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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.
1

Sorghum hot water extract : influence of grain physico-chemical characteristics

Jacobs, Helena 18 November 2011 (has links)
Traditionally, barley is the preferred cereal for traditional lager brewing. The use of sorghum for the production of European-style lager beers has recently been recognised. The use of sorghum as brewing adjunct could be a major socio-economic advantage in the developing countries in Africa. Limitations for its use, however, include its low amylolytic potential, high gelatinization temperatures, and the presence of tannins. Adjuncts are often combined with cereal malt during the brewing process to provide extra sources of fermentable carbohydrates. As with all cereals, the functional properties of sorghum grains are influenced by their physico-chemical characteristics. It is therefore critical to understand the structure, chemistry and functionality of the sorghum cultivar(s) considered for use as brewing adjuncts. Hot water extract describes the quality of the wort of an adjunct and depicts the amount of starch that was solubilised during mashing. The determination of hot water extract is expensive, laborious and time-consuming. The provision of a possible predictive marker(s) for sorghum hot water extract that is less complicated to determine, could be of great economical value to the brewer. Hot water extract was determined for 43 sorghum cultivars and then compared to various physico-chemical characteristics. Sorghum endosperm texture was visually determined. Suspensions of whole sorghum flour were pasted using a Rapid Visco Analyser (RVA) with an extended heating cycle. Significant negative correlations were obtained between extract content and pasting temperature and time in corneous endosperm samples. There was also a significant positive relationship between tannin-free sorghums and peak viscosity in pasted samples. Protein contents of 10 different sorghums were compared to their hot water extracts, where there was a significant negative relationship between these characteristics. Protein content could be used successfully as a predictive marker for extract. No significant relationship could be established between sorghum hot water extract and starch content. Tannin-containing sorghum cultivars gave significantly lower extracts and had higher malt diastatic power (DP) than non-tannin cultivars. There was no significant relationship between the DP and extract content of non-tannin sorghums. When only non-tannin sorghum cultivars that pasted were subjected to principal component analysis, it seemed that a positive relationship existed between peak viscosity and extract content. Low protein sorghum cultivars with no tannins and corneous endosperm would be suitable for use as brewing adjuncts. Protein content, the presence of tannins, endosperm texture and peak viscosity could be used as predictive markers for sorghum hot water extract / Dissertation (MSc(Agric))--University of Pretoria, 2011. / Food Science / unrestricted
2

South Africa Class F Fly Ash for roads : physical and chemical analysis

Heyns, M.W., Hassan, M. Mostafa January 2013 (has links)
Published Article / Fly Ash is a by-product at thermal power stations, also otherwise known as residues of fine particles that rise with flue gases. An industrial by-product may be inferior to the traditional materials used construction applications, but, the lower the cost of these inferior materials make it an attractive alternative if adequate performance can be achieved. The objective of this study is to evaluate the chemical and physical effectiveness of self-cementing fly ashes derived from thermal power stations for construction applications with combined standards. Using laboratory testing specimens, suitable types of Fly Ashes namely: Kendal Dump Ash, Durapozz and Pozzfill, were tested to the required standards to evaluate the potential properties. All three Fly Ashes have been classified as a Class F Fly Ash, which requires a cementing agent for reactions to take place and for early strength gains in the early stages of the reaction processes. The Fly Ashes conformed to the combination of standards and have shown that the proper reactions will take place and will continue over period of time. The use of fly ash is accepted worldwide due to saving in cement, consuming industrial waste and making durable materials, especially due to improvement in the quality fly ash products.
3

Physicochemical Properties and Exposure Assessment of Suspended Particles in Steel Plants

