Physical and microstructural properties of biodegradable films based on pea starch and PVA

[EN] The effect of storage time on the physical properties of pea starch (PS) and polyvinyl alcohol (PVA) films and their blend was studied to develop biodegradable packaging materials for food applications. To this end, an analysis was performed of the microstructural and physical properties (solubility, moisture content, barrier, mechanical and optical properties) of PS, PVA and PS:PVA films stored for five weeks (25 C 53%RH). Whereas SEM micrographs showed a homogenous appearance for PS films, PVA presented irregularities typical of semi-crystalline structures. Blend films showed a structure which was more similar to PVA films. After 5 weeks, the physical properties of PVA films did not change; in the case of PS, however, the elastic modulus and tensile strength increased markedly but the stretchability and gloss significantly decreased, which was associated with water loss in the starch matrix. All the physical properties of blend films remained unchanged throughout time, except the elastic modulus and the tensile strength, which slightly increased. Therefore, the incorporation of PVA into pea starch films improved their physical properties and inhibited the changes that occurred in the starch matrix caused by ageing.The authors wish to acknowledge the finance support from the Spanish Ministerio de Economia y Competitividad throughout the project AGL2010-20694. Amalia Cano also thanks the Spanish Ministerio de Educacion, Cultura y Deporte for the FPU grant.Cano Embuena, AI.; Cháfer Nácher, MT.; Chiralt, A.; González Martínez, MC. (2015). Physical and microstructural properties of biodegradable films based on pea starch and PVA. Journal of Food Engineering. 167(1):59-64. https://doi.org/10.1016/j.jfoodeng.2015.06.0035964167

Study of the release of limonene present in chitosan films enriched with bergamot oil in food simulants

[EN] Chitosan films containing different concentrations of bergamot oil (BO) were obtained and the migration of limonene, the major oil component, to five liquid food simulants (aqueous solutions with 0%, 10%, 50% and 95% of ethanol and isooctane) was studied at 20 degrees C. The losses of BO and limonene during the film drying were also quantified. The release kinetics of limonene from chitosan matrix was described using an empirical model which relates the reduced concentration loss of limonene and the square root of time. The results show that kinetic constants for all films increased exponentially when the ethanol concentration increased in the aqueous system and were slightly greater when the film thickness was lower. Composite films remain intact in isooctane CH-BO and no release of limonene was observed. Hydration of the film to promote molecular mobility was essential to ensure the compound release. (C) 2011 Elsevier Ltd. All rights reserved.The author L. Sanchez-Gonzalez thanks the Ministerio de Educacion y Ciencia (Spain) for a FPU Grant (AP2006-026).Sánchez González, L.; Cháfer Nácher, MT.; González Martínez, MC.; Chiralt, A.; Desobry, S. (2011). Study of the release of limonene present in chitosan films enriched with bergamot oil in food simulants. Journal of Food Engineering. 105(1):138-143. https://doi.org/10.1016/j.jfoodeng.2011.02.016S138143105

Physical and antioxidant properties of chitosan and methylcellulose based films containing resveratrol

