• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 23
  • 8
  • 5
  • 1
  • Tagged with
  • 41
  • 39
  • 16
  • 8
  • 6
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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

Atividade larvicida da Persea americana (Lauracea) sobre Aedes aegypti (Diptera, Culicidae) evidenciada por modificações morfohistológicas / Larvicida activity of Persea americana (Lauracea) on Aedes aegypti (Diptera, Culicidae) evidenced by morphohistological modifications

Guimarães, Antonella Del Buono 03 November 2014 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-05-18T17:57:20Z No. of bitstreams: 2 Dissertação - Antonella Del Buono Guimarães - 2014.pdf: 3436476 bytes, checksum: 37a24402f8fa03abb2ca15c689cd1d2d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-19T10:35:38Z (GMT) No. of bitstreams: 2 Dissertação - Antonella Del Buono Guimarães - 2014.pdf: 3436476 bytes, checksum: 37a24402f8fa03abb2ca15c689cd1d2d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-19T10:35:38Z (GMT). No. of bitstreams: 2 Dissertação - Antonella Del Buono Guimarães - 2014.pdf: 3436476 bytes, checksum: 37a24402f8fa03abb2ca15c689cd1d2d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-11-03 / Dengue has impact on public health of the intertropical regions of the world and its main vector Aedes aegypti. The measures most commonly used to control this vector, so far, are the synthetic insecticides, which applied on a large scale for a long period, did show resistance. Thus, chemical compounds from plants can be substitutes for synthetic insecticides, with the advantages of resistance retardation, due to the complexity of its components, easy degradation, lower toxicity to man and to be a safer alternative to the environment . Assays crude ethanol extract (cee) of Persea americana stem bark were performed in polystyrene cups, solutions containing 100 ppm of P. americana cee, previously dissolved in dimethylsulfoxide (DMSO) and water public Goiânia system. In each glass were placed 5 larvae of 3rd stage (L3) of the mosquito Aedes aegypti. The study was made of morfohistológic modifications from observations made with 4, 8, 12, 16, 20, 24 and 48 h treatment with the cee. In each period, the larvae were collected, fixed, dehydrated, infiltrated and embedded in historesin. of 3μm thick cuts were made in microtome semiautomatic, stained with hematoxylin / eosin (HE), analyzed and photomicrographed under a light microscope. For scanning electron microscopy (MEV) the treated and control larvae were fixed, dehydrated, dried in a critical point apparatus, metallized and analyzed in electron microscope. The morfohistológic changes were observed from 24 hours after treatment of larvae L3 with P. americana stem bark cee. The analysis of histological sections of the midgut of Ae. aegypti in light microscopy showed the presence of vacuoles in the cytoplasm of epithelial cells, large amount of secretion and folding of membrane peritrophic larvae treated for 48 hours. There was extrusion whole food content together with peritrophic matrix, thus suggesting the P.americana. toxic action on the gut of the larvae. These changes did not occur in the control group. There was no evidence of external changes by MEV. / A dengue apresenta impacto na saúde pública das regiões intertropicais do mundo e tem como principal vetor o Aedes aegypti. As medidas mais usadas no controle desse vetor, até o momento, são os inseticidas sintéticos, que aplicados em larga escala durante longo período, fez aparecer resistência. Diante disso, compostos químicos provenientes de plantas podem ser substitutos dos inseticidas sintéticos, com as vantagens do retardamento da resistência, devido à complexidade de seus constituintes, da fácil degradação, da menor toxicidade ao homem e por ser uma alternativa mais segura para o meio ambiente. Ensaios com extrato bruto etanólico (ebe) da casca do caule de Persea americana foram realizados em copos de poliestireno, contendo soluções a 100 ppm do ebe de P. americana, previamente dissolvido em dimetilsulfóxido (DMSO) e água do sistema público de Goiânia. Em cada copo foram colocadas 5 larvas de 3° estádio (L3) do mosquito Aedes aegypti. O estudo das modificações morfohistológicas foi feito a partir de observações realizadas com 4, 8, 12, 16, 20, 24 e 48 h de tratamento com o ebe. Em cada período, as larvas foram coletadas, fixadas, desidratadas, infiltradas e incluídas em historesina. Foram realizados cortes de 3μm de espessura em micrótomo semiautomático, corados pela hematoxilina/eosina (HE), analisados e fotomicrografados em microscópio de luz. Para microscopia eletrônica de varredura (MEV) as larvas tratadas e controle foram fixadas, desidratadas, secas em aparelho de ponto crítico, metalizadas e analisadas em microscópio eletrônico. As modificações morfohistológicas foram observadas a partir de 24h após o tratamento das larvas L3 com ebe de casca de caule de P. americana. As análises dos cortes histológicos do mesêntero de larvas de Ae. aegypti, em microscopia de luz, mostraram a presença de vacúolos no citoplasma das células epiteliais, grande quantidade de secreção e dobramentos da membrana peritrófica nas larvas tratadas por 48h. Houve extrusão de todo conteúdo alimentar juntamente com a matriz peritrófica, sugerindo assim a ação tóxica de P. americana sobre o tubo digestivo das larvas. Essas modificações não ocorreram no grupo controle. Não houve evidência de alterações externas pelo MEV.
32

APROVECHAMIENTO DE SUBPRODUCTOS DE CULTIVOS DE HIGO CHUMBO (Opuntia ficus-indica L.) Y AGUACATE (Persea americana)

