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Factors Affecting Phytochemical Composition and Antioxidant Activity of Ontario Vegetable CropsHu, Chanli 04 1900 (has links)
The total phenolic content (TPC) of common vegetables grown in Ontario was determined by the Folin-Ciocalteu method, and it was found that the broccoli inflorescence had an exceptionally high TPC on average value, followed by cabbage, onion, potato and carrot. The TPC values of darkpurple potatoes and carrots were higher than the common potatoes and carrots. Positive correlations between the TPC and TAA were observed with varied degrees in all vegetables. Choice of cultivar and production practices can be used to increase TPC and TAA in a wide range of vegetables. Insecticide application did not influence the TPC and TAA of broccoli leaves and flowers. Higher N rate decreased the TPC and TAA of cabbage cultivar ‘Huron’ and of carrot. Fungicide and biofungicide applications did not influence TAA in carrots. Fertilizer applications did not influence the TAA of onions, but there was a decrease in TPC. The rate of MAP (mono ammonium phosphate 52% P2O5) affected the TAA of onions, but the influence was inconsistent between two antioxidant assays. High temperature with possibly high rainfall capacity occurred in the year increased the TPC and TAA of most studied vegetable crops. / Ontario Ministry of Agriculture, Food and Rural Affairs/University of Guelph Sustainable Production Systems Program
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Sensory profile variation of pomegranate seeds and pomegranate juice : tea beverages flavor and acceptanceHiga, Federica A. January 1900 (has links)
Master of Science / Food Science Institute / Kadri Koppel / Pomegranate fruits have grown in popularity due to their known beneficial health properties. The objectives of this study were to: 1) determine if flavor differences existed among and within fruits, 2) understand appropriate numbers of replications needed for products that are naturally variable, and 3) compare individual and consensus scores for descriptive sensory analysis over 10 replications of the same product to determine whether differences are found between the methods.
Three different sections of the pomegranate fruit were individually evaluated (top, middle and bottom) to determine if flavor differences existed among the fruit sections. Furthermore, the number of repetitions needed in order to obtain small differences in a descriptive panel was calculated. Results showed that pomegranate fruits have natural variation of flavor in the different sections, as well as differences among fruits of the same cultivar. The number of repetitions increased as the differences that wanted to be detected became smaller, and they decreased, as these differences increased.
After each sections of fruit were individually evaluated, the panel discussed results and set consensus scores for each attribute. Analysis on mean individual scores and consensus data, along with Principal Component Analysis (PCA) showed that both, individual and consensus methods, provided the same reliable and reproducible information. However, this was evaluated using highly trained panelists.
Besides pomegranate juice (PJ), green tea (GT) is one of the most consumed beverages in the world, and has the highest polyphenol content of all teas. Six PJ and GT blends were prepared at different ratios: 90-10, 80-20, 70-30, 60-40, 50-50, 40-60 vol/vol. Lipton GT and Wonderful pomegranates were used to prepare the samples. The objectives of this study were to: 1) determine sensory differences in the samples, 2) consumer acceptance before and after antioxidant information of the samples was provided, and 3) determine their total phenolic content (TPC).
Results showed that samples with lower PJ were higher in attributes intensities for Green, and Tea like flavor, while attributes like Berry, Cranberry, Cherry and Sweetness were lower. Consumers liked samples higher in PJ, and sample 40-60 was the least liked. However, overall liking of all samples increased when antioxidant information was given. TPC results showed that pure PJ had the highest content, and as it was mixed with GT, TPC was the sum of the individual percentages of each component. Addition of claims in beverage labels might be a good strategy for consumers to purchase these type of products high in antioxidant content.
