Made available in DSpace on 2014-08-20T14:22:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-02 / Blueberry cultivars of rabbiteye group Bluegem, Briteblue, and Woodard are characterized by having low chilling requirement, high vigor and productivity, being able to be produced in region of Southern Brazil. Studies on cultural practices and field performance in blueberry are recent in Brazil. In order to provide more accurated informations to the growers of this fruit crop, experiments were carried out during 2009 and 2010 in a high potential region. The first experiment was carried out in a didactic orchard at the Federal University of Pelotas (Rio Grande do Sul State), and the objective was to study the field behavior of the blueberries propagated by two different techniques. Evaluations on vegetation, production, and fruit quality aspects were done in order to determine the effect of rejuvenation obtained through micropropagation technique. One year-old plants of blueberry, cultivars Bluegem, Briteblue, and Woodard, obtained from micropropagation and semi-hardwood cuttings were used. It was found that micropropagated plants showed a high initial vegetative growth, and both productivity and fruit quality similar to plants propagated by cuttings. In the second experiment, conducted in a commercial orchard located in the same city of the first experiment, it was tested different intensities of pruning on production and fruit quality aspects. Seven years-old plants, cultivars Briteblue and Woodard were used. They were pruned during the winter rest period in different intensities (low, moderate, drastic and control), and the control (no pruning). Blueberry plants which were not pruned showed high productivity, but produced smaller fruits. The moderate pruning system showed the best results. / As cultivares de mirtileiro Bluegem, Briteblue e Woodard pertencem ao grupo rabbiteye e caracterizam-se pela baixa exigência em frio, elevado vigor e alta produtividade, sendo aptas a serem produzidas nas condições do Sul do Brasil. No país ainda são recentes os estudos relativos ao manejo do pomar de mirtileiro e suas características a campo. Na tentativa de oferecer informações mais precisas aos produtores desta cultura, foram conduzidos dois experimentos durante os anos de 2009 e 2010 em região com potencial produtivo. O primeiro experimento foi conduzido em pomar didático pertencente à Universidade Federal de Pelotas, e o objetivo foi estudar o comportamento a campo de mirtileiros propagados por duas diferentes técnicas, avaliando-se aspectos vegetativos, produtivos e de qualidade dos frutos, a fim de constatar o efeito do rejuvenescimento obtido através da técnica de micropropagação. Para isso, realizou-se o plantio de mudas de mirtileiro com um ano de idade das cultivares Bluegem, Briteblue e Woodard, propagadas in vitro e por estaquia semilenhosa. Foi constatado que plantas micropropagadas apresentam, a campo, crescimento vegetativo inicial superior, além de produtividade e qualidade de frutos semelhantes às plantas propagadas por estaquia. No segundo experimento, conduzido em um pomar comercial localizado no mesmo município do primeiro, foram testadas diferentes intensidades de poda de frutificação e avaliados aspectos produtivos e de qualidade de frutos. Foram utilizadas plantas com sete anos de idade, das cultivares Briteblue e Woodard, que foram podadas no período de repouso hibernal em intensidades distintas (leve, moderada, drástica e testemunha). Plantas de mirtileiro não podadas apresentaram produtividade superior, porém produziram frutos de menor tamanho. O sistema de poda moderado foi o que apresentou melhores resultados.

