Staff publications - Cranfield Health

Permanent URI for this collection

https://dspace.lib.cranfield.ac.uk/handle/1826/2005

Browse

Now showing 1 - 20 of 33

Open Access
Application of multiple response optimization design to quantum dot-encoded microsphere bioconjugates hybridization assay
(Elsevier, 2011-07-01) Thiollet, Sarah; Bessant, Conrad M.; Morgan, Sarah L.
The optimization of DNA hybridization for genotyping assays is a complex experimental problem that depends on multiple factors such as assay formats, fluorescent probes, target sequence, experimental conditions, and data analysis. Quantum dot-doped particle bioconjugates have been previously described as fluorescent probes to identify single nucleotide polymorphisms even though this advanced fluorescent material has shown structural instability in aqueous environments. To achieve the optimization of DNA hybridization to quantum dot-doped particle bioconjugates in suspension while maximizing the stability of the probe materials, a nonsequential optimization approach was evaluated. The design of experiment with response surface methodology and multiple optimization response was used to maximize the recovery of fluorescent probe at the end of the assay simultaneously with the optimization of target-probe binding. Hybridization efficiency was evaluated by the attachment of fluorescent oligonucleotides to the fluorescent probe through continuous flow cytometry detection. Optimal conditions were predicted with the model and tested for the identification of single nucleotide polymorphisms. The design of experiment has been shown to significantly improve biochemistry and biotechnology optimization processes. Here we demonstrate the potential of this statistical approach to facilitate the optimization of experimental protocol that involves material science and molecular biology.
Open Access
Assessment of the environmental toxicity and carcinogenicity of tungsten-based shot.
(Elsevier, 2009-05) Thomas, Vernon G.; Roberts, Michael J.; Harrison, Paul T. C.
The toxicity of elemental tungsten released from discharged shot was assessed against previous studies that established a 1% toxic threshold for soil organisms. Extremely heavy theoretical shot loadings of 69,000 shot/ha were used to generate estimated environmental concentrations (EEC) for two brands of tungsten-based shot containing 51% and 95% tungsten. The corresponding tungsten EEC values were 6.5–13.5 mg W/kg soil, far below the 1% toxic threshold. The same shot loading in water produced tungsten EEC values of 2.1–4.4 mg W/L, levels that are not toxic under experimental conditions. Pure tungsten has not been shown to exhibit carcinogenic properties when ingested or embedded in animal tissues, but nickel, with which it is often alloyed, has known carcinogenicity. Given the large number of waterfowl that carry shot embedded in their body, it is advisable to screen lead shot substitutes for their carcinogenic potential through intra-muscular implantation.
Open Access
Behavior of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium in teewurst, a raw spreadable sausage
(Elsevier, 2009-04-15) Dourou, Dimitra; Porto-Fett, Anna C. S.; Shoyer, Brad; Call, Jeffrey E.; Nychas, George-John E.; Illg, Ernst K.; Luchansky, John B.
The fate of Listeria monocytogenes, Salmonella Typhimurium, or Escherichia coli O157:H7 were separately monitored both in and on teewurst, a traditional raw and spreadable sausage of Germanic origin. Multi-strain cocktails of each pathogen (ca. 5.0 log CFU/g) were used to separately inoculate teewurst that was subsequently stored at 1.5, 4, 10, and 21 °C. When inoculated into commercially-prepared batter just prior to stuffing, in general, the higher the storage temperature, the greater the lethality. Depending on the storage temperature, pathogen levels in the batter decreased by 2.3 to 3.4, ca. 3.8, and 2.2 to 3.6 log CFU/g for E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, during storage for 30 days. When inoculated onto both the top and bottom faces of sliced commercially-prepared finished product, the results for all four temperatures showed a decrease of 0.9 to 1.4, 1.4 to 1.8, and 2.2 to 3.0 log CFU/g for E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, over the course of 21 days. With the possible exceptions for salt and carbohydrate levels, chemical analyses of teewurst purchased from five commercial manufacturers revealed only subtle differences in proximate composition for this product type. Our data establish that teewurst does not provide a favourable environment for the survival of E. coli O157:H7, S. Typhimurium, or L. monocytogenes inoculated either into or onto the product.