Melgar Castañeda, Bruno 27 May 2019 (has links)
[ES] La industria agro-alimentaria se encuentra en constante evolución, adaptándose a las demandas de los consumidores. Un claro ejemplo es el de la industria frutícola, que ha partido de los productos mínimamente procesados, hacia procesos mucho más complejos como las destilaciones, requiriendo mayores cantidades de materias primas. Estos procesos conllevan a la generación de millones de toneladas de residuos frutícolas al año, produciendo en muchos de los casos grandes problemas con impactos medioambientales. No obstante, la riqueza organoléptica y de compuestos nutraceúticos en estos residuos hacen posible su revalorización, haciendo de manera sostenible un cambio sustancial en el impacto negativo medioambiental y generando nuevos productos con repercusiones económicas. En este contexto, la presente tesis doctoral explora las características nutricionales, sensoriales y nutraceúticas de dos especies frutícolas (Persea americana y Opuntia spp.) y sus subproductos, con la finalidad de generar una caracterización integral y un aprovechamiento de los residuos generados por los cultivos de ambos frutos en las industrias alimentarias (pieles y semillas), así como de especies de Opuntia no utilizadas comercialmente. Esta exploración ha sido posible usando diferentes técnicas analítica, bioquímicas y microbiológicas para llevar a cabo la detección de las posibles alternativas de uso. Como resultado a las potenciales propiedades de los frutos de aguacates y de los higos chumbos, se decidió realizar una caracterización nutricional de los principales macronutrientes, y debido a la poca información encontrada en Opuntia spp., se realizó la caracterización lipídica, de los azúcares y ácidos orgánicos de los frutos. Posteriormente se evaluaron las propiedades nutraceúticas, por un lado se evaluaron espectrofotométricamente los compuestos bioactivos de ambos subproductos frutícolas mediante distintas técnicas como Folin-Ciocalteu para la determinación de polifenoles totales, Al3Cl3 para determinación de flavonoides totales, y poder reductor, ABTS, DPPH, TBARS y ß-caroteno para la determinación de capacidad antioxidante hidrofílica e lipofílica de los extractos, además, en Opuntia spp. se analizó el contenido de los colorantes betaxantinas y betacianinas. Por otro lado, mediante el uso de técnicas cromatográficas HPLC-DAD-ESI-MS/MS, se caracterizaron los perfiles polifenólicos (ácidos fenólicos y flavonoides) de ambos subproductos frutícolas, más los perfiles betalainicos de las muestras de higos chumbos. Por último, mediante técnicas microbiológicas y ensayos citotoxicológicos, se comprobó el poder antimicrobiano, antitumoral y hepatotóxico, con ayuda de 16 cepas bacterianas, y fúngicas, 4 líneas celulares tumorales y 1 línea celular sana obtenida a partir de hígado de cerdo, denominada PLP2. Finalmente, se ha realizado un ensayo de optimización multivariable de extracción de los compuestos bioactivos de Opuntia spp. mediante extracciones asistidas por microondas y ultrasonidos, haciendo uso de un diseño experimental estadístico empleando las herramientas de metodología de respuesta de superficie acopladas a un diseño central compuesto 2^4 con 7 puntos centrales, para la obtención de modelizaciones graficas de los parámetros de respuesta, que ayudan a identificar las condiciones óptimas de los factores de extracción empleados. En definitiva, estos análisis suponen la obtención de información relevante sobre la extracción de compuestos bioactivos con aplicaciones nutraceúticas y colorantes, que pueden ser añadidos a una amplia gama de productos de las industrias farmacéuticas, cosméticas y alimentarias, para reforzar o mejorar las características y funcionalidades de estos. / [CAT] La indústria agroalimentària es troba en constant evolució, adaptant-se a les demandes dels consumidors. Un clar exemple és el de la indústria fructícola, que ha partit dels productes mínimament processats, cap a processos molt més complexos com les destil¿lacions, requerint majors quantitats de matèries primeres. Aquests processos comporten la generació de milions de tones de residus fructícoles a l'any, produint en molts dels casos grans problemes amb impacte mediambientals. No obstant això, la riquesa nutracèutica i organolèptica d'aquests residus fan possible la seua revaloració, fent de manera sostenible un canvi substancial en l'impacte negatiu mediambiental i generant nous productes amb repercussions econòmiques. En aquest context, la present tesi doctoral explora les característiques nutricionals, sensorials i nutracèutiques de dues espècies fructícoles (Persea americana i Opuntia spp.) i els seus subproductes, amb la finalitat generar una caracterització integral i un aprofitament dels residus generats pels cultius de tots dos fruits en les indústries alimentàries (pells i llavors), així com de les espècies d'Opuntia no utilitzades comercialment. Aquesta exploració ha estat possible usant diferents tècniques analítiques, bioquímiques i microbiològiques per a dur a terme la detecció de les possibles alternatives d'ús. A causa de les potencials propietats dels fruits d'alvocats i de les figues paleres, es va decidir realitzar una caracterització nutricional dels principals macronutrients, i a causa de la poca informació trobada en Opuntia spp., es va realitzar la caracterització lipídica, dels sucres i àcids orgànics dels fruits. Posteriorment es van avaluar les propietats nutracèutiques, d'una banda es van avaluar espectrofotomètricament