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Thesis (M.Sc.) -- University of Adelaide, Dept. of Zoology, 1981.

Most prawns are prepared as frozen or canned meat and the remaining waste is used as a feed supplement or directly disposed on to the land, which affects the environment. Fresh prawn bio-waste contains protein, astaxanthin, flavor compounds and chitin. The use of chitin in various applications is limited due to its water insolubility. In this research, a new method is developed to prepare water-soluble colloidal chitin (WSCC) from prawn waste. WSCC having the percentage of degree of deacetylation same with that of chitin follows non-newtonian shear thinning behaviour. The characteristic study showed that the breakage of polymer chains during processing thus reduced the molecular weight and bulk density of WSCC. Therefore, functional properties of WSCC can be controlled by optimizing the processing conditions. Astaxanthin complex has attracted considerable interest in relation to its health benefits because of its powerful antioxidant activity. Traditional extraction of astaxanthin complex from prawn waste using organic solvents requires post-purification steps, creates solvent disposal problem and degrades the pigment. This research develops an efficient way of recovering astaxanthin complex from prawn waste that eliminates the problems associated with solvent extraction methods and offers possible recyclability of the solvents used. Post-harvest blackening in prawns adversely affects both quality and consumer acceptability. However, consumer safety over the chemicals, especially sulphites used in inhibiting prawn blackening is of a major concern. This study shows that the antioxidant, astaxanthin complex can inhibit the poly phenol oxidase (PPO) catalyzed blackening reaction in prawns. Although prawns have astaxanthin complex present in their natural state, its concentration in vivo may not be sufficient to act against PPO. Therefore, astaxanthin complex-enriched feed in prawn culture may prevent prawn melanosis and may eliminate the post-harvest handling methods.

Most prawns are prepared as frozen or canned meat and the remaining waste is used as a feed supplement or directly disposed on to the land, which affects the environment. Fresh prawn bio-waste contains protein, astaxanthin, flavor compounds and chitin. The use of chitin in various applications is limited due to its water insolubility. In this research, a new method is developed to prepare water-soluble colloidal chitin (WSCC) from prawn waste. WSCC having the percentage of degree of deacetylation same with that of chitin follows non-newtonian shear thinning behaviour. The characteristic study showed that the breakage of polymer chains during processing thus reduced the molecular weight and bulk density of WSCC. Therefore, functional properties of WSCC can be controlled by optimizing the processing conditions. Astaxanthin complex has attracted considerable interest in relation to its health benefits because of its powerful antioxidant activity. Traditional extraction of astaxanthin complex from prawn waste using organic solvents requires post-purification steps, creates solvent disposal problem and degrades the pigment. This research develops an efficient way of recovering astaxanthin complex from prawn waste that eliminates the problems associated with solvent extraction methods and offers possible recyclability of the solvents used. Post-harvest blackening in prawns adversely affects both quality and consumer acceptability. However, consumer safety over the chemicals, especially sulphites used in inhibiting prawn blackening is of a major concern. This study shows that the antioxidant, astaxanthin complex can inhibit the poly phenol oxidase (PPO) catalyzed blackening reaction in prawns. Although prawns have astaxanthin complex present in their natural state, its concentration in vivo may not be sufficient to act against PPO. Therefore, astaxanthin complex-enriched feed in prawn culture may prevent prawn melanosis and may eliminate the post-harvest handling methods.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 287-338).

Larval development of Penaeus monodon from protozoea (PZ1) to postlarval stages is described on natural and commercially available artificial larval diets under controlled laboratory feed trials. Five species of live microalgae (Tetraselmis chuii, Chaetoceros calcitrans, Skeletonema costatum, Rhodomonas baltica and Pavlova lutheri) were evaluated in feed trials at seven (5-60 cells gl1) cell concentrations with protozoeal larval stages. Performance of five animal diets (rotifers, Mytilus eggs, Artemia nauplii, barnacle nauplii and crab eggs) were examined in feed trials from Mysis (Ml) to postlarvae (PL1). Best results for protozoeal stages were obtained on a combination diet T. chuii + R. baltica at 40 cells µl-', while results from mysis to postlarvae were best achieved on Artemia nauplii. Natural feeds are expensive, difficult to maintain in mass culture and often vary in nutritional value. Larval performance on ten leading brands of artificial larval diet marketed using different process technologies were evaluated in replicated feed trials, together with factors causing variability in larval growth and survival of P. monodon. It was found that nutrient leach loss from unstable artificial feeds in culture conditions increases levels of ammonia and nitrite beyond safe limits. Live microalgal species at 1000 cells µl1 added to culture water reduces these toxic levels. The role of microalgae in larval culture is also examined. To further improve larval growth and survival on artificial diets, proteins from different sources, lipid, vitamin and mineral levels were incorporated in microencapsulated feeds. As a result improvement in larval development to postlarval stage was achieved with feeds containing 60% soya + mussel protein, 5% lipid and 13.9% vitamin and mineral mix. Algal homogenates supplemented to encapsulated feeds produced larval growth and survival comparable to live feed controls. P. monodon larvae were grown to the juvenile prawn stage solely on Frippak feeds. Larval growth was comparable to growth achieved on live feed controls. This study forms a basis for further investigations into nutritional requirements of penaeid prawns.

