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Activity
Kinds of Activity Terms modified by Activity Selected AbstractsIn situ substrate conversion and assimilation by nitrifying bacteria in a model biofilmENVIRONMENTAL MICROBIOLOGY, Issue 9 2005Armin Gieseke Summary Local nitrification and carbon assimilation activities were studied in situ in a model biofilm to investigate carbon yields and contribution of distinct populations to these activities. Immobilized microcolonies (related to Nitrosomonas europaea/eutropha, Nitrosomonas oligotropha, Nitrospira sp., and to other Bacteria) were incubated with [14C]-bicarbonate under different experimental conditions. Nitrifying activity was measured concomitantly with microsensors (oxygen, ammonium, nitrite, nitrate). Biofilm thin sections were subjected to fluorescence in situ hybridization (FISH), microautoradiography (MAR), and local quantification of [14C]-bicarbonate uptake (beta microimaging). Nitrifying activity and tracer assimilation were restricted to a surface layer of different thickness in the various experiments (substrate or oxygen limitation). Excess oxygen uptake under all conditions revealed heterotrophic activity fuelled by decay or excretion products during active nitrification. Depth limits and intensity of tracer incorporation profiles were in agreement with ammonia-oxidation activity (measured with microsensors), and distribution of incorporated tracer (detected with MAR). Microautoradiography revealed a sharp individual response of distinct populations in terms of in-/activity depending on the (local) environmental conditions within the biofilm. Net in situ carbon yields on N, expressed as e, equivalent ratios, varied between 0.005 and 0.018, and, thus, were in the lower range of data reported for pure cultures of nitrifiers. [source] THE CORRELATION OF YOUTH PHYSICAL ACTIVITY WITH STATE POLICIESCONTEMPORARY ECONOMIC POLICY, Issue 4 2007JOHN CAWLEY Childhood overweight has risen dramatically in the United States during the past three decades. The search for policy solutions is limited by a lack of evidence regarding the effectiveness of state policies for increasing physical activity among youths. This paper estimates the correlation of student physical activity with a variety of state policies. We study nationwide data on high school students from the Youth Risk Behavior Surveillance System for 1999, 2001, and 2003 merged with data on state policies from several sources. We control for a variety of characteristics of states and students to mitigate bias due to the endogenous selection of policies, but we conservatively interpret our results as correlations, not causal impacts. Two policies are positively correlated with participation in physical education (PE) class for both boys and girls: a binding PE unit requirement and a state PE curriculum. We also find that state spending on parks and recreation is positively correlated with two measures of girls' overall physical activity. (JEL I18, I28) [source] THE BUSINESS OF RECONCILIATION: ENTREPRENEURSHIP AND COMMERCIAL ACTIVITY IN POST-CONFLICT RWANDAECONOMIC AFFAIRS, Issue 2 2007Karol Boudreaux In post-conflict Rwanda trade and enterprise are leading to increased levels of co-operation among former enemies. Economic interaction is providing a cost-effective alternative to state-led reconciliation programmes as a mechanism for justice and healing. Governments seeking to provide effective transitional justice and reconciliation should therefore facilitate private-sector efforts by actively working to improve the institutional environment for doing business. [source] A CITY IN MOTION: TIME-SPACE ACTIVITY AND MOBILITY PATTERNS OF SUBURBAN INHABITANTS AND THE STRUCTURATION OF THE SPATIAL ORGANIZATION OF THE PRAGUE METROPOLITAN AREAGEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 2 2007Jakub Novák ABSTRACT. This contribution attempts to reveal the relations between new suburban areas and other parts of the Prague metropolitan area by investigating the time-space activity and mobility patterns of the inhabitants of newly built suburban districts. The focus on some aspects of the everyday life of people in new suburbs helps us to identify the impact of suburbanization on the changing geography of the metropolitan region and to better understand how the spatial organization of the Prague metropolitan area is produced, reproduced and transformed. We use several interrelated concepts, which serve the theoretical foundation of our work, namely time geography, structuration theory and the post-communist city. The empirical data utilized are primarily based on 262 diaries completed by eighty-eight individuals from thirty-eight households, accompanied by household questionnaires and interviews with the heads of households. The research confirmed the implicit, generally unspoken view that new suburbs in the Prague metropolitan region are heavily dependent on the core of the metropolitan area for the provision of jobs and services. However, newly built suburban shopping facilities to some extent disrupt this pattern, keeping some daily activities of inhabitants within the suburban zone. In addition to empirical observations, the key purpose of this contribution has been to discuss and apply time geography concepts and methods to the research of urban restructuring, and to understand the structuration of metropolitan spatial organization. [source] EVALUATION OF EXTRACTS FROM BAMBOO FOR BIOLOGICAL ACTIVITY AGAINST CULEX PIPIENS PALLENSINSECT SCIENCE, Issue 4 