els compostos bioactius de tots dos fruits mitjançant diferents tècniques com Folin-Ciocalteu per a la determinació de polifenols totals, Al3Cl3 per a la determinació de flavonoides totals, i poder reductor, ABTS, DPPH, TBARS i ß-caroteno per a la determinació de capacitat antioxidant hidrofílica i lipofílica dels extractes. A més, en Opuntia spp. es va analitzar el contingut dels colorants betaxantines i betacianines. D'altra banda, mitjançant l'ús de tècniques cromatogràfiques HPLC-DAD-ESI-MS / MS, es van caracteritzar els perfils polifenòlics (àcids fenòlics i flavonoides) de tots dos fruits, més els perfils betalainics de les mostres de figues de moro. Finalment, mitjançant tècniques microbiològiques i assajos citotoxicològics, es va comprovar el poder antimicrobià, antitumoral i hepatotòxic, amb ajuda de 8 ceps bacterians, 8 ceps fúngics, 4 línies cel·lulars tumorals i 1 línia cel·lular sana obtinguda a partir de fetge de porc, anomenada PLP2 . Finalment, s'ha realitzat un assaig d'optimització multivariable d'extracció dels compostos bioactius d'Opuntia spp. mitjançant extraccions assistides per microones i ultrasons, fent ús d'un disseny experimental estadístic emprant les eines de metodologia de resposta de superfície acoplades a un disseny central compost 2 ^ 4 amb 7 punts centrals, per a l'obtenció de modelitzacions gràfiques dels paràmetres de resposta, que ajuden a identificar les condicions òptimes dels factors d'extracció empleats. En definitiva, aquestes anàlisis suposen l'obtenció d'informació rellevant sobre l'obtenció de compostos bioactius amb aplicacions nutracèutiques i colorants, que poden ser afegits a una àmplia gamma de productes de les indústries farmacèutiques, cosmètiques i alimentàries, per reforçar o millorar les característiques i funcionalitats d'aquests. / [EN] Agro-alimentary industries are constantly evolving and adapting to their customer needs, for instance, in the fruit industry, the transition between minimum processed products to more complex process such as distillation has been occurring and increasing, thus, demanding higher volumes of raw materials. All this process and operations lead to millions of tons of fruit by-products generated every year, creating deep environmental issues with high impact most of the times. Nevertheless, revalorization of the by-products it possible due to the nutraceutical and organoleptic characteristics, which brings potential benefits in both, environmental protection and positive economic repercussion in a sustainable manner. According to the previously mentioned background, this doctoral thesis focus on the nutrimental, organoleptic and nutraceutical characteristics of two different fruits (Persea americana and Opuntia spp.) and their by-products, aiming to develop an integral characterization and revalorization of the by-product produced in the food industries (seeds and peels) from both cultivars. Likewise, the exploitation of non-commercial Opuntia species. The whole exploration was possible due to the use of analytic, biochemical and microbiological techniques, which allowed us to elucidate possible alternatives of usage. As a result of avocado and prickly pears potential functional properties, a nutritional characterization from the principal macronutrients was performed, additionally, due to the lack of information on Opuntia spp., lipid, sugar and organic acids profiling were also analysed on the edible fruits. Afterwards, nutraceutical properties were assessed, on one hand, bioactive compounds from both fruits by-products were spectrophotometric analysed through different procedures such as, total phenolic profile by Folin-Ciocalteu, total flavonoid content through Al3Cl3 methodology and hydrophilic and lipophilic antioxidant capacity of the extracts via reducing power, ABTS, DPPH, TBARS and ß-carotene bleaching assays, besides, betaxhantins and betacyanins pigments quantification from Opuntia spp. was also performed. In the other hand, polyphenolic (phenolic acids and flavonoids) profiling in both fruit by-products was performed throughout chromatographic techniques such as HPLC-DAD-ESI-MS/MS, in the same manner, betalainic profile was also analysed on prickly pears. Lastly, applying microbiological techniques and cytotoxic assays, hepatotoxicity, antimicrobial and antitumor activity was tested using a freshly porcine liver extracted cell line (namely PLP2), 16 bacterial and fungus strains and 4 carcinogenic cell lines respectively. Finally, multivariable ultrasound and microwave-assisted extractions of Opuntia spp. bioactive compounds were optimized, performing an experimental design using statistical tools such as response surface methodology (RSM) coupled to 2^4 central composite design (CCD) with 7 star points, in order to obtain graph modelling of the response parameters, which help to identify the optimal conditions of the extraction factors used. Summarizing, relevant information on the extraction of bioactive compounds with nutraceutical and colouring applications was achieved through specific analysis, thus, the previously mention phytochemical molecules can then be added to a wide range of products within the pharmaceutical, cosmetic and food industries, to strengthen or improve the characteristics and functionalities of the final products. / Melgar Castañeda, B. (2019). APROVECHAMIENTO DE SUBPRODUCTOS DE CULTIVOS DE HIGO CHUMBO (Opuntia ficus-indica L.) Y AGUACATE (Persea americana) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/121145 / TESIS
33

