Texture was measured on texture analyzer TA.XT plus the manufacturer's Stable Micro System, using the methods of texture profile analysis (TPA) in the general carp fillets (Cyprinus carpio). Were measured basic textural properties such as hardness, chewiness, springiness and cohesiveness. Course of change of these textural characteristics were monitored during the freezing and marinating. In both cases, the differences statistically substantiating some textural properties.

Submitted by (edna.saturno@ufrpe.br) on 2017-02-22T13:18:21Z No. of bitstreams: 1 Talita da Silva Esposito.pdf: 1198598 bytes, checksum: 814b0f7dce6420e7e8723706bb578b48 (MD5) / Made available in DSpace on 2017-02-22T13:18:21Z (GMT). No. of bitstreams: 1 Talita da Silva Esposito.pdf: 1198598 bytes, checksum: 814b0f7dce6420e7e8723706bb578b48 (MD5) Previous issue date: 2006-02-06 / Alkaline proteases are commercially important group of enzymes and have a large variety of applications, mainly in the detergent and food industries. The proteases currently uses in the market are serine proteases produced by Bacillus strains, principally. Fish viscera have wide biotechnological potential as a source of digestive proteases. Biotechnology provides a means for transforming such materials usually discarded into valuable produts such as enzymes. The objective of this research was to test if alkaline proteases from fish viscera could be used as an additive in commercially available detergent formulations. Viscera from Colossoma macropomum, the most important native fish for Brazilian aquaculture, and Cyprinus carpio, the second exotic fish in importance for Brazilian aquaculture, were extracted and used as a source of enzyme for this research. The crude extract obtained upon the homogenization of the viscera was submitted to a partial purification with ethanol. The protein content,proteolytic activity of the fractions thus obtained was assessed. The fraction presenting the highest proteolytic activity was further studied (30-70% of ethanol) resulting in 74.9% and 142.4% of protein recovery for tambaqui and carpa, respectively. This fraction was assayed at different temperatures and pH aiming to estimate the conditions for higher proteolysis. Temperarture and pH stability experiments were also carried out. Different commercial lyavailable detergents, surfactants and hydrogen peroxide were used to test the compatibility of these proteases with detergent formulations. The results reveal that these alkaline proteases extracted from C. macropomum show desirable characteristics for its use in laundry industry such as: retention of 73% and 63% of its initial activity in the presence of Surf® and 5% H202, respectively, after 1 hour of incubation at 40ºC. In addition to that it was observed a slight increase of the proteolytic activity in the presence of non-ionic (Tween 20 and Tween 80) and ionic surfactants (Saponin and Sodium cholate). On the other hand, the proteases extracted from the intestine of C. carpio were compatible with the surfactants and oxidants tested butdid not present the same property in the presence of commercially available detergents. / As proteases alcalinas são as enzimas de maior importância comercial devido a sua vasta aplicabilidade, sendo empregadas principalmente nas indústrias de detergentes e de alimentos. Atualmente, a maior parte das proteases utilizadas no mercado é produzida por bactérias do gênero Bacillus, no entanto, elas podem ser amplamente encontradas em um dos principais resíduos da indústria pesqueira, as vísceras. Portanto, uma forma de otimizar o aproveitamento do pescado e, conseqüentemente, reduzir o desperdício é reaproveitar esses subprodutos. Neste trabalho testou-se a aplicabilidade das proteases de vísceras de peixes como aditivo de detergentes em pó comerciais. Para extração das enzimas foram utilizadas vísceras de Colossoma macropomum e de Cyprinus carpio, principal peixe nativo e segundo peixe exótico da aqüicultura continental nacional, respectivamente. A partir deste material obteve-se o extrato bruto, que passou por uma semi-purificação fracional com etanol. As frações obtidas deste procedimento tiveram sua atividade enzimática e quantidade de proteínas determinadas para escolha da fração a ser trabalhada. A fração saturada com 30- 70% de etanol apresentou maior atividade específica tanto no tambaqui quanto na carpa, com rendimentos de 74,9% e 142,4%, respectivamente. Nesta fração verificou-se em que temperatura e pH as proteases apresentavam maior atividade, além da sua estabilidade em relação a esses parâmetros. Para testar a compatibilidade com detergentes comerciais, foram utilizados quatro detergentes comerciais, cinco agentes surfactantes e peróxido de hidrogênio em diferentes concentrações. Os resultados obtidos sugerem que as proteases alcalinas encontradas nas vísceras de tambaqui apresentam características ideais para utilização na indústria de detergentes em pó, como: retenção de até 73% da sua atividade na presença de Surf® e de 63% na presença de 5% de H2O2 após 1 hora de incubação a 40ºC. Além disso, a atividade da enzima foi estimulada na presença de surfactantes não-iônicos (Tween 20 e Tween 80) e iônicos (Saponin e Colato de sódio). As proteases obtidas a partir do intestino da carpa, no entanto, só foram estáveis na presença dos diferentes surfactantes e a 5% de H2O2, perdendo estabilidade quando adicionadas aos detergentes comerciais.

