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711.
Rabie Khattab Marianne Su-Ling Brooks 《International Journal of Food Properties》2016,19(8):1708-1725
Haskap berries (Lonicera caerulea L.) are known for their high phenolics, anthocyanins, and antioxidant potential. The data on the phenolic profile of these fruits are lacking. In this study, the phenolic profiles of three haskap varieties; tundra, berry blue, and indigo gem grown in Nova Scotia, Canada were investigated for the first time using spectrophotometery and high-performance liquid chromatography. Berries were analyzed for total phenolic content/total reducing capacity, total anthocyanin content, and antioxidant potential (2,2-diphenyl-1-picrylhydrazyl radical scavenging activity). The total reducing capacity, total anthocyanin content, and 2,2-diphenyl-1-picrylhydrazyl values were 6.17–8.42 mg gallic acid equivalents/gram fresh weight, 4.49–6.97 mg cyanidin-3-glucoside equivalents/gram fresh weight, and 78.70–89.55%, respectively. The extracts were analyzed by reversed-phase diode array detector–high-performance liquid chromatography through a gradient elution using Synergi 4 µm Max-RP C12 column and the chromatograms were acquired at 520, 360, and 320 nm for athocyanins, flavonoids, and free phenolic acids, respectively. The identified anthocyanins were cyanidin-3-glucoside (82.81–91.99% of the total anthocyanins), cyanidin 3,5-di-glucoside (2.31–4.27%), cyanidin-3-rutinoside (1.54–9.20%), peonidin-3-O-glucoside (0.75–3.44%), and pelargonidin-3-glucoside (0.77–2.98%). Other flavonoids (quercetin-3-β-D-glucoside and quercetin-3-rutinoside) and free phenolic acids (chlorogenic and neochlorogenic) were also quantified. 相似文献
712.
Optimizing colour quality of modified atmosphere packed sliced meat products by control of critical packaging parameters 总被引:1,自引:0,他引:1
Nannerup LD Jakobsen M van den Berg F Jensen JS Møller JK Bertelsen G 《Meat science》2004,68(4):577-585
Distribution of fat, muscle and bone tissues was studied in bucks, wethers and doe Jebel Akhdar (JA) Omani goats raised under intensive management and slaughtered at 11, 18 or 28 kg body weight (BW). Weight of individual tissues was expressed as percentage of total respective tissue weight in the half carcass. Weight of total body fat in the empty body weight (EBW) ranged between 7.6% in bucks at 11 kg BW and 23.5% in does at 28 kg BW. At 18 kg BW, JA goats had higher TBF, carcass and non-carcass fat than those slaughtered at 12 kg BW (P<0.001). Does and wethers had a faster rate of deposition of carcass and non-carcass fat relative to EBW. Therefore, they had higher fat content (P<0.001) than bucks at 28 kg BW. The highest proportion of fat in the body was deposited intermusculary whereas the omentum constituted the highest non-carcass fat proportion. About 55% of the musculature in JA goat carcasses was found in muscle groups of the proximal hind leg, around the vertebral column and in the proximal forelimb (expensive muscle groups). Bucks had higher proportions of musculature in the forequarter (P<0.001) and intrinsic muscles of the neck but lower proportions of muscles at the proximal hind limb (P<0.001) than does and wethers. About 51% of the total skeleton was found in the axial skeleton, 22–23% in the forelimb and 22–23% in the hind limb of JA goats. There were few sex or slaughter weight effects on proportions of bone weight in the skeleton. In general, slaughter weight and sex effects on tissue distribution were more pronounced in the fat tissue. The magnitude of these effects on muscle and bone tissues was small and is unlikely to have economic impact on meat production from goats. 相似文献
713.