2004Hai-qun Cao Abstract The extracts from 7 species of bamboo were tested for larvicidal activity against Culex pipiens pallens. At the tested concentration, the extracts of selected bamboo had different degree of toxic effects on the fourth instar larvae of Culex pipiens pallens. Among them, the extracts of Pleioblastus juxianensis, Brachystachyum albostriatum, Phyllostachys platyglossa and Pleioblastus amarus were found to be effective with LC50values at 24 h of 30.65 mg/L, 53.94 mg/L, 41.21 mg/L and 54.49 mg/L respectively, against Culex pipiens pallens larvae. The extract of Pleioblastus juxianensis by Soxhlet method showed stronger activity than the extract obtained by interval-shaking, the LC50 of which were 30.65 mg/L and 48.34 mg/L, respectively. The diethyl ether extract of Pleioblastus juxianensis exhibited better larvicidal activity than the methanol extract and the petroleum ether extract. The results would help to provide the basis for the study of environment acceptable pesticide for mosquito control, and also help to comprehensively utilize the source of bamboo. [source] BIOLOGICAL ACTIVITY OF EXTRACT OF STELLERA CHAMAEJASME AGAINST FIVE PEST INSECTSINSECT SCIENCE, Issue 3 2002WANG Ya-wei Abstract Biological activity of an extract of the root of Stellera chameajasme with ethanol by dip (SCEE) against 5 insect pests, Pieris rapae, Plutella xylostella, Spodoptera litura, Myzus persicae, and Ostrina fumalis as tested. The LD, of stomach poison of SCEE against the fifth instar larvae of P. rapae was 12. 32 ,arvae day 2 after treatment. With SCEE at concentration of 5, 2. 5 and 50 mg/mL, the fifth instar larvae of P. rapae, the third instar larvae of P. xylostella, and the third instar larvae of S. litura by disc leaf dipped method, had corrected mortalities of 100%, 31. 03 % and 16. 67 % 7 days after treatment respectively. The LC50 of SCEE against M. persicae was 0. 599 2 mg/mL after day 2 treatment by leaf dipped method. With SCEE at 10 mg/mL for the third instar larvae of O. furnucalis by mixture pesticide method, the corrected mortalities of 65. 52% and 85. 72% days 7 and day 14 after treatments respectively. The results showed that SCEE possessed strong biological activity to P. rapae, O. furnacalis, and M. persicae, while possessed weak biological activity to S. litura and P. xylostella. [source] EQUILIBRIUM LENDING MECHANISM AND AGGREGATE ACTIVITY,INTERNATIONAL ECONOMIC REVIEW, Issue 3 2010Cheng Wang We construct a model of the credit market where financial contracting is subject to costly state verification and moral hazard. The economy's aggregate activity and its equilibrium lending mechanism are determined jointly. We analyze how changes in the model's exogenous variables, including the returns of the economy's investment projects and the supply of loans, affect the economy's aggregate output and the types of the credit through which investment is funded. [source] FEELING TIRED PREDICTS FUNCTIONAL STATUS, PHYSICAL ACTIVITY, AND MORTALITY IN ELDERLY PEOPLEJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 4 2009Elior Moreh MD No abstract is available for this article. [source] METABOLIC SYNDROME AND PHYSICAL ACTIVITY IN SOUTHERN BRAZILIAN COMMUNITY-DWELLING ELDERLY PEOPLEJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 7 2008Roberta R. Dalacorte MD No abstract is available for this article. [source] LIPOXYGENASE ACTIVITY IN PRICKLY PEAR FRUIT (OPUNTIA FICUS INDICA [L.] MILL.JOURNAL OF FOOD BIOCHEMISTRY, Issue 2 2010CACTACEAE) ABSTRACT Prickly pear LOX activity was detected in the membrane fractions of the fruit extracts at various stages of ripening. LOX specific activity was very low in the fruit of wild plants at the green stage (0.49 ± 0.04) and increased with fruit ripening, more than doubling in the ripened fruit (1.22 ± 0.06). Moreover, it was not influenced by the cultivar, whereas it was considerably increased (13.3 ± 1.4) by agronomic processes to which prickly pear plants are submitted to improve the organoleptic properties of fruits. The apparent molecular mass of the enzyme was estimated to be 96 kDa. The enzyme had an optimum pH value of 5.5 and a clear specificity for linolenic acid, which was oxidized at a rate one and a half times that of linoleic acid, under the same reaction conditions. The involvement of prickly pear LOX in the flavor biosynthesis of the fruit is supposed. PRACTICAL APPLICATIONS Over the last decade in particular, prickly pear fruits have been widely used as food, not only the whole fruit but also processed to make juices, jams and liquors popular the world over. Prickly pear production has therefore risen considerably and consequently both the labor force employed and revenues generated have increased. For those engaged in this sector it is therefore a prime objective to maximise the profile and thereby profitability of the fruit. It is here that our research into lipoxygenase activity can play a part, as it is known that this enzyme is responsible for the organoleptic properties of fruits and vegetables. The results are presented below. The relationship between lipoxygenase specific activity and specific agronomic processes utilized to improve the fruit quality is also addressed. [source] GLYCOSIDASE INHIBITORY ACTIVITY AND ANTIOXIDANT PROPERTIES OF A POLYSACCHARIDE FROM THE MUSHROOM INONOTUS OBLIQUUSJOURNAL OF FOOD BIOCHEMISTRY, Issue 2010HAIXIA CHEN ABSTRACT A water-soluble polysaccharide from Inonotus obliquus (IOPS) was isolated from the mushroom Inonotus obliquus (Fr.) Pilat. The chemical