Her, Chia-Ta 24 August 2004 (has links)
The objective of this study was to investigate the exposure assessment and health risk of particulate matter emitted from steel industry for high-risk inhabitants living in metro Kaohsiung. A steel plant and an electric arc plant were selected for conducting the sampling of particulate matter (PM). The physical and chemical properties of PM sampled at the working place and at the fence of selected plants were also analyzed to establish the fingerprints of PM in the steel industry. In order to accomplish this study, both personal sampling and environmental sampling were conducted in steel plants. Personal exposure sampling was undertaken at working places, while the conduction of environmental sampling might affected by various uncertain environmental factors (such as meteorological condition and other emission sources), but it could characterize the overall environmental situation and help exposure assessment. Moreover, The exposure of employers (including manufacturing workers and supporting staffs) could be further assessed based on the concentration and duration of PM exposure. Specific metal concentration was obtained from working environment, searching for exposure parameter (such as exposure frequency, exposure duration, body weight, average time, and etc.) and toxicity database (e.g. cancer slope factor and reference dose). The data could be used for assessing both cancer risk and non-cancer risk of specific heavy metal. Sampling data obtained from working places showed that the highest PM concentration were observed during the electric arc process, especially the charging and discharging procedures. The concentration of PM1.0, PM10, and TSP at the working places were 53.3~195.6 £gg/m3 ,365.7~550.0 £gg/m3, and 1085.5~2755.0 £gg/m3, respectively. Measured at the outdoor environments of working places, the highest PM10 and TSP concentration, ranging from 365.7~550.0 £gg/m3 and 1085.5 ~2755.0 £gg/m3, were observed at the sinter plants of a steel manufacturer. Sampling data obtained at the fence of steel plants (a steel plant and electric arc plant) indicated that the concentration of PM10 and TSP exceeded the ambient air quality standards. Modification of manufacturing process and improvement of PM collection system are highly required to reduce the concentration level as well as the emission of PM. Results of fingerprint of PM (PM2.5, PM2.5-10, TSP) obtained from working places showed that iron, calcium, sulfate, nitrate, calcium ion, and elemental carbon were the major chemical content of PM at the melting plant, the sinter plant, and the storage field. While, iron, calcium, sulfate, nitrate, calcium ion, and organic carbon were the major chemical content of PM at electric arc plant. Results of personal exposure concentration and exposure dose of PM showed that the highest exposure level of both manufacturing workers and supporting staffs were observed at the storage field, while the lowest exposure level was found at the sinter plant. Therefore, enforcement of wearing maskers and/or shelters at the storage field is also highly recommended to prevent manufacturing workers from the exposure of high-level PM at working places. Moreover, the cancer risk of manufacturing workers exposured to hexavalent chromium (Cr6+) at the melting plant, the sinter plant, the storage field, and the electric arc plant exceeded acceptable cancer risk standard (10-5~10-6), while the hazard index of manganese (Mn) was much higher than other metals.Meanwhile, exposuring to Cr6+, Ni, and Mn at the electric arc plant also exceeded acceptable standards (Cr6+ and Ni¡G10-5~10-6 , Mn¡G1). Several control strategies, including pollution reduction measures such as the usage of clean fuel, process modification, the improvement of collection system, the enhancement of manufacture management, the conduction of environmental monitoring and exposure assessment, floor cleanup and truck entrance management, are recommended to improve the contamination of PM at working places and surrounding environments for metallurgic industries. Moreover, enforcement of wearing maskers and/or shelters at high-risk environments is also highly recommended to prevent manufacturing workers from the exposure of high-level PM at working places. Keywords: steel industry, particulate matter sampling, physical and chemical characteristics, exposure assessment, health risk
4

Influence of winemaking practices on the chemical characteristics of winery wastewater and the water usages of wineries.

