This dissertation examines ways in which differences in states' political activity laws affect the political attitudes and reported behavior of senior state government employees. Of particular concern is whether a stringent little Hatch Act engenders any "chilling effects" that may lead these workers to shy away from permissible political activities. The study included officials employed in Pennsylvania, which has a restrictive political activity statute, and New Jersey, which has generally permissive laws. Mail questionnaires were sent to 962 officials, 512 from Pennsylvania and 450 from New Jersey. Responses were received from 582 employees, yielding a 61.91% response rate. Compared to New Jersey officials, those from Pennsylvania were less knowledgeable about their state's political activity laws. The Pennsylvania employees also reported being less politically active and less satisfied with their activity, and were more likely to indicate that they would increase their level of political activity if state prohibitions were eliminated. However, compared to their New Jersey counterparts, these officials were no less inclined to engage in permissible political activities. This finding casts doubt on the notion that a highly restrictive statutory climate spawns chilling effects. / Ph. D.

Herbaceous peonies (Paeonia lactiflora Pall.) are common perennials used both in gardens and the landscape as well as for cut flowers. Peonies require a chilling period to break dormancy but not for flower bud differentiation. For all studies discussed in this dissertation, two peony cultivars, Sarah Bernhardt and Inspecteur Lavergne, small (3–5 eye) crowns from Holland were potted in 3.8-L pots in mid-November of 2017 and 2018. Our overall objective was to determine if we could manipulate chilling time, along with application of gibberellic acid (GA3) and growth retardants, to produce marketable containerized peonies from a small crown in a single season (November to May). We evaluated chilling, GA3 and a growth retardant (uniconazole; UNZ) under controlled chilling and greenhouse forcing conditions. All potted plants were held outdoors at Battlefield Farms (Rapidan, VA, 38˚ N) for 4 weeks [in 2017, 400 chilling units (CU) according to Fulton Chilling Model] or in a 10°C cooler for 5.5 weeks (in 2018, 400 CU) to root, then placed in a 5°C cooler for 3, 4 or 5 weeks (total 752, 869 or 986 CU). GA3 was applied as a 0 or 100 mg·L-1 drench at 250 ml/pot after the plants were moved into the Virginia Tech greenhouse (Blacksburg, VA, 37˚ N) for forcing. Uniconazole drenches were applied to each cultivar under each chilling treatment at 355 ml/pot at 0, 15, or 20 mg·L-1 at 7 days after the GA3 drench applications. Three weeks chilling at 5°C (752 CU total) provided sufficient chilling for 'Sarah Bernhardt' and 'Inspecteur Lavergne'. Application of GA3 reduced production time and resulted in a greater number of shoots, and, in three of the four studies, increased the number of flowering shoots in three of the four studies. Substrate drench application of 15 mg·L-1 UNZ prior to spring emergence reduced plant width moderately resulting in improved compactness of both cultivars. We evaluated the effects of plant growth retardants applied with different methods at different stages of production on the growth and development of containerized peony under nursery conditions. All potted plants were placed in an unheated coldframe at the Virginia Tech Urban Horticulture Center (Blacksburg, VA, 37˚ N) for one month after potting to promote rooting and then were moved outdoors to a gravel pad to receive natural chilling from November to February. In 2017–18, substrate drenches of UNZ at 0, 15, 30 or 45 mg·L-1 or paclobutrazol (PBZ) at 0, 30, 60 or 90 mg·L-1 at 237 mL/pot were applied about 4 weeks after potting for both cultivars in mid-December 2017. In 2018–19, fall drenches of uniconazole at 0, 15, 30 or 45 mg·L-1 at 237 mL/pot were applied about 4 weeks after potting in mid-December 2018, or spring sprenches of uniconazole were applied at 0, 15, 30 or 45 mg·L-1 at 840 mL·m-2 in March 2019 after 50% shoot emergence for each cultivar. Plant growth retardant applications had little effect on plant growth of either cultivar, but treated plants were of a darker green color compared to the control plants. In addition, higher rates of uniconazole applied as a fall drench increased the number of flowering shoots of both cultivars and the percentage of plants flowering for 'Sarah Bernhardt' in the second season of the study where plants were more protected from spring freezes. Fall paclobutrazol drenches or spring uniconazole sprenches had little effect on flowering. To determine the best timing for spring GA3 applications under nursery conditions, we applied three models based on natural chilling accumulation. The models were a modified Fulton Chilling Model (FCM) for herbaceous peonies, Blackberry Chilling Model 5 (BCM5) for blackberry, or a visual development model (VDM) which was 10% of plants showing shoot emergence in the spring. We choose 1,000 CU for the first two chilling models as the chilling required to break dormancy and promote normal plant growth and flowering. All plants were held in an unheated coldframe at the Virginia Tech Urban Horticulture Center for one month after potting to promote rooting, then were moved outdoors to a gravel pad to receive natural chilling over the winter months. Drenches of 0 or 100 mg·L-1 GA3 were applied at 250 mL/pot to each