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Efeito das concentrações de 'alfa'-amilase maltogênica e gordura na qualidade tecnológica e sensorial de bolos / Effect of the concentrations of maltogenic 'alpha'-amylase and fat on technological and sensory quality of cakesBedoya Perales, Noelia Soledad 07 January 2011 (has links)
Orientador: Caroline Joy Steel / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-18T08:22:29Z (GMT). No. of bitstreams: 1
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Previous issue date: 2011 / Resumo: Entre os produtos de panificação, o bolo vem adquirindo crescente importância no que se refere a consumo e comercialização no Brasil. Entretanto, assim como com pães, o aumento da firmeza, atribuído à retrogradação do amido, encurta o shelf-life. Isto tem impacto econômico grande, obrigando os produtores de bolos a procurarem soluções. A gordura é um ingrediente tradicionalmente utilizado por seu efeito sobre a maciez. Outra alternativa é o uso de enzimas como a alfa-amilase maltogênica, que retarda a retrogradação do amido limitando a recristalização da amilopectina, fazendo com que perdure a elasticidade e maciez do miolo por mais tempo. O objetivo do presente trabalho foi determinar o efeito de diferentes concentrações de alfa-amilase maltogênica e gordura na qualidade tecnológica e sensorial de bolos. Para isto, utilizaram-se formulações balanceadas tomando como referência três concentrações de gordura (20, 40 e 60%, base farinha), avaliando-se a adição de alfa-amilase maltogênica (0, 500 e 1000 ppm). A farinha de trigo foi caracterizada quanto a sua composição centesimal e propriedades viscoamilográficas. A massa dos bolos foi avaliada quanto a seu pH e densidade aparente, e os bolos, quanto a seu volume específico, atividade de água, umidade, textura instrumental, cor instrumental, porosidade e análise sensorial. As determinações nos bolos foram realizadas nos dias 1, 7, 14 e 21 de estocagem. Os resultados mostraram que a combinação que apresentou os melhores resultados em termos de qualidade dos bolos (maior volume específico, maior umidade do miolo, menor firmeza do miolo e maior aceitação sensorial) foi aquela com 20% de gordura e 1000 ppm de a-amilase maltogênica (base farinha) / Abstract: Amongst bakery products, cakes are gaining importance in consumption and commercialization in Brazil. However, as with breads, the increase in firmness, attributed to starch retrogradation, shortens shelf-life. This has economical implications, so cake manufacturers are constantly looking for solutions. Fat is an ingredient which is traditionally used for its effect on cake texture. Another alternative is the use of enzymes, such as maltogenic alpha-amylase, that retards starch retrogradation by limiting amylopectin recrystallization, making crumb elasticity and softness last longer. The objective of the present study was to determine the effect of different concentrations of maltogenic alpha-amylase and fat on the technological and sensorial quality of cakes. For this, balanced formulations with 3 different fat concentrations (20, 40 and 60%, flour basis) were used to evaluate the addition of maltogenic alpha-amylase (0, 500 and 1000 ppm). Wheat flour was characterized regarding proximate composition and viscoamylographic properties. Cake batter was evaluated with respect to pH and apparent density, and cakes with respect to specific volume, water activity, moisture content, instrumental texture, instrumental color, porosity and sensory analysis. Determinations were made on days 1, 7, 14 and 21 of storage. The results showed that the combination that presented the best results in terms of cake quality (greater specific volume, higher crumb moisture content, lower crumb firmness and highest sensory acceptance) was the one with 20% fat and 1000 ppm maltogenic a-amylase (flour basis) / Mestrado / Tecnologia de Alimentos / Mestre em Tecnologia de Alimentos
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Enzimas fibrolítica e amilolítica exógenas na alimentação de vacas em lactação / Exogenous fibrolytic and amylolytic enzymes at feeding dairy cowsElissandra Maiara de Castro Zilio 23 February 2018 (has links)
As dietas de vacas em lactação são compostas principalmente por carboidratos que não estão totalmente disponíveis para fermentação microbiana no rúmen, o que pode ser um fator crítico para a obtenção de energia em ruminantes. O objetivo do presente estudo foi avaliar o efeito da adição de enzima fibrolítica (Fibrozyme®, Alltech Inc., Springfield, KY) e amilolítica (Amaize, Alltech Inc., Springfield, KY) nas dietas sobre o consumo de nutrientes, índice de seleção de partículas, digestibilidade aparente total, fermentação ruminal, metabolismo de nutrientes, produção e composição do leite de vacas em lactação. Para o experimento, 32 vacas multíparas da raça Holandesa com 181.3 ± 35.3 (média ± SD) dias em lactação (DEL), 571 ± 72.7 kg de peso vivo (PV) e 29.6 ± 5.24 kg/d de produção de leite (PL), foram distribuídas em 8 quadrados Latinos 4×4. Os tratamentos foram obtidos por esquema fatorial 2×2 pela combinação de enzima fibrolítica e amilolítica, como segue: 1) Controle (CONT): dieta basal sem adição de enzimas exógenas; 2) Enzima fibrolítica (FIB): dieta basal com adição de 1 g/kg de Fibrozyme± no concentrado da dieta (51 UI de atividade xilanase/kg de matéria seca (MS) da dieta; Alltech, Nicholasville, KY, USA; batch#: 417990-2); 3) Enzima amilolítica (AMI): dieta basal com adição de 0,66 g/kg de Amaize no concentrado da dieta (203 FAU/kg MS da dieta; Alltech Nicholasville, KY, USA; batch: 432715-1); e 4) FIB+AMI: adição de 1 e 0,66 g/kg de Fibrozyme® e Amaize, respectivamente. As enzimas foram aplicadas para atender um consumo de 12 g/dia de Fibrozyme® e 8 g/dia de Amaize, de acordo com as recomendações do fabricante. A enzima foi adicionada ao concentrado durante a preparação na fábrica de ração (toda semana). Não foram observados efeitos das enzimas sobre o consumo e digestibilidade dos nutrientes. Contudo, houve efeito de interação entre FIB e AMI para o consumo de partículas entre 19 e 8 mm. A enzima amilolítica aumentou o consumo de partículas entre 19 e 8 mm nos animais que não recebiam FIB. Além disso, AMI reduziu o consumo de partículas maiores que 19 mm. Outro efeito observado foi a interação entre FIB e AMI sobre a concentração de butirato ruminal. A enzima amilolítica aumentou a concentração de butirato apenas nos animais tratados com FIB. Houve tendência de interação entre enzimas sobre a excreção de nitrogênio (N) no leite, em que FIB reduziu a excreção de N no leite apenas nos animais não tratados com AMI. Ainda, AMI reduziu a excreção de N na urina. Ainda, houve interação entre os efeitos de enzima fibrolítica e amilolítica sobre a concentração de colesterol e a atividade