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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

Strawberries and Gut Health in Postmenopausal Women

Macneill, Morgan T 01 June 2019 (has links) (PDF)
The gut microbiota has been implicated in both health and disease. As such, diet is a significant determinant of gut health, whereby diet induced dysbiosis is associated with cardiometabolic risk. Interestingly, a higher proportion of Firmicutes and a lower proportion of Bacteroidetes are implicated in obesity. Strawberry polyphenols have been shown to reduce cardiovascular disease risk in addition to exhibiting prebiotic activity by increasing probiotic bacteria in the gut. Polyphenols have also been shown to reduce the ratio of Firmicutes to Bacteroidetes. Therefore, dietary modifications such as strawberry consumption may help improve health outcomes through the gut. The objective of this study was to analyze whether 13 g freeze dried strawberry powder (~1 cup/d fresh) consumption reduces the Firmicutes:Bacteroidetes ratio and increases microbial diversity and beneficial bacteria like Lactobacillus and Bifidobacterium. This study was a 5-week free-living diet intervention trial conducted at California Polytechnic State University, San Luis Obispo with expansion to the Eye Medical Center of Fresno. Participants (n=10) had a mean age of 60.5 ± 9.13 years and had a mean body weight of 74.71 ± 10.61 kg. The participants completed a 3-week washout before a 2-week diet intervention. Participants maintained their normal diet throughout the study while eliminating foods high in polyphenols and probiotics. Upon completion of the study, no significant differences were found for body weight (p=0.22) or BMI (p=0.26). Likewise, no significant differences were found for macronutrient, vitamin, or mineral intake except for sugar (p=0.03), vitamin B12 (p=0.03), and fruit (p=0.0014). Bacteria abundance and diversity were not found to be statistically significant following intervention. Since strawberry supplementation was not associated with a significant change in the relative abundance of bacteria with the dose and duration administered, a randomized controlled trial would better determine the effect of strawberry consumption on gut health.
2

Efeito de extratos ricos em antocianinas ou elagitaninos de amora silvestre (Morus nigra L.), amora preta (Rubus spp), e grumixama (Eugenia brasiliensis Lam) no crescimento e na expressão de genes e miRNAs de diferentes linhagens de céluas humanas de câncer de mama. / Effects of extracts rich in anthocyanins or ellagitans from mulberry (Morus nigra L.), blackberry (Rubus spp) and grumixama (Eugenia brasiliensis Lam) on cellular growth and gene and miRNAs expression from distinctive human breast cancer cell lines.