Open Access
Biofuelcells-Recent advances and applications
(Elsevier, 2007-02-15) Davis, Frank; Higson, Seamus P. J.
In 2006, the journal Biosensors and Bioelectronics published a special issue devoted exclusively to biofuel cells, including several research papers and an extensive review of the field [Bullen, R.A., Arnot, T.C., Lakeman, J.B., Walsh, F.C., 2006. Biosens. Bioelectron.]. Within this review a brief description will firstly be given of the history of biofuel cells together with coverage of some of the major historical advances. The review is intended, however, to largely concentrate on and give an overview of the advances made in recent years in this area together with a discussion surrounding the practical application of biofuel cells. There are several classes of biofuel cells: we shall firstly discuss the recent advances in biofuel cells that convert chemical fuels to produce electrical power by use of catalytic enzymes. This will be followed by a section on similar cells where micro-organisms rather than enzymes are used to convert the fuel to energy. Thirdly we shall consider hybrid biofuel cells that combine the utilisation of photochemical chemistries and biological systems for the generation of electricity. Finally we will discuss some of the proposed uses of biofuel cells together with a short consideration of future research possibilities and applications of these systems.
Open Access
Comparing the antimicrobial effectiveness of NaCl and KCl with a view to salt/sodium replacement.
(Elsevier, 2008-05-10) Bidlas, Eva; Lambert, Ronald J. W.
A study using a small range of pathogenic bacterial species (Aeromonas hydrophila, Enterobacter sakazakii, Shigella flexneri, Yersinia enterocolitica and 3 strains of Staphylococcus aureus) has shown that potassium chloride has an equivalent antimicrobial effect on these organisms when calculated on a molar basis. Combined NaCl and KCl experiments were carried out and data was analysed using a modification to the Lambert and Lambert [Lambert, R.J.W., and Lambert, R., 2003. A model for the efficacy of combined inhibitors. Journal of Applied Microbiology 95, 734–743.] model for combined inhibitors and showed that in combination KCl is a direct 1:1 molar replacement for the antimicrobial effect of common salt. If this is a general finding then, where salt is used to help preserve a product, partial or complete replacement by KCl is possible.
Open Access
Complex regulation of the aflatoxin biosynthesis gene cluster of Aspergillus flavus in relation to various combinations of water activity and temperature
(Elsevier, 2009-11-15) Schmidt-Heydt, Markus; Abdel-Hadi, Ahmed; Magan, Naresh; Geisen, Rolf
A microarray analysis was performed to study the effect of varying combinations of water activity and temperature on the activation of aflatoxin biosynthesis genes in Aspergillus flavus grown on YES medium. Generally A. flavus showed expression of the aflatoxin biosynthetic genes at all parameter combinations tested. Certain combinations of aw and temperature, especially combinations which imposed stress on the fungus resulted in a significant reduction of the growth rate. At these conditions induction of the whole aflatoxin biosynthesis gene cluster occurred, however the produced aflatoxin B1 was low. At all other combinations (25 °C/0.95 and 0.99; 30 °C/0.95 and 0.99; 35 °C/0.95 and 0.99) a reduced basal level of cluster gene expression occurred. At these combinations a high growth rate was obtained as well as high aflatoxin production. When single genes were compared, two groups with different expression profiles in relation to water activity/temperature combinations occurred. These two groups were co-ordinately localized within the aflatoxin gene cluster. The ratio of aflR/aflJ expression was correlated with increased aflatoxin biosynthesis.