enzimática da aspartato aminotransferase (AST) e gama glutamiltransferase (GGT). A enzima fibrolítica reduziu a concentração de colesterol e aumentou a atividade da enzima GGT nos animais não tratados com enzima amilolítica. No entanto, a enzima amilolítica aumentou a concentração de colesterol e a atividade da AST nos animais alimentados com enzima fibrolítica. Houve interação entre enzimas exógenas sobre a produção de proteína e lactose no leite. A enzima fibrolítica reduziu a produção de proteína e lactose nos animais não alimentados com AMI. Não houve mudanças na produção de leite com a suplementação de enzimas exógenas. Em nosso estudo foram encontrados efeitos no consumo de partículas, fermentação ruminal, excreção de N e mudanças na composição do leite, contudo não foram observadas alterações no desempenho produtivo dos animais. / Lactating cows diets are comprised mostly of carbohydrates which are not fully available for microbial fermentation in the rumen, critical factor for to obtain energy in ruminants. The aimed of this study was to evaluate the effect of fibrolytic enzyme (Fibrozyme®, Alltech Inc., Springfield, KY) on nutrient intake, sorting index, total tract digestion, ruminal fermentation, nitrogen utilization, metabolic profile, milk yield and composition in diets with or without amylolytic enzyme (Amaize, Alltech Inc., Springfield, KY) of mid-lactating dairy cows. Thirty-two multiparous Hostein cows with 181.3 ± 35.3 (mean ± SD) days in milk (DIM), 571 ± 72.7 kg of body weight (BW) and 29.6 ± 5.24 kg/d of milk yield, were blocked and randomly allocated to a sequence of treatments in a 4 × 4 Latin square experimental design. Treatments were obtained in a 2 × 2 factorial arrangement, as follows: 1) Control (CONT), basal diet without exogenous enzymes; 2) Fibrolytic enzyme (FIB), provision of Fibrozyme® (batch#: 417990-2; Alltech, Nichollasvile, KY) at 1 g/kg of concentrate (51 IU of xylanase activity/kg diet DM); 3) Amylolytic enzyme (AMY), provision of AmaizeTM (batch#: 432715-1; Alltech) at 0.66 g/kg of concentrate (203 FAU/kg diet DM); and 4) Fibrolytic enzyme plus amylolytic enzyme (FIB+AMY), enzymes added at the same rate in FIB and AMY treatments. The enzymes were applied to meet the intake of 12 and 8 g/cow/day of Fibrozyme® and AmaizeTM, respectively. Enzymes products were added to concentrate during its preparation (once a week). Enzymes no effects on intake and digestibility of nutrients. However, there was FIB and AMY interaction effect on selection index of particle size between 19 and 8 mm. Amylolytic enzyme increase selection index of particles with 19 and 8 mm, only treatments without FIB. Furthermore, AMY decreased the sorting for feed with particle size greater than 19 mm. There was FIB and AMY interaction effect on butyric acid concentration. Amylolytic enzyme increased on butyrate concentrations in cows treated with fibrolytic enzyme. Fibrolytic and amylolytic enzyme interaction effect tended on N excreted in milk, in which FIB decrease N excreted in milk only on animals non-treated with AMY. Whereas AMY reduced urinary N excretion. There was interaction effects of fibrolytic and amylolytic enzymes on cholesterol concentration and the enzymatic activity of AST and GGT. The fibrolytic enzyme reduced cholesterol concentration and increased GGT enzyme activity in animals not treated with amylolytic enzyme. There was FIB and AMY interaction effect on lactose and protein production. Fibrolytic enzyme decreased lactose and protein production, only on animals non-treated with AMY. Exogenous enzymes had no impact on milk production of dairy cows. Enzymes exogenous affected on particle size greater, ruminal fermentation and milk composition. This study did not show evidences that fibrolytic and amylolytic enzymes can alter total tract nutrient digestibility and performance of mid-lactating cows.
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Enzima amilolítica exógena na alimentação de vacas em lactação / Lactating dairy cows fed an exogenous amylolytic enzymeCaio Seiti Takiya 08 July 2016 (has links)
O objetivo deste estudo foi determinar os efeitos de doses dietéticas crescentes de um produto comercial com atividade amilolítica (AmaizeTM, Alltech Inc., Nicholasville, KY, EUA) na ingestão e digestibilidade aparente total de nutrientes, índice de seleção, fermentação ruminal, produção e composição do leite, perfil metabólico, balanço de energia e nitrogênio em vacas no terço médio de lactação. Foram utilizadas vinte e quatro vacas multíparas da raça Holandesa (162,29 ± 107,96 dias em lactação e 31,60 ± 6,51 kg/d de produção de leite, no início do experimento), sendo que 8 delas possuíam cânulas ruminais, distribuídas em seis quadrados Latinos 4 × 4 contemporâneos e balanceados de acordo com a produção de leite, dias em lactação e o peso corporal dos animais. Os períodos experimentais tiveram duração de 14 dias de adaptação aos tratamentos e 7 dias de amostragem. Os tratamentos foram: dieta basal sem adição de enzima amilolítica ou controle (CON), e dieta basal com adição de 150, 300 ou 450 FAU/kg de MS da dieta (A150, A300 ou A450, respectivamente). Uma FAU (unidade de amilase fúngica) é a quantidade de enzima capaz de dextrinizar amido solúvel na taxa de 1 g/h a 30°C e pH de 4,8. A ingestão média esperada do produto comercial pelos animais foi de 7,37; 14,45; e 21,97 g/d nos tratamentos A150, A300 e A450, respectivamente. Os tratamentos não influenciaram a ingestão de MS e de nutrientes, como também o índice de seleção. Os tratamentos não influenciaram a digestibilidade do amido; porém, a inclusão de enzimas amilolíticas aumentou linearmente a digestibilidade de proteína bruta e tendeu a aumentar linearmente a digestibilidade da MS. Os tratamentos com atividade amilolítica não afetaram o pH e a concentração de amônia no fluído ruminal. A adição de enzimas amilolíticas aumentou linearmente a produção de iso-valerato no rúmen. Além disso, os tratamentos não influenciaram a produção e composição do leite, assim como a eficiência alimentar (kg leite / ingestão de MS) dos animais. A enzima amilolítica aumentou linearmente o peso corporal. Apesar de não alterar a composição do leite, a suplementação com enzima amilolítica diminuiu linearmente a excreção de nitrogênio no leite. As doses crescentes de enzima amilolítica tenderam a diminuir linearmente a eficiência de síntese de proteína microbiana. Não foram observadas diferenças nas concentrações séricas de glicose, ureia, e enzimas que indicam lesões hepáticas. A suplementação com doses crescentes enzima amilolítica não afetou a eficiência alimentar, produção de propionato e de proteína microbiana no rúmen, e perfil metabólico de vacas em lactação. No entanto, os tratamentos aumentaram linearmente a digestibilidade de proteína bruta e o peso corporal das vacas / The objective of the current study was to determine the effects of increasing dietary doses of a commercial product with amylolytic activity (AmaizeTM, Alltech Inc., Nicholasville, KY, USA) on nutrient intake and total apparent digestibility, sorting index, ruminal fermentation, milk yield and composition, serum metabolic profile, energy and nitrogen utilization of midlactating dairy cows. Twenty-four multiparous Holstein cows (162.29 ± 107.96 days in milk and 31.60 ± 6.51 kg/d milk yield, before starting the experiment), in which 8 were ruminally cannulated, were used in a replicated 4 × 4 Latin experiment design. The squares were contemporaneous and balanced for milk production, days in milk and live weight of cows. The experimental periods consisted of 14 days to treatments adaptation and 7 days for sampling. Treatments were composed of: basal diet with no enzyme or control (CON), and basal diet with addition of 150, 300 or 450 FAU/kg diet DM (A150, A300 or A450, respectively). One FAU (fungal amylase unit) is able to dextrinize soluble starch at rate of 1g/h on 30°C and pH 4.8. The expected average intake of the commercial product for treatments A150, A300 and A450 were 7.37, 14.45 and 21.97 g/d, respectively. Treatments did not influence the DM and nutrient intake, as well as the sorting index. Treatments did not alter starch digestibility; however, they linearly increased the crude protein digestibility and tended to linearly increase the DM digestibility. Treatments with amylolytic activity did not affect the pH and ammonia concentrations of ruminal fluid. The addition of amylolytic enzyme linearly increased the iso-valerate production in the rumen. In addition, treatments did not influence the milk yield and composition, as well as the milk production efficiency (kg of milk / DM intake) of animals. Treatments linearly increased the live weight and maintenance energy utilization of cows. Despite the enzyme supplementation did not alter the milk composition, it linearly decreased the milk nitrogen excretion. Treatments tended to linearly decreased the efficiency of microbial protein synthesis. No differences were observed on serum metabolic profile of animals, including concentrations of glucose, urea and enzymes which indicate hepatic damage. The supplementation with increasing doses of amylolytic enzymes did not affect the milk production efficiency, ruminal propionate production and microbial protein synthesis, and serum metabolic profile of mid-lactating dairy cows. However, treatments linearly increased the crude protein digestibility and live weight of cows
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Análise do perfil de humor e da enzima alfa-amilase salivar em indivíduos fisicamente ativos = Analysis of profile of mood states and salivary alpha amylase enzyme in physically active individuals / Analysis of profile of mood states and salivary alpha amylase enzyme in physically active individualsTalmasky, Dalila Victoria Ayala, 1974- 20 August 2018 (has links)
Orientador: Luiz Eduardo Barreto Martins / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação Física / Made available in DSpace on 2018-08-20T15:06:59Z (GMT). No. of bitstreams: 1
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Previous issue date: 2012 / Resumo: Este trabalho investigou o instrumento de perfil de humor psicológico BRAMS e traçou o perfil humoral de uma população de jovens fisicamente ativos. Analisou também as respostas das amostras da alfa-amilase salivar e verificou a possível correlação entre os dois marcadores de estresse. Na primeira parte do trabalho foi verificado se a Escala de Humor Brasileira (BRAMS) pode ser utilizada para aferir alterações de humor em resposta a diferentes cargas de treinamento e elaborada a folha de perfil de humor para a população em questão. Realizamos, inicialmente, a análise da concordância do instrumento BRAMS frente aos seis perfis de humor que ele pretende definir. Observamos ótima concordância estatística com os fatores vigor, raiva, fadiga, tensão e confusão mental. Já o fator depressão não apresentou concordância para a população estudada. Construímos, então, uma folha de perfil de humor, oriunda de 228 testes respondidos por 123 indivíduos com idade de 18±1anos (média ± desvio padrão), praticantes de 3 horas de exercício físico diário periodizado. As respostas de um subgrupo de sujeitos (n=105) foram avaliadas em dois momentos: após quatro meses de treinamento físico sistematizado diário, e após quatro dias do término de um treino intensificado de uma semana, quando foi aplicada uma sobrecarga maior em termos físicos e psíquicos. Os dados apresentados mostraram que o instrumento BRAMS foi capaz de discriminar perfis de humor alterados em função da intensificação do treino e a construção da folha de perfil de humor para uma população fisicamente ativa permite monitoramento mais acurado das variações do estado de humor em resposta ao treinamento. Na segunda parte, foram também analisadas as respostas da alfa-amilase salivar nos dois momentos e verificado se existe correlação entre o instrumento de humor e a enzima salivar. Observou-se que os fatores dos testes de humor BRAMS apresentaram na primeira aplicação, valores para os aspectos humorais considerados negativos mais baixos e apenas o fator vigor, único estado de humor considerado positivo, foi mais elevado. Nos resultados da segunda aplicação, todos os fatores negativos foram mais elevados, e apenas o fator vigor manteve-se mais baixo que na primeira aplicação. A enzima salivar alfa-amilase também teve seus valores aumentados na segunda coleta em relação à primeira, mas foi constatado que esses valores estavam dentro do valor de referência para o horário de coleta. Baseado nos resultados deste estudo foi verificado que tanto o teste psicológico, quanto a concentração da enzima salivar alfa-amilase reproduziram variações sofridas nos dois momentos, mas não possuem correlação entre si / Abstract: This study investigated the instrument profile of psychological mood BRAMS and traced the profile of mood state of a population of physically active young. Also examined the responses of samples of salivary alpha-amylase and investigated a possible correlation between the two markers of stress. In the first part of this work it was verified that the Brazilian Mood Scale (BRAMS) can be used to assess mood changes in response to different training loads and a profile sheet of humor was constructed to the population of this study. We have initially performed the analysis of the agreement of the instrument BRAMS front of six profiles of humor that it intends to set. We observed excellent agreement with the statistical factors vigor, anger, fatigue, tension and mental confusion. But the depression factor had no correlation to the population studied. Then, We