cultivar under each chilling model when the specific conditions were met. Due to greater winter injury in the 2017–18 season, results varied by year. In the 2017–18 season, GA3 applied according to BCM5 reduce days to emergence for both cultivars and reduce the plant width of 'Inspecteur Lavergne', and later application according to BCM5 and VDM reduced plant length and diameter of 'Sarah Bernhardt'. Reductions in plant size may have been due to greater winter injury due to the earlier emergence of GA3 treated plants. In the 2018–19 season, earlier GA3 drench applications tended to reduce days to emergence for both cultivars and the FCM application reduced days to bud for 'Inspecteur Lavergne', but GA3 drench applications had no effect on plant size. GA3 can be applied after chilling (1,000 CU) using a suitable chilling model such as FCM for peonies, or BCM5, or VDM, but GA3 had little effect on plant development under nursery conditions. We also evaluated GA3 effects on peony bud differentiation and development during controlled chilling and early forcing, as well as effects on growth and flowering. All potted plants were held in a 10°C cooler for 5.5 weeks (400 CU) to root, then placed in a 5°C cooler for 4 weeks (total 869 CU). GA3 was applied at 0 or 100 mg·L-1 pre-chilling or post-chilling as a 250 ml/pot drench. Bud differentiation and development of excised buds were evaluated using a stereomicroscope at potting, after rooting (before chilling), after 1, 2, 3 or 4 weeks of chilling, and at 5, 10 or 15 days after the beginning of forcing. All buds were removed from the sample plants, measured for bud length and diameter, and dissected under a stereomicroscope to assess differentiation stages. Root dry weights and crown dry weights were also determined after rooting, after chilling, and at 15 days of forcing. Ten plants of each treatment were grown in the Virginia Tech greenhouse after chilling until flowering. GA3 applications did not advance the bud development stage because most of buds were already in the reproductive stages before dormancy, but GA3 enhanced bud elongation during chilling and the early forcing period. Our findings suggest that GA3 applications can reduce the time to emergence and flowering, as well as increase the numbers of shoots and flowering shoots. GA3 applied right after rooting in, prior to the chilling period, or before greenhouse forcing, resulted in earlier emergence and flowering with higher quality plants. However, earlier applications, pre-chilling, tended to produce plants with more shoots. Overall, our experiments indicate that three weeks of chilling at 5°C (752 CU total) is a sufficient chilling regime for forcing 'Sarah Bernhardt' and 'Inspecteur Lavergne' peonies, and 1,000 CU of naturally accumulated chilling is sufficient for nursery production. GA3 applications can reduce the time to emergence and flowering, as well as increase the numbers of total shoots and flowering shoots. Timing of GA3 application is flexible; it can be applied right after rooting, before the chilling period, just before greenhouse forcing, or after shoots have begun to emerge. Plant growth retardant applications had a little effect on the growth of tested cultivars, but all plants treated with growth retardants are generally darker green in color. Additionally, growth retardant applications have some positive effects on flowering. / Doctor of Philosophy / Herbaceous peonies (Paeonia lactiflora Pall.) are common perennials used both in gardens and the landscape as well as for cut flowers. Peonies require a chilling period to break dormancy but not for flower bud differentiation. For all studies, two peony cultivars, Sarah Bernhardt and Inspecteur Lavergne, 3 to 5 eye small crowns from Holland were potted in 3.8-L pots in mid November of 2017 and 2018. Our overall objective was to determine if we could manipulate chilling time, along with application of gibberellic acid (GA3) and growth retardants, to produce marketable containerized peonies from a small crown in a single season (November to May). We evaluated chilling, GA3 and a growth retardant (uniconazole) under controlled chilling and greenhouse forcing conditions. We evaluated the effects of plant growth retardants (uniconazole or paclobutrazol) applied with different methods (fall drenches or spring sprenches) at different stages of production on the growth and development of containerized peony under nursery conditions. To determine the best timing for spring GA3 applications under nursery conditions, we applied three models based on natural chilling accumulation. We also evaluated GA3 effects on peony bud differentiation and development during controlled chilling and early forcing, as well as growth and flowering. Overall, 3 weeks chilling at 5°C [752 chilling units (CU) total] is a sufficient chilling regime for forcing 'Sarah Bernhardt' and 'Inspecteur Lavergne' peonies, and 1000 CU naturally accumulated chilling is sufficient for nursery production. GA3 applications can reduce the time to emergence and flowering, as well as increase the numbers of shoots and flowering shoots. Timing of GA3 application is flexible, it can be applied right after rooting, after the chilling period, or after shoots have begun to emerge. Plant growth retardant applications had little effect on plant growth of either cultivar, but all plants treated with growth retardants were darker green in color. Additionally, growth retardant applications had some positive effects on flowering.

