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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

Efecto del tratamiento térmico durante el proceso de refrigeración, congelación y pasteurización sobre la capacidad antioxidante y contenido de compuestos fenólicos totales en fresas (Fragaria × ananassa)

Salgado, Adalis, Spencer, Sonia 26 May 2020 (has links)
Objetivo: Determinar el efecto del tratamiento de conservación térmica en el tiempo sobre la capacidad antioxidante y contenido de compuestos fenólicos totales en fresas (Fragaria × ananassa). Diseño: El presente estudio es de tipo experimental dentro del área de bioquímica de alimentos, debido a que vamos a evaluar parte de los compuestos bioquímicos de las fresas y su acción en procesos biológicos del organismo humano.
2

Aplicação de ozônio e de revestimentos comestíveis em morangos (Fragaria ananassa Duch.) minimamente processados / Application of ozone and edible coatings in strawberries (Fragaria ananassa Duch.) minimally processed

Holtz, Selma Garcia 25 July 2006 (has links)
Made available in DSpace on 2015-03-26T13:51:53Z (GMT). No. of bitstreams: 1 texto completo.pdf: 415623 bytes, checksum: 471cf69a811d3d23a327523b69e77068 (MD5) Previous issue date: 2006-07-25 / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / The culture of the strawberry (Fragaria ananassa Duch.) shows economic and social importance to Minas Gerais. This product is very much perishable. The minimum processing of strawberry is an alternative of commercialization. However, the washing and humid sanitization favors fungal growth. The sanitization with gaseous ozone and application of edible coatings are technologies that can be used in minimum processing of strawberries. The goal of this work was to adjust the technology of minimum processing of strawberry and to keep microbiological and physico-chemistry qualities of the product. The efficiency of methods of hygienic cleaning in the reduction of the initial contamination of the strawberries by aerobic mesophilic, molds, yeasts and total and thermotolerants coliforms was compared. The strawberries had been cleaned with air spurt and sanitized with ozone during 30 and 60 min. Washing of the strawberries in water followed of sanitization with chlorinated organic solution was also evaluated. The effect of the edible coatings application in the increase of the shelf-life of the minimally processed strawberries was evaluated. Camarosa organic strawberries had been harvested and selected following the manual removal of the calix. They had been submitted to the sanitization treatments with ozone or chlorinated organic solution, followed of cassava or maize starch edible coating. The strawberries had been packed and cooled 5° C for 15 days. The microbiological quality of the product was analyzed by aerobic and anaerobic mesophiles, psychrotrophic, molds and yeasts plate count and by the total and thermotolerants coliforms determination. Alterations of color express by the browning index and the total difference of color, pH, total soluble solids, firmness of the pulp, weight loss and total vitamin C, were evaluated too. All the comparisons had been made by the Analysis of Variance 5% of probability, with significance between the averages analyzed for the Tukey test. The initial population of aerobics mesophiles was reduced in the strawberries cleaned with air spurt and sanitized with ozone for 60 min. Molds and yeasts had been reduced with 30 and 60 min of ozonation. It did not have significant reduction of these microorganisms in the strawberries washed in water and, or sanitized with organic chlorinated solution. The biggest number of total coliforms was 1100 MPN/g, detected in the strawberries only cleaned with air spurt. Thermotolerants coliforms had not been detected in analyzed sample. The population of molds and yeasts presented minor variation during the storage, in the strawberries sanitized with gaseous and coated with maize starch, not having effect of the treatments on the populations of the other microorganisms. Browning index, pH, total soluble solids and firmness of the pulp had not varied in the strawberries sanitized with ozone or organic chlorinated solution and that