The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Ingegerd Sjöholm - One of the best experts on this subject based on the ideXlab platform.
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Mechanisms and Prevention of Plant Tissue Collapse during Dehydration: A Critical Review
Critical Reviews in Food Science and Nutrition, 2003Co-Authors: Frédéric Prothon, Lilia Ahrne, Ingegerd SjöholmAbstract:The appearance and functional properties are primordial in the quality assessment of semifinished fruit and vegetable products. These properties are often associated with shrunken, shriveled, darkened materials of poor Rehydration ability after been subjected to air-drying--the most used drying method in the food industry. Fruits and vegetables are cellular tissues containing gas-filled pores that tend to collapse when subjected to dehydration. Collapse is an overall term that has different meanings and scale-settings in the literature depending on whether the author is a plant physiologist, a food technologist, a chemical engineer, or a material scientist. Some clarifications are given in this particular but wide field. The purpose of this work was to make a state-of-the-art contribution to the structural and textural effects of different types of dehydration on edible plant products and give a basis for preventing this phenomenon. The plant tissue is described, and the primordial role of the cell wall in keeping the structural integrity is emphasized. Water and its functionality at macro and micro levels of the cellular tissue are reviewed as well as its transport during dehydration. The effects of both dehydration and Rehydration are described in detail, and the term "textural collapse" is proposed as an alternative to structural collapse.
Judy A. Driskell - One of the best experts on this subject based on the ideXlab platform.
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Carotenoid content, physicochemical, and sensory qualities of deep-fried Carrot chips as affected by dehydration/Rehydration, antioxidant, and fermentation
Journal of Agricultural and Food Chemistry, 2001Co-Authors: Ahmad Sulaeman, Laune Keeler, Steve L Taylor, David W. Giraud, Judy A. DriskellAbstract:Carrot slices were subjected to one of the following experiments prior to deep-frying: (A) dehydration/Rehydration, (B) soaking in different antioxidants, and (C) fermentation with/without blanching. There were no significant differences (P ≥ 0.05) in carotenoid contents among carrot chips treated with/without dehydration. Soaking in sodium metabisulfite resulted in the highest carotenoid content and lightness (L), redness (a), and yellowness (b) values among the antioxidant treatments. Fermentation without blanching significantly decreased (P < 0.05) carotenoid content, vitamin A activity, and fat content. Dehydration and fermentation with blanching significantly increased (P < 0.05) the lightness (L), redness (a), and yellowness (b) values of the chips. Dehydration/Rehydration, but not antioxidant and fermentation, significantly decreased (P < 0.05) the water activity of the chips. The textural values of carrot chips prepared using sodium metabisulfite, without dehydration and without fermentation, wer...
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carotenoid content physicochemical and sensory qualities of deep fried carrot chips as affected by dehydration Rehydration antioxidant and fermentation
Journal of Agricultural and Food Chemistry, 2001Co-Authors: Ahmad Sulaeman, Laune Keeler, Steve L Taylor, David W. Giraud, Judy A. DriskellAbstract:Carrot slices were subjected to one of the following experiments prior to deep-frying: (A) dehydration/Rehydration, (B) soaking in different antioxidants, and (C) fermentation with/without blanching. There were no significant differences (P ≥ 0.05) in carotenoid contents among carrot chips treated with/without dehydration. Soaking in sodium metabisulfite resulted in the highest carotenoid content and lightness (L), redness (a), and yellowness (b) values among the antioxidant treatments. Fermentation without blanching significantly decreased (P < 0.05) carotenoid content, vitamin A activity, and fat content. Dehydration and fermentation with blanching significantly increased (P < 0.05) the lightness (L), redness (a), and yellowness (b) values of the chips. Dehydration/Rehydration, but not antioxidant and fermentation, significantly decreased (P < 0.05) the water activity of the chips. The textural values of carrot chips prepared using sodium metabisulfite, without dehydration and without fermentation, wer...
Patrick Gervais - One of the best experts on this subject based on the ideXlab platform.
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Controlling the membrane fluidity of yeasts during coupled thermal and osmotic treatments
Biotechnology and Bioengineering, 2008Co-Authors: Hélène Simonin, Laurent Beney, Patrick GervaisAbstract:Yeasts are often exposed to variations in osmotic pressure in their natural environments or in their substrates when used in fermentation industries. Such changes may lead to cell death or activity loss. Previous work by our team has allowed us to relate the mortality of cells exposed to a combination of thermal and osmotic treatments to leakage of cellular components through an unstable membrane when lipid phase transition occurs. In this study, yeast viability was measured after numerous osmotic and thermal treatments. In addition, the fluidity of yeast membranes was assessed according to aw and temperature by means of 1,6‐diphenyl‐1,3,5‐hexatriene (DPH) anisotropy measurement. The results show that there is a negative correlation between the overall fluidity variation undergone by membranes during treatments and yeast survival. Using a diagram of membrane fluidity according to aw and temperature, we defined dehydration and Rehydration methods that minimize fluidity fluctuations, permitting significantly increased yeast survival. Thus, such membrane fluidity diagram should be a potential tool for controlling membrane state during dehydration and Rehydration and improve yeast survival. Overall fluidity measurements should now be completed by accurate structural analysis of membranes to better understand the plasma membrane changes occurring during dehydration and Rehydration.