Licopeno, um pigmento natural considerado o mais potente antioxidante dentre os carotenoides, é oque tem maior incidência no soro humano. Seu consumo regular está relacionado principalmente com a prevenção do câncer de próstata. Porém, estudos também demonstram sua relação com a prevenção de câncer de pâncreas e bexiga, doenças cardiovasculares como a aterosclerose e doenças neurodegenerativas. Todavia, por ser altamente insaturado o licopeno é susceptível à degradação, sendo degradado na presença de luz, oxigênio e se exposto a altas temperaturas. A microencapsulação entra como uma alternativa para tentar garantir maior estabilidade a este carotenoide. A técnica de spray-chilling, por dispensar o emprego de altas temperaturas e solventes durante o processo de atomização, representa uma alternativa promissora na encapsulação do licopeno. Os objetivos deste trabalho foram encapsular uma solução oleosa de licopeno (10%) através da técnica de spray-chilling,utilizando gordura vegetal low trans como carreador, caracterizar as micropartículas obtidas e avaliar a biodisponibilidade do licopeno livre e encapsulado em ratos wistars. Foram formulados seis tratamentos, que diferiam pela concentração de solução comercial de licopeno, sendo T1 com 20%, T2 com 23,1%, T3 com 28,6%, T4 com 33,3%, T5 com 17,9% mais 10% de goma arábica e T6 com 19,2% mais 5% de carboximetilcelulose (CMC). As micropartículas obtidas destes tratamentos foram avaliadas quanto a tamanho e distribuição, morfologia por microscopia eletrônica de varredura (MEV), espectroscopia de infravermelho com transformadas de Fourier (FT-IR), difração de raios-X (DRX). A estabilidade do licopeno encapsulado foi avaliada em diferentes condições de armazenamento (sob vácuo, umidade relativa de 33%, temperatura de refrigeração e ambiente) e também foi determinada por meio de quantificações periódicas de licopeno, bem como através da análise análise da cor instrumental. A biodisponibilidade foi avaliada utilizando-se 68 animais divididos em grupos, para os quais se administrou por gavagem o licopeno livre e o encapsulado. O tamanho das micropartículas obtidas ficou em torno de 60-110 µm e a distribuição foi polidispersa, independente da concentração de licopeno. A microscopia revelou micropartículas esféricas, com superfície rugosa, com alguns poros e tamanhos variados. No FT-IR verificou-se que não houve formação de ligações distintas na solução oleosa de licopeno e nas amostras atomizadas. Nos difratogramas observou-se a presença da forma polimórfica β para o agente carreador e para as micropartículas. Na estabilidade a adição da goma arábica e o armazenamento sob temperatura de refrigeração e vácuo, foram as melhores condições para retardar a degradação do licopeno. Os resultados dos ensaios de biodisponibilidade foram inconclusivos. Desta forma, conclui-se que é possível encapsular licopeno através da técnica de spray-chilling, porém, para trabalhos futuros, seriam necessários aprimoramentos na técnica de encapsulação e/ou na formulação para conferir maior proteção ao carotenoide, bem como adequações na metodologia para determinação de sua biodisponibilidade, para obtenção de resultados conclusivos. / Lycopene, a natural pigment considered the most potent antioxidant among the carotenoids, it has the higher incidence in the human serum. Its regular consumption is mainly related with the prevention of prostate cancer. However, studies also show its relation to the prevention of pancreatic cancer and bladder cancer, cardiovascular diseases such as atherosclerosis and neurodegenerative diseases. However, by being highly unsaturated the lycopene is susceptible to degradation, being degraded in the presence of light, oxygen and if exposed to high temperatures. The microencapsulation comes like an alternative to ensuring higher stability for this carotenoid. The technique of spray-chilling represents a promising alternative to encapsulation of lycopene. The aims of this study were to encapsulate an oily solution of lycopene (10%) through of the technique of spray-chilling, using a low-trans fat as carrier, to characterize the obtained microparticles and to evaluate the bioavailability of lycopene free and encapsulated in Wistar rats. Six treatments were formulated, that differed by the content of oily solution of lycopene:T1 with 20%, T2 with 23.1%, T3 with 28.6%, T3 with 28.6%, T4 with 33.3%, T5 with 17.9% plus 10% of Arabic gum and T6 with 19.2% plus 5% of carboxymethylcellulose (CMC). The microparticles obtained from these treatments were evaluated for size and distribution, morphology by scanning electron microscopy (SEM), infrared spectroscopy with Fourier transform (FT-IR) and X-ray difraction (XRD). The stability of the lycopene encapsulated was evaluated by its periodic quantification at different storage conditions (vacuum, relative humidity of 33%, refrigeration temperature and environment temperature). Instrumental color, \"L\" and \"a\" parameters, also was measured. The bioavailability was evaluated using 68 animals, for which the free and lycopene encapsulated were administered by gavage. The size of microparticles obtained was around 60-110 µm and the distribution was polydisperse, independent of the concentration of lycopene. The microscopy revealed spherical microparticles, with rough surface, with some pores and varying sizes. In the FT-IR it was found that there was no formation of distinct bonds in oily solution of lycopeno and the atomized samples. In the diffraction patterns observed the presence of polymorphic form \"β\" for the carrier agent and microparticles. On the stability the addition of Arabic gum and the storage at refrigerator temperature under vacuum, were the best conditions to delay the degradation of lycopene. The results of bioavailability assays were inconclusive. As conclusion, it is possible to encapsulate lycopene using the technique of spray-chilling but to future works, would be required improvements in the technique of encapsulation and/or formulations to give more protection to the carotenoid, as well as adjustments in the methodology for determination of their bioavailability, in order to obtaining conclusive results.