Conradie, Adel 04 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The production of wine globally has increased over the past years, increasing the volume of water used and wastewater generated for every litre of wine produced. In the past, the small volumes of winery wastewater that were produced by wineries had little effect on the immediate environment. However, with the increasing wine production all around the world, winery wastewater is a rising concern for the contamination of soil and subsurface flow. In order to fully understand the impacts of winery wastewater, it is important to establish the volumes and chemical characteristics of the wastewater, before considering possible treatments. The first aim of this study was to determine the influence of certain winemaking practices on the water usage. Two wineries in the Stellenbosch Winelands District were monitored during two harvests and one post-harvest season. It was evident through this study that water plays a vital role during the production of wine and that water is needed at virtually all the winemaking steps. However, the volume of clean water needed differs immensely during the course of the production process. It was noticed that throughout the harvest period at both wineries the clean water demand was highest and decreased during the course of the post-harvest period and steadily increased again towards the end of the year. The harvest period contributes between 30 and 40% of the yearly water usage at the respective wineries. It was also noticed that certain winemaking practices including filtering with a bulk filter, washing of barrels and bottling contributes heavily to the water usage throughout the year. Activities that increase water usage during harvest include the washing of the press and processing a combination of red and white grapes on the same day. Furthermore, it was identified that one of the wineries used a smaller volume of water on a daily basis and per tonnage during harvest than the other, indicating that the cleaner production strategy established 10 years earlier has a positive impact on their water usage. The second aim of this study was to monitor the raw and treated winery wastewater from the two wineries during a period of 15 months, including two harvests and one post-harvest season. This was done to investigate the characteristics of the raw and treated wastewater. Firstly, to determine the impact of the different winemaking practices on the chemical composition of the wastewater and secondly, to determine the efficiency of the existing constructed wetlands on the wastewater and the characteristics of the treated wastewater. From this study it was possible to make two main observations concerning the chemical oxygen demand (COD) concentrations of the two wineries. Primarily, it was observed there were variations in the raw wastewater characteristics of the two wineries and above all, that both wineries showed a decrease in the COD of the raw wastewater produced. Not only did the decrease in the raw wastewater COD over this period show promising results when a cleaner production plan is established and managed it also seems to show a decrease in the volumes of water used by the respective wineries and increase in quality. / AFRIKAANSE OPSOMMING: Gedurende die afgelope paar jaar het wynproduksie wêreldwyd toegeneem en as gevolg hiervan toenemende hoeveelhede water gebruik en afvalwater gegenereer. In die verlede het die klein volumes kelderafvalwater wat deur wynkelders geproduseer is min effek op die onmiddelike omgewing gehad, maar gegewe die toenemende produksie van wyn regoor die wêreld is daar groeiende kommer oor die besoedeling van gronde en ondergrondse vloei deur kelderafvalwater. Dit is belangrik om die volumes en chemiese eienskappe van die afvalwater te bepaal om die impak van die water ten volle te verstaan, voordat moontlike behandelings oorweeg word Die eerste doel van hierdie studie was om te bepaal hoe sekere wynmaakpraktyke watergebruik beïnvloed. Twee wynkelders in die Stellenbosch Wynland Distrik is gedurende twee parsseisoene en een na-pars seisoen gemonitor. Hierdeur het dit duidelik geword dat water ‘n noodsaaklike rol speel in wynproduksie en benodig word vir feitlik alle stappe in die wynmaakproses. Die volume skoon water wat benodig word verskil wel noemenswaardig tydens die produksieproses. Die gebruik van skoon water van beide kelders was hoog tydens die parsseisoen, het afgeneem gedurende die loop van die na-pars periode en het geleidelik weer toegeneem teen die einde van die jaar. Die parsseisoen dra tussen 30 en 40% by tot die jaarlikse waterverbruik van die onderskeie kelders. Dit is ook opgemerk dat sekere wynmaakpraktyke, insluitend filtrasie met ‘n grootmaat filter, die was van vate en bottelering, grootliks bydrae tot die waterverbruik deur die loop van die jaar. Aktiwiteite wat waterverbruik tydens parstyd verhoog sluit in die gebruik van die pers en die verwerking van ‘n kombinasie van rooi en wit druiwe op dieselfde dag. Daar is ook vasgestel dat een van die wynkelders tydens parstyd ‘n kleiner volume water gebruik op ‘n daaglikse basis asook per tonnemaat wat daarop dui dat die “skoner” produksie strategie wat dié kelder 10 jaar gelede gevestig het wel ‘n positiewe impak op waterverbruik het. Die tweede doel van hierdie studie was om die onbehandelde en behandelde afvalwater van hierdie twee wynkelders te monitor oor 'n tydperk van 15 maande, wat twee paste en een na-pars seisoen insluit. Dit is gedoen om die impak van verskillende wynmaakpraktyke op die chemiese samestelling van die afvalwater te ondersoek asook om die doeltreffendheid van bestaande kunsmatige vleilande in terme van afvalwaterbehandeling te bepaal en die eienskappe van die behandelde afvalwater te ondersoek. Gevolglik is twee belangrike waarnemings oor die chemiese suurstof behoefte (CSB) konsentrasie van die twee wynkelders gemaak. Variasies in die onbehandelde afvalwater eienskappe is waargeneem by beide wynkelders en daar was ‘n afname in CSB van die onbehandelde afvalwater by beide wynkelders. Die afname in CSB van die onbehandelde afvalwater oor hierdie tydperk is belowend en dit blyk dat wanneer ‘n “skoner” produksie plan opgestel en bestuur word dit wel ‘n afname in waterverbruik en verhoog in kwaliteit by die kelders tot gevolg het.
5

Duração da qualidade de ovos estocados de poedeiras criadas no sistema “cage-free” / Duration of stocked egg quality of laying created in "cage-free" system