built a profile sheet of humor, coming from 228 tests administered to 123 subjects aged 18 ± 1 years (mean ± standard deviation), practicing three hours of daily physical exercise periodized. The responses of a subgroup of subjects (n = 105) were evaluated in two moments: after four months of systematic daily physical training, and after four days of the end of an intensified workout a week, when it was applied to a larger overhead in terms of physical and psychic. Our data showed that the instrument was able to discriminate BRAMS profiles altered mood due to the intensification of training and construction of the profile sheet mood for a physically active population allows more accurate monitoring of changes in mood in response to training. In the second part, we also analyzed the responses of salivary alpha-amylase in two times and checked if there is a correlation between the instrument of humor and salivary enzyme. It was observed that the humoral factors of BRAMS showed at the first application, values for the humoral aspects considered negatives lower and only the factor force, the single mood considered positive was higher. The results of the second application showed that all the negative factors were higher, and only the factor force remained lower than the first application. The enzyme salivary alpha-amylase also had its values increased in the second collection from the first one, but it was found that these values were within the reference value for the time of the collection. Based on the results of this study, it was found that both the psychological test and the concentration of salivary alpha-amylase enzyme reproduced variations suffered on both occasions, but have no correlation / Mestrado / Biodinamica do Movimento Humano / Mestre em Educação Física
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Phytochemical and biological studies of Helichrysum cymosumJadalla, Baraa Mohamed Ibrahim Soliman January 2020 (has links)
Masters of Science / Diabetes mellitus (DM) is well known as a group of systemic metabolic disorders with a considerable mortality rate around the world. Hyperglycemia is the main consequence of DM, which results from the shortage in insulin production or degradation of produced insulin. Other internal and external factors including obesity, oxidative stress, and sedentary lifestyle have been also suggested as the causes of DM. Among the well-known existing types of DM, type 1 and 2 are the most common. Treatment of type 1 necessitates insulin injection, while type II can be controlled by physical exercises, diet control in addition to different synthetic antidiabetic drugs. However, their effectiveness is restricted because of the high cost and unfriendly side effects. There is a significant need for producing alternative and more bioactive antidiabetic drugs from natural sources. Natural products are a well-known source for the discovery of new scaffold for drugs discovery, and South Africa is one of the most important megaflora with a high percentage of endemism. South Africa is home to about 245 species of Helichrysum species, which are generally rich sources of secondary metabolites, especially flavonoids, which give them a great value for global acceptability and wide application in the pharmaceutical fields as antibacterial, anti-inflammatory, antioxidant, and antidiabetic agents. The phytochemical investigation of the methanolic extract of H. cymosum resulted in the isolation and identification of seven pure compounds (1-7). Structural characterization of these isolated compounds was conducted using 1D NMR, in comparison with reported spectroscopic data. The in vitro bio-evaluation of H. cymosum against alpha-glucosidase shown that 5 exhibited the highest alpha-glucosidase inhibitory activity with IC50 value of 13 μM, followed by 7 and 3 with IC50 values of 18.16 μM and 44.4 μM respectively. Additionally, strong total antioxidant capacities were displayed by 6 and 2 as ORAC (122.86 ± 0.7 and 91.70 ± 0.4 μM TE/mL) respectively as well as 5 and 7 as FRAP (1006.34 ± 1.7; 977.79 ± 0.8) μM AAE/g. This is the first scientific report to be carried out on alpha-glucosidase inhibitory activities and antioxidant capacities of H. cymosum constituents. The findings suggest that these compounds might become prominent natural candidates to inhibit alpha-glucosidase as well as oxidative stress related to diabetes with the prospect to be employed in the formulation of diabetes drugs upon further biological studies.
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Salivary alpha-amylase: More than an enzyme Investigating confounders of stress-induced and basal amylase activityStrahler, Jana 18 August 2010 (has links)
Summary: Salivary alpha-amylase: More than an enzyme - Investigating confounders of stress-induced and basal amylase activity (Dipl.-Psych. Jana Strahler)
The hypothalamus-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS) are two of the major systems playing a role in the adaptation of organisms to developmental changes that threaten homeostasis. The HPA system involves the secretion of glucocorticoids, including cortisol, into the circulatory system. Numerous studies have been published that introduced salivary cortisol to assess HPA axis activity and therefore strengthens its role as an easy obtainable biomarker in stress research that can be monitored easily and frequently. Recent findings suggest a possible surrogate marker of autonomic activity due to autonomic innervation of salivary glands: salivary alpha-amylase (sAA). Up to date, additional methodological research is needed for a better understanding of the advantages and disadvantages of sAA activity in comparison to already established markers of ANS activity. The aim of the present thesis is to further our knowledge of confounders of sAA activity under basal and acute stress conditions and to strengthen the validity of this enzyme as an easy obtainable alternative for ANS testing.
After introducing classical and modern stress concepts and stress system physiology (chapter 2), the reader is acquainted with anatomical basics of salivary gland innervation and secretion of salivary proteins, including sAA, due to autonomic innervation (chapter 3 and 4). Afterwards, a more nuanced review of methodological considerations of sAA determination shows gaps of knowledge concerning its usefulness as a marker of ANS activity (chapter 5). Given the fact that the integration of sAA into developmental and aging research is a relative recent phenomenon, several issues have to be addressed before a final conclusion could be drawn. Therefore, we conducted a series of studies incorporating these considerations regarding behavioral correlates of inter- and intraindividual differences in sAA activity with a special emphasis on older adults.
