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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Možnost dalšího využití bezinkových výlisků / Possibility of further use of elderberry marc

Sedláčková, Lucie January 2019 (has links)
This Diploma thesis talks about the production of concentrates and lyophilisate from the extract of elderberry moldlings (elderberry, Sambuvus nigra L.) and by determination by chosen chemical characteristics of these products. The theoretical part includes the botanical characteristics of the plant species Sambucus nigra L. Next is the part that is dedicated to biologicaly active substances found in elderberry and it‘s possible usage in the food industry. Next is the part where the extraction, purification and indentification of anthocyanic dyes are described. In the next part is the analyrical method HPLC described, including the description of instrumentation. The last part talks about the description of the used methods: methods for the concentration of the extract, UV-VIS spectrophotometry, determination of phenolic compounds, determination of dry matter, determination of active acidity and the overall titrating acidity. The experimental part contained the optimalization of the process of producing the extract from elderberry moldings. The extract obtained was then concentrated for preservation and characterization purposes based on selected chemical properties. The total content of anthocyanin dyes was chosen as a quality parameter. The most suitable process for the preparation of the extract was chosen to be the ratio of moldings and solvent 1:2, 4 (m/V). The most suitable solvent was chosen to be a mixture of water and ethanol in a ratio of 1:1 (V/V). According to the needs of the submitter, an extract with the use of water as the extraction agent is also provided. The prepared extract was then concentrated on a vacuum evaporator or lyophilized for storage purposes. The dye degradation while using the evaporator was the lowest in a 40 ° C water bath. The final products were characterized by the determination of soluble solids, pH, titration acidity, total phenolic compounds and total anthocyanin dyes. The anthocyanin pigments contained identified by liquid chromatography are: cyanidine-3-sambubioside, cyanidine-3-glucoside, cyanidine-3-sambubioside-5-glucoside, and cyanidine-3,5-diglucoside The total content of anthocyanins in the concentrate was determined to be equivalent to cyanidine-3-glucoside at 2.8 gl-1 and in the lyophilisate 2.5 gl-1.
32

Vybrané nutriční parametry některých druhů méně známého ovoce / Selected nutritional parameters of some lesser known fruit

Diblíková, Michaela January 2016 (has links)
Diploma thesis is focused on the chemical analysis of the juices of black, red and white currant and jostaberry (Ribes a Ribes x culverwellii). The theoretical part is focused to the definition of fruit, fruit importance in human nutrition, description of Ribes and Ribes x culverwellii genuses, active substances in the currants and the jostaberry, description of selected chemical parameters and the determination of some of them. The procedures of determining for the following chemical parameters are described in the experimental section: determination of reducing sugars, determination of total and soluble solids, formol number, pH, titratable acidity, determination of total phenols and anthocyanins and determination of vitamin C in two samples jostaberry, six varieties of black currants, one variety of white currant and two varieties of red currants. Based on the evaluation of the obtained results, the comparison was made with different varieties and the thesis that "overall comparison of the different varieties in the content of phenolic compounds, vitamin C and anthocyanins appears to be the most promising variety of blackcurrant demon. It should however be noted that the highest content of phenolics and anthocyanins were determined in jostaberry„ has been suggested.
33

Improving fruit soluble solids content in melon (Cucumis melo L.) (reticulatus group) in the Australian production system

Long, Robert Llewellyn, bizarrealong@hotmail.com January 2005 (has links)
Total soluble solids (TSS) is a reliable indicator of melon eating quality, with a minimum standard of 10% recommended. The state of Australian melon production with respect to this quality criterion was considered within seasons, between growing districts and over seasons. It was concluded that improvement in agronomic practice and varietal selection is required to produce sweeter melons. The scientific literature addressing melon physiology and agronomy was summarised, as a background to the work that is required to improve melon production practices in Australia. The effect of source sink manipulation was assessed for commercially grown and glasshouse grown melon plants. The timing of fruit thinning, pollination scheduling, the application of a growth inhibitor and source biomass removal were assessed in relation to fruit growth and sugar accumulation. Results are interpreted against a model in which fruit rapidly increase in weight until about two weeks before harvest, with sugar accumulation continuing as fruit growth ceases. Thus treatment response is very dependant on timing of application. For example, fruit thinning at 25 days before harvest resulted in further fruit set and increased fruit weight but did not impact on fruit TSS (at 9.8%, control 9.3%), while thinning at 5 days before harvest resulted in a significant (Pless than 0.05) increase in fruit TSS (to 10.8%, control 9.3%) and no increase in fruit weight or number. A cost/ benefit analysis is presented, allowing an estimation of the increase in sale price required to sustain the implementation of fruit thinning. The effect of irrigation scheduling was also considered with respect to increasing melon yield and quality. To date, recommended practice has been to cause an irrigation deficit close to fruit harvest, with the intent of 'drying out' or 'stressing' the plant, to 'bring on' maturity and increase sugar accumulation. Irrigation trials showed that keeping plants stress-free close to harvest and during harvest, facilitated the production of sweeter fruit. The maintenance of a TSS grade standard using either batch based (destructive) sampling or (non-invasive) grading of individual fruit is discussed. On-line grading of individual fruit is possible using near infrared spectroscopy (NIR), but the applicability of the technique to melons has received little published attention. Tissue sampling strategy was optimised, in relation to the optical geometry used (in commercial operation in Australia), both in terms of the diameter and depth of sampled tissue. NIR calibration model performance was superior when based on the TSS of outer, rather than inner mesocarp tissue. However the linear relationship between outer and middle tissue TSS was strong (r2 = 0.8) in immature fruit, though less related in maturing fruit (r2 = 0.5). The effect of fruit storage (maturation/senescence) on calibration model performance was assessed. There was a negligible effect of fruit cold storage on calibration performance. Currently, the agronomist lacks a cost-effective tool to rapidly assess fruit TSS in the field. Design parameters for such a tool were established, and several optical front ends compared for rapid, though invasive, analysis. Further, for visualisation of the spatial distribution of tissue TSS within a melon fruit, a two-dimensional, or hyper-spectral NIR imaging system based on a low cost 8-bit charge coupled device (CCD) camera and filter arrangement, was designed and characterised.
34