Open Access
Contrasting the crystallinity indicators of heated and diagenetically altered bone mineral
(Elsevier, 2010-10-01) Rogers, Keith; Beckett, Sophie; Kuhn, Samira; Chamberlain, Andrew; Clement, John
Modifications to bone mineral as a result of diagenesis or heating include a marked increase in crystallinity. Although these processes are not completely understood a number of simple, pragmatic approaches are in general use to quantify crystallinity and thus provide a relative metric for features such as preservation state. A preliminary investigation into the interpretation of crystallinity as measured by X-ray diffraction has been undertaken. The microstructural changes associated with diagenetically altered (archaeological) and heated contemporary bone have been examined. A common analysis approach was adopted and thus direct comparison between the physical features of these material systems has been possible. The data clearly demonstrate the pronounced anisotropic nature of the crystallite microstructure for both diagenetically altered and contemporary bone. The limitations of adopting simple crystallinity indices for characterising such materials are explored. Crystallite size and strain were shown to be dependent upon crystallographic direction. Overall, the diagenetically altered bone mineral possessed greater long range lattice order than that of contemporary heated bone. Further, significant differences between the directional nature of the microstructure of diagenetically altered and modern heated bone were observed. This study has enabled a direct comparison of the effects of heating and diagenesis upon bone mineral. It has demonstrated the need to consider bone microstructure anisotropically.
Open Access
Detection of β-amyloid peptide (1–16) and amyloid precursor protein (APP770) using spectroscopic ellipsometry and QCM techniques: A step forward towards Alzheimers disease diagnostics
(Elsevier, 2010-12-15) Mustafa, M. K.; Nabok, Alexei; Parkinson, D.; Tothill, Ibtisam E.; Salam, Faridah; Tsargorodskaya, A.
A highly sensitive method of spectroscopic ellipsometry in total internal reflection mode (TIRE) was exploited for detecting β-amyloid peptide (Aβ1–16) in the direct immune reaction with monoclonal DE2 antibodies (raised against Aβ1–16) electrostatically immobilised on the surface of gold. A rapid detection of Aβ1–16 in a wide range of concentrations from 5 μg/ml down to 0.05 ng/ml was achieved using a cost-effective and label-free direct immunoassay format. TIRE dynamic spectral measurements proved that the immune reaction between DE2 monoclonal antibodies and Aβ1–16 is highly specific with the affinity constant KD = 1.46 × 10−8 mol/l. The same DE2 antibodies were utilised for detection of amyloid precursor protein APP770, a larger protein containing Aβ1–16 domain, using the quartz crystal microbalance (QCM) measurements in liquid. A combination of QCM and TIRE kinetics results allowed the evaluation of the originally unknown concentration of APP770 in complete medium solution containing other proteins, salts, and amino acids.
Open Access
Development of a disposable pyruvate biosensor to determine pungency in onions (Allium cepa L.)
(Elsevier, 2006-05-15) Abayomi, Louise Anike; Terry, Leon A; White, S. F.; Warner, P. J.
A disposable prototype pyruvate biosensor was constructed using pyruvate oxidase immobilised on mediated meldolas blue electrodes to determine pungency in onions (Allium cepa L.). The optimum operating potential was +150 mV (versus Ag/AgCl). A strong correlation between the biosensor response and untreated onion juice of known pyruvate concentration 2–12 μmol/g fresh weight (FW) was demonstrated. The biosensor was able to differentiate between low and high pungency onions. The detection limit using 1 unit of pyruvate oxidase was 1–2 μmol/g FW. Optimum concentrations of co-factors TPP, FAD and MgSO4 comprising the enzyme cocktail were determined as being 0.04, 0.1 and 30 mM, respectively.
Open Access
Effect of solute and matric potential on in vitro growth and sporulation of strains from a new population of Aspergillus flavus isolated in Italy.