Chapter 7 deals with sAA activity under psychological stress conditions in different age groups. Since vulnerability to disease and disease prevalence patterns change with age, it is important to investigate stress reactivity of people in different age groups. We therefore investigated children between 6 and 10 years, because childhood is a sensitive period of growth and development, and thus plays an important role for later life health. Young adults were included to represent the most studied human age group as a reference. Older adults between 59 and 61 years were investigated, because at this age the course is set for the further development of a person’s health in later life, and because autonomic stress responses in older age might be important determinants of cardiovascular and inflammatory aging. Our goal is to test for associations of sAA with more established stress system markers, i.e., salivary cortisol as outcome measurement of HPA reactivity, heart rate (HR) and heart rate variability (HRV) as markers for autonomic reactivity, and to directly compare these responses between different age groups across the life span. Secretion of sAA and cortisol was repeatedly assessed in 62 children, 78 young adults, and 74 older adults after exposure to a standardized psychosocial stressor, the Trier Social Stress Test. In addition, cardiovascular activity was measured in both adult groups. Older adults showed attenuated sAA, HR, and HRV responses. Furthermore, we found higher sAA but lower cortisol at baseline as well as lower sAA and cortisol responses in children. Age by sex interactions were observed only for cortisol with higher responses in older male participants. No associations between the parameters were found. Results in children and young adults confirm previous results. Overall, findings implicate sAA as an alternative or additional autonomic stress marker throughout the life span, with marked and rapid responsiveness to stress in three relevant age groups.
The impact of age and chronic stress on basal sAA activity is the center of interest in chapter 8. We therefore assessed diurnal profiles of sAA and salivary cortisol in 27 younger and 31 older competitive ballroom dancers as well as 26 younger and 33 older age- and sex-matched controls. According to the Allostatic Load concept, repeated, non-habituating responses to social-evaluative conditions, which characterize the lives of competitive ballroom dancers, should be associated with stress system dysregulations. Furthermore, we expect to see an increased sympathetic drive associated higher overall alpha-amylase activity in older adults. Analyses revealed an elevated daily overall output of sAA in older adults while there was no effect of age on mean cortisol levels. Alterations of diurnal rhythms were only seen in younger male dancers showing a flattened diurnal profile of sAA and younger dancers and female older dancers showing a blunted diurnal rhythmicity of cortisol. Furthermore, we found a negative correlation between summary indices of basal sAA and the amount of physical activity. In conclusion, higher overall output of sAA in older adults was in line with the phenomenon of a “sympathetic overdrive” with increasing age. Furthermore, a lower output of sAA in people who are more physical active was in line with the hypothesis of an exercise-induced decrease of sympathetic activity.
Taken together, results of chapter 7 and 8 show a clear impact of age on sAA activity, either under acute stress or basal conditions. One problem when integrating sAA into developmental and aging research is the use of adrenergic agonists and antagonists what is very common in older adults, i.e. antihypertensive drugs (AD). As well, the previously shown sympathetic overactivity that occurs with normal aging is associated with higher blood pressure (BP). Therefore, chapter 9 deals with a possible impact of high BP and AD on diurnal sAA activity in 79 older adults (33 normotensive adults, 16 medicated vs. 45 hypertensive adults, 34 medicated). Results showed a pronounced rhythm of sAA in all groups. Diurnal profiles differed significantly between men and women with men lacking the typical decrease of sAA in the morning and showing more pronounced alterations throughout the day. An effect of AD on sAA profiles and area under the curve values indicates that subjects not using AD´s show a heightened diurnal profile and a higher total output of sAA. Descriptively, this was also true for hypertensive older adults. Hypertensive subjects and those not using AD showed the highest diurnal output of sAA and the steepest slope. In sum, our results show an impact of antihypertensive medication and a difference between normotensive and hypertensive subjects on characteristics of diurnal sAA activity. Hence, findings are of particular interest in research using sAA as a prognostic indicator of pathological states and processes.
Given the fact that hypertension was also shown to be associated with substantial changes of transmitters within the suprachiasmatic nucleus (SCN) - the “biological clock” that receives photic input from retinal glands via the retinohypothalamic pathway - and an altered output from the SCN to the sympathetic nervous system, we broaden the idea of a possible effect of different lighting conditions on morning sAA profiles in chapter 10. In a counterbalanced within-subjects design six men and 16 women of different ages collected sAA morning profiles on two consecutive days with leaving their shutters closed on the one day (= dark) and open their shutters on the other day (= bright). We were able to replicate earlier findings of light-induced changes of salivary cortisol with higher responses during the bright condition. On either day, women showed larger cortisol increases than men. Despite multisynaptic autonomic connections arising from the SCN projecting to multiple organs of the body, we could not find an effect of sunlight on sAA morning profiles. Evidence for circadian clock gene expression in human oral mucosa might account for this result and indicates that peripheral oscillators may act more like integrators of multiple different time cues, e.g. light, food intake, instead of a “master” oscillator (SCN).
Results of chapter 7 to 10 provide clear evidence that sAA is heightened in states of autonomic arousal, i.e. stress, aging and hypertension, and that its circadian rhythmicity seems to be regulated rather integrative than directly via efferent input from hypothalamic SCN neurons. In chapter 11 this thesis tries to approach one central question: What is the biological meaning of the findings made? According to this enzyme´s anti-bacterial and digestive action short term changes might not have a biological meaning itself but rather reflect just a small part of multiple coordinated body responses to stressful stimuli. While the sympathetic branch of the ANS mainly stimulates protein secretion, the parasympathetic branch stimulates saliva flow. Acute stress responses might therefore be interpreted as reflecting predominant sympathetic activity together with parasympathetic withdrawal. The same mechanism could also be suitable for the finding of higher diurnal levels of sAA in older adults or hypertensive subjects reflecting a higher peripheral sympathetic tone in these groups. Diurnal profiles of sAA itself may reflect circadian changes in autonomic balance. Circadian rhythms are of great advantage since they enable individuals to anticipate. This pre-adaptation enables the individual to cope with upcoming demands and challenges. Our finding of a relationship between sAA and salivary cortisol what strengthens the relevance of glucocorticoids that were previously shown to be able to phase shift circadian rhythms in cells and tissue. Within a food-related context there is evidence that decreasing levels of sAA in the morning could reflect increases of feeling hungry since sAA systematically increases during food consumption and with the subjective state of satiety. So far, much more research is needed to identify underlying physiological mechanisms of circadian sAA rhythmicity.
