A antracnose da videira tem como agente causal o fungo Elsinoë ampelina Shear, o qual ataca tecidos tenros da parte aérea causando lesões necróticas e comprometendo o desenvolvimento da planta com consequente queda na quantidade e qualidade dos frutos produzidos. Cultivares de Vitis apresentam diferentes níveis de susceptibilidade à antracnose. Uma vez que características anatômicas e químicas podem atuar como mecanismos de resistência a patógenos, o presente estudo propõe comparar caracteres histológicos e bioquímicos em folhas jovens de Vitis labrusca \'Niagara Rosada\' (NR, susceptível), Vitis vinifera \'Thompson Seedless\' (TS, susceptível) e V. vinifera \'Pinot Noir\' (PN, resistente). As análises anatômicas foram realizadas em folhas sadias aos 4 e 11 dias após o brotamento (DAB) e em folhas lesionadas com 11 DAB, enquanto os compostos bioquímicos foram quantificados em folhas sadias aos 4 e 11 DAB. Os caracteres analisados foram: índice estomático, densidade de idioblastos cristalíferos, espessura da cutícula da face adaxial, espessura da parede periclinal externa e altura das células epidérmicas de ambas as faces, espessura do mesofilo total, do parênquima paliçádico e do parênquima lacunoso, o conteúdo de compostos fenólicos totais, flavonoides e de clorofila a, b e total, bem como a atividade de peroxidase e de polifenoloxidase. Os dados obtidos foram submetidos à análise estatística. A cultivar TS apresentou índice estomático maior nas duas idades avaliadas em comparação com o genótipo resistente PN, a qual apresentou maior espessura de cutícula nas duas idades e de mesofilo total aos 11 DAB. Os parâmetros quantitativos das amostras inoculadas apresentaram redução significativa em relação às não inoculadas, com exceção da área foliar de PN, a qual não foi significativamente menor. Para NR e TS, 100% das amostras inoculadas apresentaram várias lesões expandidas, enquanto PN apenas 60% das folhas analisadas apresentaram poucas lesões bem delimitadas e de formato circular. A cultivar resistente PN apresentou forte reação positiva a compostos fenólicos bem como o maior conteúdo desses compostos na idade 11 DAB, enquanto a cultivar susceptível TS apresentou reação muito fraca e a menor concentração. O conteúdo de flavonoides foi maior em PN em relação à TS nas duas idades avaliadas, e NR apresentou o valor mais baixo aos 4 DAB, quando é altamente susceptível. A atividade de polifenoloxidase aos 11 DAB foi maior na cultivar PN, intermediária em NR e mais baixa em TS. A análise de todos os parâmetros anatômicos e bioquímicos avaliados indica que a maior resistência da cultivar PN esteja relacionada ao menor índice estomático, à cutícula mais espessa, ao conteúdo mais elevado de compostos fenólicos totais e de flavonoides, bem como a maior atividade enzimática de polifenoloxidase. / Grapevine anthracnose is caused by the fungus Elsinoë ampelina Shear, which attacks tissues of the aerial part causing necrotic lesions, compromising plant growth with consequent decrease in quantity and quality of the fruits produced. Vitis cultivars show different levels of susceptibility to anthracnose. Anatomical and genetic characteristics can act as a resistance mechanism against pathogens, therefore, this study proposes to compare histological and biochemical characteristics in young leaves of Vitis labrusca \'Niagara Rosada\' (NR, susceptible), Vitis vinifera \'Thompson Seedless\' (TS, susceptible) and V. vinifera \'Pinot Noir\' (PN, resistant). The anatomical analyses were performed on healthy leaves at 4 and 11 days after budding (DAB) and at 11 DAB on lesioned leaves, while biochemical compounds were quantified on healthy leaves at 4 and 11 DAB. The features analyzed were: stomatal index, idioblasts density, adaxial face cuticle thickness, external periclinal wall thickness, epidermal cell height of both faces, total mesophyll thickness, palisade parenchyma and spongy parenchyma, total phenolic compounds content, flavonoids, chlorophyll a, b, and total, and peroxidase and polyphenoloxidase activity. The data were submitted to the statistical analysis. The TS cultivar had a higher stomatal index at both ages evaluated compared to the PN resistant genotype, which presented greater cuticle thickness at leaf ages and total mesophyll at 11 DAB. The quantitative parameters of the inoculated samples presented a significant reduction in relation to the non- inoculated, except for the PN leaf area, which was not significantly lower. For NR and TS, 100% of the inoculated samples presented several expanded lesions, whereas PN only 60% of the analyzed leaves showed few lesions well delimited and circular in shape. The resistant cultivar PN showed strong positive reaction to phenolic compounds as well as the highest content of these compounds at 11 DAB, while the TS susceptible cultivar presented very weak reaction and the lowest concentration. The content of flavonoids was higher in PN compared to TS at both ages evaluated, and NR presented the lowest flavonoid content at 4 DAB, when it was highly susceptible. The polyphenoloxidase activity at 11 DAB was higher in the PN cultivar, intermediate in NR, and lower in TS. The analyses of all the anatomical and biochemical parameters indicate that the higher resistance of the PN cultivar is related to the lower stomatal index, thicker cuticle, higher content of total phenolic compounds and flavonoids, as well as higher enzymatic activity of polyphenoloxidase.