(Elsevier, 2008-05) Giorni, Paola; Battilani, Paola; Magan, Naresh
The effect of temperature and different solute (Ψs) and matric potentials (Ψm) on growth and sporulation of three aflatoxigenic strains of Aspergillus flavus isolated from contaminated maize in northern Italy was determined. The Ψs of maize-based media were modified ionically (NaCl) and non-ionically (glycerol) and the Ψm with PEG 8000 in the range −1.4 to −21.0 MPa at 25 and 30 °C. Both temperature and Ψs/Ψm stress had statistically significant effects on growth rates of the three strains. Faster growth occurred at 30 °C and −1.4 and −2.8 MPa. A. flavus strains were more sensitive to Ψm than Ψs stress with limits of −9.8 MPa and −14 to−18 MPa, respectively. Sporulation was significantly influenced by Ψs potential, solute type and temperature. This suggests that these aflatoxigenic strains of A. flavus isolated from aflatoxin-contaminated maize are probably able to colonise crop debris rapidly at prevailing temperatures and water stress conditions. This type of information on the ecology of aflatoxin producing A. flavus strains isolated in Italy will contribute to the development of a systems model to predict their activity in crop residue and colonisation of maize grain.
Open Access
Electronic nose responses and acute phase proteins correlate in blood using a bovine model of respiratory infection
(Elsevier, 2010-01) Knobloch, Henri; Schroedl, Wieland; Turner, Claire; Chambers, Mark; Reinhold, Petra
This study aimed (i) to assess the ability of electronic nose (e-nose) technology to differentiate between blood samples of experimentally infected and non-infected subjects, and (ii) to evaluate e-nose responses given by volatile organic compounds in relation to the acute phase reaction generated in the host. In an animal model of gram-negative bacterial infection (20 calves; intratracheal inoculation of Mannheimia haemolytica A1), the concentrations of the acute phase proteins (APPs; i.e. lipopolysaccharide binding protein and haptoglobin) were measured in serum samples before and after challenge, and headspaces of pre- and post-inoculation serum samples were analysed using a conducting polymer based e-nose. Significant changes of certain e-nose sensor responses allowed discrimination between samples before and after challenge. The maximal changes in responses of sensitive e-nose sensors corresponded to the peak of clinical signs. Significant correlations linked decreasing responses of multiple e-nose sensors to increasing concentrations of APPs in the peripheral blood.
Open Access
Environmental factors affect efficacy of some essential oils and resveratrol to control growth and ochratoxin A production by Penicillium verrucosum and Aspergillus westerdijkiae on wheat grain.
(Elsevier, 2008) Aldred, David; Cairns-Fuller, Victoria; Magan, Naresh
This study determined the efficacy of three essential oils (bay, clove and cinnamon oil) and the antioxidant resveratrol (0–500 μg g−1) on the control of growth and ochratoxin A (OTA) production by Penicillium verrucosum and Aspergillus westerdijkiae (=A. ochraceus) under different water activity (aw, 0.90, 0.95, 0.995), and temperature (15, 25 °C) conditions on irradiated wheat grain. The most effective treatment (resveratrol) was then tested on natural grain. The ED50 values for growth inhibition by the oils were 200–300 μg g−1 at the aw and the temperatures tested. For resveratrol, this varied from <50 μg g−1 at 0.90–0.95 aw to >350 at 0.995aw at both temperatures. The ED50 values for the control of OTA were slightly lower than for control of growth, with approx. 200 μg g−1 required for the oils and 50–100 μg g−1 of the antioxidant, at 0.90/0.95aw and both temperatures. In wet grain (0.995aw), higher concentrations were required. For growth there were statistically significant effects of single-, two- and three-way interactions between treatments except for concentration×temperature and concentration×temperature×essential oil/antioxidant treatment. For OTA control, statistically significant treatments were aw, temperature×aw, concentration×temperature, treatment×concentration, and three-way interaction of concentration×aw×treatment for P. verrucosum and A. westerdijkiae. Subsequent studies were done with the best treatment (resveratrol, 200 μg g−1) on natural wheat grain with either P. verrucosum or A. westerdijkiae at 0.85–0.995aw and 15/25 °C over 28 days storage. This showed that the populations of the mycotoxigenic species and OTA contamination could be reduced by >60% by this treatment at the end of the storage period.