Taking the next step, future studies will have to focus on the integration of sAA assessment into longitudinal studies and different disease states to prove its applicability as a marker of sympathetic neural functioning in the genesis and prognosis of disease.:Table of Contents
1. Introduction 1
2. Stress 3
2.1. Stress concepts 3
2.1.1. Traditional concepts of stress 3
2.1.2. Allostasis and Allostatic Load 4
2.2. Stress system physiology 6
2.2.1. The hypothalamic-pituitary-adrenal (HPA) axis 6
2.2.1.1. Physiology 6
2.2.1.2. HPA axis activity indicators 6
2.2.2. The autonomic nervous system (ANS) 7
2.2.2.1. Physiology 7
2.2.2.2. ANS activity indicators 8
2.2.3. Relationships between stress systems 10
3. Saliva and salivary glands 11
3.1. Physiology 11
3.1.1. Anatomy, origin, and composition 11
3.1.2. Innervation 12
3.1.3. Salivary gland physiology with aging 13
3.2. Saliva and salivary flow 13
3.3. Protein secretion 14
4. Alpha-amylase in saliva 15
4.1. Chemical characteristics 15
4.2. Secretion of alpha-amylase 15
4.3. Diagnostic value of alpha-amylase 16
5. Methodological considerations of alpha-amylase determination 17
5.1. Collection methods and preparation 17
5.1.1. Saliva collection 17
5.1.2. Impact of flow rate 17
5.1.3. Impact of pH-value 18
5.2. Biochemical determination 18
5.3. Interindividual differences in sAA activity 19
5.3.1. Basal activity 20
5.3.2. Acute responses 20
5.3.3. Age effects 21
5.3.3.1. Basal amylase activity 21
5.3.3.2. Stress-induced amylase activity 21
5.3.4. Sex differences 22
5.3.4.1. Basal amylase activity 22
5.3.4.2. Stress-induced amylase activity 23
5.3.5. Modulating factors influencing amylase (re-)activity 24
5.3.5.1. Impact of smoking 24
5.3.5.2. Impact of alcohol 25
5.3.5.3. Impact of caffeine 25
5.3.5.4. Impact of high body fat and obesity 26
5.3.5.5. Impact of food intake 26
5.3.5.6. Impact of physical exercise 27
5.3.5.7. Impact of somatic and psychiatric diseases 27
5.3.5.8. Impact of medical drugs 29
5.3.5.9. Impact of sunlight on diurnal amylase 29
6. Aims and outline of the present work 31
7. Salivary alpha-amylase stress reactivity across different age groups 32
7.1. Introduction 32
7.2. Methods 35
7.2.1. Participants 35
7.2.2. Study Protocol 35
7.2.3. Measures 36
7.2.3.1. Saliva sampling 36
7.2.3.2. Heart rate and heart rate variability 36
7.2.3.3. Biochemical analyses 37
7.2.3.4. Psychometrical analyses 37
7.2.4. Statistical analyses 38
7.3. Results 38
7.3.1. Sample characteristic 38
7.3.2. Subjective stress response 39
7.3.3. Physiological stress response 39
7.3.3.1. Salivary alpha-amylase 39
7.3.3.2. Salivary cortisol 40
7.3.3.3. Heart rate 42
7.3.3.4. Heart rate variability 43
7.3.3.5. Determinants of the salivary alpha-amylase stress response 45
7.4. Discussion 45
7.5. Conclusion 48
8. Aging diurnal rhythms and chronic stress: Distinct alteration of diurnal rhythmicity of salivary alpha-amylase and cortisol 49
8.1. Introduction 49
8.2. Methods 52
8.2.1. Participants 52
8.2.2. Study protocol 53
8.2.3. Measures 53
8.2.3.1. Saliva sampling 53
8.2.3.2. Biochemical parameters 54
8.2.3.3. Psychological parameters 54
8.2.4. Statistical analyses 54
8.2.4.1. Preliminary analyses 54
8.2.4.2. Diurnal course of salivary alpha-amylase 55
8.3. Results 56
8.3.1. Sample characteristic 56
8.3.2. Preliminary analyses: impact of oral contraceptives, blood pressure, and lipid lowering medication on diurnal profiles 56
8.3.3. Diurnal course of salivary alpha-amylase 57
8.3.3.1. Salivary alpha-amylase over the day 57
8.3.3.2. Salivary alpha-amylase after awakening 58
8.3.4. Diurnal course of salivary cortisol 59
8.3.4.1. Salivary cortisol over the day 59
8.3.4.2. Salivary cortisol after awakening 60
8.3.5. Diurnal course of salivary biomarkers: associations and determinants 61
8.4. Discussion 62
8.5. Conclusion 65
9. Impact of blood pressure and antihypertensive drugs on diurnal alpha-amylase activity: A novel marker of sympathetic drive 67
9.1. Introduction 67
9.2. Methods 68
9.2.1. Participants 68
9.2.2. Study protocol 69
9.2.3. Measures 69
9.2.3.1. Saliva sampling 69
9.2.3.2. Biochemical parameters 69
9.2.3.3. Blood pressure assessment 70
9.2.4. Statistical analyses 70
9.3. Results 70
9.3.1. Participants 70
9.3.2. Salivary alpha-amylase 71
9.3.2.1. Salivary alpha-amylase over the day 71
9.3.2.2. Salivary alpha-amylase after awakening 74
9.4. Discussion 75
9.5. Perspectives 76
10. Light affects morning salivary cortisol, but not salivary
alpha-amylase 77
10.1. Introduction 77
10.2 Methods 79
10.2.1. Participants 79
10.2.2. Study protocol 80
10.2.3. Measures 80
10.2.3.1. Saliva sampling 80
10.2.3.2. Biochemical parameters 81
10.2.4. Statistical analyses 81
10.3. Results 82
10.3.1. Sociodemographics 82
10.3.2. Salivary alpha-amylase 82
10.3.3. Salivary cortisol 84
10.3.4. Associations between biochemical parameters 85
10.4. Discussion 86
10.5. Conclusion 89
11. General discussion 90
11.1. Summary of the results 90
11.1.1. Salivary alpha-amylase stress reactivity across different age groups 91
11.1.2. Aging diurnal rhythms and chronic stress: Distinct alteration of diurnal rhythmicity of salivary alpha-amylase and cortisol 91
11.1.3. Impact of blood pressure and antihypertensive drugs on diurnal alpha-amylase activity: A novel marker of sympathetic drive 92
11.1.4. Light affects salivary morning cortisol, but not salivary alpha-amylase 93
11.2. Integration of main findings 93
11.3. Stress-induced amylase activity, basal rhythm, and its biological meaning 95
11.4. Methodological consequences 97
11.4.1. Circadian variation 97
11.4.2. Longitudinal variation 98
11.4.3. Short-term variation and stability 98
11.4.4. Long-term change 99
11.5. Outlook 100
12. References 102
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Psychobiological functioning in mid-adolescent girls and boys : Linkages to self reported stress, self-esteem and recurrent painFolkesson Hellstadius, Lisa January 2014 (has links)