Potato peel, a waste generated from potato processing is a disposal problem. But, it is a good source of phenolic compounds, sugars, and glycoalkaloids. This study examines the subcritical water extraction of phenolics, glycoalkaloids and sugars from potato peel and compares it to conventional solvent extraction. Experiments were conducted in a batch stainless steel reactor at 6 MPa, 2 mL/min and 100 to 240C for 30-120 min. The results revealed that highest recoveries of phenolic compounds (81.23 mg/100 g; fw) and sugars (75 mg/g; fw) were obtained using subcritical water at 180C and 30 min and at 160C and 120 min, respectively. Low content of glycoalkaloids (1.19 mg/100 g, fw) was obtained using subcritical water. The yields of phenolics and sugars using subcritical water were 40 and 45% higher than using a conventional solvent extraction method. Therefore, subcritical water might be a good substitute to organic solvents such as methanol and ethanol to obtain functional ingredients from potato peel. / Food Science and Technology

The main objective of the study was to encapsulate the phenolic compounds from sour cherry pulp in micro size, to investigate the physicochemical properties of capsules and their digestability in simulated gastric and intestinal fluid. The effect of different coating materials, ultrasonication time and core to coating ratio on encapsulation of phenolic compounds from sour cherry pomace was investigated. Maltodextrin and gum Arabic were chosen as coating materials. Coating material was prepared with different maltodextrin:gum Arabic (MD:GA) ratios of 10:0, 8:2, 6:4 to make the total solid content 10%. In addition, two different core to coating ratios of 1:10 and 1:20 were used. Emulsions were prepared by homogenization through ultrasonication at 160 W power and 20 KHz frequency for different time periods (5-30 min). Then, the emulsions were freeze dried for 48 hours to obtain the microcapsules. Encapsulation efficiency, antioxidant activity, surface morphology, particle size, color, digestability and glass transition temperatures of the microcapsules were determined. The microcapsules with a core to coating ratio of 1:20 were found to have higher encapsulation efficiencies (78.80-92.26%) than those with a core to coating ratio of 1:10 (69.38-77.83%). Increasing the gum Arabic ratio in the coating material increased encapsulation efficiency. Optimum conditions for encapsulation with the highest efficiency and the lowest particle size were sonication time of 22.5 min, MD:GA ratio of 8:2 and core to coating ratio of 1:20. Encapsulation was effective in preventing the release of the phenolic compounds in gastric fluid. On the other hand, phenolic compounds were released from the capsules into the intestinal fluid.