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Determinação de fenóis totais em frutos do café: avaliações em diferentes fases de maturação / Total phenolic determination in coffee beans: avaliation in different grown and developed processRossetti, Renato Pierrotti 14 September 2007 (has links)
O presente trabalho experimental focaliza o tema \"compostos fenólicos no café\". Dentre estes compostos se destacam os flavonóides, os ácidos clorogênico, cafêico, cafeilquinico, e seus isômeros. Na pesquisa foram avaliados quantitativamente, por espectrofotometria UV/VIS, as espécies fenólicas presentes após extração e complexação em amostras de cafés (cascas e sementes) com grãos em vários estágios de maturação. Foram obtidos valores na faixa de 10-6 mol.L-1 para fenóis totais nas cascas e nos grãos. O método de extração aqui proposto tornou-se bastante viável, sendo possível sua aplicação com tempo de preparo de amostras secas para análise de cerca de 40 minutos. As evidências experimentais decorrentes dessa pesquisa sugerem que tais espécies fenólicas (anti-oxidantes) podem ser aproveitadas de um material que é descartado (a casca do café), sendo, portanto um grande benefício econômico para a sustentabilidade do cultivo do café. / This experimental work has focused the theme \"Phelonic Compound in Coffee Beans\". Among these compounds have been shown flavonoids species, chlorogenic acid, caffeic acid, caffeinic acid and their isomer. The phelonic species has presented after extraction and complexation from coffee samples (peels and beans) using coffee beans in different grown and developed process has been evaluated in quantitative research by using UV/VIS Spectrophotometry Values have been got about 10-6 mol.L-1 in peels and beans. The proposed extraction method has been not only viable but its use possible with preparing time of dried samples for analyses in about 40 minutes. The experimental evidence resulting from this research has proposed that such phenolic antioxidant species can be made a good use of discarded material (the peel of coffee beans) therefore a great economical benefit for sustainable coffee cultivation.
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Proanthocyanidins, anthocyanins and phenolic acids in food barleys of diverse originHambira, Chipo 11 January 2010 (has links)
Phytochemicals found in grains complement those found in fruits and vegetables. These phytochemicals, though minor compounds, contribute to the antioxidant properties which are related to the health benefits associated with the consumption of whole grain. In this thesis project, nine barley genotypes of diverse origin namely CI2230 from Nepal, CI1248 from Israel, 3 Peruvian genotypes; Peru 3, Peru 16 and Peru 35, Hokuto Hadaka from Japan, EX116; a cross between Moroccan and Canadian genotype, EX83; a cross between two Canadian genotypes and EX127; a cross between Canadian and German genotypes were studied. The genotypes were categorized based on appearance into purple, black and yellow grains. Phenolic acids and flavonoids were identified and quantified in these diverse genotypes using HPLC-ESI-MS analysis. The main classes of dietary flavonoids studied in the barleys were anthocyanins and flavan-3-ols. Phenolic acids were identified and quantified (p-coumaric, ferulic, sinapic, caffeic, vanillic). Three ferulic acid dehydrodimers (8-0-4â DFA, 8-5â benzofuran form and 5-5â DFA) were also identified. The most abundant dimeric flavan-3-ols were procyanidins B3 and prodelphinidin B3. The monomeric unit, (+)-catechin, was the most abundant while catechin glucoside (m/z 451) was also identified. Among the Peruvian genotypes, Peru 16 and Peru 35 exhibited relatively high levels of total PA content. Total phenolic content and antioxidant activities of methanolic, acetone and alkali hydrolyzed extracts of the nine barley genotypes was determined by the Folin- Ciocalteau assay, DPPH radical scavenging assay and oxygen radical absorbance capacity (ORAC assay).The acetone extract exhibited the highest antioxidant capacity using all the methods of analysis. Furthermore, dark colored grains were found to exhibit higher contents of phenolic compounds. The phenolic acids, PAs and anthocyanins identified and quantified had significant contribution to the overall antioxidant capacity of the barley whole grain. Four hull-less genotypes namely CI2230, EX127, CI1248 and Peru 35 were further partially sprouted to establish the effects of sprouting on phenolic acid composition. Partial sprouting was observed to significantly increase the soluble conjugated phenolic acids. The barley genotypes studied were found to contain different quantities of phytochemicals and had high proanthocyanidin content thereby rendering them as alternative sources of antioxidants. Barley sprouts present a possible novel food ingredient with improved properties such as phenolic acid composition and other benefits such as easier incorporation into food products under development.