Thimotheo, Mariana [UNESP] 24 February 2016 (has links)
Submitted by Mariana Thimotheo null (marianathimotheo@gmail.com) on 2016-04-19T16:15:27Z No. of bitstreams: 1 DISSERTAÇÃO_online.pdf: 1098310 bytes, checksum: 0e047310d3c62ad22c4bfedba053563d (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-04-25T17:43:26Z (GMT) No. of bitstreams: 1 thimotheo_m_me_jabo.pdf: 1098310 bytes, checksum: 0e047310d3c62ad22c4bfedba053563d (MD5) / Made available in DSpace on 2016-04-25T17:43:26Z (GMT). No. of bitstreams: 1 thimotheo_m_me_jabo.pdf: 1098310 bytes, checksum: 0e047310d3c62ad22c4bfedba053563d (MD5) Previous issue date: 2016-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Poucas são as informações sobre a qualidade em relação aos padrões externos e internos de ovos “cage-free” produzidos no Brasil. O presente estudo analisou: (1) por até quantas horas após a postura os ovos mantêm sua qualidade interna, quando mantidos em temperatura ambiente; (2) a qualidade física e química de ovos estocados por até 28 dias em temperatura ambiente. No Capítulo 1 é apresentada uma abordagem teórica sobre o tema. O capítulo 2 aborda a duração da qualidade interna dos ovos “cage-free”. Para tanto, 480 ovos foram distribuídos em um delineamento inteiramente casualizado composto de 8 períodos (ovos recém-colocados e ovos com: 1, 2, 3, 4, 5, 6 e 7 horas pós-postura), com 60 repetições cada. Os parâmetros analisados foram: peso do ovo; percentagens de casca, albúmen e gema; unidade Haugh e índice gema. As médias obtidas foram comparadas pelo teste de Tukey a 5% de significância. Houve efeito significativo (P<0,05) dos períodos pós-postura apenas para a unidade Haugh dos ovos. Os valores médios de UH registrados na 3ª hora pós-postura foram maiores que os observados da 5ª a 7ª hora, mas mantiveram-se semelhantes aos ovos recém-colocados. Concluiu-se que os ovos mantiveram sua qualidade original similar durante o período estudado. O capítulo 3 apresenta a qualidade física e química dos ovos “cage-free” durante a estocagem. Para isso 420 ovos foram distribuídos em um delineamento inteiramente casualizado composto de 5 períodos: ovos frescos e ovos com 7, 14, 21 e 28 dias de estocagem, com 7 repetições de 12 ovos cada. Foram avaliados parâmetros físicos e químicos dos ovos. As médias obtidas foram comparadas pelo teste de Tukey a 5% de significância. Conclui-se que os períodos de estocagem influenciaram significativamente (P<0,05) os parâmetros relacionados à qualidade dos ovos. Os ovos frescos apresentaram melhor qualidade química e física quando comparados aos ovos estocados. / The information about quality regarding the external and internal patterns of cage-free eggs produced in Brazil are few. The present study analyzed (1) how long the eggs maintain their internal quality after the laying, when they are kept on room temperature; (2) the physical and chemical characteristics of the eggs stored for up to 28 days on room temperature. In Chapter 1 a theoretical approach on the theme is presented. In Chapter 2 the effects of post laying on the egg internal quality are approached. For that, 480 eggs were distributed on an entirely casual outlining composed by eight periods (fresh eggs and eggs with: 1, 2, 3, 4, 5, 6, and 7 hours post laying), with 60 repetitions each. The analyzed parameters were: egg weight; shell, albumen and yolk’s percentages; Haugh unity and yolk index. The obtained averages were compared the Tukey on 5% significance test. There was a significant effect (P<0.05) of the post laying periods only for the egg Haugh unity. The average values of UH registered on the third hour post laying were bigger than that observed between the 5th and 7th hour, but kept similar to the fresh eggs. It was concluded that the eggs kept their internal quality similar during the studied period. The Chapter 3 presents the physical and chemical characteristics from cage-free eggs stored for different periods. For that, 420 eggs were distributed on an entirely casual outlining composed by five periods: fresh eggs (analyzed on the laying and harvesting day) and eggs with 7, 14, 21 and 28 days of storage, with 7 repetitions of 12 eggs each. The internal, external and bromatological patterns of the eggs were assessed. The obtained averages were compared to the Tukey on 5% significance test. The majority of the studied parameters were significantly influenced (P<0.05) by the storage periods. It was observed that the storage periods did influence the parameters related to the eggs’ quality. The increasing of storage time reduced the eggs’ quality.
6

Radiação gama, ultravioleta (UV-C) e atmosfera controlada na conservação da qualidade de tomate ‘Débora Plus’ e ‘Pitenza’