A indústria de alimentos está constantemente desenvolvendo produtos que fornecem, além de nutrientes, benefícios adicionais à saúde, tais como os enriquecidos com vitaminas. A vitamina D3 (colecalciferol) é sintetizada na pele durante a exposição da luz solar, controla a homeostase de cálcio e fósforo, metabolismo ósseo, pressão arterial e reabsorção renal de cálcio. O processo de microencapsulação vem sendo bastante aplicado em alimentos e um dos objetivos principais é o controle da liberação do agente ativo no momento e local desejado. A tecnologia de spray chilling é interessante para a microencapsulação de vitaminas lipossolúveis. O objetivo deste trabalho foi microencapsular vitamina D3, utilizando o método de spray chilling para a produção das micropartículas lipídicas sólidas (MLS). Para produção das MLS utilizou-se gordura vegetal com ponto de fusão em torno de 48 °C como carreador. Três tratamentos foram estabelecidos: sem aditivos (T1), com adição de 1% de cera de abelha (T2) e com 1% de lecitina de soja (T3). As micropartículas foram caracterizadas quanto à morfologia por microscopia eletrônica de varredura, tamanho médio por difração a laser, espectroscopia no infravermelho por transformada de Fourier (FTIR) e foi analisada a estabilidade da vitamina D3 durante o armazenamento a 10 e 25 °C, por meio de quantificações periódicas em cromatografia líquida de alta eficiência (CLAE). As micropartículas obtidas foram esféricas, semelhantes morfologicamente e com distribuição monocaudal de partículas. O tamanho médio das partículas variou em função dos seus ingredientes, sendo que as micropartículas produzidas apenas com vitamina e gordura foram menores em relação às demais (83,0% < 100 &micro;m). A espectroscopia na região do infravermelho (FTIR) demonstrou que não ocorreu interação entre os ingredientes. A estabilidade da vitamina D3 encapsulada foi satisfatória ao longo de 65 dias com valores superiores a 87% para os três tratamentos e a temperatura apresentou influência na estabilidade. As MLS produzidas com cera apresentaram melhores resultados de estabilidade de vitamina D3 com valores de 90,18 ± 2,23 % após 65 dias de estocagem. Esses resultados são promissores e demostram a viabilidade da técnica de spray chilling na produção de MLS carregadas de vitamina D3, possibilitando uma futura aplicação em alimentos. / The food industry is constantly developing products that provide, in addition to nutrients, additional health benefits such as enriched food with vitamins. Vitamin D3 (cholecalciferol), which is synthesized in the skin during exposure of sunlight, controls the homeostasis of calcium and phosphorus, bone metabolism, blood pressure and renal reabsorption of calcium. The microencapsulation process has been widely applied in food and is a key objective to control the release of active agents at specific time and desired location. The spray chilling technology is interesting for microencapsulation of fat-soluble vitamins. The objective of this work was microencapsulating vitamin D3 using the spray chilling method for the production of solid lipid microparticles (SLM). For the production of the SLM it was used vegetable fat with melting point around at 48 °C as a carrier. Three treatments were established: no additives (T1), 1% of beeswax (T2), and 1% soybean lecithin (T3). The morphology of microparticles was characterized by scanning electron microscopy, laser diffraction (average size) and Fourier transform infrared spectroscopy (FTIR). Additionally, vitamin D3 stability was examined during storage at 10 and 25 °C, through periodic measurements by High-performance liquid chromatography (HLPC). The microparticles obtained were spherical with similar morphology and unimodal size distribution. The average particle size varied according to composition wherein microparticles produced with vitamin and fat were lower than other (83.0% of particles smaller than 100 &micro;m). Spectroscopy in the infrared (FTIR) showed that there was no interaction between the components. The stability of vitamin D3 encapsulated was satisfactory over 65 days with values greater than 87% for the three treatments and temperature have any influence on the stability. The SLM produced with wax showed better stability for vitamin D3 with values of 90.18 ± 2.23% after 65 days of storage. These results are promising and demonstrate the feasibility of spray chilling technique in the production of SLM loaded with vitamin D3, allowing future application in foods.