O mirtilo (Vaccinium spp.) é um fruto ainda pouco conhecido no Brasil, porém com grande potencial produtivo no Estado do Rio Grande do Sul (RS). Estudos relatam propriedades benéficas à saúde e elevada capacidade antioxidante deste fruto, associadas à presença de compostos bioativos, especialmente os antociânicos. O presente trabalho teve por objetivos caracterizar o mirtilo orgânico Rabbiteye, cultivado no RS, e seus produtos derivados, bem como avaliar a estabilidade das antocianinas e da capacidade antioxidante no armazenado sob refrigeração (4 ºC) de suco integral de mirtilo por dez dias, no congelamento dos frutos (-18 ºC) durante seis meses e na desidratação do mirtilo (a 70, 80 e 90 ºC). Para isso, realizaram-se análises físico-químicas, mediu-se a atividade antioxidante, através dos métodos DPPH e ABTS, e determinou-se o conteúdo de antocianinas por cromatografia líquida e espectroscopia. O mirtilo cultivado no RS apresentou capacidade antioxidante superior a de outros frutos e sucos. Quanto às antocianinas, os frutos obtiveram média superior ou inferior à de mirtilos de outras espécies e origens, porém sendo encontradas similaridades no perfil. Tanto as passas quanto o bagaço e a farinha produzida pela secagem deste resíduo sofreram perdas no processamento, mas retendo ainda grande quantidade de compostos antociânicos e atividade antioxidante. Durante o congelamento, os frutos apresentaram aumento significativo (p<0,05) na atividade antioxidante no terceiro mês, sofrendo queda ao final de seis meses, porém mantendo ainda valor superior ao “in natura”. O suco foi analisado a cada dois dias e teve a atividade antioxidante afetada a partir do oitavo dia de armazenamento, permanecendo constante até o décimo dia. As antocianinas sofreram perdas significativas tanto no congelamento dos frutos (59 %) quanto na refrigeração do suco (83 %), porém algumas degradando mais do que outras, provavelmente por diferenças na estrutura química. A capacidade antioxidante do mirtilo aumentou durante a primeira metade do tratamento térmico a 80 ºC e, após 3 h, sofreu redução significativa (p<0,05) até o final do processo. As antocianinas apresentaram tempo de meia-vida médio de 7,7 h e 6,8 h para as secagens a 70 e 80 ºC, respectivamente. A estabilidade dos compostos bioativos está relacionada tanto com a magnitude quanto com a duração do tratamento térmico. Mais estudos são necessários a fim de otimizar o tempo e a temperatura de estocagem e processamento de tais produtos. / Blueberry (Vaccinium spp.) is a little-known fruit in Brazil, but with great productive potential in the state of Rio Grande do Sul (RS). Studies have reported properties beneficial to the health and high antioxidant capacity of this fruit, associated with the presence of bioactive compounds, especially anthocyanins. This study aimed to characterize the organic Rabbiteye blueberry grown in RS, and their products, as well as evaluating the stability of anthocyanins and antioxidant capacity of whole blueberry juice stored under refrigeration (4 °C) for ten days, of fruits stored frozen (-18 °C) for six months and of the dehydration of blueberries (at 70, 80 and 90 °C). For this, physicochemical analyses were carried out, the antioxidant activity was measured through DPPH and ABTS methods, and the content of anthocyanins was determined by liquid chromatography and spectroscopy. Blueberries grown in RS showed higher antioxidant capacity than other fruits and juices. For anthocyanins, the fruits had higher or lower average than other species of blueberries and origins, but similarities had been found in the profile. Both dried fruit and pomace, as well as the flour produced by drying of this residue, they all suffered losses in their process, but still retaining large amounts of anthocyanins and antioxidant activity. During freezing, the fruits showed a significant increase (p<0,05) in antioxidant activity in the third month, decreasing in the end of six months, although still maintaining a value higher than that of the “in natura” fruit. The juice was analyzed every two days and the antioxidant activity was affected in the eighth day of storage, remaining stable up to the tenth day. Anthocyanins have suffered significant losses in both frozen fruits (59 %) and refrigerated juice (83 %), but some degrading more than others, probably due to differences in their chemical structure. The antioxidant capacity of blueberry increased during the first half of the heat treatment at 80 °C, and after 3 h was significantly decreased (p<0,05) til the end of the process. Anthocyanins showed half-life average about 7,7 h and 6,8 h for drying at 70 °C and 80 °C, respectively. The stability of bioactive compounds is related to both the magnitude and duration of heat treatment. Further studies are needed to optimize the time and temperature of storage and processing of such products.