Open Access
Environmental factors modify carbon nutritional patterns and niche overlap between Aspergillus flavus and Fusarium verticillioides strains from maize.
(Elsevier, 2009-04-15) Giorni, Paola; Magan, Naresh; Battilani, Paola
This study examined the utilization patterns of key carbon sources (CS, 24: including key sugars, amino acids and fatty acids) in maize by strains of Aspergillus flavus and Fusarium verticillioides under different water activity (aw, 0.87–0.98 aw) and temperature (20–35 °C) values and compared the niche overlap indices (NOI) that estimate the in vitro CS utilization profiles [Wilson, M., Lindow, S.E., 1994. Coexistence among epiphytic bacterial populations mediated through nutritional resource partitioning. Applied and Environmental Microbiology 60, 4468–4477.]. The ability to grow in these key CS in minimal media was studied for 120 h in 12 h steps. The NOI was calculated for inter-species (F. verticillioides–A. flavus) and for intra-species (A. flavus–A. flavus) using CS utilization patterns over the range of interacting environmental conditions. 30 °C, over the whole aw range examined, was found to be optimal for utilization of the maximum number of CS by A. flavus. In contrast, for F. verticillioides this was more so at 20 °C; 25 °C allowed a suboptimal usage of CS for both species. NOIs confirmed the nutritional dominance of A. flavus at 30 °C, especially at lower aw levels and that of F. verticillioides at 20 °C, mainly at 0.95 aw. In other conditions of aw, based on CS utilization patterns, the data indicated that A. flavus and F. verticillioides occupied different ecological niches. The variability in nutritional sources utilization between A. flavus strains was not related to their ability to produce aflatoxins (AFs). This type of data helps to explain the nutritional dominance of fungal species and strains under different environmental conditions. This could be useful in trying to find appropriate natural biocontrol microorganisms to compete with these mycotoxigenic species.
Open Access
An explanation for the effect of inoculum size on MIC and the growth/no growth interface.
(Elsevier, 2008-08-15) Bidlas, Eva; Du, Tingting; Lambert, Ronald J. W.
The inoculum effect (IE) is the phenomenon observed where changes in the inoculum size used in an experiment alters the outcome with respect to, for example, the minimum inhibitory concentration of an antimicrobial or the growth/no growth boundary for a given set of environmental conditions. Various hypotheses exist as to the cause of the IE such as population heterogeneity and quorum sensing, as well as the null hypothesis — that it is artefactual. Time to detection experiments (TTD) were carried out on different initial inoculum sizes of several bacterial species (Aeromonas hydrophila, Enterobacter sakazakii, Salmonella Poona, Escherichia coli and Listeria innocua) when challenged with different pH and with combined pH and sodium acetate. Data were modelled using a modification to a Gamma model (Lambert and Bidlas 2007, Int. J. Food Microbiology 115, 204–213), taking into account the inoculum size dependency on the TTD obtained under ideal conditions. The model suggests that changes in minimum inhibitory concentration (MIC) or in the growth–no growth boundary with respect to inoculum size are due to using a smaller or larger inoculum (i.e. is directly related to microbial number) and is not due to other, suggested, phenomena. The model used further suggests that the effect of a changing inoculum size can be modelled independently of any other factor, which implies that a simple 1 to 2-day experiment measuring the TTD of various initial inocula can be used as an adjunct to currently available models.
Open Access
Fungal volatile fingerprints: discrimination between dermatophyte species and strains by means of an electronic nose.