had received or not edible coatings. The content of vitamin C was kept until 7° day of storage in the strawberries of all the treatments. The total difference of color and the weight loss had been lesser in the strawberries only ozonated. Is concluded that, in the conditions of this study, the ozonation for 60 min was efficient: (i) to reduce the initial contamination for aerobic mesophilics, (ii) to minimize the color and weight losses and (iii), to control molds and yeasts of the minimally processed strawberries when associated to the edible coating of starch maize, keeping the shelf-life of the product for a period of seven to ten days. / A cultura do morango (Fragaria ananassa Duch.) é importante econômica e socialmente no Estado de Minas Gerais e o pseudofruto é muito perecível. O processamento mínimo do morango é uma alternativa para a comercialização, porém, a lavagem e sanitização por via úmida favorecem o crescimento fúngico. A sanitização com ozônio gasoso e a aplicação de revestimentos comestíveis são tecnologias que podem ser empregadas no processamento mínimo do morango. O objetivo deste trabalho foi adequar tecnologia de processamento mínimo de morango visando manter a qualidade microbiológica e físico-química do produto. Comparou-se a eficiência de métodos de higienização na redução da contaminação inicial dos morangos por mesófilos aeróbios, fungos filamentosos e leveduras e por coliformes totais e termotolerantes. Os morangos foram limpos com jato de ar e sanitizados com gás ozônio durante 30 e 60 min. Avaliou-se também a lavagem dos morangos com água seguida da sanitização com composto clorado orgânico. O efeito da aplicação de revestimentos comestíveis no aumento da vida útil dos morangos minimamente processados foi avaliado. Morangos orgânicos, cultivar Camarosa , foram colhidos e selecionados, seguindo-se a retirada manual do cálice. Então, foram submetidos aos tratamentos de sanitização com ozônio gasoso ou clorado orgânico, seguido de revestimento de fécula de mandioca ou de amido de milho. Os morangos foram embalados e refrigerados a 5 °C, por 15 dias. A qualidade microbiológica do produto foi analisada pelas contagens padrão de mesófilos aeróbios e anaeróbios, psicrotróficos, fungos filamentosos e leveduras e pela determinação do número de coliformes totais e termotolerantes. Alterações de cor expressa pelo índice de escurecimento e pela diferença total de cor, pH, sólidos solúveis totais, firmeza da polpa, perda de massa e vitamina C total também foram avaliadas. Os dados obtidos foram submetidos a Análise de Variância a 5% de probabilidade, com a significância entre as médias comparadas pelo teste Tukey. A população inicial de mesófilos aeróbios foi reduzida nos morangos limpos com jato de ar e sanitizados com ozônio por 60 min. Fungos filamentosos e leveduras foram reduzidos com 30 e 60 min de ozonização. Não houve redução significativa desses microrganismos nos morangos lavados em água e, ou sanitizados com solução clorada. O Número Mais Provável de coliformes totais foi de até 1100/g, determinados nos morangos limpos com jato de ar. Coliformes termotolerantes não foram detectados em nenhuma amostra analisada. Nos morangos sanitizados com ozônio e revestidos com amido de milho a população de fungos filamentosos e de leveduras apresentou menor variação durante o armazenamento, não havendo efeito dos tratamentos sobre as populações dos outros microrganismos. Os valores referentes ao índice de escurecimento, pH, sólidos solúveis totais e firmeza da polpa não variaram nos morangos sanitizados com ozônio ou clorado orgânico e que receberam ou não revestimentos comestíveis. O teor de vitamina C foi mantido até o 7° dia de armazenamento nos morangos de todos os tratamentos. A diferença total de cor e a perda de massa foram menores nos morangos ozonizados. Concluiu-se que, nas condições deste estudo, a ozonização por 60 min foi eficaz para reduzir a contaminação inicial por mesófilos aeróbios, minimizar as perdas de cor e de massa e, associada ao revestimento de amido de milho, controlar fungos e leveduras dos morangos minimamente processados, preservando a qualidade microbiológica e físico-quimica do produto, por um período de sete a dez dias.
3