compositions, molecular weight and inhibitory activities on glycosidase and antioxidant properties of IOPS were investigated. The results indicated that IOPS was an acid protein-bound polysaccharide, with a molecular weight of 1.7 × 104 Da and the contents of neutral sugar, protein and uronic acids being 42.5, 18.5 and 6.1%, respectively. IOPS exhibited an inhibitory activity against ,-glucosidase with the IC50 value of 93.3 µg/mL, whereas it had no effective inhibition on ,-amylase. Results of antioxidant activity assays revealed that IOPS had inhibitory activity on the concentration-dependent quenching of 1,1-Diphenyl-2-picrylhydrazyl and hydroxyl radicals. Furthermore, IOPS inhibited the formation of thiobarbituric acid-reactive substances in Fe2+/ascorbate-induced lipid peroxidation in rat liver tissue. These results clearly demonstrated that IOPS was one of the main bioactive components of I. obliquus that contributed to hypoglycemic activity and antioxidant activity. PRACTICAL APPLICATIONS Diabetes mellitus is one of the primary threats to human health because of its increasing prevalence, chronic course and disabling complications. Postprandial hyperglycemia plays an important role in the development of type 2 diabetes mellitus and complications associated with the disease. One therapeutic approach to decrease postprandial hyperglycemia is to retard the absorption of glucose through inhibition of carbohydrate-hydrolyzing enzymes in the digestive organs. In this study, a polysaccharide isolated from the mushroom Inonotus obliquus (IOPS) was shown to have notable glycosidase inhibitory effects and antioxidant activities. This research will benefit for the investigation of effective and safe ,-glucosidase inhibitors from natural materials. IOPS could be a good candidate for application in food and medicinal fields. It might be developed for functional food or lead compounds for use in antidiabetes. [source] ANTIOXIDANT AND ANTIMICROBIAL ACTIVITY OF DIFFERENT FLORAL ORIGIN HONEYS FROM TURKIYEJOURNAL OF FOOD BIOCHEMISTRY, Issue 2010ESRA ULUSOY ABSTRACT The bioactivities of phenolic extracts of nine Turkish honeys from different floral sources were investigated. The antioxidant properties of the extracts were assessed by ferric reducing/antioxidant power (FRAP) assay, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and cupric reducing antioxidant capacity (CUPRAC) assay. The total phenolic contents measured by Folin,Ciocalteau method varied from 66 to 223 mg/g extract as gallic acid equivalent. The antioxidant activities found with CUPRAC, expressed as trolox equivalent antioxidant capacity, ranged from 124.8 to 532 µmol/g, those determined with DPPH· expressed as IC50 ranged from 84 to 296 µg/mL, and those determined with FRAP expressed as trolox equivalent were in 33,166 µmol/g range. The antioxidant activities showed a marked correlation with total phenolics. In the antimicrobial tests using six bacteria and a yeast, Escherichia coli was moderately sensitive to each extract. There was no correlation between antimicrobial activity and total phenolic contents. PRACTICAL APPLICATIONS Honey has functional properties and promotes human health, and such properties depend largely on the floral source. Although studies on screening the antimicrobial and antioxidant activity of raw honey samples have been done densely, studies on phenolic compounds of honey are very limited. The present study demonstrates that honey phenolic compounds are partially responsible for honey antioxidant activity, displaying the relevance of honey as both healthy foodstuff and source of antioxidant. [source] ANTIOXIDANT ACTIVITY AND TOTAL PHENOLIC CONTENTS IN PEEL AND PULP OF CHINESE JUJUBE (ZIZIPHUS JUJUBA MILL) FRUITSJOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2009ZIPING XUE ABSTRACT Total phenolic contents in peel and pulp of the fruits of three Chinese jujube cultivars (Ziziphus jujuba cv. mayazao, Z. jujuba cv. dongzao and Z. jujuba cv. yuanzao) were determined. The antioxidant activities in peel and pulp of the jujube fruits were measured by different methods, including 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC). The total phenolic content in peel was five to six times higher than that in the pulp of all the three cultivars. The phenolics contents in the jujube were different with cultivars. The EC50 (Concentration of lyophilized samples needed to decrease the initial DPPH radical concentration by 50%), FRAP and TEAC values of the peel and pulp were remarkably correlated to their total phenolic contents (R = ,0.922, R = 0.985 and R = 0.997, respectively). The results indicated that the high capacity of antioxidant of Chinese jujube fruit could be attributed to the high phenolic contents in the fruit. PRACTICAL APPLICATIONS There was an expanding quest surrounding the use of antioxidant because they have the capacity to protect from the damage because of free radicals and reactive oxygen species. However, the safety of synthetic antioxidant was challenged. Much attention has been focused on the use of natural antioxidant. Interest in food phenolics had increased greatly because of their antioxidant and possible promoting-health role in human health. In this study, total phenolic contents and antioxidant capacities in vitro of Chinese jujube (Ziziphus jujuba Mill) peel and pulp were researched. The work would help to explore a natural antioxidant for possible application in food and dietary supplemental products for health promotion. [source] ANTIOXIDANT ACTIVITY AND PHENOLIC