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Sanchez-Garcia M.D.,Institute Agroquimica Y Tecnologia Of Alimentos Iata | Hilliou L.,University of Minho | Hilliou L.,University of Porto | Lagaron J.M.,Institute Agroquimica Y Tecnologia Of Alimentos Iata
Journal of Agricultural and Food Chemistry | Year: 2010

The present study presents the development and characterization of biocomposites of a red-algae-derived carrageenan, mica, and their blends with zein prolamine obtained by solvent casting. The morphology of the blends was characterized by scanning and transmission electron microscopy (SEM and TEM), optical microscopy, and atomic force microscopy (AFM). Mechanical behavior, water barrier, water uptake, and UV-vis protection of the cast films were also investigated. The results indicated that the addition of 10 wt % glycerol to the blends resulted in a better dispersion of the additive and, for that reason, a better improvement for the studied properties. The composites were seen colored but transparent and exhibited the ability to block the UV-vis radiation because of the characteristic absorbing properties of the filler. Nevertheless, the main conclusion from the work is that the nanocomposites were seen to act as a reinforcing plasticizer and also led to significantly reduced water permeability and uptake. The clay was found to be more efficient in the latter aspect than the zein prolamine as an additive. As a result, these novel carragenan-based biocomposites can have significant potential to develop packaging films and coatings for shelf-life extension of food products. © 2010 American Chemical Society.

Rodrigo D.,Institute Agroquimica Y Tecnologia Of Alimentos Iata | Sampedro F.,Institute Agroquimica Y Tecnologia Of Alimentos Iata | Silva A.,Institute Agroquimica Y Tecnologia Of Alimentos Iata | Palop A.,Institute Agroquimica Y Tecnologia Of Alimentos Iata | Martinez A.,CSIC - Institute of Agricultural Chemistry and Food Technology
British Food Journal | Year: 2010

Purpose: Most of the preservation processes are based on temperature control; they are economical, safe and well established. However, for certain foods these processes modify the valuable nutritional content and organoleptic properties. In recent years, a number of emerging food preservation processes have been developed to fill a market niche in which the consumer prefers to pay more to obtain processed foods with their natural properties. The paper seeks to address this issue. Design/methodology/approach: In this study a review of the available scientific data in relation to high hydrostatic pressure (HHP) and pulsed electric fields (PEF) are presented, highlighting the quality advantages, industrial application and safety risks in their use. Findings: Nowadays, more than 100 industrial applications are marketed and several companies design process equipments. Damage to cell membranes, enzymes or DNA is the most commonly cause of microorganisms' death by these technologies. In addition, within a population of microorganisms, some bacteria are killed, others survive, and a proportion is damaged. The latter is the concern population as the damage may be repaired and the microorganism maybe viable during the product shelf life. Acquisition of new or modified characteristics such as higher treatment resistance could also occur. Another potential risk has to do with the death pattern of microorganisms showing deviations from the traditional log-linear kinetic model (shoulders, tails and sigmoidal shape). Therefore the developing of simple mathematical models, which can adequately interpret this behaviour, is necessary. Originality/value: In summary, PEF and HHP technologies need to be evaluated by industries and regulatory authorities and more affordable equipments should be marketed to expand their use at industrial level. © Emerald Group Publishing Limited.

Fattouch S.,Tunisian National Institute of Applied Sciences and Technology | Raboudi-Fattouch F.,High Institute of Youth and Culture Animation ISAJEC | Ponce J.V.G.,Institute Agroquimica Y Tecnologia Of Alimentos Iata | Ponce J.V.G.,University of Valencia | And 5 more authors.
Food and Chemical Toxicology | Year: 2010