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Proanthocyanidins, anthocyanins and phenolic acids in food barleys of diverse originHambira, Chipo 11 January 2010 (has links)
Phytochemicals found in grains complement those found in fruits and vegetables. These phytochemicals, though minor compounds, contribute to the antioxidant properties which are related to the health benefits associated with the consumption of whole grain. In this thesis project, nine barley genotypes of diverse origin namely CI2230 from Nepal, CI1248 from Israel, 3 Peruvian genotypes; Peru 3, Peru 16 and Peru 35, Hokuto Hadaka from Japan, EX116; a cross between Moroccan and Canadian genotype, EX83; a cross between two Canadian genotypes and EX127; a cross between Canadian and German genotypes were studied. The genotypes were categorized based on appearance into purple, black and yellow grains. Phenolic acids and flavonoids were identified and quantified in these diverse genotypes using HPLC-ESI-MS analysis. The main classes of dietary flavonoids studied in the barleys were anthocyanins and flavan-3-ols. Phenolic acids were identified and quantified (p-coumaric, ferulic, sinapic, caffeic, vanillic). Three ferulic acid dehydrodimers (8-0-4â DFA, 8-5â benzofuran form and 5-5â DFA) were also identified. The most abundant dimeric flavan-3-ols were procyanidins B3 and prodelphinidin B3. The monomeric unit, (+)-catechin, was the most abundant while catechin glucoside (m/z 451) was also identified. Among the Peruvian genotypes, Peru 16 and Peru 35 exhibited relatively high levels of total PA content. Total phenolic content and antioxidant activities of methanolic, acetone and alkali hydrolyzed extracts of the nine barley genotypes was determined by the Folin- Ciocalteau assay, DPPH radical scavenging assay and oxygen radical absorbance capacity (ORAC assay).The acetone extract exhibited the highest antioxidant capacity using all the methods of analysis. Furthermore, dark colored grains were found to exhibit higher contents of phenolic compounds. The phenolic acids, PAs and anthocyanins identified and quantified had significant contribution to the overall antioxidant capacity of the barley whole grain. Four hull-less genotypes namely CI2230, EX127, CI1248 and Peru 35 were further partially sprouted to establish the effects of sprouting on phenolic acid composition. Partial sprouting was observed to significantly increase the soluble conjugated phenolic acids. The barley genotypes studied were found to contain different quantities of phytochemicals and had high proanthocyanidin content thereby rendering them as alternative sources of antioxidants. Barley sprouts present a possible novel food ingredient with improved properties such as phenolic acid composition and other benefits such as easier incorporation into food products under development.