Among adolescents, the day-to-day functioning of the hypothalamo-pituitary-adrenal-axis (HPA-axis) and of the autonomic nervous system (ANS) and their relationships with stress, subjective health complaints and psychological factors such as self-esteem, studied in naturalistic settings, have been largely unexplored. This thesis aimed to investigate the diurnal activity of the HPA-axis (Studies I & II) in terms of salivary cortisol and the ANS/SNS system (Study III) in terms of salivary alpha-amylase (sAA) in mid-adolescent girls and boys. Additionally, linkages between self-reported stress, self-esteem, recurrent pain and biomarkers were investigated. A further aim was to describe potential differences between girls and boys respectively. Study I showed that both girls and boys exhibited the typical diurnal cortisol profile with high levels in the morning that decreased throughout the day. Girls had higher total cortisol levels, while no differences emerged for measures of the cortisol increase. Study II showed no significant linkages between self-ratings of stress and cortisol. However, stress was associated with recurrent pain in girls. Study III showed that, for girls, both self-esteem and self-reported stress were related to morning levels of both cortisol and sAA, to the diurnal sAA output and to a conjoint measure of amylase over cortisol, AOC. To conclude, the findings suggest that both stress and self-esteem may be linked to different measures of ANS and HPA-axis activity, but also to measures of ANS and HPA-axis dysregulation, particularly among mid-adolescent girls. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript.</p>
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Caracterização físico-química e purificação de enzimas amilolíticas de mandioca (Manihot esculenta Crantz) cv. Zolhudinha / Characterization physical-chemistry and purification of amylolytic enzymes from cassava (Manihot esculenta Crantz) cv.ZolhudinhaPascual, Cristina de Simone Carlos Iglesias 05 August 2005 (has links)
A mandioca (Manihot esculenta Crantz) é uma raiz originária e cultivada na América do Sul, com alta perecibilidade no período pós-colheita. Seus principais processos de deterioração envolvem reações enzimáticas, oxidativas e microbiológicas. Neste trabalho foram estudadas raízes de mandioca da variedade Zolhudinha catalogada pela EMBRAPA como IM-158, provenientes da região amazônica, que se destacam pela alta atividade amilolítica. Foram analisadas as condições físico-químicas junto com o isolamento e purificação da α-amilase da raiz e a possível participação desta enzima no processo deteriorativo pós-colheita. Por ser uma variedade de mandioca não comercial, o tempo de cocção foi em média de 4,30 h, teor de umidade em tomo de 64 % e porcentagem de amido de cerca de 30 %. A atividade amilásica decai em 1/3 de sua intensidade no quinto dia pós-colheita, em contraponto a formação de açúcares redutores, cuja concentração aumenta cinco vezes. A purificação foi obtida com duas etapas cromatográficas, com DEAE-celulose e Sephacryl S-200, revelando duas isoenzimas de α-amilase treze vezes mais purificadas, com recuperação protéica de 7,5 % e com pesos moleculares entre 14 e 19 kDa. / Cassava (Manihot esculenta Crantz) is a root from a native plant, cultivated in South América, that is hightly perish on the post-harvest time. The mechanisms of the root deterioration are due to enzymatic and oxidative reactions as well as the microbiological attack. In this work were studied roots of Zolhudinha variety, EMBRAPA - IM 158, cultivated in Amazonian area, which distinguishes from others varieties by its higher amylase activity. Physicochemical properties were analyzed during the post-harvest time, the purification of α-amylase were performed to establish a possible involvement on the deteriorative process. As a non-commercial variety, the cooking time of the roots was 4.30 hours on average, with 64 % of water content and 30 % of starch. The amylase activity during the post-harvest decrease 1/3 from the original at the day 5, that matches with the reducing sugar in roots by increase of five times. The purification was achieved by two chromatography steps on DEAE-cellulose and Sephacryl S-200, providing two isozymes of α-amylase, thirteen times more purified with a recovery of 7.5 % of the protein fraction, the estimated molecular weights were between 14 and 19 kDa.
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Caracterização e síntese dos inibidores de α-amilase do feijão (Phaseolus vulgaris) / Characterization and synthesis of alpha amylase inhibitor from beans (Phaseolus vulgaris)Iguti, Antonia Miwa 30 April 1993 (has links)
Inibidores de alfa amilase de feijão (Phaseolus vulgaris) foram caracterizados. O inibidor da variedade Jalo apresentou peso molecular de 50kDa (por filtração em gel), ponto isoelétrico de 4,75 e 9,6% de carboidratos. O inibidor da variedade Argentino apresentou peso molecular de 48kDa, ponto isoelétrico de 4,90 e 7,6% de carboidratos. Ambos inibidores apresentaram pH ótimo de interação com alfa amilase pancreática de porco de 5,0 e, a pH 6,9, a complexação com a mesma enzima se deu na proporção de 1:1. Esses resultados, mais a composição de aminoácidos, indicaram que as características desses inibidores são semelhantes às de outros já purificados de diferentes variedades de feijão. As principais diferenças entre o IA do Jalo e do Argentino, foram observadas através de termogramas, do teor de carboidratos e dos ensaios imunológicos. Além disso, são sintetizados entre 20 e 30 dias após a floração, sendo que o processo ocorre simultaneamente ao da síntese das proteínas de reserva do grão. Inibidores purificados das variedades Jalo, Argentino e Rico 23, em diferentes fases do desenvolvimento, indicaram ausência de grandes alterações estruturais durante esse processo. / α-amylase inhibitors of bean (Phaseolus vulgaris) were characterized. The amylase inhibitor from Jalo had molecular weight of 50 kDa (by gel filtration), an isoeletric point of 4.75 and a carbohydrate content of 9.6%. Argentino presented molecular weight of 48 kDa, an isoeletric point of 4.90 and a carbohydrate content of 7.6%. The optimum pH for inhibition of porcine pancreatic α-amylase for both inhibitors was about 5.0 and they formed 1:1 stoichiometric complex. These results and the amino acid composition indicated that these inhibitors have characteristics similar to others already purified from beans. They were synthesized between 20 and 30 days after anthesis and this process occurred simultaneously to the storage proteins synthesis. Purified inhibitors from seeds in different phases of development indicated lack of great structural changes during this process.