(Elsevier, 2008-04-14) Sahgal, Natasha; Magan, Naresh
The potential of an electronic nose (e-nose) consisting of a hybrid gas sensor array system has been examined for species discrimination and strain identification of dermatophytes which are causative pathogens for human and animal infection. Temporal volatile production patterns have been studied at a species level for a Microsporum species, two Trichophyton species and at a strain level for the two Trichophyton species. After about 120 h principal component analysis (PCA) and cluster analysis showed possible discrimination between the species from controls. Data analysis also indicated probable differentiation between the strains of T. rubrum. The same could not however be achieved for the strains of T. mentagrophytes during preliminary experiments for the same time period, signifying a good similarity between the strains of this particular species based on their volatile fingerprints. This study suggests that volatile production patterns shows promise for species and strain identification of these dermatophytic fungi thereby facilitating early diagnosis and early management of patients.
Open Access
Home blood glucose biosensors: a commercial perspective
(Elsevier, 2005-06-15) Newman, Jeffrey D.; Turner, Anthony P. F.
Twenty years on from a review in the first issue of this journal, this contribution revisits glucose sensing for diabetes with an emphasis on commercial developments in the home blood glucose testing market. Following a brief introduction to the needs of people with diabetes, the review considers defining technologies that have enabled the introduction of commercial products and then reviews the products themselves. Drawing heavily on the performance of actual instruments and publicly available information from the companies themselves, this work is designed to complement more conventional reviews based on papers published in scholarly journals. It focuses on the commercial reality today and the products that we are likely to see in the near future.
Open Access
Impact of Trametes versicolor and Phanerochaete chrysosporium on differential breakdown of pesticide mixtures in soil microcosms at two water potentials and associated respiration and enzyme activity.
(Elsevier, 2008-12) Fragoeiro, Silvia; Magan, Naresh
This study has examined the effect of inoculation of soil microcosms with Trametes versicolor and Phanerochaete chrysosporium on wood chips on differential degradation of pesticides (simazine, trifluralin and dieldrin, 10 mg kg−1 soil) at two water potentials (−0.7 and −2.8 MPa) at 15 °C. The soil microcosms were destructively sampled after 6/12 weeks and four extracellular enzymes quantified, respiration and pesticides measured with GC and HPLC. The fungal treatments produced extracellular enzymes in soil. Respiratory activity was significantly (P = 0.05) enhanced in soil with the inocula, and higher in the pesticide mixtures. Cellulase/dehydrogenase increased in inoculated soil. Laccase increased significantly in the T. versicolor treatment. Degradation of the three pesticides by wood chip addition alone was enhanced (20–30%). T. versicolor increased degradation of simazine (27–46%), trifluralin (5–17%) and dieldrin (5–11%) and P. chrysosporium by 34–48%, 0–30% and 40–46%, respectively, when compared with controls after 12 weeks. This study has demonstrated that pesticide mixtures are differentially degraded by fungal inoculants and significant extracellular enzymes are produced in soil, even at −2.8 MPa water potential. This suggests that effective bioremediation of xenobiotic mixtures using wood chips and fungal inoculants is achievable over a relatively wide water potential range when compared with that allowing plant growth (−1.4 MPa).
Open Access
The influence of environmental factors on growth and interactions between Embellisia allii and Fusarium oxysporum f. sp. cepae isolated from garlic
(Elsevier, 2010-04) Lee, Hyang Burm; Magan, Naresh
Embellisia allii results in the formation of a bulb canker and black soot on the surface of different alliums and it has been frequently detected on garlic bulbs together with the spoilage fungus, Fusarium oxysporum f. sp. cepae, which causes bulb basal plate rot. In this study, the influence of water activity (aw) and temperature on mycelial growth of E. allii and F. oxysporum f. sp. cepae, conidial size and sporulation of E. allii, interactions between E. allii and F. oxysporum f. sp. cepae, Index of Dominance (ID), and in situ virulence on garlic were examined. Mycelial growth of E. allii was optimal (5.97 mm/day) at 0.995 aw and 25 °C, slower at 30 °C. However, almost no growth occurred at 0.937 aw/30 °C. F. oxysporum f. sp. cepae grew faster than E. allii, (6.3–7.4 mm/day) at 30 °C. Interactions between E. allii and F. oxysporum f. sp. cepae were influenced by aw and temperature. Sporulation of E. allii was more abundant on PDA than on MEA, especially at high aw (0.995) and low temperature (20 °C), but almost no sporulation occurred at 30 °C regardless of nutritional medium or aw level. The spore length of E. allii was longer on PDA than MEA, and was significantly influenced by water availability. F. oxysporum f. sp. cepae was competitive against E. allii and had a higher ID value in comparison with E. allii especially at a higher temperature (30 °C). In situ virulence tests showed that E. allii was weakly virulent on the garlic bulb cloves while that of F. oxysporum f. sp. cepae was highly dependent on aw.