Costa, Gabriela Rezende 28 September 2017 (has links)
O câncer de mama caracteriza-se globalmente como a neoplasia de maior incidência e mortalidade na população feminina. Antocianinas e elagitaninos presentes em frutas como as berries destacam-se por seu promissor efeito protetor em diferentes estágios do desenvolvimento do câncer de mama. Grumixama (G; Eugenia brasiliensis Lam) é uma espécie de cereja nativa do Brasil que assim como as amora-preta (AP; Rubus spp) e silvestre (AS; Morus nigra L.) contém alto teor de antocianinas e elagitaninos. Poucos estudos focaram na ação anticâncer destas berries no câncer de mama. Portanto, o objetivo do presente estudo foi avaliar os efeitos de extratos ricos em antocianinas ou elagitaninos de G, AP e AS no crescimento e na expressão de genes e miRNAs das linhagens de células humanas de câncer de mama MCF-7 (receptor de hormônio positiva) e MDA-MB 231 (receptor de hormônio negativa). Não se observou citotoxicidade após 72 e 96 horas de tratamento com os extratos (25-200&#181g/mL) ricos em antocianinas (ASANT, APANT e GANT) ou elagitaninos (APELA e GELA), em ambas as linhagens celulares. Após 72 horas de tratamento, GANT e APANT induziram parada de ciclo celular em G0/G1 (12,5 e 50&#181g/mL, p<0,05) em células MCF-7. Após 96h, ASANT, APANT e GANT induziram parada de ciclo celular em G0/G1 (12,5 e 50&#181g/mL; p<0,05) nessas mesmas células. Entretanto, na concentração de 200&#181g/mL apenas GANT induziu parada em G0/G1 (72 e 96h; p<0,05). Em células MDA-MB 231, após 96h APANT e GANT induziram parada de ciclo celular em G0/G1 nas concentrações testadas (12,5, 50 e 200&#181g/mL, p<0,05), assim como ASANT nas concentrações de 12,5 e 50&#181g/mL (p<0,05). Em células MCF-7, após 72h APELA e GELA induziram aumento da proporção de células em subG0 (200&#181g/mL, p<0,05). Em MDA-MB 231, após 72 e 96h, APELA e GELA (200&#181g/mL) induziram aumento da proporção de células em subG0 (p<0,05) e parada em G0/G1 (p<0,05). Em células MCF-7, GANT induziu morte celular por apoptose (p<0,05) após 72 e 96h de tratamento. Entretanto, em MDA-MB 231 os extratos ricos em antocianinas não induziram morte celular. Em células MCF-7, após 96h GELA e APELA induziram principalmente necrose (p<0,05). Em MDA-MB 231, APELA e GELA induziram apoptose (p<0,05) após 72 e 96h. Em células MDA-MB 231, após 72h de tratamento foi observada inibição da proliferação celular por GELA, GANT e APELA (200&#181g/mL; p<0,05). Em células MDA-MB 231, 48h de tratamento com GELA; GANT e APELA (200&#181g/mL) aumentaram a expressão 5 genes (ESR2, FOXA1, JUN, PTGS2,VEGFA) e inibiram a expressão de 10 genes (ADAM23, ATM, BCL2, CDH1, EGF, GLI1, ID1, MKI67, SNAI2 e THBS1) correlacionados ao câncer de mama. Adicionalmente, GELA; GANT e APELA (200&#181g/mL) induziram aumento da expressão de miR- 210(p<0,05) e APELA (200&#181g/mL) reduziu a expressão de miRNA 19a/b (p<0,05) em células MDAMB 231. Coletivamente estes resultados sugerem que antocianinas de grumixama e elagitaninos de amora preta e grumixama apresentam potencial efeito protetor contra o câncer de mama. Adicionalmente, essa ação anticarcinogênica pode ser mediada por indução de morte celular, mais especificamente apoptose, redução de proliferação celular e modulação da expressão de genes e miRNAs relacionados ao câncer de mama. / Breast cancer is characterized as the neoplasia with the highest incidence and mortality rates in women worldwide. Anthocyanins and ellagitannins present in certain fruits, such as berries, stand out for their promising protective effect at different stages of breast cancer development. Grumixama (G; Eugenia brasiliensis Lam), a cherry species from Brazil, as well as blackberry (AP; Rubus spp) and mulberry (AS; Morus nigra L.) contain elevated concentrations of anthocyanins and ellagitannins. Few studies focused on the anticarcinogenic action of these berries in breast cancer development. Therefore, the aim of the present study was to evaluate the effects of extracts rich in anthocyanins or ellagitannins from G, AP and AS on cellular growth and genes and miRNAs expression in human MCF-7 (hormone receptor positive) and MDA-MB 231 (hormone receptor negative) cell lines. No cytotoxicity was observed after 72 and 96 hours of treatment with extracts rich in anthocyanin (25-200 &#181g/mL) (ASANT, APANT and GANT) or ellagitannins (APELA and GELA) in both cell lines. After 72 hours of treatment, GANT and APANT induced cell cycle arrest at G0/G1 (12.5&#181g/mL and 50&#181g/mL, p<0.05) in MCF-7 cells. After 96h, ASANT, APANT and GANT induced cycle arrest at G0/G1 (12.5 and 50&#181g/mL; p<0.05) in MCF-7 cells. However, at 200&#181g/mL, only GANT induced G0/G1 (72 and 96h; p<0.05). In MDA-MB 231 cells, after 96h APANT and GANT induced cell cycle arrest at G0/G1 with the three tested concentrations (12.5, 50 and 200&#181g/mL, p<0.05), as well as ASANT at concentrations 12,5 and 50&#181g/mL (p <0.05). In MCF-7 cells, after 72h APELA and GELA induced an increase in the proportion of cells in subG0 (200&#181g/mL, p<0.05). In MDA-MB 231, after 72 and 96h, APELA and GELA (200&#181g/mL) induced an increase in the proportion of cells in subG0 (p<0.05) and cell cycle arrest in G0/G1 (p<0.05). In MCF-7 cells, GANT induced apoptosis (p<0.05) after 72 and 96h of treatment. However, in MDA-MB 231, extracts rich in anthocyanins did not induce cell death. In MCF-7 cells, after 96h GELA and APELA induced mainly necrosis (p<0.05). In MDA-MB 231, APELA and GELA induced apoptosis (p<0.05) after 72 and 96h. In MDA-MB 231 cells, inhibition of cell proliferation by GELA, GANT and APELA (200?g/mL; p<0.05) was observed after 72h of treatment. In MDA-MB 231 cells, treatment for 48h with GELA, GANT and APELA (200&#181g) increased expression of 5 genes (ESR2, FOXA1, JUN, PTGS2, VEGFA) and inhibited expression of 10 genes (ADAM23, ATM, BCL2, CDH1, EGF, GLI1, ID1, MKI67, SNAI2 and THBS1) correlated with breast cancer. In addition, GELA; GANT and APELA (200&#181g/mL) induced increased expression of miR-210 (p<0.05) and APELA (200&#181g/mL) reduced the expression of miRNA 19a/b (p<0.05) in MDA-MB cells 231. Collectively these results suggest that anthocyanins of grumixama and ellagitannins of blackberry and grumixama have potential protective effect against breast cancer. Additionally, this anticarcinogenic action can be mediated by induction of cell death, more specifically apoptosis, reduction of cell proliferation and modulation of the expression of genes and miRNAs related to breast cancer.
3