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Submitted by JOSUÉ FERNANDES FROTA FILHO (frotafilho.jf@outlook.com) on 2018-04-24T17:00:58Z No. of bitstreams: 1 Josue_Dissertação_24_04_FINAL.pdf: 705810 bytes, checksum: c7f70d2764da25e302dc2b38af6c84bd (MD5) / Rejected by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br), reason: Solicitamos que realize correções na submissão seguindo as orientações abaixo: O arquivo pdf submetido ao repositório deve conter a ficha catalográfica e o certificado de aprovação (documentos obrigatórios). Favor inserir no arquivo pdf a ficha catalográfica e o certificado de aprovação (tudo em um arquivo só). Agradecemos a compreensão. on 2018-04-25T12:56:05Z (GMT) / Submitted by JOSUÉ FERNANDES FROTA FILHO (frotafilho.jf@outlook.com) on 2018-04-26T11:48:21Z No. of bitstreams: 1 Josue_Dissertação_24_04_FINAL corrigido.pdf: 927542 bytes, checksum: a658dd423a96120871bc91bfa99cbc9b (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-04-26T12:10:28Z (GMT) No. of bitstreams: 1 fotafilho_jf_me_jabo.pdf: 927542 bytes, checksum: a658dd423a96120871bc91bfa99cbc9b (MD5) / Made available in DSpace on 2018-04-26T12:10:28Z (GMT). No. of bitstreams: 1 fotafilho_jf_me_jabo.pdf: 927542 bytes, checksum: a658dd423a96120871bc91bfa99cbc9b (MD5) Previous issue date: 2018-04-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O crescimento acelerado da aquicultura vem sendo acompanhado pela crescente preocupação em se garantir a sustentabilidade das atividades aquícolas. A sustentabilidade neste trabalho é baseada principalmente em duas dimensões: ambiental, e econômica. O presente trabalho teve como objetivo avaliar a sustentabilidade ambiental e a viabilidade econômica em pequena escala de produção de pós-larvas do camarão de água doce da espécie Macrobrachium amazonicum, por meio de um conjunto indicadores de sustentabilidade. Foram considerados os ciclos de produção durante um ano de cultivo de pós-larvas do camarão-da-amazônia. A capacidade produtiva considerada foi de 290 milheiros de pós-larvas/mês. A sustentabilidade ambiental foi medida com base na utilização de recursos naturais, eficiência no uso destes recursos e poluição liberada ao ambiente pelo meio de cultivo. A sustentabilidade econômica foi medida com base nos aspectos sobre a eficiência no uso dos recursos financeiros e a capacidade de gerar recursos para reinvestimentos na atividade. Os resultados sugerem que há viabilidade econômica para o produtor que realiza larvicultura em sistemas de fundo de quintal (backyard hatchery). Além disso, os dados obtidos também mostraram que embora a larvicultura seja uma atividade bastante intensificada, há eficiência na utilização dos recursos naturais, sendo mais sustentável do que outras fases de produção, como o berçário e crescimento final da mesma espécie. Desse modo, o modelo utilizado é uma alternativa viável com sustentabilidade econômica e ambiental para produção de pós-larvas de M. amazonicum em sistemas familiares de produção. / The rapid growth of aquaculture has been accompanied by the increasing concern to ensure sustainability of aquatic activities. In this work, sustainability is based on environmental and economic dimensions. The objective of the study is to evaluate the environmental and economic sustainability of a small scale Macrobrachium amazonicum post-larvae production using a set of indicators for sustainability. Production cycles during one year of the Amazon Prawn hatchery was considered. The considered productive capacity was 290 thousand post larvae/month. Environmental sustainability measurements were based on the use of natural resources, efficiency in the use of resources and pollution released to environment from the production facility. Economic sustainability measurements were based on the aspects of efficiency in the use of financial resources and the capacity to generate resources for reinvestments in the activity. Results show that there is economic feasibility for the ‘backyard’ hatcheries system for freshwater prawn farmers. In addition, data indicate that in spite of hatchery being a highly intensified activity, there is efficiency in using natural resources, and it is more sustainable than other production phases, such as nursery and grow-out phase of the same species. To sum it up, the hatchery model studied is a feasible and sustainable alternative to produce M. amazonicum post-larvae with environmental and economic sustainability to be operated using either family labour production. / 88882.156917/2017-01

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