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Estudo da produção de enzimas amiloliticas pelo fungo Metarhizium / Study of the amylolytic enzymes production by Metarhizium anisopilae using chaff and rice bran as substratesGuandalini, Natalia Capeletti 15 February 2007 (has links)
Orientador: Ranulfo Monte Alegre, Vanildo Luiz Del Bianchi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-08T12:41:54Z (GMT). No. of bitstreams: 1
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Previous issue date: 2007 / Resumo: O fungo Metharhizium anisopliae tem sido empregado no biocontrole de insetos em diferentes regiões do Brasil, com aplicação principal em lavouras de cana-de-açúcar. O processo de biocontrole envolve a adesão dos esporos do fungo à superfície do inseto, a destruição do mesmo através da pressão mecânica das hifas, além de processos de digestão enzimática de proteínas, quitinas e lipídeos. Por esse motivo, estudos indicam a viabilidade da produção de amilases, proteases, lipases e quitinases pelo fungo. Além disso, este fungo tem sido objeto de estudos como produtor de swainsonine, um alcalóide com ação potencial na inibição da metástase celular e do crescimento primário de tumores, sendo promissora a sua utilização em tratamentos contra o câncer e AIDS. Sendo assim, este trabalho teve como objetivo estudar o potencial amilolítico de linhagens de Metarhizium anisopliae. Para a produção das enzimas utilizou-se fermentação em meio sólido. Para tanto, o microrganismo mantido em meio BDA foi inoculado através da suspensão de células na concentração de 107 esporos/g em 10 g de meio farelo e casca de arroz, em proporções de 7/3 (p/p), 6/4 (p/p) e 8/2 (p/p). A umidade inicial dos meios de cultivo variou em 47%, 65% e 74%. A fermentação ocorreu em sacos de polipropileno, os quais foram mantidos a 28ºC durante 480 horas, sendo retiradas amostras a cada 24 horas. No extrato enzimático obtido foram determinadas as atividades de a-amilase e de amiloglicosidase. Para o estudo da influência da interação de fatores como meio de cultivo, umidade, pH e concentração de esporos na produção das enzimas em estudo, foi utilizado um planejamento experimental 24-1, onde se observou que o pH apresenta influência na produção de a-amilase. Para a produção de a-amilase e amiloglicosidase, observou-se que o melhor meio de cultivo foi o constituído por farelo e casca de arroz na proporção 6/4 (p/p), com umidade de 47%. O pH ótimo para a atividade de a¿amilase e de amiloglicosidase foi de 5 - 5,5, apresentando estabilidade numa faixa de 5 ¿ 6,5 para a a¿amilase e de 5,5 ¿ 6 para a amiloglicosidase. A temperatura ótima para a atividade enzimática de a¿amilase foi de 70ºC e de 60ºC para a amiloglicosidase, apresentando estabilidade numa faixa de 10 a 50ºC. A atividade enzimática de a¿amilase foi influenciada positivamente pelos íons Mg+2, Mn+2, K+, Ca+2 e EDTA, enquanto o íon Zn+2 influenciou negativamente a atividade da enzima. Para a amiloglicosidase, todos os íons testados apresentaram efeito negativo, com destaque para o Zn+2 que apresentou a maior redução na atividade enzimática / Abstract: The fungus Metharhizium anisopliae has been used as biocontrol agent, actuating on insects in different areas of Brazil, with main application in sugarcane farmings. Such a biocontrol process involves the adhesion of the fungus spores to the surface of the insect, destruction of the same through the mechanical pressure of the hyphal, as well the processes of enzymatic digestion of proteins, chitins and lipids. For that reason, studies indicate the viability of the production of amylases, proteases, lipases and chitinases by this fungus. Besides, it is object of studies as producer of swainsonine, an alkaloid with potential action in the metastasis cellular and in the primary growth of tumors, being promising its use in treatments against the cancer and AIDS. The objective of this work was to evaluate the amylolytic potential of the strains of Metharizium anisopliae. For the enzymes production, it was utilized solid state fermentation. For that, the microorganism maintained in PDA media was inoculated through the suspension of cells in the concentration of 107 spores/g in 10 g of media constituted by bran and rice chaff, in proportions of 7/3 (p/p), 6/4 (p/p) and 8/2 (p/p). The initial moisture content of fermentation was varied on 47%, 65% and 74%. The experiments were carried in polypropylene bags, which were incubated at 28ºC for 480 hours of fermentation, being removed from it, samples every 24 hours. From the crude enzymatic solution, there were determined the activities of a-amylase and the amiloglucosidase. For the study of the interaction of factors such as cultivation medium, moisture, pH and inoculum size in the enzymes production, a statistical design 24-1 was used, where it was observed that the pH presents influence in the production of a-amylase. For the production of a-amylase and amiloglicosidase, it was concluded that the best cultivation medium is constituted by bran and rice chaff in the proportion 6/4 (p/p), with a moisture content of 47%. The optimum pH for a-amylase and amiloglicosidase was of 5 - 5,5, presenting stability in a pH range from 5 to 6,5 for the a- amylase and 5,5 to 6 for the amiloglicosidase activity. The best temperature for a-amylase activity was 70ºC and 60ºC for the amiloglicosidase, presenting stability in a range from 10 to 50ºC. The a-amylase activity was influenced positively by the ions Mg+2, Mn+2, K+, Ca+2 and EDTA, while the ion Zn+2 influenced negatively the enzyme activity. For the amiloglicosidase, all of the tested ions presented negative effect, with prominence for Zn+2 that presented the largest reduction in the enzymatic activity / Mestrado / Mestre em Engenharia de Alimentos
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