Efeito de extratos ricos em antocianinas ou elagitaninos de amora silvestre (Morus nigra L.), amora preta (Rubus spp), e grumixama (Eugenia brasiliensis Lam) no crescimento e na expressão de genes e miRNAs de diferentes linhagens de céluas humanas de câncer de mama. / Effects of extracts rich in anthocyanins or ellagitans from mulberry (Morus nigra L.), blackberry (Rubus spp) and grumixama (Eugenia brasiliensis Lam) on cellular growth and gene and miRNAs expression from distinctive human breast cancer cell lines.

Gabriela Rezende Costa 28 September 2017 (has links)
O câncer de mama caracteriza-se globalmente como a neoplasia de maior incidência e mortalidade na população feminina. Antocianinas e elagitaninos presentes em frutas como as berries destacam-se por seu promissor efeito protetor em diferentes estágios do desenvolvimento do câncer de mama. Grumixama (G; Eugenia brasiliensis Lam) é uma espécie de cereja nativa do Brasil que assim como as amora-preta (AP; Rubus spp) e silvestre (AS; Morus nigra L.) contém alto teor de antocianinas e elagitaninos. Poucos estudos focaram na ação anticâncer destas berries no câncer de mama. Portanto, o objetivo do presente estudo foi avaliar os efeitos de extratos ricos em antocianinas ou elagitaninos de G, AP e AS no crescimento e na expressão de genes e miRNAs das linhagens de células humanas de câncer de mama MCF-7 (receptor de hormônio positiva) e MDA-MB 231 (receptor de hormônio negativa). Não se observou citotoxicidade após 72 e 96 horas de tratamento com os extratos (25-200&#181g/mL) ricos em antocianinas (ASANT, APANT e GANT) ou elagitaninos (APELA e GELA), em ambas as linhagens celulares. Após 72 horas de tratamento, GANT e APANT induziram parada de ciclo celular em G0/G1 (12,5 e 50&#181g/mL, p<0,05) em células MCF-7. Após 96h, ASANT, APANT e GANT induziram parada de ciclo celular em G0/G1 (12,5 e 50&#181g/mL; p<0,05) nessas mesmas células. Entretanto, na concentração de 200&#181g/mL apenas GANT induziu parada em G0/G1 (72 e 96h; p<0,05). Em células MDA-MB 231, após 96h APANT e GANT induziram parada de ciclo celular em G0/G1 nas concentrações testadas (12,5, 50 e 200&#181g/mL, p<0,05), assim como ASANT nas concentrações de 12,5 e 50&#181g/mL (p<0,05). Em células MCF-7, após 72h APELA e GELA induziram aumento da proporção de células em subG0 (200&#181g/mL, p<0,05). Em MDA-MB 231, após 72 e 96h, APELA e GELA (200&#181g/mL) induziram aumento da proporção de células em subG0 (p<0,05) e parada em G0/G1 (p<0,05). Em células MCF-7, GANT induziu morte celular por apoptose (p<0,05) após 72 e 96h de tratamento. Entretanto, em MDA-MB 231 os extratos ricos em antocianinas não induziram morte celular. Em células MCF-7, após 96h GELA e APELA induziram principalmente necrose (p<0,05). Em MDA-MB 231, APELA e GELA induziram apoptose (p<0,05) após 72 e 96h. Em células MDA-MB 231, após 72h de tratamento foi observada inibição da proliferação celular por GELA, GANT e APELA (200&#181g/mL; p<0,05). Em células MDA-MB 231, 48h de tratamento com GELA; GANT e APELA (200&#181g/mL) aumentaram a expressão 5 genes (ESR2, FOXA1, JUN, PTGS2,VEGFA) e inibiram a expressão de 10 genes (ADAM23, ATM, BCL2, CDH1, EGF, GLI1, ID1, MKI67, SNAI2 e THBS1) correlacionados ao câncer de mama. Adicionalmente, GELA; GANT e APELA (200&#181g/mL) induziram aumento da expressão de miR- 210(p<0,05) e APELA (200&#181g/mL) reduziu a expressão de miRNA 19a/b (p<0,05) em células MDAMB 231. Coletivamente estes resultados sugerem que antocianinas de grumixama e elagitaninos de