[EN] New trends in edible films focus on the improvement of their functionality through the incorporation of active compounds, such as antimicrobial or antioxidant agents. Resveratrol is a natural antioxidant found in a variety of plant species, such as grapes, and could be used for minimizing or preventing lipid oxidation in food products, retarding the formation of oxidation products, maintaining nutritional quality and prolonging the food shelf life. The aim of this work was to develop and characterize two different polymeric composite films (made with chitosan (CH) and methylcellulose (MC)) containing different amounts of resveratrol. This compound could be incorporated efficiently into both films, but provoke structural changes in the matrices, which became less stretchable (65-70% reduction of deformation at break at the greatest resveratrol content) and resistant to fracture (26 and 54% reduction of tensile at break for MC and CH, respectively, at the greatest resveratrol content) more opaque (significant reduction of the internal transmittance) and less glossy (about 60-65% reduction of gloss at the greatest resveratrol content). Film barrier properties were hardly improved by the presence of resveratrol; water vapour and oxygen permeability tend to slightly decrease when resveratrol was incorporated into both polymers. Composite films showed antioxidant activity, which was proportional to the resveratrol concentration in the film. None of the films showed antimicrobial activity against Penicillium italicum and Botrytis cinerea. Thus, these films could be applied to food products which are sensitive to oxidative processes to prolong their shelf life. (C) 2012 Elsevier Ltd. All rights reserved.The authors acknowledge the financial support from the Spanish Ministerio de Ciencia e Innovación throughout the project AGL2010-20694.Pastor Navarro, C.; Sánchez González, L.; Chiralt, A.; Cháfer Nácher, MT.; González Martínez, MC. (2013). Physical and antioxidant properties of chitosan and methylcellulose based films containing resveratrol. Food Hydrocolloids. 30(1):272-280. https://doi.org/10.1016/j.foodhyd.2012.05.026S27228030

Biodegradation behavior of starch-PVA films as affected by the incorporation of different antimicrobials

The effect that the incorporation of different antimicrobial substances into S-PVA films had on their disintegration and biodegradation process was analysed. To this end, starch, PVA and S-PVA films containing different concentrations of neem oil, oregano essential oil and silver nanoparticles were submitted to composting conditions in order to determine the disintegration and biodegradability percentages for 73 and 45 days, respectively. Additionally, thermogravimetric and structural analyses were also carried out throughout the composting period. The biodegradation and disintegration behavior of S-PVA films was intermediate between S and PVA films. The addition of neem and oregano essential oils slightly affected the biodegradation and disintegration profile of starch-PVA films, enhancing both disintegration and biodegradation levels. So, the presence of these antimicrobials did not compromise the compostable and biodegradable character of the starch-PVA blend films. Nevertheless, the biodegradation capacity of films containing 9.8% silver species was seriously affected, reaching values of only 58% after 45 days of composting, despite their high disintegration capacity. Thus, lower silver concentrations are recommended in order to avoid possible alterations in compost microbial activity.The authors acknowledge the financial support from the Spanish Ministerio de Economia y Competitividad through the projects AGL2013-42989-R. Amalia Cano also thanks the Spanish Ministerio de Education, Cultura y Deporte for the FPU grant (AP2010-4377).Cano Embuena, AI.; Cháfer Nácher, MT.; Chiralt Boix, MA.; González Martínez, MC. (2016). Biodegradation behavior of starch-PVA films as affected by the incorporation of different antimicrobials. Polymer Degradation and Stability. 132:1-10. https://doi.org/10.1016/j.polymdegradstab.2016.04.014S11013

Effect of high pressure homogenization and heat treatment on physical properties and stability of almond and hazelnut milks

[EN] The effect of high pressure homogenisation (HPH) and heat treatments on physicochemical properties and physical stability of almond and hazelnut milks was studied. Vegetable milks were obtained and homogenised by applying 62, 103 and 172 MPa (MF1, MF2 and MF3, respectively). Untreated and MF3 samples were also submitted to two different heat treatments (85ºC/30 min (LH) or 121ºC/15 min (HH)). Physical and structural properties of the products were greatly affected by heat treatments and HPH. In almond milk, homogenised samples showed a significant reduction in particle size, which turned from bimodal and polydisperse to monodisperse distributions. Particle surface charge, clarity and Whiteness Index were increased and physical stability of samples was improved, without affecting either viscosity or protein stability. Hazelnut beverages showed similar trends, but HPH notably increased their viscosity while change their rheological behaviour, which suggested changes in protein conformation. HH treatments caused an increment of particle size due to the formation oil droplet-protein body clusters, associated with protein denaturation. Samples submitted to the combined treatment MF3 and LH showed the greatest stability.The authors acknowledge the financial support provided by Universitat Politecnica de Valencia (Valencia, Spain) for the project (PAID 05-11-2740). Author N. Bernat appreciates the Conselleria de Eduacion of Valencia (Spain) for a FPI Grant (Programa VALi + d para investigadores en formacion. ACIF/2011).Bernat Pérez, N.; Cháfer Nácher, MT.; Rodríguez García, J.; Chiralt, A.; González Martínez, MC. (2015). Effect of high pressure homogenization and heat treatment on physical properties and stability of almond and hazelnut milks. Food Science and Technology. 62:488-496. https://doi.org/10.1016/j.lwt.2014.10.045S4884966