Campos, André José de [UNESP] 30 January 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-01-30Bitstream added on 2014-06-13T20:22:24Z : No. of bitstreams: 1 campos_aj_dr_botfca.pdf: 601357 bytes, checksum: 3a5914e72b302ec456a369dc11e2383e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O tomate é uma hortaliça de grande importância econômica e fonte de vitaminas e vários compostos com propriedades antioxidantes benéficas para a saúde. Em alguns produtos hortifrutícolas colhidos, a aplicação da irradiação gama, irradiação ultravioleta C (UV-C) ou de atmosferas controladas (AC) tem inibido o desenvolvimento de podridões. Mas até agora se desconhece o efeito da radiação UV-C, sozinha ou combinada com AC, sobre atributos básicos do amadurecimento e qualidade do tomate colhido. O presente trabalho teve por objetivos avaliar o efeito da irradiação gama, irradiação ultravioleta C (UV-C) e atmosfera controlada (AC) na conservação do tomate ‘Débora plus’ e ‘Pitenza’, verificando as variáveis de qualidade: físicos, físico-químicos, químicos, bioativos e enzimáticos. Foram utilizados os tomates ‘Débora plus’ e ‘Pitenza’, sendo provenientes da região de Botucatu/SP – Brasil e da região de Cartagena – Espanha, respectivamente. Após a colheita, os tomates de Botucatu foram transportados para o laboratório de frutas e hortaliças, pertencente ao Departamento de Gestão e Tecnologia Agroindustrial, da Faculdade de Ciências Agronômicas – UNESP – Campus de Botucatu, SP; enquanto os de Cartagena foram imediatamente transportados ao Laboratório de Postrecolección e Refrigeración (Planta Piloto) do Departamento de Ciencia y Tecnologia Agrária da Escuela Técnica Superior de Ingenieria Agronomica – Universidad Politécnica de Cartagena/Espanha, aonde se mantiveram a 12ºC até a manhã seguinte. Posteriormente em cada Laboratório, os tomates foram selecionados quanto ao tamanho, injúrias, defeitos, aparência, visando uniformizar o lote... / Tomato is a great economic importance vegetable and source of vitamins and several compounds with antioxidant properties favorable for health. In some harvested products, the application of gamma irradiation, ultraviolet irradiation C (UV-C) or controlled atmospheres (CA) has inhibited the rotten development. But so far, the radiation UV-C is unknown alone or with CA on ripeness basic attributes and quality of the harvested tomato. This work has as aim, to evaluate the effect of gamma irradiation, ultraviolet irradiation C (UV-C) and controlled atmospheres (CA) in the conservation of ‘Débora Plus’ and ‘Pitenza’ tomato verifying the quality variables: physical, physic-chemical, chemical, bioactive and enzymatic. ‘Débora Plus’ and ‘Pitenza’ tomatoes from the region of Botucatu, SP, Brazil and the region of Cartagena, Spain, were used, respectively. After the crop, the tomatoes from Botucatu were transported to the vegetable and fruit laboratory of the Department Gestão e Tecnologia Agroindustrial, da Faculdade de Ciências Agronômicas – UNESP – Campus de Botucatu, SP; while the tomatoes from Cartagena were immediately transported to the Laboratório de Postrecolección y Refrigeración (Planta Piloto) of the Departament de Ciencia y Tecnologia Agrária da Escuela Técnica Superior de Ingenieria Agronomica – Universidad Politécnica de Cartagena, Spain, where they were kept in 12ºC until the following morning. Afterwards, in each laboratory, the tomatoes were selected by the size, injuries, defects, appearance, aiming to uniform the portion. To quantify better the isolated effect of the different techniques of conservation: gamma irradiation, ultraviolet irradiation C (UV-C) and controlled atmosphere...(Complete abstract, click electronic access below)
7

Biometria e qualidade da romã orgânica durante o armazenamento. / Biometry and quality of organic pomegranate during storage.