ACID CONSTITUENTS OF CHESTNUT (CASTANIA SATIVA MILL.) HONEY AND PROPOLISJOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2009ALI OSMAN SARIKAYA ABSTRACT This study describes the constituents of phenolic acids and antioxidant activities of chestnut (Castania sativa Mill.) honeys and propolis in Turkey. Antioxidant activity of the chestnut honeys and propolis were examined by three different methods, namely scavenging of free radical 2, 2-diphenyl-1-picrylhydrazyl, FRAP, and cupric reducing antioxidant power. Total phenolic contents were determined by using Folin,Ciocalteu reagent as GA equivalent. The phenolic constituents were also determined by HPLC. The antioxidant activities were compared with standard antioxidants such as catechin, BHT and Trolox. The antioxidant activities of all the samples were found high and related to the sample concentrations. The ethanolic propolis extracts showed the highest antioxidant activity. The major phenolic acids of the chestnut honeys and propolis identified by HPLC with PDA detection were coumaric acid, FA, cinnamic acid, CA and ChA. PRACTICAL APPLICATIONS In this study, some phenolic acid components and antioxidant capacity of chestnut (Castania sativa Mill.) honey and propolis were measured. The comparative findings from antioxidant activities and phenolic acid analyses of honey and propolis samples of chestnut origin provide important criteria for considering their nutritional and nutraceutical potentials. Comparison of our results with literature data also ranks the chestnut honey and propolis as better sources of antioxidants among those from other floral origins. [source] AN ESTEROLYTIC ACTIVITY FROM A WILD EDIBLE MUSHROOM, LYCOPERDON PERLATUMJOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2009AHMET COLAK ABSTRACT Lycoperdon perlatum Pers. (Lycoperdaceae, Agaricales, Agaricomycetidae, Agaricomycetes, Basidiomycota, Fungi) was evaluated for its esterolytic potential. Native electrophoresis of the crude extracts showed four bands having Rf values of 0.34, 0.39, 0.52 and 0.59. The esterase showed the highest activity toward a short-chain substrate, p -nitrophenyl acetate. Optimum reaction conditions for L. perlatum crude extract were attained at pH 8.0 and 40C. Esterolytic activity of enzyme extract was stimulated in the presence of Mn2+, Fe2+, Ca2+ and Zn2+ in the reaction mixture. The enzyme activity was stimulated by incubation at pH 6.0 but retained 77% of its original activity at its optimum pH after 24 h. Thermal inactivation was displayed after incubation for 20 min at various temperatures above 30C. At 1 mM final concentration, 2-mercaptoethanol, dithiothreitol, ethylenediamine tetraacetic acid and p -methylphenyl sulfonylfluoride inhibited the esterolytic reaction. These results support that the crude L. perlatum extract possesses an esterolytic activity having properties similar to other esterases. PRACTICAL APPLICATIONS Esterases catalyzing the cleavage and formation of ester bonds are known ,/,-hydrolases (EC 3.1.1.X). Esterases are used for the synthesis of flavor esters for the food industry, modification of triglycerides for fat and oil industry and resolution of racemic mixtures used for the synthesis of fine chemicals for the pharmaceutical industry. Therefore, the search for new enzyme sources is important for the development of new enzymes and applications. [source] ESR SPECTROSCOPY INVESTIGATION OF ANTIOXIDANT ACTIVITY AND PROTECTIVE EFFECT ON HYDROXYL RADICAL-INDUCED DNA DAMAGE OF ENZYMATIC EXTRACTS FROM PICRORRHIZA KURROAJOURNAL OF FOOD BIOCHEMISTRY, Issue 6 2008SOUNG-HEE CHOI ABSTRACT The potential antioxidant activity of enzymatic extracts from Picrorrhiza kurroa was evaluated on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, hydroxyl radical and alkyl radical-scavenging activities using an electron spin resonance spectrometer (JEOL Ltd., Tokyo, Japan). P. kurroa was enzymatically hydrolyzed by seven carbohydrases and five proteases to prepare water-soluble extracts. The DPPH radical-scavenging activities of the pancreatic trypsin and Amyloglucosidase (AMG) (artificial carbohydrase by Novozyme Nordisk, Bagsvaerd, Denmark) extracts from P. kurroa were the highest among protease and carbohydrase extracts, and 50% inhibitory concentration (IC50) values were 35.58 and 29.03 µg/mL, respectively. The hydroxyl radical-scavenging activity of the Protamex and Viscozyme extracts from P. kurroa were the highest scavenging activities, and the IC50 values were 0.46 and 1.89 mg/mL, respectively. In addition, the Protamex and Maltogenase extracts from P. kurroa showed the highest alkyl radical-scavenging activities, and the IC50 values were 18.03 and 10.66 µg/mL, respectively. The protective effect of the Protamex extracts from P. kurroa on DNA damage which was free radical-induced was 92% at 3 mg/mL. These results indicate that enzymatic extracts of P. kurroa show potent antioxidant activity. PRACTICAL APPLICATIONS Picrorrhiza kurroa could be used to produce protein and carbohydrate extracts with antioxidative activity. Many industrial commercial enzymes such as Promozyme, Celluclast 1.5 L FG, Maltogenase L, Viscozyme L, Termamyl SC, Dextrozyme E, AMG 300 L, Protamex, Flavourzyme 500 MG, Neutrase 0.8 L, Pancreatic Trypsin and Alcalase 2.4 L could be also used to attain the extracts processing the high antioxidative activity. The extracts can be used as natural antioxidants. [source] CHRACTERIZATION AND 1,1-DIPHENYL-2-PICRYLHYDRAZYL RADICAL SCAVENGING ACTIVITY OF METHANOL AND SUPERCRITICAL CARBON