Organic production of strawberries : focus on practical applications /

Berglund, Rakel, January 2007 (has links) (PDF)
Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniversitet, 2007. / Härtill 4 uppsatser.
4

Biofilmes a base de amido, gelatina e extrato de Tetradenia riparia na conservação de morango / Biofilms based on starch, gelatine and Tetradenia riparia extract on strawberry conservation

Friedrich, Jussara Carla Conti 02 March 2017 (has links)
Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2017-09-28T20:16:38Z No. of bitstreams: 1 Jussara_C_C_Friedrich_2017.pdf: 2490952 bytes, checksum: b514f94e0cb058f511bb4a2167bd8821 (MD5) / Made available in DSpace on 2017-09-28T20:16:38Z (GMT). No. of bitstreams: 1 Jussara_C_C_Friedrich_2017.pdf: 2490952 bytes, checksum: b514f94e0cb058f511bb4a2167bd8821 (MD5) Previous issue date: 2017-03-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Strawberry is a non-climacteric pseudofruit and has a short shelf life after harvest. Among the factors responsible for the loss of quality of strawberries are high metabolic activity and high susceptibility to microbial attack. Therefore, studies with edible coverings or coverings are being one of the most appropriate alternatives to assist in the post harvest conservation of fruits, especially non-climacteric ones such as strawberry. These coatings have excellent barrier properties, mainly to the transport of gases and water vapor, among other factors that contribute to the maintenance of fruit quality. Therefore, the objective of this work was to evaluate the effect of edible films produced from gelatine, native starch, sorbitol and Tetradenia riparia extract (antimicrobial agent) in the post harvest harvesting of strawberries (Fragaria ananassa). The films were analyzed for thickness, solubility, opacity, colorimetry, TVA (water vapor transmission) and mechanical analysis. The films that received the addition of Tetradenia riparia extract became thicker with lower solubility and opacity, and greater luminosity. These data corroborated the mechanical analysis, in which the films with extract were more elastic, in addition, it was necessary to apply a greater force to break, that is, more resistant. Regarding the fruits, the analyzes were performed on alternate days, during 10 days of storage, under temperature and humidity of refrigerator with temperature of 8ºC at 10ºC and relative humidity of approximately 75%, being evaluated the loss of mass, microbiological analysis, analysis Antioxidant, calorimetry, vitamin C contents, total soluble solids (TSS), titratable total acidity (TTA) and the relationship between both SST / ATT. The loss of mass increased with the prolongation of the storage, that is to say, when adding the extract of Tetradenia riparia both in medium and in high inhibition the losses of mass of the fruits were superior to 10% in the 4th day of storage, for the two treatments mentioned above. As for the contents of total soluble solids and titratable total acidity the contents increased with the increase of the storage period, this fact may be related to the respiratory process and consumption of organic acids. Regarding the vitamin C content, only the treatments that did not receive the addition of extract continued to increase the contents at the end of the experiment. This proves the importance of using biofilm as a protective agent, it is also observed that these fruits that the coloration decreases, leaving the less looking less shiny. Microbiological analysis showed that the most effective treatment was the high inhibition of starch film (FAAI), that is, 500 μg / ml of Tetradenia riparia extract was enough to decrease the number of colony forming units at the end of experiment. For the antioxidant activity it was observed that the most efficient treatments were those with the addition of T. riparia extract to the films that is, when adding 500μg / ml or 1000μg / ml, they presented a decrease of the antioxidant activity, indicating that the Extract may reduce metabolic activity and delay fruit senescence. / O morango é um pseudofruto não climatérico e que tem uma curta vida útil após a colheita. Entre os fatores responsáveis pela perda de qualidade dos morangos estão alta atividade metabólica e alta susceptibilidade ao ataque microbiano. Diante disso, estudos com revestimentos ou coberturas comestíveis estão sendo uma das alternativas mais apropriada para auxiliar na conservação pós colheita de frutas principalmente as não climatéricas como é o caso do morango. Estes recobrimentos podem possuir excelentes propriedades de barreira, principalmente ao transporte de gases e vapor de água, entre outros fatores que contribuem para manutenção da qualidade do fruto. Desta forma, o objetivo deste trabalho foi avaliar o efeito de filmes comestíveis produzidos a partir de gelatina, amido nativo, sorbitol e extrato de Tetradenia riparia (agente antimicrobiano) na conservação de morangos em pós- colheita. Os filmes foram analisados em relação à espessura, solubilidade, opacidadade, colorimetria, TVA (transmissao de vapor de agua) e análise mecânica. Em relação aos frutos, as análises foram realizadas em dias alternados, durante 10 dias de armazenamento, sob refrigeracão com temperatura de 8ºC á 10ºC e umidade relativa de aproximadamente 75%, sendo avaliados a perda de massa, análise microbiológica, análise antioxidante, calorimetria, vitamina C, sólidos solúveis totais (SST), acidez total titulável (ATT) SST/ATT. Os filmes que receberam a adição do extrato de Tetradenia riparia tornaram-se mais espessos com menor solubilidade e opacidade, e maior luminosidade. Estes dados corroboraram a análise mecânica, em que, os filmes com extrato mostraram-se mais elásticos, além disso, foi necessário aplicar uma força maior para que se rompesse, ou seja, mais resistentes. A perda de massa aumentou com o prolongamento do armazenamento, ou seja, ao adicionar o extrato de T. riparia tanto em média quanto em alta concentracao as perdas de massa dos frutos foram superiores a 10% no 4º dia de armazenamento, para os dois tratamentos citados acima. Quanto aos teores de sólidos solúveis totais e acidez total titulável os teores aumentaram com o aumento do período de armazenamento. Em relação ao teor de vitamina C, apenas os tratamentos que não receberam a adição de extrato continuaram a aumentar os teores ao final do experimento. Isto comprova a importância da utilização de biofilme como agente de proteção, também observa-se que estes frutos que a coloração diminui, deixando os menos com aspecto menos brilhante. A análise microbiologica mostrou que o tratamento mais eficaz, foi o filme de amido com alta concentracao de extrato (FAAI), ou seja, 500µg/ml de extrato de T. riparia foi o suficiente para diminuir o número de unidades formadoras de colônias ao final do experimento. Para a atividade antioxidante observou-se que os tratamentos mais eficientes foram aqueles com a adição de extrato de T. riparia aos filmes, ou seja ao adicionar 500µg/ml ou 1000µg/ml, os mesmos apresentaram uma diminuição da atividade antioxidante, indicando que o extrato pode reduzir a atividade metabólica e retardar a senescência dos frutos.
5