O aquecimento ôhmico consiste na passagem de corrente elétrica alternada através de um alimento, transformando energia elétrica em energia térmica, promovendo, assim, um aumento de temperatura em seu interior. A habilidade desse método de gerar calor internamente no alimento permite que o aumento de temperatura seja rápido e uniforme. Essa habilidade resulta em um produto de maior qualidade, tornando a tecnologia de aquecimento ôhmico uma alternativa aos processos convencionais. O mirtilo é rico em compostos fenólicos, dentre esses estão as antocianinas. As antocianinas são compostos fenólicos com alto potencial antioxidante, sendo esse potencial relacionado a efeitos benéficos para a saúde humana no tratamento e prevenção de diversas doenças. O objetivo deste trabalho foi elaborar um sistema de aquecimento ôhmico em escala de bancada e utilizá-lo no tratamento térmico da polpa de mirtilo, visando avaliar o efeito deste processo na degradação das antocianinas. Para tal, foi investigado o efeito da tensão (160–240 V) e do teor total de sólidos (4–16 %), utilizando um planejamento composto central. Foram determinadas algumas propriedades físicas do produto para posterior modelagem do processo. O sistema de aquecimento ôhmico construído opera em batelada e é composto por um variador de tensão, um sistema de aquisição de dados para monitoramento de temperatura, corrente elétrica e tensão e uma célula ôhmica. O teor total de antocianinas foi quantificado prévia e posteriormente ao aquecimento ôhmico, utilizando as metodologias de cromatografia líquida de alta eficiência e a espectrometria. O sistema de aquecimento ôhmico teve desempenho e validação satisfatórios. A degradação de antocianinas do mirtilo variou entre 5,71 e 14,67% nas faixas de tensão e de concentração de sólidos estudadas. O planejamento experimental demonstrou que apenas a tensão exerceu efeito significativo sobre a degradação. O aquecimento ôhmico, quando realizado utilizando altas tensões, apresentou níveis de degradação superiores ao aquecimento convencional. Por outro lado, quando aplicadas tensões mais baixas, a degradação de antocianinas foi inferior à apresentada pelo tratamento convencional. / Ohmic heating is based on the passage of alternating electrical current through food, transforming electrical energy in thermal energy, promoting an increase in temperature. The ability of this method in generating heat from inside the product, allows the heating process to be fast and homogeneous. This ability results in a product of superior quality and presents itself as an alternative to conventional processing. Blueberry fruits contain an array of phenolics, including anthocyanins. Anthocyanins are phenolic compounds with high antioxidant capacity, being this potential related to benefits to human health in the treatment and prevention of several diseases. The aim of this work was to elaborate a bench ohmic heating system and apply it in the thermal treatment of blueberry pulp, in order to evaluate the effect of this process on anthocyanin degradation. For this purpose, the influence of different voltages (160–240 V) and total solids content (4–16 %) was evaluated using a central composite design. Some of the pulp physical properties were evaluated for posterior process modeling. The ohmic heating apparatus, operates in batch configuration and it consists of a voltage regulator; a system for temperature, tension and electrical current data acquisition; and an ohmic heating cell in which the pulp was inserted. Total anthocyanin content was determined previously and after ohmic heating by high performance liquid chromatography and spectrometry analysis. Satisfactory performance and validation were obtained considering the ohmic heating system built. Blueberry anthocyanins’ degradation varied from 5.71 to 14.67% in the tensions and solids contend range analyzed in this study. The central design composite showed that only tension exerted significant influence over anthocyanin degradation. Ohmic heating experiments, when carried out with high voltages, presented higher degradation levels than conventional heating. However, when lower voltages were applied, anthocyanin degradation was inferior when compared to conventional heating.

O aquecimento ôhmico consiste na passagem de corrente elétrica alternada através de um alimento, transformando energia elétrica em energia térmica, promovendo, assim, um aumento de temperatura em seu interior. A habilidade desse método de gerar calor internamente no alimento permite que o aumento de temperatura seja rápido e uniforme. Essa habilidade resulta em um produto de maior qualidade, tornando a tecnologia de aquecimento ôhmico uma alternativa aos processos convencionais. O mirtilo é rico em compostos fenólicos, dentre esses estão as antocianinas. As antocianinas são compostos fenólicos com alto potencial antioxidante, sendo esse potencial relacionado a efeitos benéficos para a saúde humana no tratamento e prevenção de diversas doenças. O objetivo deste trabalho foi elaborar um sistema de aquecimento ôhmico em escala