DIOXIDE EXTRACTS FROM LEAVES OF ADINANDRA NITIDAJOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2008BENGUO LIU ABSTRACT Leaves of Adinandra nitida are consumed in southern China as health tea (Shiyacha) and as herbal medicine. In this study, the methanol and supercritical fluid extracts from leaves of A. nitida were obtained by traditional solvent extraction and supercritical carbon dioxide extraction, respectively. Both the extracts showed high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. By using ultraviolet-visible spectrometry (UV), infrared spectrometry (IR), nuclear magnetic resonance, electrospray ionization mass spectrometry (ESI-MS), high-performance liquid chromatography-ESI/MS, the main bioactive constituents in the methanol extract (ME) were identified as camellianin A, camellianin B, apigenin. By analysis of gas chromatography-mass spectrometry, a total of 16 compounds accounting for 98.79% of the supercritical fluid extract (SFE) were identified as ,-sitosterol, vitamin E, ,-tocopherol and so on. These compounds found in ME and SFE could contribute to the DPPH radical scavenging performance of the extracts in this study. PRACTICAL APPLICATION Adinandra nitida is a kind of particular wild plant in South China. Few reports have been published about it in the world. In this study, the methanol and supercritical fluid extracts from leaves of A. nitida were respectively obtained by two kinds of industrially significant methods, traditional solvent extraction and supercritical carbon dioxide extraction. By using ultraviolet-visible spectrometry (UV), infrared spectrometry (IR), nuclear magnetic resonance, electrospray ionization mass spectrometry (ESI-MS), high-performance liquid chromatography-ESI/MS, gas chromatography-MS, the main bioactive constituents in the two extracts were identified as flavonoids and plant sterols. Both the extracts showed high 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and this activity of the flavonoid-rich methanol extract was 10 times more than that of butylated hydroxytoluene. These results showed that leaves of A. nitida is a new kind of natural antioxidant-rich, flavonoid-rich plant source with great commercial interest in the food and phytopharmaceutical market. [source] DISTRIBUTION AND ANTIOXIDANT ACTIVITY OF POLYPHENOLS IN RIPE AND UNRIPE TREE PEPPER (CAPSICUM PUBESCENS)JOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2007G. OBOH ABSTRACT Capsicum pubescens, commonly known as tree pepper with its distinctive thick-fleshed pungent fruit (ripe and unripe), is used as a vegetable condiment or made into a sauce. The present study sought to determine the distribution of polyphenols and antioxidant activity in its thick flesh and seeds. Free, bound and total phenol content of each extract was subsequently determined, while reducing power, Fe (II)-chelating ability, OH radical-scavenging ability and ability of the extracts to inhibit lipid peroxidation in basal and Fe (II)-induced lipid peroxidation in brain was used for antioxidant capacity. Unripe pepper had higher total phenol content than ripe pepper; however, there was no significant difference ( P > 0.05) in the total phenol content of flesh for both peppers (unripe [110 mg/100g], ripe [95 mg/100 g]) and the seed (unripe [110.0 mg/100 g ], ripe [90 mg/100 g]). Nevertheless, the free polyphenols in flesh and seed of the peppers were significantly higher ( P < 0.05) than the bound polyphenols. All the extracts inhibited lipid peroxidation in a dose-dependent manner, although free polyphenols from the flesh of ripe pepper caused the highest inhibition in malondialdehyde production in rat's brain. Free and bound polyphenols from the flesh of unripe pepper had the highest Fe (II)-chelating and OH radical-scavenging ability. While the free polyphenols from the flesh of ripe pepper had the highest reducing power, this may have accounted for its ability to reduce Fe (II)-induced lipid peroxidation. Therefore, by removing the seed from pepper, a 50% loss in the total phenol content would result, which will substantially reduce antioxidant activity. PRACTICAL APPLICATIONS Because many degenerative human diseases have been recognized as being a consequence of free radical damage, there have been many studies undertaken on how to delay or prevent the onset of these diseases. The most likely and practical way to fight against degenerative diseases is to improve body antioxidant status, which could be achieved by higher consumption of vegetables and fruits. Foods from plant origin usually contain natural antioxidants that can scavenge free radical. The inclusion of either ripe or unripe pepper in a diet is a common practice in Africa and some other parts of the world; our recent findings on the antioxidant properties of Capsicum pubescens clearly indicate that its inclusion in the diet will contribute greatly in the prevention of neuro-degenerative diseases associated with oxidative stress, by inhibiting lipid peroxidation. Moreover, removing the seeds of this pepper during food processing will reduce the total phenol content by 50%, and consequently reduce the antioxidant activity. [source] ANTIOXIDANT ACTIVITY OF FERMENTED BERRY JUICES AND THEIR EFFECTS ON NITRIC OXIDE AND TUMOR NECROSIS FACTOR-ALPHA PRODUCTION IN MACROPHAGES 264.7 GAMMA NO(,) CELL LINEJOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2006TRI VUONG ABSTRACT Serratia vaccinii, a novel bacterium isolated from blueberry microflora, increased the phenolic content of berry juices, and thus