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Determinação de fenóis totais em frutos do café: avaliações em diferentes fases de maturação / Total phenolic determination in coffee beans: avaliation in different grown and developed processRenato Pierrotti Rossetti 14 September 2007 (has links)
O presente trabalho experimental focaliza o tema \"compostos fenólicos no café\". Dentre estes compostos se destacam os flavonóides, os ácidos clorogênico, cafêico, cafeilquinico, e seus isômeros. Na pesquisa foram avaliados quantitativamente, por espectrofotometria UV/VIS, as espécies fenólicas presentes após extração e complexação em amostras de cafés (cascas e sementes) com grãos em vários estágios de maturação. Foram obtidos valores na faixa de 10-6 mol.L-1 para fenóis totais nas cascas e nos grãos. O método de extração aqui proposto tornou-se bastante viável, sendo possível sua aplicação com tempo de preparo de amostras secas para análise de cerca de 40 minutos. As evidências experimentais decorrentes dessa pesquisa sugerem que tais espécies fenólicas (anti-oxidantes) podem ser aproveitadas de um material que é descartado (a casca do café), sendo, portanto um grande benefício econômico para a sustentabilidade do cultivo do café. / This experimental work has focused the theme \"Phelonic Compound in Coffee Beans\". Among these compounds have been shown flavonoids species, chlorogenic acid, caffeic acid, caffeinic acid and their isomer. The phelonic species has presented after extraction and complexation from coffee samples (peels and beans) using coffee beans in different grown and developed process has been evaluated in quantitative research by using UV/VIS Spectrophotometry Values have been got about 10-6 mol.L-1 in peels and beans. The proposed extraction method has been not only viable but its use possible with preparing time of dried samples for analyses in about 40 minutes. The experimental evidence resulting from this research has proposed that such phenolic antioxidant species can be made a good use of discarded material (the peel of coffee beans) therefore a great economical benefit for sustainable coffee cultivation.
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Effect of Prohexadione-Calcium on Spearmint (Mentha spicata L.)Meagy, Md J. 01 January 2009 (has links) (PDF)
Prohexadione-calcium (Pro-Ca), a plant growth regulator used primarily in fruit trees to suppress excessive vegetative growth and to inhibit disease incidence, is known to inhibit dioxygenase enzymes and to inhibit GA biosynthesis. It induces genes for polyphenols synthesis. The objective of this project was to determine if the bioregulator Pro-Ca would alter the yield of essential oil, secondary metabolites, and growth in spearmint. Spearmint shoot cuttings from the same mother plant were used in this study. The plants were treated with 0, 125, 250, 375, and 500 mg/L a.i. of Pro-Ca over four weeks, and growth responses were measured every week and at harvest. Compared with the untreated control plants, plant height, branch length, number of nodes, and fresh weight were decreased with increased concentration of Pro-Ca treatment, and total phenolics accumulation increased. Rosmarinic acid and total chlorophyll content were reduced relative to control after treatment. Treatment with increased concentration of Pro-Ca altered the accumulation of flavonoids compounds. Increased concentration of catechin and eriodictyol-7-glucoside, and decreased concentrations of procyanidin and luteolin occurred compared with the untreated plant. Modification of newly formed flavonoid synthesis could be used as a new potential strategy in plant protection.
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Ultrasound Assisted And Supercritical Carbon Dioxide Extraction Of Antioxidants From Roasted Wheat GermGelmez, Nilufer 01 February 2008 (has links) (PDF)
This study covers the extraction of antioxidants from wheat germ / which is the byproduct of the flour-milling industry and a rich source of antioxidants / with Ultrasound Assisted (UAE) and Supercritical Carbon Dioxide (SC-CO2) extractions. Extraction conditions were ultrasonication time (1&ndash / 11 min), temperature (20&ndash / 60° / C) and ethanol level (5&ndash / 95%) for UAE, and pressure (148&ndash / 602 bar), temperature (40&ndash / 60° / C) and time (10&ndash / 60 min) for SC-CO2 extraction. The extraction conditions were optimized based on yield (%), total phenolic contents (TPC, mg GAE/g extract) and antioxidant activities (AA, mg scavenged DPPH& / #729 / /g extract) of the extracts, using Central Composite Rotatable Design. Total tocopherol contents (TTC) of the extracts were determined, as well.
UAE (at 60° / C) with low ethanol level (~5-30%) and short times (1-3 min) provided protein rich extracts with high yield, medium TPC and AA. On the other hand, with high ethanol level (~90%) and long times (6-11 min), waxy structured extracts with low yield but high TPC and AA were obtained.