amora preta e grumixama apresentam potencial efeito protetor contra o câncer de mama. Adicionalmente, essa ação anticarcinogênica pode ser mediada por indução de morte celular, mais especificamente apoptose, redução de proliferação celular e modulação da expressão de genes e miRNAs relacionados ao câncer de mama. / Breast cancer is characterized as the neoplasia with the highest incidence and mortality rates in women worldwide. Anthocyanins and ellagitannins present in certain fruits, such as berries, stand out for their promising protective effect at different stages of breast cancer development. Grumixama (G; Eugenia brasiliensis Lam), a cherry species from Brazil, as well as blackberry (AP; Rubus spp) and mulberry (AS; Morus nigra L.) contain elevated concentrations of anthocyanins and ellagitannins. Few studies focused on the anticarcinogenic action of these berries in breast cancer development. Therefore, the aim of the present study was to evaluate the effects of extracts rich in anthocyanins or ellagitannins from G, AP and AS on cellular growth and genes and miRNAs expression in human MCF-7 (hormone receptor positive) and MDA-MB 231 (hormone receptor negative) cell lines. No cytotoxicity was observed after 72 and 96 hours of treatment with extracts rich in anthocyanin (25-200 &#181g/mL) (ASANT, APANT and GANT) or ellagitannins (APELA and GELA) in both cell lines. After 72 hours of treatment, GANT and APANT induced cell cycle arrest at G0/G1 (12.5&#181g/mL and 50&#181g/mL, p<0.05) in MCF-7 cells. After 96h, ASANT, APANT and GANT induced cycle arrest at G0/G1 (12.5 and 50&#181g/mL; p<0.05) in MCF-7 cells. However, at 200&#181g/mL, only GANT induced G0/G1 (72 and 96h; p<0.05). In MDA-MB 231 cells, after 96h APANT and GANT induced cell cycle arrest at G0/G1 with the three tested concentrations (12.5, 50 and 200&#181g/mL, p<0.05), as well as ASANT at concentrations 12,5 and 50&#181g/mL (p <0.05). In MCF-7 cells, after 72h APELA and GELA induced an increase in the proportion of cells in subG0 (200&#181g/mL, p<0.05). In MDA-MB 231, after 72 and 96h, APELA and GELA (200&#181g/mL) induced an increase in the proportion of cells in subG0 (p<0.05) and cell cycle arrest in G0/G1 (p<0.05). In MCF-7 cells, GANT induced apoptosis (p<0.05) after 72 and 96h of treatment. However, in MDA-MB 231, extracts rich in anthocyanins did not induce cell death. In MCF-7 cells, after 96h GELA and APELA induced mainly necrosis (p<0.05). In MDA-MB 231, APELA and GELA induced apoptosis (p<0.05) after 72 and 96h. In MDA-MB 231 cells, inhibition of cell proliferation by GELA, GANT and APELA (200?g/mL; p<0.05) was observed after 72h of treatment. In MDA-MB 231 cells, treatment for 48h with GELA, GANT and APELA (200&#181g) increased expression of 5 genes (ESR2, FOXA1, JUN, PTGS2, VEGFA) and inhibited expression of 10 genes (ADAM23, ATM, BCL2, CDH1, EGF, GLI1, ID1, MKI67, SNAI2 and THBS1) correlated with breast cancer. In addition, GELA; GANT and APELA (200&#181g/mL) induced increased expression of miR-210 (p<0.05) and APELA (200&#181g/mL) reduced the expression of miRNA 19a/b (p<0.05) in MDA-MB cells 231. Collectively these results suggest that anthocyanins of grumixama and ellagitannins of blackberry and grumixama have potential protective effect against breast cancer. Additionally, this anticarcinogenic action can be mediated by induction of cell death, more specifically apoptosis, reduction of cell proliferation and modulation of the expression of genes and miRNAs related to breast cancer.
4