This diploma thesis was focused on the possibilities of extending the shelf-life of fish products by dipping containing seven commercial additives. ANTIBAK, MIC STAB, Bakont, SEA-F75, Misocarine LR, SAFE A Plus and AMX liquid. The effectiveness of these substances on the extending of shelf-life was evaluated on the basis of tests of TVC (total viable count), level of fat and protein oxidation, determination of nutritional parameters of muscle, and finaly sensory analysis. Experimental species were 2 important commodities for the Czech aquaculture rainbow trout (Oncorhynchus mykiss) and common carp (Cyprinus carpio). The project was divided into 6 sub-stages. During testing was the initial number of aditives (7) limited by stepwise selection for 2 preparations. Namely Bakont and AMX liquid, which were tested further on trout (filet with skin and scales) and carp (filets with skin without scales) chilled bulk and chilled packaged under vakuum. For trout was studied antimicrobial effect of dipping on eviscerated fish with the head with- or without gills. Treated trout fillets in bulk and vakuum-packed showed significantly less abundance of muscle mikroflora. In the case of carp fillets chilled bulk we can not say that the bath had influence on the CMP in meat. However, the combination of dipping and vakuum packaging was singnificantly different between the control and product Bakont. AMX liquid was not applied in this case in sufficient dose or in sufficient time to carp muscle. A positive finding is that the application of the aditives to the product "eviscerated trout with head" it does not matter, whether the gills are left in fish or not. However, in all cases the analysis of the presence of pathogens Escherichia coli, Salmonella spp. or Listeria monocytogenes were negative. From the results of sensory analysis can be concluded, that the substances contained in aditives are not reflected in the sensory properties of tested fish.

The objective of this thesis was to test the environmental friendly additive substance, in particular sodium caseinate, which is not subject to designation "E" on the label of the product, which is unpopular among the consumers, and which would provide so-called a "higher value" to a product of economically important fish species in the Czech Republic, specifically the common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix) and the rainbow trout (Oncorhynchus mykiss).Determination of the influence of this additive on microbial and biochemical processes, and also on organoleptic properties of the selected smoked fish was another goal of the work. Three concentrations of this product were used for application in total, in particular 25, 50 and 100 g×kg-1. The results of this work confirmed that, due to caseinate (concentration of 100 g×kg-1) such losses of water were avoided, as observed in case of the control group, to which no additive product was applied, and which served for comparison with the groups treated with caseinate. General carp had an average loss of 12.9 % for the samples treated with sodium caseinate and 14 % for the control group. The silver carp white showed similar results. The group treated with caseinate lost 12.4 % in average, and the control group of approximately 14 %. The best results were recorded with the rainbow trout, which, due to caseinate withheld the largest amount of water, respectively, it did not lose so much of weight, in particular 15.9 % for sodium caseinate compared to 19.3 % measured in the control group, however these differences were not confirmed as statistically conclusive. As for the texture of the meat, tougher samples came out for the ones treated with sodium caseinate compared to the more brittle control group. In carp and trout no statistically noteworthy dissimilarity in stiffness of meat was proved between the control group and the group with the applied additive product. While these differences were significant in silver carp. While for silver carp were these differences significant. The control group showed clearly (p<0.05) lower stiffness compared to the group, to which the additive product was applied. Microbiological analysis was performed on the 7th day after smoking, and the values were in the range of 2×10 to 1.9×10^2 CFU×g-1. In the experiment, groups of test fish species did not show any statistically significant difference (p>0.05). Tests for the possible presence of Listeria monocytogenes in all of the smoked fish samples and the control group were negative. Nutrient composition was mainly focused on the basic nutrient components, which were the proteins, fats and carbohydrates. The control group did not show any significant differences compared to the group to which sodium caseinate was applied. The results from the consumers and sensory analysis by a panel of trained persons were very similar. No statistically significant differences between the group treated with caseinate sodium, and the untreated so called control group of smoked species of fish.