H Zhang DR Worton M Lewandowski J Ortega CL Rubitschun JH Park K Kristensen P Campuzano-Jost DA Day JL Jimenez M Jaoui JH Offenberg TE Kleindienst J Gilman WC Kuster J de Gouw C Park GW Schade AA Frossard L Russell L Kaser W Jud A Hansel L Cappellin T Karl M Glasius A Guenther AH Goldstein JH Seinfeld A Gold RM Kamens JD Surratt 《Environmental science & technology》2012,46(17):9437-9446
2-Methyl-3-buten-2-ol (MBO) is an important biogenic volatile organic compound (BVOC) emitted by pine trees and a potential precursor of atmospheric secondary organic aerosol (SOA) in forested regions. In the present study, hydroxyl radical (OH)-initiated oxidation of MBO was examined in smog chambers under varied initial nitric oxide (NO) and aerosol acidity levels. Results indicate measurable SOA from MBO under low-NO conditions. Moreover, increasing aerosol acidity was found to enhance MBO SOA. Chemical characterization of laboratory-generated MBO SOA reveals that an organosulfate species (C(5)H(12)O(6)S, MW 200) formed and was substantially enhanced with elevated aerosol acidity. Ambient fine aerosol (PM(2.5)) samples collected from the BEARPEX campaign during 2007 and 2009, as well as from the BEACHON-RoMBAS campaign during 2011, were also analyzed. The MBO-derived organosulfate characterized from laboratory-generated aerosol was observed in PM(2.5) collected from these campaigns, demonstrating that it is a molecular tracer for MBO-initiated SOA in the atmosphere. Furthermore, mass concentrations of the MBO-derived organosulfate are well correlated with MBO mixing ratio, temperature, and acidity in the field campaigns. Importantly, this compound accounted for an average of 0.25% and as high as 1% of the total organic aerosol mass during BEARPEX 2009. An epoxide intermediate generated under low-NO conditions is tentatively proposed to produce MBO SOA. 相似文献
714.
This study evaluated the effect of carbon dioxide addition on microbiological quality during refrigerated storage of raw milk collected in Curitiba city, Brazil. A three factor-two level full factorial design was used to investigate the effect of the pH (5.8-6.4), storage time (0-10 days) and storage temperature (5-10 ℃), on the responses, namely, mesophiles, psychrotrophs, lipolytic psychrotrophs and proteolytic psychrotrophs counts. Results showed that increase in pH and storage time had significant effect on the microbial count. No significant effect of storage temperature was observed for all the microorganisms studied. All responses were well predicted by selected mathematical models, as denoted by coefficient of determination above 0.95. 相似文献
715.
Begoa de Ancos M Pilar Cano Almudena Hernandez Marianne Monreal 《Journal of the science of food and agriculture》1999,79(5):663-670
Microwave energy was applied to inactivate the oxydoreductases peroxidase (POD, EC 1.11.1.7) and polyphenol oxidase (PPO, EC 1.14.18.1) in processed fruit products. Microwave blanching of papaya, strawberry and kiwi purees at various conditions of power and time produced inactivation of PPO and POD activities depending on the fruit and the heating conditions. Treatment at 850 W/60 s produced about 60% of POD inactivation for papaya and kiwi fruit. POD activity in strawberry, however, seemed to be more resistant to microwave inactivation; treatment at 850 W/60 s only achieved a loss of POD activity near 8%. Papaya oxidoreductases showed lower stability in the microwave treatments tested. Microwave blanching at 475 W/45 s produced about 75% inactivation of POD activity and nearly complete PPO inactivation. Kiwi fruit and strawberry purees exhibited similar inactivation of PPO – 32% at 475 W/30 s and 70% at 475 W/60 s. The decrease of PPO activity in both products was almost linear at constant power. This thermal treatment, however, directly affects the colour of the fruit pulps. Papaya, kiwi and strawberry purees suffered slight colour (CIE L* a*b*) changes. Carotenoid, chlorophyll and anthocyanin changes were evaluated by HPLC and related to objective colour. Microwave treatments produced small modifications of the quantitative and qualitative composition of carotenoids (in papaya) and anthocyanins (in strawberry). Chlorophylls (kiwi) showed significant degradation as a consequence of microwave heating. © 1999 Society of Chemical Industry 相似文献
716.