Diffusion of sugar, acids and pigments during processing and storage of canned berries

Boziotis, Constantinos Andreas 08 March 1963 (has links)
Processing and storage of berry fruits is accompanied by various changes, the important ones being the changes in the soluble solids content, titratable acidity, pH, pigments, and texture. A study was made of these changes in processed strawberries, raspberries, blackberries and blueberries, still cooked and stored at 78°F for one and six months in No. 10 cans. Three samples of the above four berries were analyzed before processing, immediately after processing and after one and six months of storage at 78°F. Five samples of syrups were collected from both center and side of the cans by means of 50 ml pipettes. These five samples were from top, 1 3/4", 3 l/2", and 5 1/4" from the top and from the bottom and a mean sample was taken from the drained syrup. The cans were then drained on an 8 mesh 10" screen. 100 gram samples of the drained solids from top, middle and bottom were collected for texture measurements. The results indicated the following: 1. There is a decrease in soluble solids of the syrup and drained weight of the fruit immediately after processing. Softening of berries progresses with storage. 2. There is an increase in titratable acidity, pH and pigments of the syrup immediately after processing. Titratable acidity and pigments increase with storage and pH values were lower. 3. There is a tendency to reach an equilibrium in the can with regards to soluble solids in all berries and pigments in case of strawberries with a lower tendency for raspberries. In the case of titratable acidity equilibrium was almost realized in strawberries and blueberries. All berry packs showed no equilibrium in the pH value after six months. 4. No noticeable differences between samples collected from centers and side of the can. / Graduation date: 1963
5

Energy-efficient industrial dryers of berries

Yuting, Wang January 2013 (has links)
Saving energy is considered about by much more people nowadays. The energy use of industrial drying occupies a large part of total energy usage. Not only the governments, but also the industry owners are trying to find ways to cut down the usage of energy. The aim of this work is to find suitable technologies for industrial drying of berries which can be energy-efficient at the same time. More specifically, to find suitable dryers for drying aronia berry in Sweden. The research is based on secondary data collected by literature review. Good options for other circumstances like fluidized bed drying, freeze drying and solar drying were not discussed in detail. After the study, a continuous hot air dryer with explosion puffing system and heat pumping system seems to be the best solution for drying aronia berry in Sweden. It is easy to be controlled, cost acceptable (both capital and operational costs), environmental friendly and has high drying rate and high product quality. The extra means for improve drying process such as combined with dielectric or conductive dryer, adding pre-treatment such as osmotic drying were also discussed. Combined dryers can reduce the drying time and osmotic drying can cut the operation cost. Careful experiments shall be done before large amount of investment due to the complexity of dehydration.
6