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Sequence of occurring damages in yeast plasma membrane during dehydration and Rehydration: Mechanisms of cell death
Biochimica et Biophysica Acta:Biomembranes, 2007Co-Authors: Hélène Simonin, Laurent Beney, Patrick GervaisAbstract:Yeasts are often exposed to variations in osmotic pressure in their natural environments or in their substrates when used in fermentation industries. Such changes may lead to cell death or activity loss. Although the involvement of the plasma membrane is strongly suspected, the mechanism remains unclear. Here, the integrity and functionality of the yeast plasma membrane at different levels of dehydration and Rehydration during an osmotic treatment were assessed using various fluorescent dyes. Flow cytometry and confocal microscopy of cells stained with oxonol, propidium iodide, and lucifer yellow were used to study changes in membrane polarization, permeabilization, and endocytosis, respectively. Cell volume contraction, reversible depolarization, permeabilization, and endovesicle formation were successively observed with increasing levels of osmotic pressure during dehydration. The maximum survival rate was also detected at a specific Rehydration level, of 20 MPa, above which cells were strongly permeabilized. Thus, we show that the two steps of an osmotic treatment, dehydration and Rehydration, are both involved in the induction of cell death. Permeabilization of the plasma membranes is the critical event related to cell death. It may result from lipidic phase transitions in the membrane and from variations in the area-to-volume ratio during the osmotic treatment.
Melvin J Oliver - One of the best experts on this subject based on the ideXlab platform.
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sporobolus stapfianus insights into desiccation tolerance in the resurrection grasses from linking transcriptomics to metabolomics
BMC Plant Biology, 2017Co-Authors: Abou Yobi, Karen Schlauch, Richard L Tillett, Catherine Espinoza, Bernard W M Wone, John C Cushman, Melvin J OliverAbstract:Understanding the response of resurrection angiosperms to dehydration and Rehydration is critical for deciphering the mechanisms of how plants cope with the rigors of water loss from their vegetative tissues. We have focused our studies on the C4 resurrection grass, Sporobolus stapfianus Gandoger, as a member of a group of important forage grasses. We have combined non-targeted metabolomics with transcriptomics, via a NimbleGen array platform, to develop an understanding of how gene expression and metabolite profiles can be linked to generate a more detailed mechanistic appreciation of the cellular response to both desiccation and Rehydration. The Rehydration transcriptome and metabolome are primarily geared towards the rapid return of photosynthesis, energy metabolism, protein turnover, and protein synthesis during the Rehydration phase. However, there are some metabolites associated with ROS protection that remain elevated during Rehydration, most notably the tocopherols. The analysis of the dehydration transcriptome reveals a strong concordance between transcript abundance and the associated metabolite abundance reported earlier, but only in responses that are directly related to cellular protection during dehydration: carbohydrate metabolism and redox homeostasis. The transcriptome response also provides strong support for the involvement of cellular protection processes as exemplified by the increases in the abundance of transcripts encoding late embryogenesis abundant (LEA) proteins, anti-oxidant enzymes, early light-induced proteins (ELIP) proteins, and cell-wall modification enzymes. There is little concordance between transcript and metabolite abundance for processes such as amino acid metabolism that do not appear to contribute directly to cellular protection, but are nonetheless important for the desiccation tolerant phenotype of S. stapfianus. The transcriptomes of both dehydration and Rehydration offer insight into the complexity of the regulation of responses to these processes that involve complex signaling pathways and associated transcription factors. ABA appears to be important in the control of gene expression in both the latter stages of the dehydration and the early stages of Rehydration. These findings add to the growing body of information detailing how plants tolerate and survive the severe cellular perturbations of dehydration, desiccation, and Rehydration.
Fredy Altpeter - One of the best experts on this subject based on the ideXlab platform.
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Constitutive expression of the barley HvWRKY38 transcription factor enhances drought tolerance in turf and forage grass (paspalum notatum flugge)
Molecular Breeding, 2010Co-Authors: Xi Xiong, Victoria A. James, Hangning Zhang, Fredy AltpeterAbstract:WRKY proteins constitute a family of transcription factors involved in many plant processes, including responses to biotic and abiotic stress. A constitutive HvWRKY38 expression cassette was introduced into apomictic bahiagrass cultivar 'Argentine' by biolistic gene transfer. HvWRKY38 integration and expression was detected in transgenic bahiagrass plants and their apomictic seed progeny by Southern blot, PCR and quantitative real-time RT-PCR analysis, respectively. Transgenic and wildtype plants were grown hydroponically to allow uniform dehydration and Rehydration treatments and measure whole plant relative water content and biomass. Transgenic bahiagrass plants retained water better during dehydration, recovered faster and produced more biomass following Rehydration and survived severe dehydration stress under controlled environment conditions in contrast to non-transgenic plants. The observed dehydration tolerance is very desirable in perennial grasses like bahiagrass, where seasonal droughts affect establishment, persistence or productivity. Our results confirm the regulatory role of HvWRKY38 in dehydration tolerance.