SILVA, Isana Maria Brito Roque. 15 May 2018 (has links)
Submitted by Élida Maeli Fernandes Quirino (maely_sax@hotmail.com) on 2018-05-15T14:06:32Z No. of bitstreams: 1 ISANA MARIA BRITO ROQUE SILVA - DISSERTAÇÃO PPGSA PROFISSIONAL 2013..pdf: 499595 bytes, checksum: edeabb2bf3b0ce32b35d6105114f6efb (MD5) / Made available in DSpace on 2018-05-15T14:06:33Z (GMT). No. of bitstreams: 1 ISANA MARIA BRITO ROQUE SILVA - DISSERTAÇÃO PPGSA PROFISSIONAL 2013..pdf: 499595 bytes, checksum: edeabb2bf3b0ce32b35d6105114f6efb (MD5) Previous issue date: 2013-09-17 / O objetivo deste trabalho foi determinar a qualidade pós-colheita da romã ‘Molar’, acondicionada in natura sob condições ambiente. Os frutos foram colhidos em uma propriedade comercial localizada no município de Sousa-PB e, em seguida, transportados ao Laboratório de Análise de Alimentos da Universidade Federal de Campina Grande, Campus de Pombal-PB. O experimento foi instalado em delineamento inteiramente casualizado (DIC), cujos tratamentos foram representados por condições de armazenamento a 0, 3, 6, 9, 12, 15 e 18 dias a 27ºC e 28% UR com quatro repetições, sendo cada repetição constituída por cinco frutos (n=20), que foram analisados quanto à características biométricas, físico-químicas e visuais. A roma 'Molar', produzida em sistema orgânico no semiárido paraibano são classificadas como doces, com baixa acidez, inferior a 0,75% de ácido cítrico e sólido solúveis entre 12 e 15%. Quanto ao amanho, as romãs são classificadas como pequenas, com peso abaixo de 200g e menos de 74 mm de diâmetro. O armazenamento dos frutos a 27ºC, 28% UR até seis dias mantém as características biométricas, físico-químicas e visuais apropriadas para a comercialização in natura. O armazenamento dos frutos a 27ºC, 28% UR por 18 dias proporciona intensa desidratação da casca, porém, não prejudica a qualidade nem o rendimento de suco extraído dos arilos. / The objective of this study was to determine the postharvest quality of pomegranate 'Molar', storage in nature under ambient conditions. The fruits were harvested at a commercial property located in the municipality of Sousa-PB and then transported to the Food Analysis Laboratory of the Universidade Federal de Campina Grande, Pombal-PB. The experiment was conducted in completely randomized design ( CRD) in which treatments were represented by conditions of storage at 0 , 3 , 6 , 9 , 12 , 15 and 18 days at 27 ºC and 28 % RH with four replicates, each replicate consisting five fruits (n = 20), which were analyzed for biometrics, physical-chemical and visual characteristics . The roma 'Molar', produced in an organic system in semiarid Paraiba are classified as sweet, with low acidity, less than 0,75 % citric acid and soluble solid between 12 and 15%. As for size, the pomegranates are classified as small, weighing less than 200g and less than 74 mm in diameter. The storage of fruits at 27 º C, 28 %RH up to six days maintains appropriate biometric, physical-chemical and visual characteristics for the fresh fruit market. The storage of fruits at 27 ºC, 28 %RH for 18 days provides intense dehydration of the skin, but not affect the quality or yield of juice extracted from the arils.
8

Radiação gama, ultravioleta (UV-C) e atmosfera controlada na conservação da qualidade de tomate 'Débora Plus' e 'Pitenza' /