Effect of cellulose nanocrystals on the properties of pea starch-poly(vinyl alcohol) blend films

[EN] Incorporation of cellulose nanocrystals (CNC) to pea starch-poly(vinyl alcohol) (PVA) (1:2 ratio) blend films was carried out in order to improve their physical properties. Different ratios (1, 3 and 5 % wt) of CNC were used and structural, thermal and physical (barrier, mechanical and optical) properties were analysed in comparison to the control film without CNC. Incorporation of CNC enhanced phase separation of polymers in two layers. The upper PVA rich phase contained lumps of starch which emerged from the film surface, thus reducing the film gloss. CNC were dispersed in both polymeric phases as aggregates, whose size increased with the CNC ratio rise. CNC addition did not implied changes in water vapour barrier of the films, but they became slightly stiffer and more stretchable, while crystallization of PVA was partially inhibited.The authors acknowledge the financial support from the Spanish Ministerio de Economia y Competitividad throughout the Projects AGL2010-20694 and AGL2013-42989-R. Amalia Cano also thanks the Spanish Ministerio de Educacion, Cultura y Deporte for the FPU grant and COST-STSM-FA1001-14253 for the financial support for the collaboration.Fortunati, E.; Cano Embuena, AI.; Cháfer Nácher, MT.; González Martínez, MC.; Chiralt, A.; Kenny, J. (2015). Effect of cellulose nanocrystals on the properties of pea starch-poly(vinyl alcohol) blend films. Journal of Materials Science. 50(21):6979-6992. https://doi.org/10.1007/s10853-015-9249-9S697969925021Armentano I, Dottori M, Fortunati E, Mattioli S, Kenny JM (2010) Biodegradable polymer matrix nanocomposites for tissue engineering: a review. Polym Degrad Stab 95:2126–2146Fortunati E, Peltzer M, Armentano I, Jiménez A, Kenny JM (2013) Combined effects of cellulose nanocrystals and silver nanoparticles on the barrier and migration properties of PLA nano-biocomposites. J Food Eng 118:117–124Siracusa V, Rocculi P, Romani S, Rosa MD (2008) Biodegradable polymers for food packaging: a review. Trends Food Sci Technol 19:634–643Anandjiwala RD (2006) The role of research and development in the global competitiveness of natural fibre products, In: Natural Fibres Vision 2020 New Delhi, pp 1–15Chen Y, Liu Ch, Chang PR, Cao X, Anderson DP (2009) Bionanocomposites based on pea starch and cellulose nanowhiskers hydrolyzed from pea hull fibre: effect of hydrolysis time. Carbohydr Polym 76:607–615Habibi Y, Lucia LA, Rojas OJ (2010) Cellulose nanocrystals: chemistry, self-assembly, and applications. Chem Rev 110(6):3479–3500Lee SY, Mohan DJ, Kang IE, Doh G-H, Lee S, Han SO (2009) Nanocellulose reinforced PVA composite films: effects of acid treatment and filler loading. Fibers Polym 10:77–82Zhang W, Yang X, Li C, Liang M, Lu C, Deng Y (2011) Mechanical activation of cellulose and its thermoplastic polyvinyl alcohol composites with enhanced physicochemical properties. Carbohydr Polym 83:257–263Fortunati E, Armentano I, Zhou Q, Iannoni A, Saino E, Visai L, Berglund LA, Kenny JM (2012) Multifunctional bionanocomposite films of poly(lactic acid), cellulose nanocrystals and silver nanoparticles. Carbohydr Polym 87:1596–1605Fortunati E, Puglia D, Luzi F, Santulli C, Kenny JM, Torre L (2013) Binary PVA bio-nanocomposites containing cellulose nanocrystals extracted from different natural sources: part I. Carbohydr Polym 97:825–836Cavaille JY, Ruiz MM, Dufrense A, Gerard JF, Graillat C (2000) Processing and characterization of new thermoset