de bancada e utilizá-lo no tratamento térmico da polpa de mirtilo, visando avaliar o efeito deste processo na degradação das antocianinas. Para tal, foi investigado o efeito da tensão (160–240 V) e do teor total de sólidos (4–16 %), utilizando um planejamento composto central. Foram determinadas algumas propriedades físicas do produto para posterior modelagem do processo. O sistema de aquecimento ôhmico construído opera em batelada e é composto por um variador de tensão, um sistema de aquisição de dados para monitoramento de temperatura, corrente elétrica e tensão e uma célula ôhmica. O teor total de antocianinas foi quantificado prévia e posteriormente ao aquecimento ôhmico, utilizando as metodologias de cromatografia líquida de alta eficiência e a espectrometria. O sistema de aquecimento ôhmico teve desempenho e validação satisfatórios. A degradação de antocianinas do mirtilo variou entre 5,71 e 14,67% nas faixas de tensão e de concentração de sólidos estudadas. O planejamento experimental demonstrou que apenas a tensão exerceu efeito significativo sobre a degradação. O aquecimento ôhmico, quando realizado utilizando altas tensões, apresentou níveis de degradação superiores ao aquecimento convencional. Por outro lado, quando aplicadas tensões mais baixas, a degradação de antocianinas foi inferior à apresentada pelo tratamento convencional. / Ohmic heating is based on the passage of alternating electrical current through food, transforming electrical energy in thermal energy, promoting an increase in temperature. The ability of this method in generating heat from inside the product, allows the heating process to be fast and homogeneous. This ability results in a product of superior quality and presents itself as an alternative to conventional processing. Blueberry fruits contain an array of phenolics, including anthocyanins. Anthocyanins are phenolic compounds with high antioxidant capacity, being this potential related to benefits to human health in the treatment and prevention of several diseases. The aim of this work was to elaborate a bench ohmic heating system and apply it in the thermal treatment of blueberry pulp, in order to evaluate the effect of this process on anthocyanin degradation. For this purpose, the influence of different voltages (160–240 V) and total solids content (4–16 %) was evaluated using a central composite design. Some of the pulp physical properties were evaluated for posterior process modeling. The ohmic heating apparatus, operates in batch configuration and it consists of a voltage regulator; a system for temperature, tension and electrical current data acquisition; and an ohmic heating cell in which the pulp was inserted. Total anthocyanin content was determined previously and after ohmic heating by high performance liquid chromatography and spectrometry analysis. Satisfactory performance and validation were obtained considering the ohmic heating system built. Blueberry anthocyanins’ degradation varied from 5.71 to 14.67% in the tensions and solids contend range analyzed in this study. The central design composite showed that only tension exerted significant influence over anthocyanin degradation. Ohmic heating experiments, when carried out with high voltages, presented higher degradation levels than conventional heating. However, when lower voltages were applied, anthocyanin degradation was inferior when compared to conventional heating.

O mirtilo (Vaccinium spp.) é um fruto ainda pouco conhecido no Brasil, porém com grande potencial produtivo no Estado do Rio Grande do Sul (RS). Estudos relatam propriedades benéficas à saúde e elevada capacidade antioxidante deste fruto, associadas à presença de compostos bioativos, especialmente os antociânicos. O presente trabalho teve por objetivos caracterizar o mirtilo orgânico Rabbiteye, cultivado no RS, e seus produtos derivados, bem como avaliar a estabilidade das antocianinas e da capacidade antioxidante no armazenado sob refrigeração (4 ºC) de suco integral de mirtilo por dez dias, no congelamento dos frutos (-18 ºC) durante seis meses e na desidratação do mirtilo (a 70, 80 e 90 ºC). Para isso, realizaram-se análises físico-químicas, mediu-se a atividade antioxidante, através dos métodos DPPH e ABTS, e determinou-se o conteúdo de antocianinas por cromatografia líquida e espectroscopia. O mirtilo cultivado no RS apresentou capacidade antioxidante superior a de outros frutos e sucos. Quanto às antocianinas, os frutos obtiveram média superior ou inferior à de mirtilos de outras espécies e origens, porém sendo encontradas similaridades no perfil. Tanto as passas quanto o bagaço e a farinha produzida pela secagem deste resíduo sofreram perdas no processamento, mas retendo ainda grande quantidade de compostos antociânicos e atividade antioxidante. Durante o congelamento, os frutos apresentaram aumento significativo (p<0,05) na atividade antioxidante no terceiro mês, sofrendo queda ao final de seis meses, porém mantendo ainda valor superior ao “in natura”. O suco foi analisado a cada dois dias e teve a atividade antioxidante afetada a partir