Campos, André José de, 1978- January 2008 (has links)
Orientador: Rogério Lopes Vieites / Banca: Giuseppina Pace Pereira Lima / Banca: José Fernando Durigan / Banca: Eliane Aparecida Benato Rodrigues da Silva / Banca: Atila Francisco Mogor / Resumo: O tomate é uma hortaliça de grande importância econômica e fonte de vitaminas e vários compostos com propriedades antioxidantes benéficas para a saúde. Em alguns produtos hortifrutícolas colhidos, a aplicação da irradiação gama, irradiação ultravioleta C (UV-C) ou de atmosferas controladas (AC) tem inibido o desenvolvimento de podridões. Mas até agora se desconhece o efeito da radiação UV-C, sozinha ou combinada com AC, sobre atributos básicos do amadurecimento e qualidade do tomate colhido. O presente trabalho teve por objetivos avaliar o efeito da irradiação gama, irradiação ultravioleta C (UV-C) e atmosfera controlada (AC) na conservação do tomate 'Débora plus' e 'Pitenza', verificando as variáveis de qualidade: físicos, físico-químicos, químicos, bioativos e enzimáticos. Foram utilizados os tomates 'Débora plus' e 'Pitenza', sendo provenientes da região de Botucatu/SP - Brasil e da região de Cartagena - Espanha, respectivamente. Após a colheita, os tomates de Botucatu foram transportados para o laboratório de frutas e hortaliças, pertencente ao Departamento de Gestão e Tecnologia Agroindustrial, da Faculdade de Ciências Agronômicas - UNESP - Campus de Botucatu, SP; enquanto os de Cartagena foram imediatamente transportados ao Laboratório de Postrecolección e Refrigeración (Planta Piloto) do Departamento de Ciencia y Tecnologia Agrária da Escuela Técnica Superior de Ingenieria Agronomica - Universidad Politécnica de Cartagena/Espanha, aonde se mantiveram a 12ºC até a manhã seguinte. Posteriormente em cada Laboratório, os tomates foram selecionados quanto ao tamanho, injúrias, defeitos, aparência, visando uniformizar o lote...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Tomato is a great economic importance vegetable and source of vitamins and several compounds with antioxidant properties favorable for health. In some harvested products, the application of gamma irradiation, ultraviolet irradiation C (UV-C) or controlled atmospheres (CA) has inhibited the rotten development. But so far, the radiation UV-C is unknown alone or with CA on ripeness basic attributes and quality of the harvested tomato. This work has as aim, to evaluate the effect of gamma irradiation, ultraviolet irradiation C (UV-C) and controlled atmospheres (CA) in the conservation of 'Débora Plus' and 'Pitenza' tomato verifying the quality variables: physical, physic-chemical, chemical, bioactive and enzymatic. 'Débora Plus' and 'Pitenza' tomatoes from the region of Botucatu, SP, Brazil and the region of Cartagena, Spain, were used, respectively. After the crop, the tomatoes from Botucatu were transported to the vegetable and fruit laboratory of the Department Gestão e Tecnologia Agroindustrial, da Faculdade de Ciências Agronômicas - UNESP - Campus de Botucatu, SP; while the tomatoes from Cartagena were immediately transported to the Laboratório de Postrecolección y Refrigeración (Planta Piloto) of the Departament de Ciencia y Tecnologia Agrária da Escuela Técnica Superior de Ingenieria Agronomica - Universidad Politécnica de Cartagena, Spain, where they were kept in 12ºC until the following morning. Afterwards, in each laboratory, the tomatoes were selected by the size, injuries, defects, appearance, aiming to uniform the portion. To quantify better the isolated effect of the different techniques of conservation: gamma irradiation, ultraviolet irradiation C (UV-C) and controlled atmosphere...(Complete abstract, click electronic access below) / Doutor
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Sensory quality of deep fat fried potato chips manufactured from potatoes with different physico-chemical characteristics

Ndungu, Eric Kimondo 29 July 2008 (has links)
Studies generally agree on the critical influence of physico-chemical characteristics of raw potatoes on the physico-chemical and sensory characteristics of potato chips. However, the actual magnitude of differences in sensory quality and consumer acceptance of potato chips as a result of differences in the physico-chemical characteristics of raw potatoes are scarcely reported in most studies. This research was conducted to determine the effect of different physico-chemical characteristics of potato samples on the sensory quality and acceptance of potato chips. The potato samples which represented typical variations in physico-chemical characteristics that a potato chip manufacturer experiences were sourced over a six month period. The samples comprised of four potato varieties (A, B, C, D) sourced from five regions (V, W, X, Y, Z). The samples were coded AV, BW1, BW2, CW, CX, DY, DW and DZ. BW1 and BW2 were of the same variety and grown in the same region but harvested at different time periods. The sourcing of potatoes and potato chips were done at the manufacturer’s processing line during regular production. The potatoes were analyzed for physico-chemical characteristics generally reported to influence potato chip sensory quality, i.e. specific gravity (solids contents), starch content and reducing sugars content. After processing, the physico-chemical characteristics i.e. moisture content, colour and oil content of the respective unflavoured potato chip samples were analysed. The sensory qualities of both unflavoured and flavoured (sour cream and onion) potato chips of the respective potato samples were also determined. There were significant differences (p<0.05) in the specific gravity/solids content of the potato samples. The specific gravity and solids content ranged from 1.073 to 1.098g/cm3 and 19.2 to 24.9% respectively. Reducing sugars were not detected in any of the potato samples at a minimum detection level of 0.05 %. The potato chip samples differed significantly (p<0.05) in moisture content, oil content and colour (a * and b* values, chroma, hue angle) with ranges of 1.2 to 1.9 % (moisture), 33.1 to 40.8 % d.b (oil content), 0.39 to 3.69 (a *), 15.88 to 21.26 (b*), 15.93 to 21.37 (chroma) and 79.92 to 88.96 o (hue angle). Descriptive sensory evaluation showed that 6 and 8 of the attributes identified in the unflavoured and flavoured potato chip samples, respectively, differed significantly (p<0.05). Consumer sensory evaluation indicated that there was no clear preference of one chip sample over the others despite of differences observed through descriptive sensory analysis and physico-chemical characteristics. All the chip samples were generally liked. To the manufacturer this research could be regarded as of a quality control nature since the potato chip samples used in this study were of chipping varieties actually used by the manufacturer. The value of this research to the chip manufacturer was the fact that despite of slight differences in the physico-chemical characteristics (specific gravity/solids content and starch content) of potato samples, potato chips of acceptable sensory quality to the consumers were produced. / Dissertation (MSc)--University of Pretoria, 2011. / Food Science / unrestricted
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Caracterização físico-química e qualidade microbiológica de amostras de mel de abelhas sem ferrão (Apidae, Meliponinae) do Estado da Bahia, com ênfase em Melipona Illiger, 1806 / Physico-chemical characterization and microbiological quality of stingless bees (Apidae, Meliponinae) honey samples from the State of Bahia, Brazil, with emphasis on Melipona Illiger, 1806