nanocomposites based in cellulose whiskers. Compos Interface 7(2):117–131Khoshkava V, Kamal MR (2014) Effect of drying conditions on cellulose nanocrystals (CNC) agglomerate porosity and dispersibility in polymer nanocomposites. Poweder Technol 261:288–298Sturcová A, Davies GR, Eichhorn SJ (2005) Elastic modulus and stress-transfer properties f tunicate cellulose whiskers. Biomacromolecules 6:1055–1061Fortunati E, Armentano I, Zhou Q, Puglia D, Terenzi A, Berglund LA, Kenny JM (2012) Microstructure and nanoisothermal cold crystallization of PLA composites based on silver nanoparticles and nanocrystalline cellulose. Polym Degrad Stab 97:2027–2036Rescignano N, Fortunati E, Montesano S, Emilianini C, Kenny JM, Martino S, Armentano I (2014) PVA bio-nanocomposites: a new take-off using cellulose nanocrystals and PLGA nanoparticles. Carbohydr Polym 99:47–58Siqueira G, Brasa J, Follain N, Belbekhouche S, Marais S, Dufresne A (2013) Thermal and mechanical properties of bio-nanocomposites reinforced by Luffa cylindrical cellulose nanocrystals. Carbohydr Polym 91(2):711–717Choi Y, Simonsen J (2006) Cellulose nanocrystals-filled carboxymethyl cellulose nanocomposites. J Nanosci Nanocompos 6(3):633–639Pereda M, Dufresne A, Aranguren MI, Marcovich E (2014) Polyelectrolyte films based on chitosan/olive oil and reinforced with cellulose nanocrystals. Carbohydr Polym 101:1013–1026Ma X, Chang PR, Yu J (2008) Properties of biodegradable thermoplastic pea starch/carboxymethyl cellulose and pea starch/microcrystalline cellulose composites. Carbohydr Polym 72:369–375Arrieta M, Fortunati E, Dominici F, Rayón E, Lopez J, Kenny JM (2014) PLA-PHB/cellulose based films: mechanical, barrier and disintegration properties. Carbohydr Polym 107:139–149Arrieta M, Fortunati E, Dominici F, Rayón E, Lopez J, Kenny JM (2014) Multifunctional PLA-PHB/cellulose nanocrystals films: processing, structural and thermal behavior. Carbohydr Polym 107:16–24Jiménez A, Fabra MJ, Talens P, Chiralt A (2012) Influence of hydroxypropylmethylcellulose addition and homogenization conditions on properties and ageing of corn starch based films. Carbohydr Polym 89(2):676–686Bonilla J, Atarés L, Vargas M, Chiralt A (2013) Properties of wheat starch film-forming dispersions and films as affected by chitosan addition. J Food Eng 114(3):303–312Cano A, Fortunati E, Cháfer M, Kenny JM, Chiralt A, González C (2015) Properties and ageing behavior of pea starch films as affected by blend with poly(vinyl alcohol). Food Hydrocoll 48:84–93Siddaramaiah Raj B, Somashekar R (2004) Structure–property relation in polyvinyl alcohol/starch composites. J Appl Polym Sci 9:630–635Priya B, Gupta VK, Pathania D, Singh AS (2014) Synthesis, characterization and antibacterial activity of biodegradable starch/PVA composite films reinforced with cellulosic fibre. Carbohydr Polym 109:171–179Luo X, Li J, Lin X (2012) Effect of gelatinization and additives on morphology and thermal behaviour of cornstarch/PVA blend films. Carbohydr Polym 90:1595–1600Shi R, Bi J, Zhang Z, Zhu A, Chen D, Zhou X, Zhang L, Tian W (2008) The effect of citric acid on the structural properties and cytotoxicity of the polyvinylalcohol/starch films when molding at high temperature. Carbohydr Polym 74:763–770Jiang X, Jiang T, Gan L, Zhang X, Dai H, Zhang X (2012) The plasticizing mechanism and effect of calcium chloride on starch/poly(vinyl alcohol) films. Carbohydr Polym 90:1677–1684Yoon S, Park M, Byun H (2012) Mechanical and water barrier properties of starch/PVA composite films by adding