Host Plant Resistance in Strawberries to Anthracnose and Colonization of Crown and Root Tissue by Verticillium dahliae and Macrophomina phaseolina

Gonzalez-Benitez, Omar A 01 June 2020 (has links) (PDF)
Strawberries are considered an important crop in California where in 2018 it was in the top 5 valued fruit and vegetable commodities valued at $2.84 billion accounting for 88% of the total U.S. production. Strawberry production can be severely impacted by soilborne pathogens that can affect strawberry roots, crowns and leaves which can result in plant mortality. As much as 50 to 60% mortality can occur in one field. Pathogens responsible for such losses include Colletotrichum acutatum (syn.C. nymphaeae), Macrophomina phaseolina and Verticillium dahliae. With the phaseout of methyl bromide, host resistance and an understanding of host-pathogen interactions can play an important role in control of these diseases. A two-year study was conducted in order to evaluate host resistance of anthracnose in 105 cultivars and elite breeding lines developed by six strawberry breeding programs. Cultivars and elite breeding lines were inoculated using three local isolates in both years. All breeding programs provided genotypes that had a wide range of anthracnose susceptibility ranging from 0 to 100% mortality during both years. In both years an average of 78% of all the plant mortality occurred by 1 January. From the 105 cultivars and elite breeding lines, 30 cultivars were common to both years. Of these 30 cultivars, nine of them differed in their disease susceptibility between experiments by more than 20%. This suggests that several years of field evaluation may be necessary to determine susceptibility to anthracnose. Popular cultivars that represent the spectrum of susceptibility are Monterey (susceptible), Festival (moderately resistant), and Sensation (resistant). A second study was conducted toevaluate pathogen colonization of resistant and susceptible strawberry cultivars, testing interactions among crown and root plant tissue and two sampling timings. These cultivars were challenged with two soilborne pathogens, Macrophomina phaseolinaand Verticillium dahliae,over two years. Existing qPCR protocols for M. phaseolina and V. dahliae were used in order to quantify how much pathogen DNA was detected in crown and root samples. For the 2016-2017 V. dahliae trial there were significant effects for cultivar. Cultivar Benicia had significantly higher pathogen DNA compared to resistant cultivars Marquis, UC-12 and Camino Real. Susceptible cultivar BG 1975 had significantly less pathogen DNA compared to resistant cultivars San Andreas and Petaluma. In the 2017-2018 V. dahliaetrial pathogen DNA amount was not significantly different based on cultivar, plant part colonization, or the sampling period. In the 2017-2018 M. phaseolina trial all three of the fixed factors, cultivars, plant part colonization and sampling period were statistically significant. Cultivar ‘Sweet Ann’ had a significantly higher level of M. phaseolinaDNA in the early vs. the late sampling.
6

Produção de mudas de morangueiro fora do solo sob diferentes concentrações de nitrogênio nas matrizes e datas de plantio das mudas na região sul do RS / PRODUCTION OF SEEDLINGS OF STRAWBERRY OUT OF THE SOIL UNDER DIFFERENT CONCENTRATIONS OF NITROGEN IN THE MATRICES, AND DATES OF PLANTING OF SEEDLINGS IN THE SOUTHERN REGION OF RS.