Effect of processing and storage on the texture of canned berries

Rao, Akkinapally Venketeshwer 06 March 1963 (has links)
The texture of processed berry fruits changes both during processing and subsequent storage. A study was made of these changes in processed strawberries, raspberries, blackberries, and blue- berries, spin-cooked and stored at 100°F. for 28 days in tin and glass containers. Four samples, from each of the two replications of the above, four berries,were analyzed immediately after processing and after 3, 7, 14, and 28 days of storage at 100°F. Physical measurement of texture was obtained by the use of Maryland Shear-press. The work diagrams thus obtained were studied in detail. These samples, after being subjected to the Shear-press, were analyzed for percent A.I.S. and total pectin. The results indicated the following: 1. There was no significant difference in the texture, percent A.I.S. and total pectin, between berries processed and stored in tin and glass containers over a period of 28 days at 100°F, 2. Highest correlation was obtained between texture as measured by partial work and total pectin in case of strawberries and blueberries and between maximum force and percent A.I.S. in raspberries and blackberries. 3. Maryland Shear-press gave characteristic work diagrams for each of the four berries, which were consistent throughout. 4. A linear relationship was obtained between sample size and texture as measured by the total work. / Graduation date: 1963
7

An investigation into the effects of soft fruit extracts with high anthocyanin content on glycaemia in overweight or obese people with or without Type II Diabetes, and an exploration of their potential use to make healthier food products

Alnajjar, Mahasin January 2016 (has links)
No description available.
8

Plan de negocios para la exportación de berries orgánicos a Canadá

Badilla Obreque, Álvaro Omar January 2015 (has links)
Autor no autoriza el acceso a texto completo de su documento hasta el 8/5/2020. / Magíster en Gestión para la Globalización / Este trabajo de tesis tiene como objetivo desarrollar un plan de negocios que permita evaluar la exportación a la provincia de Quebec, Canadá, de berries orgánicos certificados provenientes del sur de Chile por parte de la empresa chilena AGROILS CHILE S.A. El proyecto se ve impulsado por la inquietud de la empresa de explorar nuevos mercados. Otro factor es que Chile presenta una oferta de berries llamados súper fruits con alto contenido nutricional que, producidos bajo certificaciones orgánicas y de responsabilidad social, son el producto perfecto para el mercado canadiense. Las exportaciones están orientadas al segmento HORECA (Hoteles, Restaurantes y Catering), donde en el subsegmento restaurantes posee un tamaño de USD 74 millones en Canadá, y de USD 20 millones en la provincia de Quebec. El mercado canadiense en un mercado altamente receptivo a productos exportados con altos contenidos nutricionales y orgánicos. El público objetivo es adulto joven con ingresos medio alto que está dispuesto a pagar por calidad. La metodología utilizada para realizar este trabajo consistió en primer lugar en un análisis de factores medioambientales a través de la herramienta PESTEL, y el análisis estratégico de las cinco Fuerzas de Porter. Esta metodología permitió evaluar las oportunidades y amenazas que presenta el país. Adicionalmente, existe una revisión de la producción de berries a nivel mundial y la revisión de los principales competidores a nivel nacional e internacional. Para evaluar la propuesta de valor, se elaboró un modelo de negocios bajo la metodología CANVAS, donde destaca la proposición de valor de productos con una huella de producción sustentable y sostenible. La estrategia de marketing apunta a generar presencia en el mercado canadiense, apoyándose en instituciones nacionales como ProChile y la búsqueda de un socio estratégico como los intermediarios o brokers canadienses. Se plantea una etapa de pilotaje para la inserción en el mercado canadiense trabajando el primer año con un prestigioso hotel de Quebec. Paralelamente se evaluó económicamente esta proyecto en un horizonte de 5 años utilizando una inversión de USD $34.745, obteniendo de él un VAN positivo de USD $68.378,92 y una TIR de 79% utilizando una tasa de descuento del 12%, haciendo rentable el proyecto. Por otro lado, se elaboraron las proyecciones de ventas de acuerdo a los volúmenes de producción definidos. La recomendación es implementar este plan de negocios y evaluar otros posibles mercados en Canadá aumentando las cantidades exportadas y ofreciendo otros productos en la gama de productos orgánicos.
9