nano-sized poly(methylmethacrylate-co-acrylamide) particles. Carbohydr Polym 87:676–686Cranston ED, Gray DG (2006) Morphological and optical characterization of polyelectrolyte multilayers incorporating nanocrystalline cellulose. Biomacromolecules 7:2522–2530UNE-EN ISO (2008) Paper, board and pulps—determination of dry matter content—oven-drying method, vol 638Jiménez A, Fabra MJ, Talens P, Chiralt A (2012) Effect of re-crystallization on tensile, optical and water vapour barrier properties of corn starch films containing fatty acids. Food Hydrocoll 26:302–310Roohani M, Habibi Y, Belgacem NM, Ebrahim G, NaghiKarimi A, Dufresne A (2008) Cellulose whiskers reinforced polyvinyl alcohol copolymers nanocomposites. Eur Polym J 44:2489–2498ASTM (1995) Standard test methods for water vapour transmission of materials. Standard designations: E96-95 Annual book of ASTM standards, American Society for Testing and Materials, Philadelphia, pp 406–413Cano A, Jiménez A, Cháfer M, González C, Chiralt A (2014) Effect of amylose: amylopectin ratio and rice bran addition on starch films properties. Carbohydr Polym 111:543–555UNE-ISO 527-1 (2012) Plastics e determination of tensile properties e part 1: general principlesASTM (1999) Standard test methods for specular gloss. Designation (D523). In Annual book of ASTM standards, vol 06.01. American Society for Testing and Materials, PhiladelphiaEuropean Standard EN 1186-1:2002 Materials and articles in contact with foodstuffs. Plastics. Guide to the selection of conditions and test methods for overall migrationCommission Regulation (EU) No 10/2011 of 14 January 2011 on plastic materials and articles intended to come into contact with foodSreekumar PA, Al-Harthi MA, De SK (2012) Studies on compatibility of biodegradable starch/polyvinyl alcohol blends. Polym Eng Sci 52(10):2167–2172Chen J, Liu Ch, Chen Y, Chen Y, Chang PR (2008) Comparative study on the films of poly(vinyl alcohol)/pea starch nanocrystals and poly(vinyl alcohol)/native pea starch. Carbohydr Polym 73:8–17Jiménez A, Sánchez-González L, Desorby S, Chiralt A, Tehrany EA (2013) Influence of nanoliposomes incorporation on properties of film forming dispersions and films based on corn starch and sodium caseinate. Food Hydrocoll 35:159–169Jagadish RS, Raj B (2011) Properties and sorption studies of polyethylene oxide-starch blended films. Food Hydrocoll 25:1572–1580Fortunati E, Puglia D, Monti M, Santulli C, Maniruzzaman M, Kenny JM (2013) Cellulose nanocrystals extracted from Okra Fibers in PVA nanocomposites. J Appl Polym Sci 128:3220–3230. doi: 10.1002/APP.38524Abdelrazek EM, Elashmawi IS, Labeeb S (2010) Chitosan filler effects on the experimental characterization, spectroscopic investigation and thermal studies of PVA/PVP blend films. Phys B 405:2021–2027Peresin MS, Habibi Y, Zoppe JO, Pawlak JJ, Rojas OJ (2010) Nanofiber composites of polyvinyl alcohol and cellulose nanocrystals: manufacture and characterization. Biomacromolecules 11(3):674–681Favier V, Cavaillé JY, Canova GR, Shrivastavas SC (1997) Mechanical percolation in cellulose whisker nanocomposites. Polym Eng Sci 37(10):1732–1739Schmidt B, Katiyar V, Plackett D, Larsen EH, Gerds N, Bender Koch C (2011) Migration of nanosized layered double hydroxide platelets from polylactide nanocomposite films. Food Addit Contam 28:956–966Fortunati E, Peltzer M, Armentano I, Torre L, Jiménez A, Kenny JM (2012) Effects of modified cellulose nanocrystals on the barrier and migration properties of PLA nano-biocomposites. Carbohydr Polym 90:948–95

