Arapoglou D.,Greek National Agricultural Research Foundation |
Varzakas T.,Technological Educational Institute of Kalamata |
Vlyssides A.,National Technical University of Athens |
Israilides C.,Greek National Agricultural Research Foundation
Waste Management | Year: 2010
Considerable concern is caused by the problem of potato peel waste (PPW) to potato industries in Europe. An integrated, environmentally-friendly solution is yet to be found and is currently undergoing investigation. Potato peel is a zero value waste produced by potato processing plants. However, bio-ethanol produced from potato wastes has a large potential market. If Federal Government regulations are adopted in light of the Kyoto agreement, the mandatory blending of bio-ethanol with traditional gasoline in amounts up to 10% will result in a demand for large quantities of bio-ethanol. PPW contain sufficient quantities of starch, cellulose, hemicellulose and fermentable sugars to warrant use as an ethanol feedstock. In the present study, a number of batches of PPW were hydrolyzed with various enzymes and/or acid, and fermented by Saccharomyces cerevisae var. bayanus to determine fermentability and ethanol production. Enzymatic hydrolysis with a combination of three enzymes, released 18.5gL -1 reducing sugar and produced 7.6gL -1 of ethanol after fermentation. The results demonstrate that PPW, a by-product of the potato industry features a high potential for ethanol production. © 2010 Elsevier Ltd.
Fousekis K.,National and Kapodistrian University of Athens |
Tsepis E.,Technological Educational Institute of Kalamata |
Vagenas G.,National and Kapodistrian University of Athens
American Journal of Sports Medicine | Year: 2012
Background: Ankle sprain is an extremely common injury in soccer players. Despite extensive research, the intrinsic cause of this injury under noncontact conditions remains unclear. Purpose: To identify intrinsic risk factors for noncontact ankle sprains in professional soccer players. Study Design: Cohort study; Level of evidence, 2 Methods: One hundred professional soccer players were assessed in the preseason for potential risk factors of noncontact ankle sprains. The assessment included (A) ankle joint asymmetries (right-left) in isokinetic muscle strength, flexibility, proprioception, and stability; (B) somatometric asymmetries; (C) previous injuries; and (D) lateral dominance traits. Noncontact ankle sprains were prospectively recorded and diagnosed for a full competition period (10 months). Results: Seventeen of the players sustained at least 1 noncontact ankle sprain. Logistic regression revealed that players with (A) eccentric isokinetic ankle flexion strength asymmetries (odds ratio [OR] = 8.88; 95% confidence interval [CI], 1.95-40.36, P = .005), (B) increased body mass index (OR = 8.16; 95% CI, 1.42-46.63, P = .018), and (C) increased body weight (OR = 5.72; 95% CI, 1.37-23.95, P = .017 ) each had a significantly higher risk of a noncontact ankle sprain. A trend for younger players (OR = 0.28; 95% CI, 0.061-1.24, P = .092) and for players with ankle laxity asymmetries (OR = 3.38; 95% CI, 0.82-14.00, P = .093) to be at greater risk for ankle sprain was also apparent to the limit of statistical significance (.05
Papadopoulos D.F.,University of Peloponnese |
Anastassi Z.A.,Technological Educational Institute of Kalamata |
Simos T.E.,University of Peloponnese
Journal of Molecular Modeling | Year: 2010
A new Runge-Kutta-Nyström method, with phase-lag and amplification error of order infinity, for the numerical solution of the Schrödinger equation is developed in this paper. The new method is based on the Runge-Kutta-Nyström method with fourth algebraic order, developed by Dormand, El-Mikkawy and Prince. Numerical illustrations indicate that the new method is much more efficient than other methods derived for the same purpose. © Springer-Verlag 2010.
Stavroyiannis S.,Technological Educational Institute of Kalamata |
Simos T.E.,University of Peloponnese
Computer Physics Communications | Year: 2010
We examine a nonlinear explicit two-step method of fourth algebraic order and infinite phase-lag order for solving one-dimensional second-order linear periodic initial value problems (IVPs) of ordinary differential equations. Applying special vector arithmetic with respect to an analytic function, the method can be extended to be vector-applicable for multidimensional problems. Numerical results to illustrate the efficiency of the method are presented and sensitivity analysis indicates the validity of the method in the frequency regime. © 2010 Elsevier B.V. All rights reserved.