Koinis–Mitchell Daphne; McQuaid Elizabeth L.; Seifer Ronald; Kopel Sheryl J.; Nassau Jack H.; Klein Robert B.; Feldman Jonathan; Wamboldt Marianne Z.; Fritz Gregory K. 《Canadian Metallurgical Quarterly》2009,28(2):226
Objective: This study tested the differential effects of several cognitive and psychological variables on children's perception of asthma symptoms by use of an Asthma Risk Grid. Children's subjective and objective assessments of PEFR (peak expiratory flow rate) were characterized as representing perceptual accuracy, symptom magnification, and/or underestimation of asthma symptoms. Design: The study included 270 children with asthma (ages 7–17) and their primary caregivers who completed measures assessing cognitive and psychological factors and a 5 to 6 week symptom perception assessment. Main Outcome Measures: Children's symptom perception scores by use of the Asthma Risk Grid. Results: Children's attentional abilities had more of a bearing on their symptom monitoring abilities than their IQ estimates and psychological symptoms. The more time children took on Trails and Cancellation Tasks and the fewer errors they made on these tasks, the more likely they were to perceive their asthma symptoms accurately. More time on these tasks was associated with more symptom magnification scores, and fewer errors were related to fewer symptom magnification scores. More errors and higher total scores on the Continuous Performance Task were associated with a greater proportion of scores in the danger zone. Conclusion: Statistical support was provided for the utility of attentional-based instruments for identifying children who may have problems with perceptual accuracy, and who are at risk for asthma morbidity. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
717.
The goal of the present research was to investigate whether high or low power leads to more interpersonal sensitivity and what potentially mediates and moderates this effect. In Study 1, 76 participants in either a high- or low-power position interacted; in Study 2, 134 participants were implicitly primed with either high- or low-power or neutral words; and in Study 3, 96 participants were asked to remember a situation in which they felt high or low power (plus a control condition). In Study 4, 157 participants were told to identify with either an egoistic, empathic, or neutral leadership style. In all studies, interpersonal sensitivity, defined as correctly assessing other people, was then measured using different instruments in each study. Consistently, high power resulted in more interpersonal sensitivity than low power. Feeling respected and proud was partially responsible for this effect. Empathic power as a personality trait was related to more interpersonal sensitivity, and high-power individuals who adopted an empathic instead of an egoistic leadership style were more interpersonally sensitive. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
718.
The mechanical properties of a short glass-fiber reinforced composite based on a commercial polypropylene grade was compared to a composite system where the bulk material had been replaced by a propylene/4-(hept-6-enyl)-2,6-di-tert-butylphenol copolymer. The mechanical properties of the composites were determined by standard tensile tests. The results indicated that the composite based on the copolymer exhibited a noticeable improvement in tensile properties compared to the composite based on commercial polypropylene. The improved mechanical properties can be attributed to higher wetting of the fibers and to enhanced interfacial adhesion between the fiber and the matrix relative to the composite based on the commercial polypropylene. These assumptions are supported by scanning electron microscopy analysis. © 1993 John Wiley & Sons, Inc. 相似文献
719.
Yasmin Ioannides John Seers Marianne Defernez Carol Raithatha M. Scott Howarth Andrew Smith E. Kate Kemsley 《Food quality and preference》2009,20(3):203-215
Electromyography (EMG) of the masticatory muscles was compared with puncture testing and sensory evaluation, in a study of the textural properties of Red Delicious apples. An aim of the work was to use EMG in predictive models of sensory mealiness, as this property is strongly negatively associated with apple acceptability. It was found that subjects’ EMG sensitivity and repeatability are as good as, and frequently better, than their sensory sensitivity and reliability. In addition to systematic effects associated with data recording session and subject, EMG data was also systematically affected by subjects’ behavioural changes, specifically, the sensory evaluation being undertaken. Once these unwanted sources of variance were removed using suitable data pre-treatment, frequency-domain EMG data were correlated with puncture test data, and a significant relationship obtained for six out of thirteen subjects. For five out of these six subjects, the strength of this relationship was improved by making use only of higher frequencies (>15 Hz) in the EMG spectrum. EMG and puncture test data were each correlated with the sensory data. The nature of these relationships, in which the EMG frequency dependence effect was also clearly exhibited, demonstrated substantial common information content between the techniques. Finally, EMG and puncture test data were collectively used to model sensory mealiness, using univariate, bivariate and stepwise regression. Highly significant models were obtained for all but one subject’s sensory mealiness scores. In most cases, the best models used combinations of puncture test and EMG data from up to two of the four available electrodes. 相似文献
720.
Black Arsenic–Phosphorus: Layered Anisotropic Infrared Semiconductors with Highly Tunable Compositions and Properties 下载免费PDF全文