Phenolic compounds are the chemicals which are used by many different industries and as a result of this spread to the environment. These compounds can be absorbed easily through the human and animal skin and through the mucosal membrane, mix in to the blood circulation and thus create a toxic effect on several tissue and organs including, liver, lung and kidneys. For this reason, determination of phenolic compounds emitted to environment is a very important issue. In fact, there are standard methods for the determination of these compounds like HPLC, Spectrophotometric and calorimetric methods however, these are time consuming methods and requires to be expertise. On the other hand, there are also different types of biosensors developed for the phenolic compound detection. In this study, a new, disposable, cheap and convenient tyrosinase biosensor was developed for the phenolic compound detection. By means of absorption method, the enzyme tyrosinase and the chromophore MBTH were immobilized on the support material and as a model substrate L- dopa was used. As a result of optimization studies 1mg/ml tyrosinase concentration and 1.5mM MBTH concentration were determined for using in biosensor construction. Detection limit of l-dopa, model substrate, found as 0,064 mM and for other phenolic compounds, 4-chlorophenol, catechol, m-cresol and p-cresol, detection limit was obtained 0.032 mM, 0.032 mM, 0.128 mM, 0.128 mM, respectively. In addition, we found that the biosensor response was not affected by pH changes ranging from 3 to 11. The stability of biosensor which is one of the important parameter for commercialization was not change through 70 days at room temperature and 4&deg / C when compared to at the beginning response.

The main object of the presented study was investigation of the use of cross-linked enzyme (tyrosinase) aggregates (CLTA) obtained from crude mushroom extract for a rapid phenolic content analysis in wines. In addition, a comparison of phenolic characteristics of Turkish red wines was performed. Reproducible and reliable results in total phenolic measurement were obtained with CLTAs similar to pure tyrosinase and tyrosinase obtained from crude mushroom extract. Measurement of total phenolic content is possible both in standard solutions and in complex matrices, such as wine. In a very short time period, 10 seconds, phenolics content in red and white wines produced from grapes of Turkey were investigated by using CLTAs. Results were consistent when compared to a well known phenolic measurement method, Folin-Ciocalteau. CLTAs exhibited very high operational stability and retained more than 90% of its activity after 30th use. Moreover, it showed good shelf-life stability for about 2 months storage by maintaining 90% of its maximum activity. So, use of CLTAs prepared from crude mushroom extract is an effective, fast and cheap alternative in total phenolics measurements in wines. Moreover, a novel catalase phenoloxidase (CATPO) produced by a fungal microorganism, Scytalidium thermophilum, was studied to check its capabilities in phenolics measurements. This novel catalase phenol oxidase showed similarly good results, exhibiting widesubstrate selectivity.

This thesis was aimed to analyze phenol oxidation by the bifunctional catalase/phenol oxidase of the thermophilic fungus Scytalidium thermophilum. Several reactive oxygen species (ROS) are continuously produced in fungi under oxidative stress. Depending on the nature of the ROS species, some are highly toxic and are rapidly detoxified by various cellular enzymatic mechanisms, including the production of catalase. S. thermophilum produces a novel bifunctional catalase-phenol oxidase (CATPO) which is capable of oxidizing phenolics in the absence of hydrogen peroxide. Phenol oxidases convert phenolic compounds to quinones, which are then polymerized mainly by free- radical mediated reactions. In this study, 14 phenolic compounds were selected according to their different chemical structures and functional properties and were analyzed as substrates of CATPO. Among 14 phenolic compounds, only in catechol, chlorogenic acid, catechin and caffeic acid distinct oxidation products were observed by HPLC. The oxidation products of catechol, caffeic acid, chlorogenic acid and catechin were characterized by LC-ESI-MS. Dimer, trimer, tetramer and oligomer formations were detected. While the maximum conversion efficiency, at 1 hour of reaction, was observed with catechin, minimum conversion efficiency was attained by caffeic acid, under the specified conditions. The oxidation products observed after oxidation of catechol, chlorogenic acid, catechin and caffeic acid by CATPO was compared with the same phenolic compounds oxidation products oxidized by laccase and tyrosinase. CATPO was incapable of oxidizing tyrosinase and laccase-specific substrates tyrosine and ABTS respectively. However, the oxidizing spectrum of substrates indicates that the nature of phenol oxidation by CATPO appears to resemble mainly those of laccase.