Becker, Tais Barbosa 03 March 2017 (has links)
Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2017-03-31T13:45:54Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação Tais Barbosa Becker.pdf: 1060596 bytes, checksum: 0f90b7287d92bbaef370fc137f99cea5 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-04-24T13:09:51Z (GMT) No. of bitstreams: 2 Dissertação Tais Barbosa Becker.pdf: 1060596 bytes, checksum: 0f90b7287d92bbaef370fc137f99cea5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-24T13:09:51Z (GMT). No. of bitstreams: 2 Dissertação Tais Barbosa Becker.pdf: 1060596 bytes, checksum: 0f90b7287d92bbaef370fc137f99cea5 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / A fase de produção de mudas é uma etapa importante dentro da cadeia produtiva do morangueiro, uma vez que as plantas em cultivo no solo precisam ser renovadas anualmente, devido ao acúmulo de doenças e pragas de um ano de cultivo para outro, acarretando em baixa produtividade. O estudo teve como objetivo avaliar o efeito da concentração de nitrogênio na produção e na qualidade de mudas envasadas (com torrão) produzidas a partir de matrizes suspensas cultivadas fora do solo e avaliar o comportamento dessas mudas no campo com diferentes datas de plantio para Pelotas-RS. Os fatores avaliados foram: cultivar (Aromas, Camarosa, Festival e Oso Grande), solução nutritiva (padrão ‘1’ e metade da quantidade de nitrogênio ‘2’) no experimento 1 e cultivar (Aromas, Camarosa, Festival e Oso Grande) e datas de plantio (16/03; 01/04 e 01/04) no experimento 2, conduzidos em área experimental pertencente a Embrapa Clima Temperado, em Pelotas, RS, durante os anos de 2015 e 2016. O sistema de produção de mudas fora do solo estudado neste período é eficiente, pois as cultivares Camarosa, Festival e Oso Grande expressam seu potencial produtivo, no que diz respeito ao elevado número de propágulos produzidos pela planta-matriz, obtido em Pelotas-RS. Além de fornecer plantas antecipadamente para a cadeia de produção. A menor quantidade de nitrogênio fornecida favorece maior produção de estolões e mudas por planta matriz. O plantio entre março e abril (precoce para a região, pois normalmente ocorre entre o final de maio e início de junho, quando as mudas importadas chegam aos produtores) é uma alternativa viável aos produtores, para obter uma produção precoce em um período em que o produto é mais valorizado. As produções obtidas são altas, e quanto mais antecipada a data de plantio maior a produção por planta, sendo 'Camarosa' e 'Festival' as cultivares mais produtivas nas condições do estudo. / The seedling production phase is an important step in the strawberry production chain, since the plants in soil cultivation need to be renewed annually, due to the accumulation of diseases and pests from one year of cultivation to another, resulting in low productivity. The study aimed to evaluate the effect of nitrogen concentration on the production and quality of botted plant produced from suspended matrices under cultivation soilless and assess the behavior of these seedlings in the field with different planting dates for the Pelotas-RS city. The evaluated factors were: cultivar (Aromas, Camarosa, Festival and Oso Grande), nutrient solution (standard '1' and half of the amount of nitrogen '2') in experiment 1 and cultivar (Aromas, Camarosa, Festival and Oso Grande), and planting dates (03/16, 04/01 and 04/16) in experiment 2, conducted in an experimental area belonging to Embrapa Clima Temperado, in Pelotas, RS, during the years of 2015 and 2016. The system of production of seedlings soilless studied in this period is efficient, because the cultivars Camarosa, Festival and Oso Grande express their productive potential, in relation to the high number of propagules produced by the matrix plant, obtained in PelotasRS. In addition to supplying plants in advance to the production chain. The smaller amount of nitrogen provided favors greater production of stolons and seedlings per plant. Planting between march and april (early for the region, normally occurs between the May late and early June, when the imported seedlings arrive to the growers) is a viable alternative to the growers, to obtain an early production and in a period in which the product is more valued and reach more profit. The early and total productions obtained are high, and how more anticipated the plantinning date is better production per plant is obtained, being 'Camarosa' and 'Festival' the most productive under the conditions of the study.

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