Drying characteristics of Saskatoon berries under microwave and combined microwave-convection heating

Reddy N., Lakshminarayana 12 February 2008
The study on dehydration of frozen saskatoon berries and the need for dried fruits have been strategically identified in the Canadian Prairies. The motivation for this research was to find a suitable method for dehydration and extend saskatoon berry shelf life for long term preservation. Microwave, convection and microwave-convection combination drying processes were identified to finish-dry saskatoon berries after osmotic dehydration, using sucrose and high fructose corn syrup (HFCS) sugar solutions. Osmotic dehydration removes moisture in small quantities introducing solutes into the fruit that acts as a preservative and also reduces the total drying time. <p>Due to the very short harvesting season of saskatoon berries, an accelerated process such as the microwave combination drying can reduce the moisture to safe storage levels immediately after harvest. Untreated and osmotically dehydrated berries were subjected to convection (control), microwave and microwave-convection combination drying conditions at different product drying temperatures (60, 70 and 80oC) until final moisture content was 25% dry basis. A laboratory-scale microwave combination dryer was developed with integrated temperature and moisture loss data acquisition systems using LabView 6i software. A thin-layer cross flow dryer was used for convection-only drying and for comparison. <p>Drying kinetics of the process were studied and curve fitting with five empirical equations, including the Page equation, was carried out to determine drying constant, R2 and standard error values. The microwave-combination drying method proved to be the best for drying saskatoon berries. Dehydrated product quality analyses were accomplished by measuring the color changes, rehydration ratio and any structural changes, using a scanning electron microscope technique.<p>This research was instrumental in the modification and development of a novel drying system for high-moisture agricultural materials (fruits). Microwave-convection combination drying at 70oC, yielded good results with higher drying rates and better end-product quality.
10

Drying characteristics of Saskatoon berries under microwave and combined microwave-convection heating

Reddy N., Lakshminarayana 12 February 2008 (has links)
The study on dehydration of frozen saskatoon berries and the need for dried fruits have been strategically identified in the Canadian Prairies. The motivation for this research was to find a suitable method for dehydration and extend saskatoon berry shelf life for long term preservation. Microwave, convection and microwave-convection combination drying processes were identified to finish-dry saskatoon berries after osmotic dehydration, using sucrose and high fructose corn syrup (HFCS) sugar solutions. Osmotic dehydration removes moisture in small quantities introducing solutes into the fruit that acts as a preservative and also reduces the total drying time. <p>Due to the very short harvesting season of saskatoon berries, an accelerated process such as the microwave combination drying can reduce the moisture to safe storage levels immediately after harvest. Untreated and osmotically dehydrated berries were subjected to convection (control), microwave and microwave-convection combination drying conditions at different product drying temperatures (60, 70 and 80oC) until final moisture content was 25% dry basis. A laboratory-scale microwave combination dryer was developed with integrated temperature and moisture loss data acquisition systems using LabView 6i software. A thin-layer cross flow dryer was used for convection-only drying and for comparison. <p>Drying kinetics of the process were studied and curve fitting with five empirical equations, including the Page equation, was carried out to determine drying constant, R2 and standard error values. The microwave-combination drying method proved to be the best for drying saskatoon berries. Dehydrated product quality analyses were accomplished by measuring the color changes, rehydration ratio and any structural changes, using a scanning electron microscope technique.<p>This research was instrumental in the modification and development of a novel drying system for high-moisture agricultural materials (fruits). Microwave-convection combination drying at 70oC, yielded good results with higher drying rates and better end-product quality.

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