Antimicrobial, anticancer and catalytic activities of green synthesized Avocado seed extract-gold nanoparticles

Ngungeni, Yonela January 2019 (has links)
>Magister Scientiae - MSc / Nature through billions of years of trial and error has produced an immeasurable amount of natural systems like plants, birds and animals. The intelligence of nature is hidden in these natural systems and researchers are turning towards “Nature’s intelligence” to find inspiration and advance novelty in the development of nanomaterials. Gold nanoparticles (AuNPs) have unique optical, electronic and physicochemical features which has gained them popularity and widespread exploitation in various applications. The conventional methods used for AuNPs synthesis employs toxic chemicals which makes these NPs unsafe for biomedical applications. Hence, there is a search for new, ‘green’ and more cost effective methods for AuNPs synthesis. Plant extracts are regarded as a highly desirable system for nanoparticle synthesis due to their tremendous capability to produce a wide range of phytochemicals that can act as reducing agents. The main goal of this study was to synthesize AuNPs in a cost effective manner without the use of toxic chemicals in the synthesis process. Avocado seeds which are an agricultural waste by-product were used for the biosynthesis of AuNPs. The study reports on the synthesis optimization, characterization and activities of the biogenic AuNPs. The avocado seed extract mediated - AuNPs (AvoSE-AuNPs) were optimized by varying reaction parameters and characterized by UV-visible, Dynamic Light Scattering (DLS) and High Resolution Transmission Electron Microscopy (HRTEM), Zetasizer and Fourier Transform Infrared Spectroscopy (FTIR). The formation of AvoSE-AuNPs had an absorption maximum at 534 nm. HRTEM and DLS confirmed that the NPs were polydispersed and present in different shapes. The presence of phytochemical constituents on the AvoSE-AuNPs were confirmed by FTIR. Their potential antibacterial activity was tested on bacterial strains known to exhibit resistance to a number of current antibiotics. The catalytic activity of AvoSE-AuNPs was also assessed as a means to contribute to the development of new methods aimed at alleviating organic pollutants such as nitrophenols in the environment. The AvoSE-AuNPs demonstrated excellent catalytic activity in the reduction of 4-NP by NaBH4 as shown by the rapid decrease in the nitrophenolate absorption band at 400 nm and the appearance of new absorption band at 298 nm, revealing the formation of the 4-aminophenol. Furthermore, the rate constants calculated demonstrated that the reaction occurs faster in the presence AvoSEAuNPs. The AvoSE-AuNPs showed low significant cytotoxicity. Cell cycle analysis was conducted to further investigate the apparent exhibited toxicity of the AvoSE-AuNPs. The results showed that in both cell lines treated with AvoSE-AuNPs and AvoSE there was a ii | P a g e disruption in the regulation of cell cycle. Cell cycle analysis helped improve understanding of the low cytotoxicity observed by the MTT assay results. The results presented in this study clearly demonstrate the feasibility of using AvoSE for the synthesis of AuNPs. This study demonstrated that AvoSE mediated AuNPs synthesis is a greener alternative as it abides by the green chemistry principles. Furthermore, the study outcomes contributed to minimizing environmental pollution by finding use for agricultural waste and thus ultimately adding value to the field.
34

Functional and Predictive Structural Characterization of WRINKLED2, A Unique Oil Biosynthesis Regulator in Avocado

Behera, Jyoti R., Rahman, M., Bhatia, Shina, Shockey, Jay, Kilaru, Aruna 08 June 2021 (has links)
WRINKLED1 (WRI1), a member of the APETALA2 (AP2) class of transcription factors regulates fatty acid biosynthesis and triacylglycerol (TAG) accumulation in plants. Among the four known Arabidopsis WRI1 paralogs, only WRI2 was unable to complement and restore fatty acid content in wri1-1 mutant seeds. Avocado (Persea americana) mesocarp, which accumulates 60-70% dry weight oil content, showed high expression levels for orthologs of WRI2, along with WRI1 and WRI3, during fruit development. While the role of WRI1 as a master regulator of oil biosynthesis is well-established, the function of WRI1 paralogs is poorly understood. Comprehensive and comparative in silico analyses of WRI1 paralogs from avocado (a basal angiosperm) with higher angiosperms Arabidopsis (dicot), maize (monocot) revealed distinct features. Predictive structural analyses of the WRI orthologs from these three species revealed the presence of AP2 domains and other highly conserved features, such as intrinsically disordered regions associated with predicted PEST motifs and phosphorylation sites. Additionally, avocado WRI proteins also contained distinct features that were absent in the nonfunctional Arabidopsis ortholog AtWRI2. Through transient expression assays, we demonstrated that both avocado WRI1 and WRI2 are functional and drive TAG accumulation in Nicotiana benthamiana leaves. We predict that the unique features and activities of ancestral PaWRI2 were likely lost in orthologous genes such as AtWRI2 during evolution and speciation, leading to at least partial loss of function in some higher eudicots. This study provides us with new targets to enhance oil biosynthesis in plants.
35

Atividade antioxidante, compostos fenólicos totais e cor em abacate ‘hass’ submetido a diferentes tratamentos físicos