SC-CO2 extraction at 442 bar, 40º / C and 48 min. enabled almost 100% recovery of wheat germ oil (9% yield) but TPC and AA of the extracts were low. On the contrary, the extracts obtained at lower pressures (~150bar) and shorter times (~10 min) at 50-60º / C had high TPC and AA since the oil yield was low. However, TPC and AA of these extracts were only half of those extracted by UAE. Maximum tocopherol (7.142 mg tocopherol/g extract) extraction was achieved at 240 bar, 56º / C for 20 min. Both of the methods extracted high amounts of tocopherols from roasted wheat germ (SC-CO2 extraction / 0.31 mg tocopherol/g germ, UAE / 0.33 mg tocopherol/g germ) but TTC of the extracts obtained by SC-CO2 extraction was superior compared to 1.170 mg tocopherol/g extract obtained by UAE at 9 min, 58º / C and 95% ethanol level.
All these extracts with different characteristics have potential uses in cosmetic and food industry depending on the targeted specific application.
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Étude de la fonctionnalité alimentaire de plats industriels / Study of functionnality of different food preparationsHyardin, Aude 25 September 2008 (has links)
Consommateurs, chercheurs et industriels cherchent de plus en plus à associer à la valeur nutritionnelle des aliments, un effet bénéfique pour la santé. Les aliments caractérisés par des pouvoirs antioxydants élevés semblent correspondre à cette demande. En effet, plusieurs travaux mentionnent les bénéfices santé de ces aliments. Pour répondre à cette demande les industriels mettent en avant ce critère. La fonctionnalité alimentaire, aux bénéfices prometteurs pour la santé publique, reste un concept néanmoins complexe dans la pratique. Ce travail met l’accent sur le fait que les propriétés fonctionnelles d’un aliment ne sont pas directement liées à la composition en ingrédients. L’évaluation du pouvoir antioxydant d'un aliment est dans la plupart des cas réalisée à partir des valeurs des différents ingrédients avant formulation et mise en œuvre des procédés. Pourtant, plusieurs phénomènes sont susceptibles de modifier le pouvoir antioxydant lors de la durée de vie d'un produit alimentaire. D’un point de vue industriel, il est nécessaire de développer une méthode de prédiction de cette activité. Les objectifs de ce travail étaient d’adapter une méthode reproductible et facile à réaliser de quantification du pouvoir antioxydant sur des aliments complexes et de comparer cet index d'un ensemble de produits contenant une large gamme de matières premières. Enfin, a été discuté l’intérêt que représente, dans le domaine des propriétés anti oxydantes, la quantification de l’index créé. Au moment où les industriels vont être amenés à proposer des allégations liées à l’effet bénéfique de l’aliment choisi parmi un échantillon de plus en plus ample / Consumers, researchers and industrialists try more and more to associate with the nutritional value of food, a beneficial effect for the health. Food characterized by high antioxidant powers seems to correspond to this demand. From an industrial point of view, it is necessary to develop methods of predicting this antioxidant capacity. The objectives of this work were to adapt a method reproducible and easy to realize of quantification of the antioxidant power on complex food and to compare this index of a set of products containing a wide range of raw materials. Until now, it has been considered that the use of raw materials characterized by a high antioxidant capacity also leads to a preparation with a high antioxidant activity. We evaluated many of the factors affecting the antioxidant activity of convenience foods (phenol content, effects of formulation, culinary reheating, and preservation) and to provide data on convenience foods consumed by the French population. The total antioxidant capacity of the ethanolic extracts was evaluated by the method of the equivalent Trolox (TEAC) using the radical cation ABTS•+. The concentration of the total phenolic compounds of the same extracts was determined by the Folin-Ciocalteu method. The results show that the food matrix is an important factor for the modulation of activities of antioxidants. A standardised testing protocol for evaluating antioxidative effects is necessary. Then, we discussed the interest of an index, as the industrialists are going to be brought to claim to the beneficial effect of the food chosen among a more and more ample sample
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Avaliação da capacidade antioxidante e conteúdo de compostos fenólicos de frutas vermelhas submetidas a processamentos por calor (micro-ondas, sous vide, fervura e desidratação)Colpo, Lucinéia Puiatti 27 February 2015 (has links)
