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Liu Y.,Beijing Technology and Business University | Hu X.,China Agricultural University | Zhao X.,Beijing Academy of Agriculture and Forestry Sciences | Song H.,Beijing Technology and Business University
Innovative Food Science and Emerging Technologies | Year: 2012

The aim of this study was to investigate the combined effect of high pressure carbon dioxide (HPCD) and mild heat treatment on the overall quality of watermelon juice. The residual activity of polyphenoloxidase (PPO), peroxidase (POD), and pectin methylesterase (PME) decreased with pressure and treatment time after HPCD and heat treatment. The total color difference (E) value was greater than 3.5, suggesting the significant change of color. Browning degree (BD) decreased with pressure and treatment time; pH and lycopene content of HPCD-treated juice slightly decreased; cloudiness and titratable acidity (TA) increased; and viscosity of 10 and 20 MPa treated juice at 31.62 1 s - 1 did not change. While after control treatment, the residual activity of enzymes and BD decreased slightly; cloudiness decreased greatly; pH, TA, lycopene content, and color were stable. HPCD and mild heat treatment inactivated enzyme activities drastically which affected the shelf life and quality of watermelon juice greatly during storage. And it increased cloudy stability that was the important parameter to influence appearance of juice. Overall, HPCD treatment has greater advantages to maintain the quality of watermelon juice. Industrial relevance: The application of high pressure carbon dioxide (HPCD) processing on several food products has already been proven to be successful for pasteurization. HPCD processing to inactivate endogenous enzymes and retain quality of food needs to be further studied. Studies dealing with the combination effect of pressure and mild heat conditions on enzyme activities and quality parameters are relevant to understand the prospects for watermelon juice processing. © 2011 Elsevier Ltd.

Chen Z.,Beijing Normal University | Gao B.,Beijing Academy of Agriculture and Forestry Sciences
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing | Year: 2014

Airborne Lidar (Light detection and ranging) data have been widely used for classifying different land cover types. However, few researchers have conducted urban land cover classification using discrete airborne Lidar data as the sole data source. This research explores the possibility of applying airborne Lidar data to land cover classification in urban areas. The elevation difference and intensity difference between the first and last return, which may not work efficiently in pixel-based classification, were employed as two key attributes at the object level. Since tree objects have a much larger proportion of returns which show the elevation and intensity difference, the two indicators were used to classify the most indistinguishable land cover types, buildings and trees. In addition, height and intensity information were integrated to classify other land cover types. A case study was conducted in the city of Cambridge and eight urban land cover types were classified with an overall accuracy of 93.6%. Each land cover type was classified with an accuracy of between 80% and 100% and among these types, the accuracy of more than 90% for trees and buildings was satisfactory. © 2014 IEEE.

The main objective of GoodBerry is to provide the necessary knowledge and procedures to facilitate the development of highly productive and top quality berry fruits, even under multiple suboptimal growth conditions, at a competitive cost. The project is based on an integrative multi-actor approach, from cultivation techniques to molecular studies, aiming the development and validation of a range of tools to improve competitiveness of European berry production, and eventually the attraction and confidence of consumers. The selection of the model species can be considered as strategic since strawberry is the most important berry crop in Europe and the production of raspberry and blackcurrant are increasing strongly in recent years. The project will apply the most recent technical advances in: a) The identification of berry germplasm exhibiting advantageous balance of production vs nutritional quality throughout the EU, b) The search of innovative production systems to maintain high yield in a range of European-wide environments, c) The development of standardized and reliable analytical tools to evaluate berry production and fruit quality. As result, it is expected: a) the implementation of modern breeding strategies to accelerate the release of new berry cultivars; b) The adoption by EU-growers of high quality production systems to improve fruit quality. The proposal establishes as obligatory to disseminate and communicate the results to the scientific community, industry, the broad public and interested stakeholders user. The final impact will be to consolidate the emerging needs of high-quality berries, and to boost consumer and market confidence supported by an improved competitiveness of producers. It is a multidisciplinary, collaborative project based on complementary expertise and skills of internationally recognized berry research institutions, and highly involved key berry SMEs that will combine their effort to secure the robustness of the results.

Zeng X.,University of Tennessee at Knoxville | Mo Y.,University of Tennessee at Knoxville | Xu F.,University of Tennessee at Knoxville | Xu F.,Beijing Academy of Agriculture and Forestry Sciences | Lin J.,University of Tennessee at Knoxville
Molecular Microbiology | Year: 2013

Ferric enterobactin (FeEnt) acquisition is a highly efficient and conserved iron scavenging system in Gram-negative bacteria. Recently, we have characterized two FeEnt receptors (CfrA and CfrB) in Campylobacter jejuni and C. coli, the enteric human pathogens that do not produce any siderophores. In this study, whole-genome sequencing and comparative genomic analysis identified a unique Ent trilactone esterase Cee (Cj1376) in C.jejuni. Genomic analysis and biochemical assay strongly suggested that Cee is the sole trilactone esterase in C.jejuni. Thin-layer chromatography and HPLC analyses showed high efficiency of the purified Cee to hydrolyse Ent. Three Cee homologues previously characterized from other bacteria (IroE, IroD and Fes) were also purified and analysed together with Cee, indicating that Cee, Fes and IroD displayed similar hydrolysis dynamics for both apo and ferric forms of Ent while IroE catalysed Ent inefficiently. Unlike cytoplasmic Fes and IroD, Cee is localized in the periplasm as demonstrated by immunoblotting using Cee-specific antibodies. Genetic manipulation of diverse Campylobacter strains demonstrated that Cee is not only essential for CfrB-dependent FeEnt acquisition but also involved in CfrA-dependent pathway. Together, this study identified and characterized a novel periplasmic trilactone esterase and suggested a new model of FeEnt acquisition in Campylobacter. © 2012 Blackwell Publishing Ltd.

Li T.,CAS Research Center for Eco Environmental Sciences | Hu Y.-J.,CAS Research Center for Eco Environmental Sciences | Hao Z.-P.,CAS Research Center for Eco Environmental Sciences | Li H.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
New Phytologist | Year: 2013

Arbuscular mycorrhizal (AM) symbiosis is known to stimulate plant drought tolerance. However, the molecular basis for the direct involvement of AM fungi (AMF) in plant water relations has not been established. Two full-length aquaporin genes, namely GintAQPF1 and GintAQPF2, were cloned by rapid amplification of cDNA 5′- and 3′-ends from an AMF, Glomus intraradices. Aquaporin localization, activities and water permeability were examined by heterologous expression in yeast. Gene expression during symbiosis was also analyzed by quantitative real-time polymerase chain reaction. GintAQPF1 was localized to the plasma membrane of yeast, whereas GintAQPF2 was localized to both plasma and intracellular membranes. Transformed yeast cells exhibited a significant decrease in cell volume on hyperosmotic shock and faster protoplast bursting on hypo-osmotic shock. Polyethylene glycol (PEG) stimulated, but glycerol inhibited, the aquaporin activities. Furthermore, the expression of the two genes in arbuscule-enriched cortical cells and extraradical mycelia of maize roots was also enhanced significantly under drought stress. GintAQPF1 and GintAQPF2 are the first two functional aquaporin genes from AMF reported to date. Our data strongly support potential water transport via AMF to host plants, which leads to a better understanding of the important role of AMF in plant drought tolerance. © 2012 Research Centre for Eco-Environmental Sciences, CAS New Phytologist © 2012 New Phytologist Trust.

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