Tremocoldi, Maria Augusta [UNESP] 03 March 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-03Bitstream added on 2014-06-13T20:34:24Z : No. of bitstreams: 1 tremocoldi_ma_me_botfca.pdf: 616438 bytes, checksum: 67f1da03c193fb8aca4f0e4cbb1ebdac (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O presente trabalho teve por objetivo determinar a atividade antioxidante, compostos fenólicos totais e cor em abacate ‘Hass’ submetido ao tratamento térmico, radiação gama e ultravioleta. Após a colheita, os frutos foram selecionados para tornar o lote homogêneo. Foi realizada a caracterização do fruto verde e amadurecido quanto a acidez titulável, pH, umidade, teor de lipídios, cinzas (minerais), proteína (nitrogênio bruto), açúcar total e coloração. Foram realizados 3 experimentos com frutos recém colhidos. Experimento I: imersão dos frutos em água a 45ºC por 5, 10, 15 e 20 minutos; Experimento II: radiação gama nas doses 0,2; 0,4; 0,6 e 1,0kGy e Experimento III: radiação ultravioleta (UVC) por 5, 10, 15 e 20 minutos. Após os tratamentos, os frutos foram armazenados em temperatura ambiente (21ºC±1 e 70±5% de UR) e refrigerado (10ºC±1 e 90±5% de UR). Os frutos foram analisados quanto à capacidade antioxidante pelo método DPPH e compostos fenólicos totais aos 0, 3, 9 e 12 dias. A coloração foi avaliada aos 0, 3, 6, 9, 12 e 15 dias. Os resultados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey ao nível de 1% de probabilidade. Nas condições em que os experimentos foram realizados, pode-se concluir que os frutos do tratamento testemunha e mantidos sob refrigeração apresentaram maior capacidade antioxidante e teor de compostos fenólicos totais ao longo do período de armazenamento; o tratamento térmico por 5 e 10 minutos foi efetivo na manutenção da capacidade antioxidante e dos compostos fenólicos; a dose de 0,6kGy não foi efetiva na manutenção da capacidade antioxidante; a radiação ultravioleta (UV-C) não manteve a capacidade antioxidante dos frutos, no entanto ocasionou aumento na quantidade de compostos fenólicos; o tratamento térmico e a radiação ultravioleta não afetaram a coloração da polpa / This study aimed to determine the antioxidant activity, total phenolic compounds and color in avocado 'Hass' submitted to heat treatment, gamma and ultraviolet radiation. After harvest, fruits were selected to make the homogeneous portion. The characterization was performed of the green fruit and mature as acidity, pH, moisture, lipids, ash (minerals), protein (nitrogen gross), total sugar and coloring. 3 experiments were performed with freshly harvested fruits. Experiment I: immersion of fruits in water at 45 ° C for 5, 10, 15 and 20 minutes; Experiment II: gamma radiation doses 0.2, 0.4, 0.6 and 1.0 kGy and Experiment III: ultraviolet radiation (UV-C) for 5, 10, 15 and 20 minutes. After treatments, fruits were stored at room temperature (21±1ºC and 70±5% HR) and refrigeration (10ºC±1 and 90±5% HR). The fruits were analyzed for their antioxidant capacity by DPPH method and phenolic compounds at 0, 3, 9 and 12 days. The color was measured at 0, 3, 6, 9, 12 and 15 days. Data were subjected to analysis of variance and mean comparison using Tukey’s test at 1% probability. In conditions where the experiments were performed, one can conclude that the fruits of control treatment and kept under refrigeration had higher antioxidant capacity and content of phenolic compounds during the storage period, the heat treatment for 5 and 10 minutes was effective the maintenance of antioxidant capacity and phenolic compounds, the dose of 0.6 kGy was not effective in maintenance the antioxidant capacity, ultraviolet radiation (UV-C) did not maintain the antioxidant capacity of fruits, however caused an increase in the content of phenolic compounds, heat treatment and ultraviolet radiation did not affect the pulp color
36

Efeito de injúrias mecânicas na qualidade pós-colheita de abacates

Sanches, Juliana [UNESP] 19 April 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-04-19Bitstream added on 2014-06-13T19:23:56Z : No. of bitstreams: 1 sanches_j_dr_jabo.pdf: 1095068 bytes, checksum: ecb21f712a2b32ecca0a02942022c438 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo deste trabalho foi avaliar os efeitos de injúrias mecânicas, por impacto, compressão e corte, na fisiologia de abacates, através de análises físicas, químicas, bioquímicas e sensoriais, tomografia de ressonância magnética e microscopia eletrônica de varredura. O impacto foi aplicado nos lados opostos do fruto e provocados por queda livre de 2,00 m; a compressão, submetendo-os a pesos de 117,6 N, por 24 horas; e o corte, com quatro incisões longitudinais, com 80 mm de comprimento e 4 mm de profundidade, nos lados opostos do fruto. As diferentes lesões aplicadas aos abacates ocasionaram danos irreparáveis à qualidade dos frutos, onde os efeitos mais nocivos foram encontrados com os cortes. As imagens tomográficas não demonstraram a ocorrência de lesionamento interno em abacates 'Hass', enquanto que os frutos da 'Quintal', submetidos à compressão e ao impacto, apesar de não mostrarem lesões externas, as imagens indicaram a ocorrência de lesionamento interno e a evolução do mesmo durante o amadurecimento. A microscopia eletrônica de varredura mostrou que os tecidos da polpa de abacates 'Quintal' injuriados apresentaram desordem celular em suas estruturas e que eles podem ser protegidos por diferentes processos de cicatrização. / This work aimed to evaluate the effects of mechanical injuries, for impact, compression and cut, in the physiology of avocados, by physical, chemical, biochemical and sensorial analysis, and by use of magnetic resonance imaging and scanning electron microscopy. The impact was applied in the opposed sides of the fruit and provoked by free fall from 2.00 m; compression, submitting them to weights of 117.6 N, for 24 hours; and cut, with four longitudinal incisions, with 80 mm of length and 4 mm of depth, in the opposed sides of the fruit. The different injuries applied to the avocados caused irreparable damages to the quality of these fruits, where the most injurious effects were found for the cuts. The tomography images did not indicate the occurrence of internal injuries in 'Hass' avocados, while the fruits of the 'Quintal', submitted to the compression and the impact, although did not show external lesions, the images indicated the occurrence of internal injuries and evolution of them during the ripening. The scanning electron microscopy showed that 'Quintal' avocados tissues mechanically injured presented cellular disorder in their structures and that they can be protected by different cicatrization processes.
37

Distúrbio fisiológico provocado pelo frio e prevenção com tratamentos térmicos em abacates