No description available.

Six rivers within the upper Mumbidgee catchment were sampled for larval and juvenile fish. The rivers represented both regulated and unregulated flow regimes and varied widely in size. There was wide variation in the larval fish communities supported by each river, both in terms of the species diversity and total abundance of fish sampled. The highly regulated reach of the Mumbidgee River sampled during this study had the highest numbers of native species and native individuals of any river sampled. In the two rivers selected for further study, the Murmmbidgee and Goodradigbee, there was a high level of inter-annual consistency in the species composition within the reaches sampled, despite considerable change in the temperature and flow regimes of both rivers. This indicates that at least some spawning of those species sampled may occur each year, regardless of environmental conditions. Estimates of the relative abundance of each species sampled changed markedly between years, and it is argued, on the basis of growth information contained in the otoliths, that differential survival of larvae and juveniles was largely responsible for this shift in relative abundance. Otolith microstructure provided information on the date of spawning and early growth patterns of all species sampled in the upper Mumumbidgee catchment. In addition to determining the age and thus 'birth-date' of an individual, the effect of a particular event or series of events has on growth, and subsequent survival, is permanently recorded in the otolith microstructure. This enables accurate back-calculation and correlation to management actions or natural events. No other research tool has this ability to retrospectively assess, on a daily basis, the impacts of management actions on condition and subsequent survival of fish larvae. Species sampled could be separated into three groups based on spawning requirements; those linked with flow, those linked with temperature and generalist species that appear to have river independent cues, such as photoperiod or moon phase. Patterns in growth rate during the early life history stages enabled quantification of the consequences of variation in environmental conditions on the survival and recruitment of various species. Growth was not always highly correlated with water temperature, in fact, for mountain galaxias, high temperatures appear to negatively affect larval condition and subsequent survival. Conversely, carp exhibited a strategy more consistent with common perceptions, with growth and survival increasing with increasing temperature. The study uncovered spawning and growth patterns that were unexpected. Age analysis of western carp gudgeon demonstrated that they had undertaken a mid-winter spawning, when the water temperature in the main channel was far lower than that at which spawning was previously recorded for this species. Redfin perch from the unregulated Goodradigbee River exhibited growth rates exceeding the published upper limits for this and other closely related species. This growth could not be correlated with either temperature or flow, indicating that there are additional factors that dominate growth rates of redfin perch in the Goodradigbee River. The proportion and abundance of native species alone is not necessarily indicative of a 'healthy' or pristine system; some native species may be positively affected by river regulation, at least as juveniles. Comparison of the current larval fish community with likely pre-European fish communities does provide an indication of change to the system. The results of this study suggest that larval fish growth rates can be strongly influenced by environmental conditions, thus providing a powerful tool for monitoring future change and the factors which cause it. This study has demonstrated the value of larval and juvenile fish age and growth information, derived from otolith microstructure techniques, for many aspects of river management. Current river management priorities for which these techniques provide unique information include the determination of environmental flow regimes and the control of undesirable exotic species such as carp.

No description available.