O objetivo desse trabalho foi avaliar o chocolate meio amargo, uma matriz alimentícia pouco explorada no mercado de produtos probióticos, porém muito atrativa para os consumidores, para a adição de Lactobacillus acidophilus (LA3) e Bifidobacterium animalis subsp. lactis (BLC1) na forma livre ou encapsulada. Na primeira etapa do trabalho, micropartículas sólidas lipídicas (MSL) foram produzidas por spray chilling ou recobertas por interação eletrostática dos polímeros (PLRIE), sendo em seguida caracterizadas para verificar se os métodos de encapsulação foram eficientes para a proteção dos probióticos. Na segunda etapa, foram elaboradas e caracterizadas amostras de chocolate meio amargo adicionadas dos probióticos nas formas livre ou encapsulada por spray chilling. Além disso, os produtos foram avaliados sensorialmente por 100 provadores para verificar sua aceitação sensorial. Em relação ao ensaio de sobrevivência dos micro-organismos aos fluidos gastrointestinais simulados, as contagens das populações de LA3 e BLC1 livres, antes de serem aplicados em chocolate, reduziram respectivamente 2,5 e 4 log UFC/g. Após a aplicação dos probióticos em chocolate meio amargo, LA3 e BLC1 livres apresentaram reduções em suas populações de 0,25 e 0,30 log UFC/g, respectivamente, sendo que ambas as contagens das populações encapsuladas apresentaram um decréscimo de aproximadamente 0,50 e 1,10 log UFC/g. Após 120 dias de estocagem do chocolate a 25 °C, as contagens das populações de LA3 e BLC1, na forma livre, apresentaram reduções de 1,40 e 0,70 log UFC/g, enquanto que para as populações dos micro-organismos encapsulados, as contagens foram abaixo do limite de detecção do método. As amostras de chocolate apresentaram aw abaixo de 0,6, pH entre 5,77 - 5,87, teor de gordura e de fenólicos, respectivamente de 34% e 15 mg de ácido gálico equivalente/g de chocolate. Em relação à textura, foi verificado que todas as amostras de chocolate apresentaram um ligeiro incremento da dureza após o período de armazenamento. Por meio do microscópio eletrônico de varredura (MEV) foi visualizada a presença de cristais de gordura, fat bloom, após 120 dias de estocagem em todas amostras de chocolate, o que pode ser relacionado também com o aumento do índice de brancura. Na avaliação sensorial, todas as amostras apresentaram nota de aceitação acima de 7,1, na escala hedônica de 9 pontos. Além disso, todos os produtos apresentaram pelo menos 75% de intenção de compra. Portanto, demonstrou-se que o chocolate meio amargo é uma ótima matriz alimentícia devido a sua composição e características físico-químicas para incorporação de probióticos, não sendo necessária a refrigeração do produto para manter a população dos probióticos durante esse período de estocagem, somando-se ao fato do produto não ter sido alterado sensorialmente após a adição dos micro-organismos probióticos. / The aim of this study was to evaluate the semisweet chocolate, a food matrix little explored in the market of probiotic products, however, very attractive for consumers, for the addition of Lactobacillus acidophilus (LA3) and Bifidobacterium animalis subsp. lactis (BLC1) in free form or encapsulated. In the first stage of the work, solid lipid microparticles (SLM) were produced by spray chilling or covered by electrostatic interaction of polymers (LPCEI), and then characterized to verify if encapsulation methods were efficient for the protection of probiotic cells. In the second stage, semisweet chocolate samples added of probiotics in free form or encapsulated by spray chilling were prepared and characterized. Moreover, the products were evaluated sensorially by 100 panelists to verify their global acceptance.With respect to the test of microorganism survival to simulated gastrointestinal fluids, the counts of LA3 and BLC1 in free form, before being added to chocolate, have reduced respectively 2,5 and 4 log CFU/g. After the application of probiotics in semisweet chocolate, LA3 and BLC1 free have shown reductions in their populations of 0,25 and 0,30 log CFU/g, respectively, and both counts of encapsulated populations have decreased approximately 0,50 and 1,10 log CFU/g. After 120 days of storage of the chocolate at 25 ° C, the counts of LA3 and BLC1 in free form showed reductions of 1,40 and 0,70 log CFU/g, while in the populations of encapsulated microorganisms, the counts were below method detection limit. The samples of chocolate presented aw below 0,6, pH between 5,77 to 5,87, fat and phenolic, respectively, 34% and 15 mg gallic acid equivalent/g of chocolate. Concerning the texture, it has been found that all samples chocolate showed a slight increase in the hardness after storage. Scanning electron microscope (SEM) has been used to visualize the presence of fat crystals and all samples of chocolate presented fat bloom after 120 days of storage, which can also be correlated with the increase in whiteness index. Regarding the sensory evaluation, all samples have shown acceptance mark above 7,1, on a hedonic scale of 9 points. In addition, all products have had at least 75% of purchase intent. Therefore, it has been demonstrated that the semisweet chocolate is an excellent food matrix due to its composition and physical-chemical properties for incorporation of probiotics, adding to the fact that is not necessary to cool the product to maintain the bacterial population during this storage period, as well as it has not been altered sensory after the addition of probiotics microorganisms.