Donadon, Juliana Rodrigues [UNESP] 12 February 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-12Bitstream added on 2014-06-13T21:06:48Z : No. of bitstreams: 1 donadon_jr_dr_jabo.pdf: 1135948 bytes, checksum: 6419595edbc660b8ae6be913637b435b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Um dos objetivos deste trabalho foi determinar as combinações entre temperatura e tempo capazes de ocasionar alterações no metabolismo de abacates ‘Hass’, ‘Geada’, ‘Quintal’ e ‘Fortuna’. Os outros objetivos foram: avaliar a influência deste distúrbio na qualidade dos frutos, assim como avaliar o uso de tratamentos hidrotérmicos para minimizar seus efeitos. Abacates colhidos no ponto de maturação “de vez”, da cv Hass, foram armazenados a 5ºC, 10ºC e 15ºC por 7, 14 e 21 dias, no Experimento I, e a 1±0,5°C e 4ºC por 15, 30 e 45 dias, no Experimento II. Os frutos das cvs. Geada, Quintal e Fortuna foram armazenados a 4ºC e 11ºC, por 7, 14, 21 e 28 dias. Ao final de cada período, eles foram transferidos para ambiente a 22ºC. Os frutos foram avaliados durante o armazenamento refrigerado, assim como depois de transferidos ao ambiente. Avaliou-se a aparência, a coloração da casca e da polpa, a perda de massa fresca, a resistência da polpa e os teores de óleo, sólidos solúveis (SS) e acidez titulável (AT). Os frutos armazenados sob refrigeração, quando transferidos ao ambiente, foram comparados com aqueles armazenados a 22ºC (Tratamento testemunha). Depois de amadurecidos, eles foram avaliados quanto ao escurecimento interno e por analistas, quanto a aparência e odor. Nos abacates ‘Hass’, os sintomas de injúria por frio, na forma de manchas escuras, apareceram nos armazenados a 1±0,5°C por 15 ou mais dias, e em frutos armazenados a 4ºC, por 30 ou mais dias. Em abacates ‘Geada’ e ‘Quintal’, essas injúrias ocorreram em frutos armazenados a 4ºC, por períodos superiores a 14 dias, e em ‘Fortuna’, nos armazenados a 4ºC, por 21 dias ou mais. O armazenamento a 10ºC ou acima, somente retardou o amadurecimento. A vida útil dos abacates ‘Hass’, depois de transferidos ao ambiente, foi de 8 - 12 dias, quando armazenados... / One of the objectives of this study was to determine either temperature and time able to cause metabolic modifications of the avocados ‘Hass’, ‘Geada’, ‘Quintal’ and ‘Fortuna’. The other objectives were to evaluate the influence of these disturbances on fruit quality as well as to test the use of hydrothermical treatments in order to minimize their effects. In the Experiment I avocados of cv Hass were harvested at maturity state breaker and stored at 5ºC, 10ºC and 15ºC for 7, 14 and 21 days. In the Experiment II, they were stored at 1±0,5°C and 4ºC for 15, 30 and 45 days. Fruits of cvs. Geada, Quintal and Fortuna were stored at 4ºC and 11ºC, for 7, 14, 21 and 28 days. At the end of each period fruits were transferred to ambient at 22ºC. Fruits were evaluated during cold storage as well as after transference to ambient. The appearance, skin and pulp color, weight loss, firmness and the contents of fat, solid solids (SS) and titratable acidity (TA) were determined. Cold stored fruits when transferred to ambient were compared with control fruits and those stored at 22ºC. After getting ripe, fruit internal browning was determined and the appearance and odor were evaluated by untrained personnel. The symptoms of chilling injury, black spots, of ‘Hass’ avocados appeared when fruits were stored at 1±0,5°C for 15 or more days, and after 30 days when they were stored at 4ºC. The same symptoms occurred in ‘Geada’ and ‘Quintal’ avocados when the fruits were stored at 4ºC for more than 14 days, and on ‘Fortuna’ avocados stored at 4ºC, chilling injury appeared after 21 days. The storage at 10ºC or higher temperatures just retard ripening. The shelf-life of ‘Hass’ avocados, after transference to ambient, was of 8-12 days, when stored at 1±0,5°C or at 4ºC, for up to 30 days. These fruits maintained in good conditions for up to 20 days... (Complete abstract click electronic access below)
38

Efficacy of water soluble silicon for control of phytophthora cinnamomi root rot of avocado