do oitavo dia de armazenamento, permanecendo constante até o décimo dia. As antocianinas sofreram perdas significativas tanto no congelamento dos frutos (59 %) quanto na refrigeração do suco (83 %), porém algumas degradando mais do que outras, provavelmente por diferenças na estrutura química. A capacidade antioxidante do mirtilo aumentou durante a primeira metade do tratamento térmico a 80 ºC e, após 3 h, sofreu redução significativa (p<0,05) até o final do processo. As antocianinas apresentaram tempo de meia-vida médio de 7,7 h e 6,8 h para as secagens a 70 e 80 ºC, respectivamente. A estabilidade dos compostos bioativos está relacionada tanto com a magnitude quanto com a duração do tratamento térmico. Mais estudos são necessários a fim de otimizar o tempo e a temperatura de estocagem e processamento de tais produtos. / Blueberry (Vaccinium spp.) is a little-known fruit in Brazil, but with great productive potential in the state of Rio Grande do Sul (RS). Studies have reported properties beneficial to the health and high antioxidant capacity of this fruit, associated with the presence of bioactive compounds, especially anthocyanins. This study aimed to characterize the organic Rabbiteye blueberry grown in RS, and their products, as well as evaluating the stability of anthocyanins and antioxidant capacity of whole blueberry juice stored under refrigeration (4 °C) for ten days, of fruits stored frozen (-18 °C) for six months and of the dehydration of blueberries (at 70, 80 and 90 °C). For this, physicochemical analyses were carried out, the antioxidant activity was measured through DPPH and ABTS methods, and the content of anthocyanins was determined by liquid chromatography and spectroscopy. Blueberries grown in RS showed higher antioxidant capacity than other fruits and juices. For anthocyanins, the fruits had higher or lower average than other species of blueberries and origins, but similarities had been found in the profile. Both dried fruit and pomace, as well as the flour produced by drying of this residue, they all suffered losses in their process, but still retaining large amounts of anthocyanins and antioxidant activity. During freezing, the fruits showed a significant increase (p<0,05) in antioxidant activity in the third month, decreasing in the end of six months, although still maintaining a value higher than that of the “in natura” fruit. The juice was analyzed every two days and the antioxidant activity was affected in the eighth day of storage, remaining stable up to the tenth day. Anthocyanins have suffered significant losses in both frozen fruits (59 %) and refrigerated juice (83 %), but some degrading more than others, probably due to differences in their chemical structure. The antioxidant capacity of blueberry increased during the first half of the heat treatment at 80 °C, and after 3 h was significantly decreased (p<0,05) til the end of the process. Anthocyanins showed half-life average about 7,7 h and 6,8 h for drying at 70 °C and 80 °C, respectively. The stability of bioactive compounds is related to both the magnitude and duration of heat treatment. Further studies are needed to optimize the time and temperature of storage and processing of such products.

Made available in DSpace on 2014-08-20T14:22:03Z (GMT). No. of bitstreams: 1 dissertacao_andre_de_souza.pdf: 1505540 bytes, checksum: d992967fc84ee46bcd594a64a2a642a6 (MD5) Previous issue date: 2011-03-02 / Blueberry cultivars of rabbiteye group Bluegem, Briteblue, and Woodard are characterized by having low chilling requirement, high vigor and productivity, being able to be produced in region of Southern Brazil. Studies on cultural practices and field performance in blueberry are recent in Brazil. In order to provide more accurated informations to the growers of this fruit crop, experiments were carried out during 2009 and 2010 in a high potential region. The first experiment was carried out in a didactic orchard at the Federal University of Pelotas (Rio Grande do Sul State), and the objective was to study the field behavior of the blueberries propagated by two different techniques. Evaluations on vegetation, production, and fruit quality aspects were done in order to determine the effect of rejuvenation obtained through micropropagation technique. One year-old plants of blueberry, cultivars Bluegem, Briteblue, and Woodard, obtained from micropropagation and semi-hardwood cuttings were used. It was found that micropropagated plants showed a high initial vegetative growth, and both productivity and fruit quality similar to plants propagated by cuttings. In the second experiment, conducted in a commercial orchard located in the same city of the first experiment, it was tested different intensities of pruning on production and fruit quality aspects. Seven years-old plants, cultivars Briteblue and Woodard were used. They were pruned during the winter rest period in different intensities (low, moderate, drastic and control), and the control (no pruning). Blueberry plants which were not pruned showed high productivity, but produced smaller