Crescimento, produtividade e qualidade das frutas de morangueiro em hidroponia: efeito da concentração de nutrientes e da densidade de plantio. / Growth, yield and fruit quality of strawberry crop in hydroponics: effects of nutrient concentration and plant density.

Portela, Isabelita Pereira 23 February 2011 (has links)
Made available in DSpace on 2014-08-20T14:33:14Z (GMT). No. of bitstreams: 1 Dissertacao_Tatiane_Kuka_Valente_Gandra.pdf: 6435645 bytes, checksum: d575f0c3d4782ff59377ccfc558b3d8a (MD5) Previous issue date: 2011-02-23 / The strawberry crop presents great importance for the Horticulture sector of the Southern part of Rio Grande do Sul due to its high yield and economic income, once the fruit has guaranteed market and high marketable price. Hydroponic cultivation allows optimizing the greenhouse vertical area, leading to a higher yield, reduces the diseases occurrence and also makes easier crop management and, as a consequence, enhances farmer life quality. However, there are few studies on the adaptation of the crop to this cultivation system, especially focusing concentrations of the nutrient solution and, overall, plant densities. Aiming to study growth, yield and fruit quality of strawberry crop in hydroponics system, two trials were conducted in a plastic greenhouse at Universidade Federal de Pelotas , RS. NFT (nutrient film technique) hydroponic system was employed. It consists of cement tiles cultivation benches. The first trial aimed to study different ionic concentrations of the nutrient solution for cultivar Camarosa and was replicated in two consecutive years (2009/2010). The analyzed experimental factor was the nutrient solution electrical conductivity (EC) at four levels: 0.9, 1.5, 2.1, 2.7dS m-1 (2009) and five levels: 0.7, 1.2, 1.7, 2.2, 2.7 dS m-1 (2010). The second trial was conducted in order to verify the effect of different plant densities on cultivar Camino Real. The experimental factor was plant density at four levels: 15.0, 12.5, 10.7, and 9.3 plants m-2. Fresh and dry matter of leaves, crown, roots and fruit, leaf area, fruit number and average fruit weight were evaluated. Samples of fruits were analyzed regarding to total soluble solids content (TSS), titratable total acidity (TTA)  for both trials of 2010  concentrations of anthocyanins, L-ascorbic acid, total phenolics compounds and 12 antioxidant capacity only for EC trial in 2010. The obtained results of the first trial indicated that EC from 1.2 to 1.5dS m-1 promotes plant growth and fruit yield. Growth and yield decreased when EC is below or above these values. The fruits total soluble solids content, antocyanin and L-ascorbic acid concentrations were increased at 1.7dS m-1 EC. The concentration of total phenolic compounds was increased reducing the EC to 1.2dS m-1. While soluble solids, anthocyanin and L-ascorbic acid content, respectively, decreased by 17, 17 and 15%, fruit yield was increased by 52% and phenolic compounds concentration by 22 %, when the EC decreased from 1.7 to 1.2dS m-1.The average fruit weight was reduced with increasing EC in 2009 and it was not affected in 2010, as well as the acidity and the antioxidant capacity. We can conclude that nutrient solution from 1.2 to 1.5 dS m-1 EC can be used to achieve higher yieldy, without great losses in fruit quality of cultivar Camarosa grown in NFT hydroponic system. The results obtained from the second trial indicated that growth and yield of individual plants of strawberry cultivar Camino Real was not affect by increasing plant density in the rage from 9.3 to 15.0 plants m-2. Growth and yield per square meter, as well as chemical characteristics related to the organoleptic quality of fruits (TSS and TSS/TTA), present linear response to increasing plant density. We suggest the adoption of the plant density of 12.5 plants m-2, which provides high yield, with appropriate organoleptic characteristics of fruits, and reduction in the number of plants required in relation to 15.0 plants m-2 plant density. However, it is necessary to carry out additional studies on cultivar Camino Real in order to promote changes in the system and its management and check the economic feasibility of its cultivation in