increased antioxidant activities. The fermentation capacity of Serratia was investigated with Saskatoon berries, cranberries, strawberries and grapes in both aerobic and anaerobic conditions. It was shown to be compatible with wine yeast in anaerobic fermentations, producing wine with high antioxidant activity. The effects of fermented berry juices were tested on lipopolysaccharide/inferon-gamma-activated macrophages 264.7 NO(,). Data indicated that fermented berry juices strongly inhibited activated-macrophage NO production but induced tumor necrosis factor-alpha production. [source] EFFECT OF HIGH-PRESSURE TREATMENT OF MILK ON LIPASE AND ,-GLUTAMYL TRANSFERASE ACTIVITYJOURNAL OF FOOD BIOCHEMISTRY, Issue 6 2004P. K. PANDEY ABSTRACT High-pressure (HP) treatment (0,180 min at 300,400 MPa) was applied to milk to evaluate the pressure effects on the activities of lipoprotein lipase and ,-glutamyl transferase. Short time pressure exposure resulted in some enhancement in the activity of both enzymes, and for lipase, there was no inactivation during the entire pressure hold time (up to 100 min). With ,-glutamyl transferase, the extent of enhancement in activity was pressure level dependent, with lower pressure resulting in a greater enhancement. Furthermore, longer pressure treatment times resulted in inactivation of ,-glutamyl transferase, following a first order kinetic model. The pressure sensitivity of the inactivation parameters (k and D -values) for ,-glutamyl transferase was adequately described by the pressure death time and Arrhenius models with a zpof 543 MPa and an associated volume of activation, ,V,, of ,3.28 × 10,8 m3/mole. [source] COMPARATIVE STUDIES ON PROTEOLYTIC ACTIVITY OF SPLENIC EXTRACT FROM THREE TUNA SPECIES COMMONLY USED IN THAILANDJOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2004SUPPASITH KLOMKLAO ABSTRACT Proteolytic activities of splenic extract from three tuna species including skipjack tuna (Katsuwonus pelamis), yellowfin tuna (Thunnus albacores) and tongol tuna (Thunnus tonggol) were studied. Optimal activity of splenic extract from all tuna species was at pH 9.0 and 55C when casein was used as a substrate. Among all species tested, yellowfin tuna showed the highest activity, followed by skipjack tuna and tongol tuna. The proteolytic activity was strongly inhibited by soybean trypsin inhibitor, TLCK and partially inhibited by ethylenediaminetetraacetic acid. E-64, N-ethylmaleimide, iodoacetic acid, TPCK and pepstatin A showed no inhibition. The effect of NaCl and CaCl2 on proteolytic activity was also investigated. Activities continuously decreased as NaCl concentration increased, and no activity remained in the presence of 30% NaCl. On the other hand, activities increased as CaCl2 concentration increased. The highest activity was obtained in the presence of 1 mM CaCl2. SDS-substrate gel electrophoresis revealed that major proteinases in splenic extract from different tuna species were different in apparent molecular weights and sensitivity to TLCK. Although the major activity bands of all species were strongly inhibited by soybean trypsin inhibitor, varying sensitivity to TLCK probably implied the differences in binding characteristic of enzyme to substrate and/or inhibitors. The results suggest that major proteinases in spleen of all tuna species were trypsin-like serine proteinases. [source] TRICHODERMA REESEI,-GALACTOSIDASE ACTIVITY ON LOCUST BEAN AND GUAR GALACTOMANNANSJOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2004SANG MOO KIM The effect of side-chain density on the kinetic parameters of a side-chain-cleaving hemicellulase was determined. Kinetic parameters were based on the rate of Trichoderma reesei ,- galactosidase-catalyzed liberation of galactose from galactomannan (guar and locust bean) substrates. The focus enzyme was the predominant ,-galactosidase obtained from the fungus'galactomannan-supplemented cell-free culture medium. Substrate concentrations were based on the number of galactosyl moieties per volume reaction mixture. The Km values for the galactomannan substrates differed approximately 4.3-fold (28.36 and 121.16 ,M), the more branched substrate having the higher Km. In contrast, the corresponding Vmax values were found to be essentially the same. The results indicate the enzyme preferentially acts at sites of low side-chain density. [source] PROTEOLYTIC ACTIVITY OF LACTOBACILLUS SAKEI, LACTOBACILLUS FARCIMINIS AND LACTOBACILLUS PLANTARUM ON SARCOPLASMIC PROTEINS OF PORK LEANJOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2004ANNA LISA BASSO The aim of this study was to assess the proteolytic activity of Lactobacillus sakei (DSM 6333), L. plantarum (B21), and to a lesser extent, L. farciminis (DSM 20184) on meat sarcoplasmic proteins. The protein composition was assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and capillary electrophoresis after incubation of meat extract inoculated with bacteria. All strains showed proteolytic activity: a band about 94 kDa disappeared in samples inoculated with L. farciminis and L. plantarum and strongly decreased in those inoculated with L. sakei. The intensity of the bands with a molecular weight between 94 and 38 kDa decreased in all samples. Capillary electrophoresis analysis ascertained the disappearance of the fractions corresponding to 8.64 and 8.66 min retention time in all samples. The bands corresponding to 94 kDa and 38 kDa were, respectively, identified as glycogen phosphorylase muscle isoform and glyceraldehyde 3-phosphate dehydrogenase, by in