fruits. The moderate pruning system showed the best results. / As cultivares de mirtileiro Bluegem, Briteblue e Woodard pertencem ao grupo rabbiteye e caracterizam-se pela baixa exigência em frio, elevado vigor e alta produtividade, sendo aptas a serem produzidas nas condições do Sul do Brasil. No país ainda são recentes os estudos relativos ao manejo do pomar de mirtileiro e suas características a campo. Na tentativa de oferecer informações mais precisas aos produtores desta cultura, foram conduzidos dois experimentos durante os anos de 2009 e 2010 em região com potencial produtivo. O primeiro experimento foi conduzido em pomar didático pertencente à Universidade Federal de Pelotas, e o objetivo foi estudar o comportamento a campo de mirtileiros propagados por duas diferentes técnicas, avaliando-se aspectos vegetativos, produtivos e de qualidade dos frutos, a fim de constatar o efeito do rejuvenescimento obtido através da técnica de micropropagação. Para isso, realizou-se o plantio de mudas de mirtileiro com um ano de idade das cultivares Bluegem, Briteblue e Woodard, propagadas in vitro e por estaquia semilenhosa. Foi constatado que plantas micropropagadas apresentam, a campo, crescimento vegetativo inicial superior, além de produtividade e qualidade de frutos semelhantes às plantas propagadas por estaquia. No segundo experimento, conduzido em um pomar comercial localizado no mesmo município do primeiro, foram testadas diferentes intensidades de poda de frutificação e avaliados aspectos produtivos e de qualidade de frutos. Foram utilizadas plantas com sete anos de idade, das cultivares Briteblue e Woodard, que foram podadas no período de repouso hibernal em intensidades distintas (leve, moderada, drástica e testemunha). Plantas de mirtileiro não podadas apresentaram produtividade superior, porém produziram frutos de menor tamanho. O sistema de poda moderado foi o que apresentou melhores resultados.

Perturbations to extravillous trophoblast (EVT) cell migration and invasion are associated with the development of placenta-mediated diseases. Dietary polyphenols have been shown to influence cell migration and invasion in models of tumorigenesis and non-cancerous, healthy cells; however, never shown in EVT cells. We hypothesize that polyphenols present in V. angustifolium leaves will promote trophoblast migration and invasion through ERK and AKT activation. Using the HTR-8/SVneo cell line as a model for EVT cells, the leaf extract increased trophoblast migration and invasion, in an ERK- and AKT-independent manner, and had no effect on cell proliferation or viability. One major polyphenol of the leaf extract was identified and may be an active compound. We have demonstrated for the first time that V. angustifolium leaf extract increases EVT migration and invasion in vitro, thus further investigations examining potential therapeutic applications of this extract in the context of placenta-mediated diseases are warranted.

Fruit and vegetable derived polyphenols have been linked with many health benefits. In light of this, many consumers are seeking to increase their intake of polyphenols, with many turning to dietary supplements that contain concentrated doses of purified polyphenols. However, the safety of this consumption modality is not known, nor are the dose-dependent metabolic changes that may be present, especially when considering colonically generated phenolic metabolites. Using blueberry polyphenols as a model, we explored these phenomena in a rat model. Animals were dosed with blueberry polyphenols at levels up to 20 times what would be consumed in 1-2 servings of whole blueberries in an adult human. In the first study, animals were acutely dosed with blueberry polyphenols and urine and plasma pharmacokinetics measured. In the second study, animals were repeatedly dosed for 90d, with urinary metabolites monitored throughout the study and a complete necropsy performed following standard guidelines. In both studies, metabolite excretion patterns were similar: cinnamic acids accounted for a majority of the observed metabolites, followed by hippuric acids and then phenylpropionic acids (PPA). A dose-dependent shift in metabolite production was observed; as the dose increased, the relative amounts of PPA increased while hippuric acids decreased. No adverse or toxic effects were found, and, though there were several statistically significant differences in toxicological endpoints, all measured parameters remained in the normal range for these animals and thus were not deemed biologically significant. These results indicate that high doses of blueberry polyphenols, as may be present in dietary supplements, are safe for consumption. These results also demonstrate dose-dependent shifts in metabolism that may impact gut function and affect the health benefits derived from blueberry polyphenols.<br>