The main objective of this study was to extract phenolic compounds from caper and oleaster by using microwave. The effects of microwave power (400 and 700 W), extraction time (5-20 min), solid to solvent ratio (1:10, 1:20 and 1:30) and solvent type (water, ethanol and different ratios of ethanol-water mixture) on total phenolic content, antioxidant activity and concentration of the phenolic compounds in the extracts were investigated. In conventional extraction, extraction time and solvent type were used as independent variables. Microwave extraction was compared with conventional extraction. In caper and oleaster extracts that were obtained by using microwave, total phenolic compounds ranged between 5.0-52.4 and 2.6-43.0 mg GAE/g dry material while the antioxidant activity were between 0.5-2.0 and 0.2-3.7 mg DPPH/g dry material, respectively. Higher total phenolic content was observed with increasing solvent amount. The highest total phenolic content was obtained when 50% ethanol-water mixture was used as solvent. Microwave power did not affect total phenolic content significantly. The highest total phenolic contents were obtained when 400 W microwave power, 50% ethanol-water mixture and solid to solvent ratio of 1:30 were used in the extraction from both caper and oleaster. The best extraction time for caper was 5 min while it was 15 min for oleaster. The main constituents were rutin and kaempferol for both caper and oleaster extracts. For caper and oleaster there was no difference between extraction methods in terms of concentration of phenolic compounds. However, extraction time decreased significantly by using microwave, as compared to conventional extraction.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2009. / Härtill 5 uppsatser.

Vaistinės arbatos mišiniai vertingi dėl jose esančių komponentų, kaip fenoliniai junginiai (atsakingi už antimikrobinį veikimą) ir flavonoidai (natūralūs antioksidantai, surišantys laisvuosius radikalus). Flavonoidų cheminės savybės apžvelgtos darbe. Šio darbo tikslas - atlikti flavonoidų ir fenolinių junginių kiekybinę ir kokybinę analizę bei nustatyti bendrą antioksidacinį aktyvumą vaistinių arbatų mišinių ekstraktuose. Paruošti metanoliniai vaistinių arbatų mišinių ekstraktai po kietafazės ekstrakcijos buvo analizuojami spektrofotometru, kapiliarine elektroforeze ir efektyviąja skysčių chromatografija su reakcijos detektoriumi. Spektrofotometru išmatuotas bendras fenolinių junginių, flavonoidų kiekis vaistinėse arbatose. Įvertintos metanolinių ekstraktų laikymo sąlygos šaldytuve bei sausos žaliavos laikymo sąlygos sausoje, vėsioje vietoje. Efektyviąja skysčių chromatografija įvertintas fenolinių junginių kiekis ir jų antioksidacinis aktyvumas su 2,2 - difenil – 1 - pikrilhidrazilo (DPPH ) laisvuoju radikalu. Blukinimo reakcija matuota UV detektoriumi ties 517 nm. Efektyviaja skysčių chromatografija išskirstyti fenoliniai junginiai, taikant gradientą. Atliktas kapiliarinės elektroforezės metodo optimizavimas: įvertintas buferio pH, organinio tirpiklio priedo, įtampos įtaka skirstymo efektyvumui, skiriamajai gebai. Atlikti įteisinimo žingsniai: įvertintos aptikimo ir nustatymo ribos, matavimų glaudumas, stabilumas ir atrankumas. Priedo metodu buvo identifikuoti flavonoidų... [toliau žr. visą tekstą] / Previous studies refer mostly to the HPLC analysis of the flavonoids, for oxidative product deterioration and radicals scavenging action. Methanolic extracts after solid phase extraction of 6 different functional teas were analyzed by means of capillary zone electrophoresis (CZE) and high performence liquid chromatography (HPLC) with reaction detector. A rapid on-line method for screening components was developed using methanolic solution 2,2 – diphenyl – picrylhydrazyl (DPPH) as stable free radical. Bleaching reaction is detected as a negative peak by an absorbance detector at 517 nm. HPLC gradient runs with mobile phase composition ranging from 33 to 90% organic solvent (methanol) in water with 0.1% TFA. The activity of compounds in functional teas (complex mixtures) was determined. Development and validation of the CZE method was carried out.. Limits of detection and quantification were determined. The results obtained using CZE are comparable to the spectrophotometric and HPLC analysis results. The influence of the extraction conditions (with solid phase extraction (SPE) and without SPE extraction), amount of flavonoids and phenolic compounds in the various functional teas was studied. The highest content of flavonoids was obtained in Choleretic herbs mixture 2,08 mg/g and the highest content of phenolic compounds was determined in Diaphoretic functional tea 3,53mg/g in raw dry medicinal functional tea herbs. The total amount of flavonoids did not directly correlate... [to full text]

No description available.