situ digestion of protein gel bands and peptide map analysis using Matrix Assisted Laser Desorption/Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS). [source] ATPASE ACTIVITY, SURFACE HYDROPHOBICITY, SULFHYDRYL CONTENT AND PROTEIN DEGRADATION IN REFRIGERATED SEABASS MUSCLE IN MODIFIED ATMOSPHERE PACKAGINGJOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2004PAYAP MASNIYOM The effect of modified atmosphere packaging (80% CO2, 10% O2, 10% N2) on ATPase activity, surface hydrophobicity, sulfhydryl content and degradation of proteins in seabass muscle during storage at 4C was investigated. No changes in Ca2+ -, Mg2+ -, Mg2+ -Ca2+ -ATPase activities of natural actomyosin (NAM) in seabass slices kept under MAP were observed throughout the storage for up to 21 days (P > 0.05). However, a slightly increased Mg2+ -EGTA-ATPase was found. For seabass slices stored under air atmosphere, Ca2+ -ATPase activity decreased, whereas Mg2+ -EGTA-ATPase activity increased (P < 0.05) with a concomitant loss in Ca2+ -sensitivity. Lower decreases in total sulfhydryl content but higher increases in surface hydrophobicity were observed in samples stored under MAP, compared to those kept under air atmosphere. No marked autolytic degradation in samples kept under MAP was observed throughout the storage as monitored by no changes in myosin heavy chain, free ,-amino acid and trichloroacetic acid soluble peptide. Conversely, a considerable degradation was found in samples kept under air atmosphere, especially after 9 days of storage. Therefore, MAP is a promising means to retard the changes in muscle proteins, especially degradation. [source] EFFECT OF WATER ACTIVITY ON PHYSICAL PROPERTIES OF CONJUGATED LINOLEIC ACID (CLA) MICROCAPSULESJOURNAL OF FOOD PROCESS ENGINEERING, Issue 3 2010MARIBEL JIMENEZ ABSTRACT The physical properties of spray drying powders must be considered for the design of equipment. Conjugated linoleic acid (CLA) microcapsules were spray dried by using the following as wall materials: whey protein concentrate (WPC), a blend of whey protein concentrate,maltodextrins (WPC-MD) and gum arabic (GA). These were prepared and their physical properties were studied. The bulk density, packed density, particle density, compressibility and color of the microcapsules were evaluated in a range of water activities from 0.108 to 0.898. No significant differences in the physical properties were found when WPC was used as a wall material in the microcapsules stored at the whole range of water activities tested. Maltodextrins conferred changes in some of the physical properties of the microcapsules (WPC-MD) upon storage at high water activities. GA microcapsules showed drastic changes in all physical properties studied at water activities above 0.628. PRACTICAL APPLICATIONS This work shows the best conditions for storing conjugated linoleic acid (CLA) microcapsules elaborated with different wall materials, which have been reported to have a high potential as a food additive because of the nutraceutical properties of CLA. This research should reveal the behavior of water activity during storage on physical properties, and make it possible to predict what characteristics need to be added to a food, besides being important for the design of equipment, packing and transport. [source] EVALUATION OF GLOBAL YIELD, COMPOSITION, ANTIOXIDANT ACTIVITY AND COST OF MANUFACTURING OF EXTRACTS FROM LEMON VERBENA (ALOYSIA TRIPHYLLA[L'HÉRIT.] BRITTON) AND MANGO (MANGIFERA INDICA L.) LEAVESJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2007CAMILA G. PEREIRA ABSTRACT In this work, the global yields, composition and antioxidant activity (AA) of extracts from lemon verbena (Aloysia triphylla) and mango (Mangifera indica) leaves obtained by different separation processes were determined. Lemon verbena extracts were obtained by supercritical fluid extraction (SFE), while mango leaf extracts were obtained by SFE, low-pressure solvent extraction (LPSE) and hydrodistillation. The extract's constituents were analyzed by thin-layer chromatography, gas chromatography/mass spectrometry and gas chromatography/flame ionization detector. The AA of the extracts was evaluated by the coupled reaction of , -carotene/linolenic acid. The cost of manufacturing (COM) was estimated for the SFE extracts. Higher global yields were obtained using SFE at 350 bar/45C (1.49%) for lemon verbena and LPSE (3.04%) for mango. The AAs of the extracts were larger than that of the , -carotene for both plants. The minimum values of COM were U.S.$26.96 and 52.45/kg of extract for lemon verbena and mango, respectively. [source] ATTRITION EVALUATION FOR SELECTED AGGLOMERATED FOOD POWDERS: THE EFFECT OF AGGLOMERATE SIZE AND WATER ACTIVITYJOURNAL OF FOOD PROCESS ENGINEERING, Issue 1 2001HONG YAN ABSTRACT Investigation of the attrition of agglomerates is very important for assessing the agglomerate strength, compaction characteristics, and quality control. A one-term exponential attrition index model and the Hausner ratio were used to study the effects of agglomerate size and water activity on the attrition kinetics of some selected agglomerated food powders. It was found that the agglomerate size and water activity played significant roles in affecting the attrition: the larger the agglomerate size and the higher the water activity, the higher the attrition index under the same tap number. The Hausner ratio was well correlated with the attrition index at high tap numbers and might be used as a simple index to evaluate attrition severity for