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Previous issue date: 2015-02-27 / Nenhuma / Há um crescente interesse na relação entre alimentação e saúde, destacando-se o consumo de antioxidantes naturalmente presentes em alimentos. As frutas, principalmente as que apresentam a coloração vermelha/azul, contêm elevadas quantidades de antioxidantes, sendo importantes fontes de compostos fenólicos. Aos compostos antioxidantes tem sido atribuída uma grande gama de efeitos biológicos, incluindo ações de prevenção contra doenças. Acredita-se que o consumo regular destas frutas, aliado a um estilo de vida saudável, incluindo dieta equilibrada e exercícios físicos, pode trazer potenciais benefícios à saúde. Porém, nem sempre as frutas e verduras são consumidas in natura, muitas vezes são consumidas após serem submetidas a algum tipo de processamento, o que pode alterar suas características nutricionais. Com isso se torna muito importante compreender melhor a estabilidade destes compostos em alimentos, frente ao processamento a que são submetidos antes da ingestão. Dessa forma, o objetivo deste trabalho foi o de avaliar o efeito do processamento por diferentes métodos de cocção (sous vide, micro-ondas, fervura e desidratação) sobre as propriedades antioxidantes de frutas vermelhas (amora, mirtilo, cereja, jabuticaba e morango). Para isso, verificou-se o conteúdo de compostos fenólicos e a capacidade antioxidante de cada uma delas in natura e processadas. De uma forma geral, foi possível observar que a jabuticaba foi a fruta que apresentou maior conteúdo de compostos fenólicos e maior atividade antioxidante dentre todas as frutas vermelhas estudadas, em todos os processos avaliados, com exceção da desidratação, na qual amora e morango tiveram os maiores resultados nas condições estudadas. Além disso, foi possível observar também que as frutas em geral processadas por cocção em micro-ondas e desidratação apresentaram maior conteúdo de compostos fenólicos e maior atividade antioxidante do que as submetidas aos demais processos. Os resultados obtidos demonstram haver clara influência do tipo de processo a que a fruta é submetida sobre as propriedades antioxidantes da mesma. Novos estudos, no entanto, se fazem necessários a fim de melhor esclarecer os efeitos do processamento sobre a atividade antioxidante das frutas vermelhas. / There is an increasing interest in the relationship between food and health. Recently the intake of food containing naturally occurring antioxidants has gained increasing evidence. Fruits, specially blue or red ones, contain high amounts of antioxidants and are important sources of total phenolic compounds. A wide range of biological effects, including disease prevention, have already been attributed to antioxidant compounds. It is widely believed that a regular fruit and vegetable consumption, along with a healthy life style including balanced diet and physical exercise, can bring potential benefits to human health. However, fruits and vegetables are not always consumed fresh, they are often consumed after being submitted to some kind of processing, which can alter its nutritional properties. It seems therefore important to study the stability of these compounds in food processed prior to consumption. In this way, the aim of this work was to evaluate the effects of heat processing by different methods (sous vide, microwave, boiling and dehydration) in the antioxidant properties of red fruit (blackberry, bilberry, cherry, jaboticaba and strawberry). Total phenolic compound content and antioxidant activity of each fruit were evaluated, both fresh and processed by different heating methods. It was observed that jaboticaba presented the highest phenolic compound content and also the highest antioxidant activity among all red fruits studied, in all processes evaluated, except in dehydration, in which blackeberry and strawberry had higher results in the conditions studied. Besides, it could be observed that red fruits processed by microwave and dehydration presented higher phenolic compound content and higher antioxidant activity than those submitted to the other processes studied. Results obtained show that appears to be a clear influence of the kind of process used into red fruits antioxidant properties. However, more studies are needed do better understand the effects of heat processing in antioxidant activity of red fruits.
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