FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Os sucos de frutas sÃo importantes fontes de vitaminas, sais minerais, Ãcidos orgÃnicos e fibras, e incluÃdos na dieta da populaÃÃo podem ajudar a manter a saÃde. Durante as etapas de processamento de sucos, podem ocorrer modificaÃÃes nos componentes dos frutos, afetando suas propriedades sensoriais e nutritivas. Estudos sobre os efeitos do processamento nos constituintes nutricionais dos sucos tropicais sÃo escassos. Geralmente, sÃo avaliadas somente as perdas de vitamina C. Este trabalho objetivou determinar as possÃveis alteraÃÃes quÃmicas e fÃsico-quÃmicas em suco tropical de goiaba durante as etapas de processamento (extraÃÃo, formulaÃÃo / homogeneizaÃÃo e pasteurizaÃÃo) e armazenamento (30 dias). Foram efetuadas determinaÃÃes de sÃlidos solÃveis, pH, acidez, aÃÃcares redutores, aÃÃcares totais, atividade de Ãgua, cor, vitamina C, antocianinas, carotenÃides, compostos fenÃlicos e atividade da pectinametilesterase. Ao final do estudo, constatou-se que somente os parÃmetros de pH, carotenÃides e atividade da pectinametilesterase apresentaram variaÃÃes significativas, durante as etapas de processamento do suco. O suco de goiaba se manteve ao final do processamento com elevados teores de vitamina C, compostos fenÃlicos, antocianinas totais, alÃm do aumento da quantidade de carotenÃides totais. No suco de goiaba armazenado por 30 dias observou-se que os parÃmetros analisados nÃo apresentaram diferenÃa significativa entre o tempo zero e o trinta dias. Concluindo que as caracterÃsticas quÃmicas e fÃsico-quÃmicas sÃo pouco afetadas pelo processamento e armazenamento (30 dias), pode-se considerar, portanto o processo de enchimento à quente (hot fill), as embalagens de vidro utilizadas e os conservantes adicionados como sendo bons fatores de preservaÃÃo para o produto em estudo. / Fruit juices are important vitamin sources, mineral salts, organic acids and fibers, and including in the diet of the population, they can help to keep people healthy. During the stages of juice processing, some modifications in the fruit compounds can happen, affecting its sensorial and nutritional properties. Researches on the effects of processing on the nutritional compound tropical juice are scarce. Usually, only vitamin C losses are evaluated. This study determined the possible chemical and physical-chemical changes during the stages of guava tropical juice processing (extration, formulation / homogenization and pausterization) and storage (30 days). Soluble solids, pH, acidity, reducing sugars, total sugars, water activity, colour, vitamin C, anthocyanins, carotenoids, phenolic compounds and pectinametilesterase activity were analysed. We saw that only pH, carotenoids and pectinametilesterase activity parameters showed significant variations during the stages of juice processing. At the end of the processing, vitamin C, phenolic compounds and total anthocyanins contents were high, and it was an increase of total carotenoid amount in the guava juice. For the guava juice stored during 30 days it was observed no significant difference between the times zero and thirty days, for the analysed parameters. We conclude that since the chemical and physicochemical characteristics were affected just a little by processing and stored during 30 days, the hot fill processing, the glass packings used and added conservant were good factors of product preservation in this study.

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This thesis discusses how a variety of factors like socio-economic status and educational levels of family/parents affect Std 8 pupils' school performance in twelve selected secondary schools in Thohoyandou, Venda in the Northern Province. It further examines how parents motivate pupils to do well at school, and how the expectations of parents and other relatives as well as teachers as significant others contribute to the academic attainment of pupils.. It also focuses on the favourable conditions in the pupils' learning home environment such as availability of a private study-room, language used at home, adequacy of time for both relaxation and schoolwork, learning facilities, parental involvement and nutritional values that help in promoting and enhancing pupil school performance. Finally, the author provides some recommendations about how parents can actively involve themselves in their children's education. AFRIKAANS : Hierdie tesis bespreek die wyse waarop 'n aantal faktore, soos die sosioekonomiese status en die opvoedkundige peil van die familie/ouers, st. 8 leerlinge se skoolprestasies beinvloed in twaalf geselekteerde skole in Thohoyandou, Venda, in die Noordelike Provinsie. Dit ondersoek ook die wyse waarop ouers leerlinge motiveer om goed te doen op skoal, asook hoe dit wat betekenisvolle mense soos ouers, ooms, tantes en onderwysers van hulle verwag, bydra tot die bereik van die verlangde akademiese sukses van die leerlinge. Dit fokus ook op gunstige toestande in die leerling se tuisomgewing, byvoorbeeld die beskikbaarheid van 'n private studeerkamer, taalgebruik by die huis, genoeg tyd om te slaap en te eet, ontspanning en skoolwerk, leerfassiliteite, ouerlike betrokkenheid en die voedingsvlakke wat help om leerlinge se skoolprestasies aan te moedig en te verbeter. Ten laaste voorsien die outeur ook 'n paar voorstelle oor hoe ouers aktief betrokke kan raak by 'n leerling se opvoeding. / Dissertation (MA)--University of Pretoria, 1997. / Sociology / unrestricted