<div>Osteoporosis is the most common bone disease in older adults and is characterized by low bone mass and increased fragility. Women are at a higher risk for osteoporosis because of the rapid loss of bone during menopause. The decline of estrogen is accompanied by an increased bone resorption and a decreased bone formation which results in negative bone balance. Due to adverse effects on the uterus, breast and cardiovascular system, hormone replacement therapy has been discouraged. Nutritional strategies for osteoporosis prevention are being sought. It has been suggested that (poly)phenol-rich fruits may have bone protective effects. Blueberries are one of the richest sources of (poly)phenols, thus the aim of this dissertation was to determine whether a blueberry-enriched diet could aid in bone loss prevention in the ovariectomized rat model.</div><div><br></div><div>There are hundreds of blueberry varieties which differ in (poly)phenol profiles and content. Five blueberry varieties (Ira, Montgomery, SHF2B1-21:3, Onslow and Wild Blueberry) were chosen to assess the bioavailability of its individual (poly)phenols. Bioavailability of individual phenolic metabolites was determined through a pharmacokinetic study in ovariectomized rats. The results showed that Montgomery blueberry had significantly higher bioavailability of malvidin, cyanidin and myricetin metabolites, while Ira had significantly higher bioavailability of quercetin metabolites, thus suggesting that the absorption of blueberry polyphenols and their potential to reach target tissues differed between blueberry varieties.</div><div><br></div><div>It is important to assess what is the most appropriate dose of blueberry necessary to exert beneficial effects on bone. To determine the most adequate dose of wild blueberry to prevent bone loss in ovariectomized rats, a randomized crossover study was carried out to assess the effects of four different blueberry doses on net bone calcium retention over a 10-day treatment period. The results showed that the only dose to significantly increase net bone calcium retention by 25.6% (p = 0.0426) was the 5% blueberry diet (% w/w), while the higher doses of 10% and 15% had no effect on net bone calcium retention. This informed the last study where Montgomery blueberry and wild blueberry at a 5% dose (% w/w) were chosen to investigate the effects of an 8-week chronic feeding study on calcium metabolism, kinetics, bone microarchitecture and strength and polyphenol metabolism and distribution. A chronic consumption of the wild blueberry resulted in a trend towards minimal trabecular bone loss protection in comparison to the control diet (p=0.08). Kinetic modeling of calcium showed that the Montgomery blueberry had anabolic effects on bone through significantly increasing calcium absorption and bone deposition. The phenolic metabolism differed among blueberry varieties due to each berry’s polyphenol content and profiles and a chronic consumption of blueberry resulted in significant changes in absorption and metabolism of polyphenols. The bone marrow was investigated to determine whether there was any accumulation of phenolic acids in the tissue. Hippuric acid accumulation was significantly higher with the Montgomery blueberry treatments in comparison to control diet. Interestingly, hippuric acid content in the bone marrow was significantly and positively correlated with bone deposition calculated from kinetic modeling. Although no differences were observed on bone mineral density, strength, and microarchitecture, previous studies with a duration of 12-14 weeks have shown significant protection of a blueberry-enriched diet on bone mineral density. Because our study showed a trend for increased trabecular bone (p = 0.08) with the blueberry treatments, we conclude that an 8-week treatment was insufficient time to detect significant differences between the control and blueberry treatments. Since previous researchers before us have reported significant attenuation to bone loss immediately after OVX, it is possible that blueberry that in our study, blueberry was unable to rescue bone once lost after ovariectomy.<br></div><div><br></div><div>A blueberry-enriched diet resulted in a minimal protection to bone after stabilized to OVX, but showed significant increases in calcium absorption and bone turnover in ovariectomized rats. Colonic metabolite profiles from the chronic consumption of blueberry significantly changed over time, thus providing an insight into the effects of blueberry consumption on polyphenol metabolism.<br></div><div><br></div>

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / The Blueberry situation in Peru is in a stage of development, in which it is necessary to incorporate good management practices as well as productive to raise the competitiveness of the enterprises. The findings were synthesized and analyzed, to propose improvements and to support the growth of the small companies in the long term. The improvement proposal is based on the best practices and supply chain models applied in the industry. Also, the research was based on sources of information from researchers with experience in evaluating and analyzing the supply chain of the perishable sector in different scenarios worldwide. / Revisión por pares