O objetivo desse trabalho foi avaliar o chocolate meio amargo, uma matriz alimentícia pouco explorada no mercado de produtos probióticos, porém muito atrativa para os consumidores, para a adição de Lactobacillus acidophilus (LA3) e Bifidobacterium animalis subsp. lactis (BLC1) na forma livre ou encapsulada. Na primeira etapa do trabalho, micropartículas sólidas lipídicas (MSL) foram produzidas por spray chilling ou recobertas por interação eletrostática dos polímeros (PLRIE), sendo em seguida caracterizadas para verificar se os métodos de encapsulação foram eficientes para a proteção dos probióticos. Na segunda etapa, foram elaboradas e caracterizadas amostras de chocolate meio amargo adicionadas dos probióticos nas formas livre ou encapsulada por spray chilling. Além disso, os produtos foram avaliados sensorialmente por 100 provadores para verificar sua aceitação sensorial. Em relação ao ensaio de sobrevivência dos micro-organismos aos fluidos gastrointestinais simulados, as contagens das populações de LA3 e BLC1 livres, antes de serem aplicados em chocolate, reduziram respectivamente 2,5 e 4 log UFC/g. Após a aplicação dos probióticos em chocolate meio amargo, LA3 e BLC1 livres apresentaram reduções em suas populações de 0,25 e 0,30 log UFC/g, respectivamente, sendo que ambas as contagens das populações encapsuladas apresentaram um decréscimo de aproximadamente 0,50 e 1,10 log UFC/g. Após 120 dias de estocagem do chocolate a 25 °C, as contagens das populações de LA3 e BLC1, na forma livre, apresentaram reduções de 1,40 e 0,70 log UFC/g, enquanto que para as populações dos micro-organismos encapsulados, as contagens foram abaixo do limite de detecção do método. As amostras de chocolate apresentaram aw abaixo de 0,6, pH entre 5,77 - 5,87, teor de gordura e de fenólicos, respectivamente de 34% e 15 mg de ácido gálico equivalente/g de chocolate. Em relação à textura, foi verificado que todas as amostras de chocolate apresentaram um ligeiro incremento da dureza após o período de armazenamento. Por meio do microscópio eletrônico de varredura (MEV) foi visualizada a presença de cristais de gordura, fat bloom, após 120 dias de estocagem em todas amostras de chocolate, o que pode ser relacionado também com o aumento do índice de brancura. Na avaliação sensorial, todas as amostras apresentaram nota de aceitação acima de 7,1, na escala hedônica de 9 pontos. Além disso, todos os produtos apresentaram pelo menos 75% de intenção de compra. Portanto, demonstrou-se que o chocolate meio amargo é uma ótima matriz alimentícia devido a sua composição e características físico-químicas para incorporação de probióticos, não sendo necessária a refrigeração do produto para manter a população dos probióticos durante esse período de estocagem, somando-se ao fato do produto não ter sido alterado sensorialmente após a adição dos micro-organismos probióticos. / The aim of this study was to evaluate the semisweet chocolate, a food matrix little explored in the market of probiotic products, however, very attractive for consumers, for the addition of Lactobacillus acidophilus (LA3) and Bifidobacterium animalis subsp. lactis (BLC1) in free form or encapsulated. In the first stage of the work, solid lipid microparticles (SLM) were produced by spray chilling or covered by electrostatic interaction of polymers (LPCEI), and then characterized to verify if encapsulation methods were efficient for the protection of probiotic cells. In the second stage, semisweet chocolate samples added of probiotics in free form or encapsulated by spray chilling were prepared and characterized. Moreover, the products were evaluated sensorially by 100 panelists to verify their global acceptance.With respect to the test of microorganism survival to simulated gastrointestinal fluids, the counts of LA3 and BLC1 in free form, before being added to chocolate, have reduced respectively 2,5 and 4 log CFU/g. After the application of probiotics in semisweet chocolate, LA3 and BLC1 free have shown reductions in their populations of 0,25 and 0,30 log CFU/g, respectively, and both counts of encapsulated populations have decreased approximately 0,50 and 1,10 log CFU/g. After 120 days of storage of the chocolate at 25 ° C, the counts of LA3 and BLC1 in free form showed reductions of 1,40 and 0,70 log CFU/g, while in the populations of encapsulated microorganisms, the counts were below method detection limit. The samples of chocolate presented aw below 0,6, pH between 5,77 to 5,87, fat and phenolic, respectively, 34% and 15 mg gallic acid equivalent/g of chocolate. Concerning the texture, it has been found that all samples chocolate showed a slight increase in the hardness after storage. Scanning electron microscope (SEM) has been used to visualize the presence of fat crystals and all samples of chocolate presented fat bloom after 120 days of storage, which can also be correlated with the increase in whiteness index. Regarding the sensory evaluation, all samples have shown acceptance mark above 7,1, on a hedonic scale of 9 points. In addition, all products have had at least 75% of purchase intent. Therefore, it has been demonstrated that the semisweet chocolate is an excellent food matrix due to its composition and physical-chemical properties for incorporation of probiotics, adding to the fact that is not necessary to cool the product to maintain the bacterial population during this storage period, as well as it has not been altered sensory after the addition of probiotics microorganisms.