hydroponics. / A cultura do morangueiro possui grande importância para o setor hortigranjeiro da Região Sul do Rio Grande do Sul, pois permite atingir altas produtividades e alto rendimento econômico, uma vez que as frutas tem mercado garantido e um alto valor. O cultivo hidropônico permite a otimização do espaço vertical do ambiente protegido, resultando em maior produtividade, diminuindo a ocorrência de doenças e, ainda, facilitando os tratos culturais e beneficiando a qualidade de vida do agricultor. Porém, há poucos estudos sobre a adaptação da cultura a este tipo de sistema de produção, principalmente em se tratando de concentrações da solução nutritiva e, sobretudo, de densidades de plantio. Com o objetivo de se estudar o crescimento, a produtividade e a qualidade das frutas de morangueiro em sistema hidropônico, dois experimentos foram realizados em condições de estufa plástica, no Campus da Universidade Federal de Pelotas, RS. O sistema hidropônico empregado era do tipo NFT (técnica da lâmina de nutrientes), constituído de bancadas de cultivo construídas com telhas de fibrocimento. O primeiro experimento teve o objetivo de estudar diferentes concentrações iônicas da solução nutritiva para a cultivar Camarosa e foi repetido em dois anos consecutivos (2009/2010). O fator experimental estudado foi a condutividade elétrica da solução nutritiva (CE) em quatro níveis: 0,9; 1,5; 2,1; 2,7dS m-1 (2009); e cinco níveis: 0,7; 1,2; 1,7; 2,2 e 2,7 dS m-1 (2010). O segundo experimento foi conduzido a fim de verificar o efeito de 9 diferentes densidades de plantio sobre a cultivar Camino Real. O fator experimental estudado foi a densidade de plantio em quatro níveis: 15,0; 12,5; 10,7 e 9,3 plantas m-2. Avaliaram-se a matéria fresca e seca de folhas, coroa, raízes e frutas, a área foliar, o número de frutas e o peso médio das frutas. Amostras das frutas foram analisadas em relação ao teor de sólidos solúveis totais (SST), à acidez total titulável (ATT)  em ambos os experimentos realizados em 2010, às concentrações de antocianinas, ácido L-ascórbico, compostos fenólicos totais e à capacidade antioxidante  somente no experimento sobre CE, em 2010. Os resultados obtidos no primeiro experimento indicam que a CE entre 1,2 e 1,5dS m-1 favoreceu o crescimento da planta e a produtividade das frutas. O crescimento e a produtividade diminuíram quando a CE foi mantida abaixo ou acima destes valores. Os teores de SST, de antocianinas e de ácido L-ascórbico das frutas foram aumentados com a elevação da CE para 1,7dS m-1. A concentração de compostos fenólicos totais elevou-se com a diminuição da CE para 1,2dS m-1. Enquanto os teores de SST, de antocianinas e de ácido L-ascórbico, respectivamente, diminuíram em 17, 17 e 15%, a produtividade foi aumentada em 52% e a concentração de compostos fenólicos totais em 22%, quando a CE diminuiu de 1,7 para 1,2dS m-1. O peso médio das frutas foi reduzido com a elevação da CE em 2009 e não foi afetado em 2010, assim como a ATT e a capacidade antioxidante. Conclui-se que a solução nutritiva com CE entre 1,2 e 1,5dS m-1 pode ser indicada para obter maior produtividade, sem grandes perdas na qualidade das frutas da cultivar Camarosa em sistema hidropônico NFT. Os resultados obtidos no segundo experimento indicam que o crescimento e a produtividade individual das plantas da cultivar de morangueiro Camino Real não foram afetados pela elevação da densidade de plantio, no intervalo entre 9,3 e 15,0 plantas m-2. O crescimento e a produtividade por unidade de área, bem como as características químicas relacionadas à qualidade organoléptica das frutas (concentração de SST e relação SST/ATT), apresentaram resposta linear ao incremento da densidade de plantio. Sugere-se a adoção da densidade de plantio de 12,5 plantas m-2, que proporciona rendimento elevado e frutas com adequadas características organolépticas e redução no número de mudas necessárias, em relação à densidade de 15,0 plantas m-2. Porém, existe a necessidade de desenvolver novos estudos com a cultivar Camino Real, a fim de promover adaptações no sistema e seu manejo e verificar a viabilidade econômica de seu cultivo em hidroponia.

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