Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.

Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.

Thesis (M.Sc. Hons.) -- University of Western Sydney, Hawkesbury. / Includes bibliographical references.

Shelf life studies of raw Macadamia integrifolia nuts were carried out at different storage temperatures, relative humidities and time. An accelerated shelf life test was conducted, and the influence of water activity on kernel texture was studied. The antioxidants naturally present were identified by the use of thin layer chromatography. Accelerated shelf life tests showed that hydrolytic rancidity followed apparent zero order kinetics within the water activity range of 0.3 to 0.5. Oxidative rancidity measured by peroxide value appeared to follow different orders of reaction at different temperatures. At two months of storage rancidity was detected at which the headspace concentration of hexanal was 0.39 ppm and a peroxide value of 0.37 meq/kg. Headspace gas chromatography was done to find a quick and effective method for measuring oxidative rancidity. The presence of natural antioxidants was verified to explain the shelf life of macadamia nuts. In textural study, correlations were found between subjective and objective measurements. The product became unacceptable organoleptically above water activity 0.415 when stored at 20 degrees C. This level was established as the critical water activity. There is a need to establish a water activity at which the consumer is likely to reject the product. / Master of Science (Hons) (Food Science and Nutrition)

Made available in DSpace on 2014-06-11T19:31:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-12-16Bitstream added on 2014-06-13T20:42:07Z : No. of bitstreams: 1 piza_plbt_dr_botfca.pdf: 576119 bytes, checksum: e10fb2efd0d10e64fe9dc7061c5a81e8 (MD5) / A pós-colheita da noz macadâmia é uma das etapas mais críticas de sua cadeia produtiva, as baixas produtividades nos primeiros anos de vida dos pomares não permitem que os agricultores realizem grandes investimentos neste período, iniciando, assim, um processo de improvisações que se perpetuará ao longo do tempo. Este trabalho teve como principal objetivo melhorar o rendimento operacional de um processo de pré-limpeza de macadâmia, desenvolvendo, a partir de um sistema existente, uma nova unidade, com capacidade de receber e processar, no mínimo, 8.000 kg de produto por dia. O experimento foi realizado em uma fazenda situada no município de Dois Córregos, Estado de São Paulo, nas safras de 2003, 2004 e 2005. A partir do processo existente foram desenvolvidas 3 novas unidades. As duas primeiras apresentaram aumentos na produtividade e reduções nos custos operacionais, entretanto, não atenderam as condições de recebimento e processamento. A terceira unidade, representou a somatória dos conhecimentos obtidos nas análises anteriores, e, atendeu os objetivos propostos no presente trabalho. A análise econômica dos custos para migrar do processo existente para a unidade de melhor rendimento mostrou que, os investimentos em equipamentos e automação foram pagos em aproximadamente 50 dias de processamento. / The macadamia nut post-harvest is one of the most critical stages of the productive chain, the low orchards productivity in the first life years does not allow farmers much investments in this period, initiating, thus, a process of improvisations that will be perpetuated trough the years. This work had as main objective to improve the efficiency of a cleaning macadamia process. It was developed a new unit based as an existing system with capable to process, at least, 8,000 kg of product per day. The experiments were carried out in a farm situated in Dois Córregos city, São Paulo, during harvest season of 2003, 2004 and 2005. From the existing process three new units were developed. The first two ones shoud increases in productivity and reductions in operational costs, however, it did not attend the necessities of receiving and processing. The third unit, represented incorporation of the knowledge obtained in the previous analyses, and, fulfilled the objectives of this work. The costs analysis to go from the existing process to the better income unit, showed that, the investments in equipment and automation had been paid in approximately 50 processing days.

Thesis (Ph.D.) - University of Queensland, 2003. / Includes bibliography.

Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.

Orientador: Antonio Carlos de Oliveira Ferraz / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-07-22T15:13:36Z (GMT). No. of bitstreams: 1 Rodrigues_AndreLuisGunes_M.pdf: 2152247 bytes, checksum: b112b59fce9531a4f53a0fadb3dc33b1 (MD5) Previous issue date: 1996 / Mestrado / Mestre em Engenharia Agrícola

Environmental and nutritional imperatives make it necessary to carry out regular and reliable / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2007.

The global macadamia nut industry is fast developing at present. South Africa is currently the third largest global producer. There are many contributing factors influencing the increased demand for macadamia nuts. The most important factor would probably be the nutritional value provided by the nuts. It is important for the macadamia nut industry to demonstrate strong leadership in order to ensure that the growers and the industry develop ahead of the markets and retain a competitive edge as the industry develops. In agricultural terms the investment into a macadamia farm is significant.Developing a farm with a long gestation period and high capital input cost requires a significant commitment from a grower. The risk associated with error is potentially very high and may have serious financial repercussions to the growers and their long term sustainability. Strong leadership and innovation practices within the industry should be a continuous improvement process in order to challenge and enhance current practices within the industryand to mitigate risks associated with the industry as a whole. The purpose of this research was to understand the perceptions of growers and the macadamia nut industry regarding the role of leadership and innovative behaviour to support increased growth and sustainability of growers and the industry alike. / Graduate School of Business Leadership / (M.B.A.)