli were found in the treated surimi. In addition, the microstructure of surimi with WA showed more compact matrix and higher water holding capacity. On the other hand, most tested indexes showed quality losses throughout the frozen storage in both samples. Proteins underwent denaturation as indicated by the reduction in band intensities, especially myosin heavy chain (MHC) bands. Peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) measurements showed that lipid oxidation took place during storage; however, the degree of lipid oxidation was not relevant. Therefore, it was proved that the addition of whitening agents had a marked effect on the production of surimi with better functional attributes including whiteness, water holding capacity, and mechanical properties.     

Potential of acrylamide formation,sugars, and free asparagine in potatoes: a comparison of cultivars and farming systems

Glucose, fructose, sucrose, free asparagine, and free glutamine were analyzed in 74 potato samples from 17 potato cultivars grown in 2002 at various locations in Switzerland and different farming systems. The potential of these potatoes for acrylamide formation was measured with a standardized heat treatment. These potentials correlated well with the product of the concentrations of reducing sugars and asparagine. Glucose and fructose were found to determine acrylamide formation. The cultivars showed large differences in their potential of acrylamide formation which was primarily related to their sugar contents. Agricultural practice neither influenced sugars and free asparagine nor the potential of acrylamide formation. It is concluded that acrylamide contents in potato products can be substantially reduced primarily by selecting cultivars with low concentrations of reducing sugars.     

A systems analysis framework of a national forestry sector: Nigeria

As in many underdeveloped regions of the world, some African countries are at present going through stages of rapid economic changes. Such changes include relatively rapid increases in national income, urbanisation, proportion of population going to school in the ‘modern’ sense, etc. In other words, the traditional sectors of many countries are gradually being transformed into modern ones. In Nigeria such changes are accelerated by the present high world market prices for petroleum products and expanded drilling for petroleum in Nigeria which generate high growth rates for national income.These changes have important consequences for wood consumption because, as traditional economic activities decline and modern ones expand, demand for fuelwood and unprocessed wood salvaged and used on the farm declines and demand for processed wood produced commercially expands.Part I of this paper, in a general way, specifies aspects of the Nigerian forestry sector which should be considered in formulating the systems simulation model of the sector. Part II specifies an analytical model which can simulate the transfer of population from the traditional to the modern sector as economic conditions improve and enable the consequences of such a transformation on wood consumption to be traced through time. The analytical model is also tested in Part II by using the model to predict the annual consumption of various wood products in Nigeria by the year 1990.     

肉类加工机刀具制造与修复的新方法

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Identification,occurrence and clinical findings of canine hemoplasmas in southern Brazil

Hemoplasmas are ubiquitous pleomorphic and epicellular bacteria detected in erythrocytes in several species. In Brazil, studies on hemoplasmas have not included information on occurrence, clinical signs, and risk factors in dogs. This paper investigates the occurrence of hemoplasmas in dogs, focusing on risk factors and clinical status. Conventional PCR for the four types of canine hemoplasmas was performed in 331 blood samples collected from dogs clinically treated at a teaching veterinary hospital. Of all samples, 17/331 (5.1%) were positive for Mycoplasma haemocanis and 6/331 (1.8%) were positive for a ‘Candidatus Mycoplasma haemominutum-like’ organism. Risk factors included the presence of vectors, old age, dog bite wounds, and neoplastic diseases. In the multivariate analysis, a 4.40 odds ratio in dogs with vector-borne diseases indicated risk for hemoplasmosis. There was correlation between hemoplasma infection and neoplastic disease, suggesting that neoplastic conditions are a risk factor for hemoplasma infection in dogs.     

Structural basis for gluten intolerance in celiac sprue

Celiac Sprue, a widely prevalent autoimmune disease of the small intestine, is induced in genetically susceptible individuals by exposure to dietary gluten. A 33-mer peptide was identified that has several characteristics suggesting it is the primary initiator of the inflammatory response to gluten in Celiac Sprue patients. In vitro and in vivo studies in rats and humans demonstrated that it is stable toward breakdown by all gastric, pancreatic, and intestinal brush-border membrane proteases. The peptide reacted with tissue transglutaminase, the major autoantigen in Celiac Sprue, with substantially greater selectivity than known natural substrates of this extracellular enzyme. It was a potent inducer of gut-derived human T cell lines from 14 of 14 Celiac Sprue patients. Homologs of this peptide were found in all food grains that are toxic to Celiac Sprue patients but are absent from all nontoxic food grains. The peptide could be detoxified in in vitro and in vivo assays by exposure to a bacterial prolyl endopeptidase, suggesting a strategy for oral peptidase supplement therapy for Celiac Sprue.     

Asymmetric T lymphocyte division in the initiation of adaptive immune responses

A hallmark of mammalian immunity is the heterogeneity of cell fate that exists among pathogen-experienced lymphocytes. We show that a dividing T lymphocyte initially responding to a microbe exhibits unequal partitioning of proteins that mediate signaling, cell fate specification, and asymmetric cell division. Asymmetric segregation of determinants appears to be coordinated by prolonged interaction between the T cell and its antigen-presenting cell before division. Additionally, the first two daughter T cells displayed phenotypic and functional indicators of being differentially fated toward effector and memory lineages. These results suggest a mechanism by which a single lymphocyte can apportion diverse cell fates necessary for adaptive immunity.