Polyphenol oxidase (PPO) catalyzes the oxidation of o-diphenols to their respective quinones which undergo autopolymerization and form dark pigments. The interaction of PPO with various substrates and effectors remains the focus of intensive investigations due to the enzyme's key role in pigments biosynthesis including animal melanogenesis and fruit/fungi enzymatic browning. In this study, the effect of a range of commonly used pesticides on the enzyme activity has been evaluated using the purified quince (Cydonia oblonga Miller) PPO. The biochemical analysis showed that, in the presence of high pesticide concentrations, the enzyme was competitively inhibited, particularly with benomyl, carbaryl, deltamethrine and parathion methyl for which inhibition constants (Ki) were 8.3, 5.7, 12 and 4 μM, respectively. At lower pesticide concentrations (2-10 μM), however, the catecholase activity was significantly activated (p < 0.01), suggesting a homotropic behavior of these chemical compounds. Furthermore, the use of in silico structure-based analyses, known as computational docking, highlighted the nature of the PPO-pesticides interactions and confirmed the in vitro observations. Catechol substrate and parathion methyl inhibitor showed lower total energy scores of -120.06 and -117.43 kcal mol-1, indicating that these ligands had higher PPO-binding affinities. The obtained data bring to light new pesticide functional features of great interest in the medicinal, agro-chemical and environmental circles. © 2010 Elsevier Ltd. All rights reserved.

Harries E.,Institute Agroquimica Y Tecnologia Of Alimentos Iata | Harries E.,CONICET | Gandia M.,Institute Agroquimica Y Tecnologia Of Alimentos Iata | Carmona L.,Institute Agroquimica Y Tecnologia Of Alimentos Iata | Marcos J.F.,Institute Agroquimica Y Tecnologia Of Alimentos Iata
Molecular Plant Pathology | Year: 2015

The activity of protein O-mannosyltransferases (Pmts) affects the morphogenesis and virulence of fungal pathogens. Recently, PMT genes have been shown to determine the sensitivity of Saccharomyces cerevisiae to the antifungal peptide PAF26. This study reports the identification and characterization of the three Pdpmt genes in the citrus post-harvest pathogen Penicillium digitatum. The Pdpmt genes are expressed during fungal growth and fruit infection, with the highest induction for Pdpmt2. Pdpmt2 complemented the growth defect of the S.cerevisiae Δpmt2 strain. The Pdpmt2 gene mutation in P.digitatum caused pleiotropic effects, including a reduction in fungal growth and virulence, whereas its constitutive expression had no phenotypic effect. The Pdpmt2 null mutants also showed a distinctive colourless phenotype with a strong reduction in the number of conidia, which was associated with severe alterations in the development of conidiophores. Additional effects of the Pdpmt2 mutation were hyphal morphological alterations, increased sensitivity to cell wall-interfering compounds and a blockage of invasive growth. In contrast, the Pdpmt2 mutation increased tolerance to oxidative stress and to the antifungal activity of PAF26. These data confirm the role of protein O-glycosylation in the PAF26-mediated antifungal mechanism present in distantly related fungal species. Important to future crop protection strategies, this study demonstrates that a mutation rendering fungi more resistant to an antifungal peptide results in severe deleterious effects on fungal growth and virulence. © 2014 BSPP AND JOHN WILEY & SONS LTD.

Pons E.,Instituto Valenciano Of Investigaciones Agrarias Ivia | Alquezar B.,Instituto Valenciano Of Investigaciones Agrarias Ivia | Rodriguez A.,Instituto Valenciano Of Investigaciones Agrarias Ivia | Martorell P.,Biopolis SL | And 5 more authors.
Plant Biotechnology Journal | Year: 2014

Orange is a major crop and an important source of health-promoting bioactive compounds. Increasing the levels of specific antioxidants in orange fruit through metabolic engineering could strengthen the fruit's health benefits. In this work, we have afforded enhancing the β-carotene content of orange fruit through blocking by RNA interference the expression of an endogenous β-carotene hydroxylase gene (Csβ-CHX) that is involved in the conversion of β-carotene into xanthophylls. Additionally, we have simultaneously overexpressed a key regulator gene of flowering transition, the FLOWERING LOCUS T from sweet orange (CsFT), in the transgenic juvenile plants, which allowed us to obtain fruit in an extremely short period of time. Silencing the Csβ-CHX gene resulted in oranges with a deep yellow ('golden') phenotype and significant increases (up to 36-fold) in β-carotene content in the pulp. The capacity of β-carotene-enriched oranges for protection against oxidative stress in vivo was assessed using Caenorhabditis elegans as experimental animal model. Golden oranges induced a 20% higher antioxidant effect than the isogenic control. This is the first example of the successful metabolic engineering of the β-carotene content (or the content of any other phytonutrient) in oranges and demonstrates the potential of genetic engineering for the nutritional enhancement of fruit tree crops. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

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