agglomerates. Knowing the effects of agglomerate size and water activity is very useful to minimize the attrition phenomenon during the handling and processing of agglomerated powders. [source] ANTIBACTERIAL ACTIVITY AND CHEMICAL CONSTITUTIONS OF OLEA EUROPAEA L. LEAF EXTRACTSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2010MIHRIBAN KORUKLUOGLU ABSTRACT The in vitro antimicrobial activity of aqueous, acetone, diethyl ether and ethyl alcohol extracts of olive leaves (Olea europaea L.) was studied. The aqueous extract of olive leaves had no antibacterial effect against the test microorganisms, whereas acetone extract showed inhibitory effect on Salmonella enteritidis, Bacillus cereus, Klebsiella pneumoniae, Escherichia coli, Enterococcus faecalis, Streptococcus thermophilus and Lactobacillus bulgaricus. Furthermore, the antimicrobial activities of some phenolic compounds against microorganisms were tested. The most effective compound was found to be oleuropein while syringic acid was found ineffective. The characterization of phenolic compounds in different extracts determined by high performance liquid chromatography-air pressure chemical ionization-mass spectrometry detector (HPLC-APCI-MSD GC-MS) gas chromatography-mass spectrometry (GC-MS). The acetone and the ethyl alcohol extracts had the most and the least oleuropein content, respectively. PRACTICAL APPLICATIONS In recent years the extracts of many plant species have become popular, and attempts to characterize their bioactive principles have gained speed for many pharmaceutical and food-processing applications. Especially, antimicrobial properties of plants have revived as a consequence of current problems associated with the use of chemical preservatives. Because of consumers' negative perspectives of synthetic preservatives, attention is shifting toward natural alternatives. The findings suggest that olive leaf extracts and their phenolic compounds have good potential as antibacterial substances in food preservation as they may be more acceptable to consumers and the regulatory agencies in comparison with synthetic chemical compounds. [source] STABILITY OF ANTHOCYANINS, PHENOLS AND FREE RADICAL SCAVENGING ACTIVITY THROUGH SUGAR ADDITION DURING FROZEN STORAGE OF BLACKBERRIESJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2009MIRELA KOPJAR ABSTRACT Influence of sugar and mixtures of sugar on color retention of two varieties of blackberries, Thornfree and Cacanska bestrna, were investigated during storage at ,18C for 12 months. After harvest, blackberries were coated with sugars (sucrose, fructose and glucose) and different sugar (sucrose + fructose + glucose, fructose + glucose, fructose + sucrose) mixtures. Anthocynin content, total phenol content and free radical scavenging activity of prepared samples were evaluated. Ratio of fruit : sugar was 1:1. The highest anthocyanin retention was in blackberry samples with glucose addition and the lowest in samples with sucrose addition, in both cultivars. Blackberry samples with sucrose addition had even lower retention than samples without sugar addition. Samples with an addition of other sugars had higher retention of anthocyanin than samples stored without sugars. PRACTICAL APPLICATION Possibility of phenols retention of blackberries due to sugar addition, during cold storage was investigated. Results showed that glucose had the most positive effect on anthocyanins retention as well as total phenolic compounds content. For that reason, certain amount of sucrose in fruit preserves can be replaced by addition of glucose, and for that reason retention of phenolic compounds can be higher and, as could be expected, more effective against oxidative stress in human body due to intake of product formulation with glucose. [source] THE EFFECT OF AIR-DRYING, FREEZE-DRYING AND STORAGE ON THE QUALITY AND ANTIOXIDANT ACTIVITY OF SOME SELECTED BERRIESJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2009MAGDALENA MICHALCZYK ABSTRACT The aim of this study was to analyze the effects of air-drying and freeze-drying and subsequent storage of dried products on the content of polyphenols, anthocyanins and the antioxidant properties of selected berry fruits. The material was raspberry (Rubus ideaus L.), strawberry (Fragaria ananassa Duch) and bilberry (Vaccinum myrtillus). Despite exposure to atmospheric oxygen, the stored freeze-dried fruit retained the properties of the raw material better than the air-dried product. In the case of the latter, there were considerable differences in the retention of total polyphenolic and anthocyanin content as well as antioxidant properties in the three fruit species examined. In particular, bilberry maintained a high polyphenol and anthocyanin content and high antioxidant potential despite the greatest losses of these compounds. PRACTICAL APPLICATIONS Consumer demand for food with health-promoting qualities is increasing. The food industry has intensified its efforts to provide high quality, semi-processed products that fulfil this requirement. The results presented in this work indicate that even after long-term storage and despite exposure to atmospheric oxygen, freeze-dried berries retain the antioxidant properties of the raw material to a very high degree. Therefore, lyophilisates can satisfy this particular need. Air-dried berries are much less stable during long-term storage. The dynamics of the changes occurring during the storage of both kinds of product are presented in detail. [source] | |||||||||||||||||||||||||||||||||||||||||||