Souza, Bruno de Almeida 18 February 2008 (has links)
Aproveito este espaço para contar um pouco da minha trajetória com as abelhas, mas também para falar sobre as atividades desenvolvidas e possibilidades surgidas no decorrer do curso de Doutorado, informações estas que normalmente passam despercebidas. Nascido em Salvador, tive meu primeiro contato com as abelhas com pouco mais de 12 anos por iniciativa de meu pai, que nesta época já era um entusiasta pela atividade e possuía conhecimentos práticos. Alguns anos após, fizemos nosso primeiro curso de iniciação em apicultura para consolidar as nossas experiências práticas e as informações obtidas em literatura. Terminei por cursar a graduação em Engenharia Agronômica na Escola de Agronomia da UFBA, atualmente Centro de Ciências Agrárias, Ambientais e Biológicas da Universidade Federal do Recôncavo da Bahia. Foi um período de crescimento em que me envolvi com atividades de iniciação científica, em outras áreas que não apicultura. Já no mestrado, me foi dada a oportunidade de trabalhar com um grupo de abelhas até então novo para mim, os meliponíneos, e de ter como orientador o Prof. Dr. Carlos Alfredo Carvalho, pessoa que me direcionou para o futuro curso de doutorado na USP, dando continuidade à linha de pesquisa iniciada no mestrado. Em 2004 iniciei o meu doutoramento na ESALQ/USP sob orientação do Prof. Dr. Luis Carlos Marchini. Fazendo um balanço desta última etapa, além do desenvolvimento das atividades regulares do programa tive a oportunidade de me envolver com a formulação de projetos de pesquisa para agências de fomento, de participar de eventos nacionais e internacionais, de publicar artigos científicos e de consolidar parcerias de trabalho no Brasil e no exterior. Em síntese, este período de doutorado que se encerra (2004 - 2008) pode ser representado em números por: quatro cursos realizados como formação complementar, quatro premiações em eventos científicos, nove trabalhos publicados em periódicos (alguns submetidos antes de ingressar no doutorado), quatro livros, três capítulos de livros, três cartilhas, dois textos em revista de divulgação, quatro trabalhos completos publicados em anais de congressos, 40 resumos, 17 trabalhos apresentados e participação em 12 eventos técnico-científicos; além do envolvimento em atividades de monitoria junto a disciplinas de graduação, treinamento este fundamental para uma futura atividade de docência. Acredito que todas estas amizades feitas, parcerias consolidadas, atividades desenvolvidas e produções decorrentes do doutorado contribuirão de forma substancial e decisiva para esta nova etapa que se inicia em minha vida. / The stingless bees honey is a product presenting a growing market demand but, in spite of its consumption as food and even medicinal use, there are few studies to define quality standards for its commercialization. This work was carried out to determine the physico-chemical characteristics and microbiological quality of honey samples produced by meliponid species from Bahia State, Brazil, contributing to the establishment of quality control standards of this product. Forty-seven samples collected from December 2004 to May 2006 were analyzed, being determined their physico-chemical characteristics and microbiological quality, regarding to the standard counting of moulds and yeasts, and presence of microorganisms of the coliform group. Concerning the physico-chemical characteristics, the obtained medium values, excepting moisture content, fulfill the quality criteria established by the current Brazilian Legislation. Considering the number of samples individually disqualified, adjustments in reducing sugars limits should be made for best attend to the requirements of meliponid honey, as well as the use of the diastasic activity in the Melipona honeys as quality criterion. In the microbiologic analyses, 53.2% of the honey samples presented standard counting for moulds and yeasts above the maximum value allowed by the Brazilian Legislation. For microorganisms of the coliform group only one sample was positive for coliform at 35ºC. The presence of these microorganisms, mainly moulds and yeasts, even in samples aseptically harvested indicates the need of identification of this microbiota and its possible natural occurrence in the honey produced by this group of bees.

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