Thesis (Ph.D. (Botany))--North-West University, Potchefstroom Campus, 2009.

Thesis (Ph.D. (Botany))--North-West University, Potchefstroom Campus, 2009.

A indústria de alimentos está constantemente desenvolvendo produtos que fornecem, além de nutrientes, benefícios adicionais à saúde, tais como os enriquecidos com vitaminas. A vitamina D3 (colecalciferol) é sintetizada na pele durante a exposição da luz solar, controla a homeostase de cálcio e fósforo, metabolismo ósseo, pressão arterial e reabsorção renal de cálcio. O processo de microencapsulação vem sendo bastante aplicado em alimentos e um dos objetivos principais é o controle da liberação do agente ativo no momento e local desejado. A tecnologia de spray chilling é interessante para a microencapsulação de vitaminas lipossolúveis. O objetivo deste trabalho foi microencapsular vitamina D3, utilizando o método de spray chilling para a produção das micropartículas lipídicas sólidas (MLS). Para produção das MLS utilizou-se gordura vegetal com ponto de fusão em torno de 48 °C como carreador. Três tratamentos foram estabelecidos: sem aditivos (T1), com adição de 1% de cera de abelha (T2) e com 1% de lecitina de soja (T3). As micropartículas foram caracterizadas quanto à morfologia por microscopia eletrônica de varredura, tamanho médio por difração a laser, espectroscopia no infravermelho por transformada de Fourier (FTIR) e foi analisada a estabilidade da vitamina D3 durante o armazenamento a 10 e 25 °C, por meio de quantificações periódicas em cromatografia líquida de alta eficiência (CLAE). As micropartículas obtidas foram esféricas, semelhantes morfologicamente e com distribuição monocaudal de partículas. O tamanho médio das partículas variou em função dos seus ingredientes, sendo que as micropartículas produzidas apenas com vitamina e gordura foram menores em relação às demais (83,0% < 100 &micro;m). A espectroscopia na região do infravermelho (FTIR) demonstrou que não ocorreu interação entre os ingredientes. A estabilidade da vitamina D3 encapsulada foi satisfatória ao longo de 65 dias com valores superiores a 87% para os três tratamentos e a temperatura apresentou influência na estabilidade. As MLS produzidas com cera apresentaram melhores resultados de estabilidade de vitamina D3 com valores de 90,18 ± 2,23 % após 65 dias de estocagem. Esses resultados são promissores e demostram a viabilidade da técnica de spray chilling na produção de MLS carregadas de vitamina D3, possibilitando uma futura aplicação em alimentos. / The food industry is constantly developing products that provide, in addition to nutrients, additional health benefits such as enriched food with vitamins. Vitamin D3 (cholecalciferol), which is synthesized in the skin during exposure of sunlight, controls the homeostasis of calcium and phosphorus, bone metabolism, blood pressure and renal reabsorption of calcium. The microencapsulation process has been widely applied in food and is a key objective to control the release of active agents at specific time and desired location. The spray chilling technology is interesting for microencapsulation of fat-soluble vitamins. The objective of this work was microencapsulating vitamin D3 using the spray chilling method for the production of solid lipid microparticles (SLM). For the production of the SLM it was used vegetable fat with melting point around at 48 °C as a carrier. Three treatments were established: no additives (T1), 1% of beeswax (T2), and 1% soybean lecithin (T3). The morphology of microparticles was characterized by scanning electron microscopy, laser diffraction (average size) and Fourier transform infrared spectroscopy (FTIR). Additionally, vitamin D3 stability was examined during storage at 10 and 25 °C, through periodic measurements by High-performance liquid chromatography (HLPC). The microparticles obtained were spherical with similar morphology and unimodal size distribution. The average particle size varied according to composition wherein microparticles produced with vitamin and fat were lower than other (83.0% of particles smaller than 100 &micro;m). Spectroscopy in the infrared (FTIR) showed that there was no interaction between the components. The stability of vitamin D3 encapsulated was satisfactory over 65 days with values greater than 87% for the three treatments and temperature have any influence on the stability. The SLM produced with wax showed better stability for vitamin D3 with values of 90.18 ± 2.23% after 65 days of storage. These results are promising and demonstrate the feasibility of spray chilling technique in the production of SLM loaded with vitamin D3, allowing future application in foods.