Bekker, Theo Frederik 17 September 2007 (has links)
In the current study potassium silicate (20.7% SiO2) induced a 100% inhibition of P. cinnamomi mycelial growth at all concentrations tested. Total inhibition for all fungi tested (Alternaria solani, Colletotrichum gloeosporioides, Curvularia lunata, Drechslera sp., Fusarium oxysporum, Fusarium solani, Glomerella cingulata, Lasiodiplodia theobromae, Mucor pusillus, Natrassia sp., Pestalotiopsis maculans, Phomopsis perniciosa, Phytophthora capsicii, Phytophthora cinnamomi, Pythium F-group, Sclerotinia sclerotiorum, Sclerotium rolfsii, Stemphylium herbarum and Verticillium tricorpus) was attained at a concentration of 40ml.l-1 and higher. Although the high pH of potassium silicate solutions does contribute to the inhibition of fungal growth, the inhibitory effect of potassium silicate on fungal growth in vitro is mostly fungicidal rather than attributed to a pH effect. Phytophthora root rot of avocado nursery trees can be inhibited successfully by potassium silicate application. The effectiveness of potassium silicate application depends however on the repetition of applications. These findings are of paramount importance as this implies that potassium silicate may be a alternative control measure to inhibit the effects of P. cinnamomi on avocado nursery trees. Silicon either stimulates plant growth or imparts some form of protection to avocado roots if applied prior to P. cinnamomi inoculation. Potassium silicate applied as a soil drench resulted in higher root densities compared to that of potassium phosphonate (Avoguard®) injections and untreated control trees. Reapplication again resulted in the best disease suppression and stimulation of new root growth. These results correlated well with tree canopy ratings, as trees that received silicon frequently, showed better canopy conditions compared to the untreated control treatments. Potassium silicate application leads to effective inhibition of Phytophthora cinnamomi infection in avocado orchards. Potassium silicate application resulted in an increase of crude phenols and phenolic polymers in avocado roots cells to similar levels to that obtained in roots from potassium phosphonate (Avoguard®) treated trees. Potassium silicate application leads to lower cell wall bound phenolics. The results of the current study support the hypothesis that silicon application, through an elevation of the total phenolic levels, causes an increase of resistance against P. cinnamomi root rot in avocados. AFRIKAANS : Kaliumsilikaat (20.7% SiO2) induseer ‘n 100% inhibisie van P. cinnamomi groei by alle getoetste konsentrasies. Totale inhibisie van alle swamme getoets (Alternaria solani, Colletotrichum gloeosporioides, Curvularia lunata, Drechslera sp., Fusarium oxysporum, Fusarium solani, Glomerella cingulata, Lasiodiplodia theobromae, Mucor pusillus, Natrassia sp., Pestalotiopsis maculans, Phomopsis perniciosa, Phytophthora capsicii, Phytophthora cinnamomi, Pythium F-groep, Sclerotinia sclerotiorum, Sclerotium rolfsii, Stemphylium herbarum en Verticillium tricorpus) was verkry by ‘n konsentrasie van 40ml.l-1 en hoër. Alhoewel die hoë pH van kaliumsilikaat wel ‘n inhiberende uitwerking het op swamgroei, is die suksesvolle inhibisie van swamgroei grootliks toe te skryf aan die swamwerende effek van kaliumsilikaat op swamgroei in vitro eerder as ‘n pH effek. Phytophthora wortelvrot van avokado kwekelinge kan suksesvol onderdruk word met kaliumsilikaat toediening. Die effektiwiteit van die toediening hang wel af van die hertoediening daarvan. Hierdie bevindinge is van kardinale belang aangesien dit impliseer dat kalium silikaat ‘n alternatiewe beheer middel is om Phytophthora wortelvrot te inhibeer in avokado kwekelinge. Of silikon stimuleer plant groei, of dit induseer ‘n vorm van beskerming in avokado wortels voor infeksie plaasvind. Kaliumsilikaat toediening as ‘n grond-benatter lei tot hoër worteldigthede in vergelyking met kaliumfosfaat (Avoguard®) staminspuitings en onbehandelde kontrole bome. Hertoediening lewer die beste resultate, maar drie toedienings per seisoen is voldoende. Worteldigdheid verhoging na silikaat toedienings korreleer goed met blaredak gesondheid, aangesien bome wat gereeld behandel is met silikon beter blaredekking getoon het in vergelyking met die kontrole bome. Kaliumsilikaat toediening lei to effektiewe inhibisie van Phytophthora cinnamomi infeksie in avokado boorde. Kaliumsilikaat toediening lei tot ‘n toename in totale fenole en fenoliese polimere in avokado wortel selle tot soortgelyke vlakke soos gevind in avokado weefsel vanaf kaliumfosfaat behandelde bome. terselfdertyd lei silikaat toediening tot laer selwand gebinde fenole. Hierdie resultate ondersteun die hipotese dat kaliumsilikaat toediening, deur die verhoging van oplosbare fenole in avokado wortelselle, die plant se weerstand verhoog, en die effek wat Phytophthora wortelvrot het op avokado plante inhibeer. Copyright / Dissertation (MSc (Agric) Horticulture)--University of Pretoria, 2011. / Plant Production and Soil Science / unrestricted
39

Atividade antioxidante, compostos fenólicos totais e cor em abacate 'hass' submetido a diferentes tratamentos físicos /