Sarigiannis Y.,Technological Educational Institute of Kalamata |
Spiliopoulos I.K.,Technological Educational Institute of Kalamata
Polymer International | Year: 2013
Two new polyfluorenes were synthesized by Suzuki coupling polymerization, and their photophysical and electrochemical properties were studied. Both polymers contained the bipolar unit 4-(2,6-diphenylpyridin-4-yl)phenyl-diphenylamine consisting of pyridine (Py) and triphenylamine (TPA) subunits. The bipolar unit was linked to the polymer chain via TPA or Py subunit, which affected the properties of the polymers. The polymers showed a weak intramolecular charge transfer character. They showed emission at 466 nm in solution and at 512-538 nm in thin film. Their emission could be tuned by protonation and N-alkylation of Py. Cyclic voltammetry experiments showed a quasi-reversible oxidation process for both polymers. Their highest occupied molecular orbital levels were estimated at - 5.13 and - 5.21 eV. © 2012 Society of Chemical Industry.
Kiokias S.,Technological Educational Institute of Kalamata |
Varzakas T.,Technological Educational Institute of Kalamata
Food Chemistry | Year: 2014
The antioxidant effects of flavonoids and β-carotene during the thermal auto-oxidation of food relevant oil-in-water emulsions were spectrophotometrically assessed by measuring the formation of primary oxidation products (conjugated dienes and lipid hydroperoxides). An oxidatively "sensitive" model emulsion was selected as substrate of this study in terms of processing and compositional factors. At a concentration of 1.5 mmol kgr-1, only quercetin among the tested compounds significantly reduced the oxidative deterioration of cottonseed oil-in-water emulsions. Structural characteristics (positioning of hydroxyl group) or partitioning behaviour between the emulsion phases may modulate the flavonoid activity. The high oxygen pressure conditions of the experimental system may explain the lack of any antioxidant activity for β-carotene. The antioxidant potential of quercetin increased with its concentration until a specific level. On the contrary, the antioxidant concentration within the same tested range (0.75-3 mmol kgr-1) did not impact the activity of catechin and β-carotene. Mixtures of β-carotene with flavonoids did not exert a tendency for increasing the activity of each individual compound. © 2013 Elsevier Ltd. All rights reserved.
Varzakas T.H.,Technological Educational Institute of Kalamata
Critical Reviews in Food Science and Nutrition | Year: 2011
The Failure Mode and Effect Analysis (FMEA) model has been applied for the risk assessment of pastry processing. A tentative approach of FMEA application to the pastry industry was attempted in conjunction with ISO22000. Preliminary Hazard Analysis was used to analyze and predict the occurring failure modes in a food chain system (pastry processing plant), based on the functions, characteristics, and/or interactions of the ingredients or the processes, upon which the system depends. Critical Control points have been identified and implemented in the cause and effect diagram (also known as Ishikawa, tree diagram, and fishbone diagram). In this work a comparison of ISO22000 analysis with HACCP is carried out over pastry processing and packaging. However, the main emphasis was put on the quantification of risk assessment by determining the Risk Priority Number (RPN) per identified processing hazard. Storage of raw materials and storage of final products at -18 C followed by freezing were the processes identified as the ones with the highest RPN (225, 225, and 144 respectively) and corrective actions were undertaken. Following the application of corrective actions, a second calculation of RPN values was carried out leading to considerably lower values (below the upper acceptable limit of 130). It is noteworthy that the application of Ishikawa (Cause and Effect or Tree diagram) led to converging results thus corroborating the validity of conclusions derived from risk assessment and FMEA. Therefore, the incorporation of FMEA analysis within the ISO22000 system of a pastry processing industry is considered imperative. © Taylor and Francis Group, LLC.