Orientador: Míriam Dupas Hubinger / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-24T20:09:52Z (GMT). No. of bitstreams: 1 Consoli_Larissa_M.pdf: 32030703 bytes, checksum: 03d005ea2ebe3bbcf9a246d82a8d00a2 (MD5) Previous issue date: 2014 / Resumo: Os compostos fenólicos são conhecidos por suas propriedades antioxidantes, mas podem apresentar susceptibilidade a fatores como oxigênio e luz, perdendo estas propriedades. A microencapsulação pode ser uma alternativa para a proteção destes compostos. A técnica de spray chilling apresenta vantagens como custo relativamente baixo e possibilidade de ampliação de escala. Este trabalho teve como objetivo a aplicação da tecnologia spray chilling à microencapsulação de compostos fenólicos, utilizando ácido gálico como composto fenólico modelo. Misturas de óleo de soja (OS) e óleo de soja totalmente hidrogenado (OSTH) (com proporções de 20 a 90 % de OSTH) foram avaliadas como materiais de parede. Os lipídios foram caracterizados quanto à composição em ácidos graxos, comportamento térmico por calorimetria de varredura diferencial (DSC) e isoterma de cristalização. Avaliou-se a capacidade de formação de partículas de cada mistura através da atomização em spray chilling. O ácido gálico (solução aquosa a 6 % g/g e 60 °C) foi disperso nas misturas lipídicas com o emulsificante PGPR (polirricinoleato de poliglicerol) para formação de emulsões, preparadas com 4 % de emulsificante (em relação à massa lipídica) e 4 minutos de agitação a 9.500 rpm. As micropartículas foram produzidas variando-se a proporção OSTH : OS (60:40, 70:30, 80:20 e 90:10) e a razão MP:MR (material de parede e material de recheio ¿ 70:30 e 80:20), com os seguintes parâmetros: diâmetro do bico atomizador de 0,7 mm, vazão do ar de resfriamento e do ar no bico atomizador, de 35.000 L/h e 667 L/h, respectivamente. A vazão de alimentação da emulsão foi de 0,530 L/h. Foram obtidas micropartículas com eficiências de encapsulação variando de 54,14 ± 2,82 (%) até 101,83 ± 6,74 (%). Maiores proporções de OSTH na mistura lipídica e a menor razão MP : MR influenciaram no aumento da eficiência de encapsulação. Os diâmetros médios variaram de 23,91 ± 1,60 µm a 35,98 ± 2,17 µm e apresentarem oscilação pequena em função das variáveis. A morfologia mostrou partículas de forma esférica e superfície lisa, com presença de cristais e alguns aglomerados de partículas menores. Avaliou-se a estabilidade de duas formulações por 28 dias armazenadas a 5 e 25 °C. A estocagem refrigerada conferiu melhores características de liberação do recheio no meio aquoso e evitou a formação de aglomerados de partículas / Abstract: Phenolic compounds are known for their antioxidant properties, but they may exhibit susceptibility to factors such as oxygen and light, which may cause them to lose these properties. Microencapsulation can be an alternative for the protection of these compounds. The spray chilling technique presents advantages such as relatively low cost and the possibility of scaling-up. This work presented aimed the implementation of the spray chilling technique for the microencapsulation of phenolic compounds, using gallic acid as a model phenolic compound. Blends of soybean oil (SO) with fully hydrogenated soybean oil (FHSO) (in proportions from 20 up to 90% of FHSO) were assessed as wall materials. Lipids were characterized for fatty acid composition, thermal behavior by differential scanning calorimetry (DSC) and isothermal crystallization. The particle-forming ability of each blend was evaluated by atomization in spray chilling. Gallic acid (aqueous solution at 6 % wt/wt - 60 °C) was dispersed in the lipid blends with the emulsifier PGPR (polyglycerol polyricinoleate) for forming emulsions, which were prepared with 4 % of emulsifier (relative to mass of lipid) and stirred for 4 minutes at 9500 rpm. Production of microparticles were made varying the proportion FHSO : OS (60:40 , 70:30 , 80:20 and 90:10) and the ratio WM : CM (wall material to core material - 70:30 and 80:20 ), with the following parameters: diameter of the atomizer nozzle 0.7 mm, cooling air flow and atomizing air flow rates were, respectively, 35,000 L/h and 667 L/h. The feed flow rate of the emulsion was 0.530 L/h. Encapsulation efficiencies of microparticles ranged from 54.14 ± 2.82 (%) to 101.83 ± 6.74 (%). Higher proportions of FHSO in the lipid mixture and the smallest ratio WM : CM led to greater encapsulation efficiencies. The average diameters ranged from 23.91 ± 1.60 µm to 35.98 ± 2.17 µm and presented small variation in function of the variables. The morphology showed particles of spherical shape and smooth surface with some crystals and agglomerates of smaller particles. The stability of two formulations was evaluated over 28 days under different storage temperatures (5 and 25 °C). Storage under refrigeration gave the best release characteristics in aqueous media and prevented the formation of particle agglomerates / Mestrado / Engenharia de Alimentos / Mestra em Engenharia de Alimentos