Open Access
Lactic acid bacteria population dynamics during minced beef storage under aerobic or modified atmosphere packaging conditions
(Elsevier, 2010-12) Doulgeraki, Agapi I.; Paramithiotis, Spiros; Kagkli, Dafni-Maria; Nychas, George-John E.
A total of 266 lactic acid bacteria (LAB) have been isolated from minced beef stored at 0, 5, 10 and 15 °C aerobically and under modified atmosphere packaging consisting of 40% CO2–30% O2–30% N2 in the presence MAP (+) and absence MAP (−) of oregano essential oil. Sequencing of their 16S rRNA gene along with presence of the katA gene demonstrated dominance of the LAB microbiota by Leuconostoc spp. during aerobic storage at 5, 10 and 15 °C, as well as during MAP (−) and MAP (+) storage at 10 and 15 °C; Lactobacillus sakei prevailed during aerobic storage at 0 °C, as well as at MAP (−) and MAP (+) storage at 0 and 5 °C. The sporadic presence of other species such as Leuconostoc mesenteroides, Weisella viridescens, Lactobacillus casei and Lactobacillus curvatus has also been determined. Pulsed-Field Gel Electrophoresis of high molecular weight genomic DNA revealed the dynamics of the isolated LAB strains. Prevalence of Leuconostoc spp. was attributed to one strain only. On the other hand, packaging conditions affected Lb. sakei strain spoilage dynamics.
Open Access
Manipulating the taste-related composition of strawberry fruits (Fragaria x ananassa) from different cultivars using deficit irrigation
(Elsevier, 2010-10-15) Bordonaba, J. Giné; Terry, Leon A
Demand and, consequently, production of strawberry fruits has increased over the past few years and, as a result, the water abstractions for cultivation of this fruit have risen considerably. To limit the amounts of water used for several horticultural crops, water deficit irrigation (DI) has been seen as a potential alternative for new cultivation systems. DI in strawberry fruits is generally associated with reduction in berry size and yield; however, a recent study demonstrated that DI on strawberry can increase the concentration of some taste- and health-related compounds in fruits from cv. Elsanta. Hence, the aim of the present study was to further corroborate such findings and to assess the response (and variability) among different strawberry cultivars (namely Christine, Elsanta, Florence, Sonata and Symphony) to imposed water-DI conditions. Water-DI affected both fruit physiology and biochemistry. Nevertheless, the response to drought stress was different for each of the cultivars tested. Plants from cvs. Elsanta, Sonata and Symphony showed a greater reduction in berry size, accompanied by a significant increase in dry matter content for fruit harvested from DI-treated plants. Concomitant to this, and where dry matter was increased, the concentrations of sugars and some acids were generally higher in DI-derived fruit. In contrast, cvs. Florence and Christine did not show significant variations in berry weight or any of the target analytes measured when grown under the conditions imposed in this study. The results presented herein suggest that reducing water irrigation between flower initiation and fruit harvest may be a viable technique for increasing the concentrations of taste-related compounds in cvs. Elsanta, Sonata and Symphony and it may not have a negative impact on overall fruit size of cvs. Christine and Florence.