Tremocoldi, Maria Augusta, 1983- January 2011 (has links)
Orientador: Rogério Lopes Vieites / Banca: Erica Regina Daiuto / Banca: Severino Matias de Alencar / Resumo: O presente trabalho teve por objetivo determinar a atividade antioxidante, compostos fenólicos totais e cor em abacate 'Hass' submetido ao tratamento térmico, radiação gama e ultravioleta. Após a colheita, os frutos foram selecionados para tornar o lote homogêneo. Foi realizada a caracterização do fruto verde e amadurecido quanto a acidez titulável, pH, umidade, teor de lipídios, cinzas (minerais), proteína (nitrogênio bruto), açúcar total e coloração. Foram realizados 3 experimentos com frutos recém colhidos. Experimento I: imersão dos frutos em água a 45ºC por 5, 10, 15 e 20 minutos; Experimento II: radiação gama nas doses 0,2; 0,4; 0,6 e 1,0kGy e Experimento III: radiação ultravioleta (UVC) por 5, 10, 15 e 20 minutos. Após os tratamentos, os frutos foram armazenados em temperatura ambiente (21ºC±1 e 70±5% de UR) e refrigerado (10ºC±1 e 90±5% de UR). Os frutos foram analisados quanto à capacidade antioxidante pelo método DPPH e compostos fenólicos totais aos 0, 3, 9 e 12 dias. A coloração foi avaliada aos 0, 3, 6, 9, 12 e 15 dias. Os resultados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey ao nível de 1% de probabilidade. Nas condições em que os experimentos foram realizados, pode-se concluir que os frutos do tratamento testemunha e mantidos sob refrigeração apresentaram maior capacidade antioxidante e teor de compostos fenólicos totais ao longo do período de armazenamento; o tratamento térmico por 5 e 10 minutos foi efetivo na manutenção da capacidade antioxidante e dos compostos fenólicos; a dose de 0,6kGy não foi efetiva na manutenção da capacidade antioxidante; a radiação ultravioleta (UV-C) não manteve a capacidade antioxidante dos frutos, no entanto ocasionou aumento na quantidade de compostos fenólicos; o tratamento térmico e a radiação ultravioleta não afetaram a coloração da polpa / Abstract: This study aimed to determine the antioxidant activity, total phenolic compounds and color in avocado 'Hass' submitted to heat treatment, gamma and ultraviolet radiation. After harvest, fruits were selected to make the homogeneous portion. The characterization was performed of the green fruit and mature as acidity, pH, moisture, lipids, ash (minerals), protein (nitrogen gross), total sugar and coloring. 3 experiments were performed with freshly harvested fruits. Experiment I: immersion of fruits in water at 45 ° C for 5, 10, 15 and 20 minutes; Experiment II: gamma radiation doses 0.2, 0.4, 0.6 and 1.0 kGy and Experiment III: ultraviolet radiation (UV-C) for 5, 10, 15 and 20 minutes. After treatments, fruits were stored at room temperature (21±1ºC and 70±5% HR) and refrigeration (10ºC±1 and 90±5% HR). The fruits were analyzed for their antioxidant capacity by DPPH method and phenolic compounds at 0, 3, 9 and 12 days. The color was measured at 0, 3, 6, 9, 12 and 15 days. Data were subjected to analysis of variance and mean comparison using Tukey's test at 1% probability. In conditions where the experiments were performed, one can conclude that the fruits of control treatment and kept under refrigeration had higher antioxidant capacity and content of phenolic compounds during the storage period, the heat treatment for 5 and 10 minutes was effective the maintenance of antioxidant capacity and phenolic compounds, the dose of 0.6 kGy was not effective in maintenance the antioxidant capacity, ultraviolet radiation (UV-C) did not maintain the antioxidant capacity of fruits, however caused an increase in the content of phenolic compounds, heat treatment and ultraviolet radiation did not affect the pulp color / Mestre
40

Evaluation of the nutritional composition of noodles made from the partial substitution of wheat flour for Persea americana (avocado) shell flour

Castro Miranda, Angela Zarela, Reyes Suarez, Natalia Rebeca 12 April 2021 (has links)
. / Introduction: The present study aimed to take advantage of residues such as the Persea Americana (avocado) peel to obtain flour used in the preparation of a food of high consumption in the Peruvian population, noodles. Objectives: To evaluate the nutritional composition of the production of noodles by partially substituting wheat flour for Persea Americana shell flour. Methods: Laboratory study carried out in the laboratories of the Peruvian University of Applied Sciences (UPC) and Certificaciones Del Perú CERPER. Results: Titratable acidity (1.0), ash (2.85), fiber (50.08) and moisture (6.89) were determined in avocado peel flour. Wheat flour was substituted for avocado peel flour at 0, 10, 15 and 20%, being F0, F1, F2 and F3 respectively. In F0, ash (0.56), moisture (32.7), proteins (10.13), fats (3), fiber (0.85) and carbohydrates (53.49) were determined. In F1 ashes (0.76), moisture (35.60), proteins (9.68), fats (3.20), fiber (3.44) and carbohydrates (50.76). F2 ashes (0.85), moisture (37.25), proteins (9.23), fats (3.11), fiber (5.18) and carbohydrates (49.56). Finally, F3 ashes (0.94), moisture (41.21), proteins (7.71), fats (2.66), fiber (9.88) and carbohydrates (47.48).  Conclusions: Flour and noodles met the characteristics stipulated by Peruvian Technical Standards (NTP 205.053:1987 y NTS 071-2008 DIGESA - MINSA) and CODEX (Codex Stan 152-1985). The fiber in the final product was highlighted and the microbiological parameters requested by DIGESA - MINSA were met. / Introducción: El presente estudio tuvo como finalidad aprovechar residuos como la cáscara de Persea Americana (palta) para la obtención de harina usada en la elaboración de un alimento de alto consumo en la población peruana, fideos. Objetivo general: Evaluar la composición nutricional de la elaboración de fideos mediante sustitución parcial de harina de trigo por harina de cáscara de Persea Americana. Métodos: Estudio de laboratorio realizado en los laboratorios de la Universidad Peruana de Ciencias Aplicadas (UPC) y Certificaciones Del Perú CERPER. Resultados: En la harina de cáscara de palta se determinó acidez titulable (1.0), cenizas (2.85), fibra (50.08) y humedad (6.89). Se realizaron sustituciones de harina de trigo por harina de cáscara de palta al 0, 10, 15 y 20%, siendo F0, F1, F2 y F3 respectivamente. En F0 se determinó cenizas (0.56), humedad (32.7), proteínas (10.13), grasas (3), fibra (0.85) y carbohidratos (53.49). En F1 cenizas (0.76), humedad (35.60), proteínas (9.68), grasas (3.20), fibra (3.44) y carbohidratos (50.76). F2 cenizas (0.85), humedad (37.25), proteínas (9.23), grasas (3.11), fibra (5.18) y carbohidratos (49.56). Finalmente, F3 cenizas (0.94), humedad (41.21), proteínas (7.71), grasas (2.66), fibra (9.88) y carbohidratos (47.48). Conclusiones: Harina y fideos cumplieron con características estipuladas por Normas Técnicas Peruanas (NTP 205.053:1987 y NTS 071-2008 DIGESA - MINSA) y las normas CODEX (Codex Stan 152-1985). Se destacó la fibra en el producto final y se cumplió con los parámetros microbiológicos solicitados por DIGESA - MINSA. / Tesis

Page generated in 0.3872 seconds