Christopoulou S.C.,Technological Educational Institute of Kalamata
Health and Technology | Year: 2013
This paper focuses on the development of a citizen-oriented lifelong healthcare assistant system, which will support not only health Care Delivery Organizations (CDOs) but also health care providers. In other words this work proposes an u-Health system that will enhance not only the health care services but it will also provide individuals with the opportunity to manage their health needs via a "Five Cs" comprehensive and consistent scheme. Its goal is to take advantage of the ongoing emerging technologies by including them in the process of healthcare with the synergy among health experts' and the continuous interactive-exchange of knowledge and information in connection with the providers' and the users' experiences. Acting in this direction, the smart citizen healthcare assistant (sCHcA) framework proposes the infrastructure and the tools necessary in order to achieve the continuous monitoring and provision of care no matter where the individual may be. Specifically, this article presents a platform for a mobile mashup system that can be established on a CDO server and it will extend to a group of interrelated widgets that will work as a mobile service. The system will be able to create, install and operate as an integrated construction that will monitor and gather data from various health sensors and then send them to the CDO server and further may implement individuals' health matters. Healthcare professionals and organizations can further exploit this novel integrated tele-monitoring mechanism. Moreover, they may also utilize it as a ubiquitous individual home health care service and facilitate vulnerable groups, those living in remote areas, patients suffering from incurable diseases and long-term patients. © 2013 IUPESM and Springer-Verlag Berlin Heidelberg.
Darras A.I.,Technological Educational Institute of Kalamata |
Demopoulos V.,Technological Educational Institute of Kalamata |
Tiniakou C.,Technological Educational Institute of Kalamata
Postharvest Biology and Technology | Year: 2012
UV-C (λ=254nm) irradiation was effective in reducing Botrytis cinerea floret specking (i.e., lesion development) and maintaining a better postharvest quality of cut gerbera flowers. A range of UV-C doses (0.5-10.0kJm-2) was tested on 'Ice cream' and 'Ecco' gerbera flowers to activate germicidal and inducible defence mechanisms. Irradiation of B. cinerea cultures with 0.5, 1.0, 2.5 and 5.0kJm-2 UV-C resulted in up to a 10-fold reduction of conidial germination percentages and significant (P<0.05) delay of mycelium growth, compared to the non-irradiated control cultures. Moreover, lesion diameters on gerbera florets inoculated with UV-C irradiated B. cinerea cultures were reduced by up to 70%, suggesting that UV-C had a negative effect on the pathogenic strength of the fungi. Lesion diameters on florets of UV-C irradiated gerberas were reduced by up to 55% giving evidence that defence responses in the host tissue were induced. Concentration of total phenolics seemed to be unaffected by 0.5kJm-2 UV-C treatment in both cultivars, but polyphenol oxidase (PPO) activity increased and remained higher compared to the non-irradiated control flowers throughout the 48h storage period at 20°C. The increase of PPO suggests that this enzyme might play an important role in host defence mechanisms that suppressed B. cinerea floret specking. Gerbera flowers irradiated with 1.0 or 10.0kJm-2 UV-C showed improvement in vase-life by 1.8 and 2.4 d, decrease in stem break percentages by 43 and 29% and delay in stem break incidence by 3.3 and 1.3 d, respectively. © 2011 Elsevier B.V.
Varzakas T.,Technological Educational Institute of Kalamata
Critical Reviews in Food Science and Nutrition | Year: 2015
Cereals and, most specifically, wheat are described in this chapter highlighting on their safety and quality aspects. Moreover, wheat quality aspects are adequately addressed since they are used to characterize dough properties and baking quality. Determination of dough properties is also mentioned and pasta quality is also described in this chapter. Chemometrics-multivariate analysis is one of the analyses carried out. Regarding production weighing/mixing of flours, kneading, extruded wheat flours, and sodium chloride are important processing steps/raw materials used in the manufacturing of pastry products. Staling of cereal-based products is also taken into account. Finally, safety aspects of cereal-based products are well documented with special emphasis on mycotoxins, acrylamide, and near infrared methodology. © Taylor and Francis Group, LLC.