Probiotic fermented almond milk as an alternative to cow-milk yoghurt

Copyright ➞2015 ISEKI-Food Association (IFA)[EN] Probiotics in almond-based matrices were considered as a means of obtaining fermented products which would cover both the current demand for health-promoting foods and for alternatives to standard yoghurts. Firstly, the effect of high pressure homogenisation (HPH) and heat treatments on the physical stability of almond milk was studied. The beverage was homogenised by applying 62, 103 and 172 MPa (MF1, MF2 and MF3 respectively); MF3 was also combined with two different heat treatments (85 ºC-30 min (LH) and 121 ºC-15 min (HH)). Both microstructure and colloidal stability were analysed in all the processed samples to select the most suitable treatment with which to obtain a stable product. The selected almond milk was then fermented with probiotic Lactobacillus reuteri and Streptococcus thermophilus and the final product was characterised throughout cold storage time (28 days) as to pH, acidity, serum retention and starter viability. A sensory evaluation and probiotic survival to in vitro digestion was also conducted. The results showed that the physical and structural almond-milk properties were affected by both HPH and heat treatments, obtaining the greatest stability in MF3-LH samples. The fermented milk permitted probiotic survivals above the level suggested as minimum for ensuring health benefits during the entire controlled time and, hence, can be considered as a functional food. No differences in the sensory acceptability of the product were found between 1 and 28 storage days. Therefore, a new, functional, fermented product was developed, which was suitable for targeted groups, such as the lactose-intolerant and cow-milk-protein allergic populations.This research has been carried out thanks to a project funded by the Universitat Politècnica de València (PAID-05-11-2740). This work was also supported by the “Conselleria d’Educació” of Valencian government, which awarded a grant to the author N. Bernat (ACIF/2011).Bernat Pérez, N.; Cháfer Nácher, MT.; Chiralt, A.; González Martínez, MC. (2015). Probiotic fermented almond milk as an alternative to cow-milk yoghurt. International Journal of Food Studies. 4:201-211. https://doi.org/10.7455/ijfs/4.2.2015.a8S201211

USO DEL SCREENCAST Y LA e-EVALUACIÓN EN LAS PRÁCTICAS DE LA ASIGNATURA ¿TECNOLOGÍA POSTCOSECHA¿ EN LA UNIVERSITAT POLITÈCNICA DE VALÈNCIA

[Otros] Nowadays, thanks to the new technologies, there are more tools available to ease the lecturer¿s job as a guide for students in their process of learning. In this context, the fullfilment of different assignments is considerable improved when it is possible to access several times to the explatination to perform them. Likewise, it is widely proved that knowledge is reafirmed from the correction of mistakes. For that, it is important to know the reasons why the answer is wrong in each case. Thus, the aim of this article is to show the teaching innovations applied in the subject of Postharvest Technology taught at university. Concretely, presentations with audio (screencast) have been incorporated to support the lectures carried out to perfom the practical tasks. Besides that, online exams have been used in PoliformaT educational Platform by programming the remarks for uncorrect answers. Students appreciate these innovations in the teaching methodology and they have shown a remarkable perfomance. Furthermore, the participative assessment between lecturers and students has been incorporated, reaching previously and agreement in the assessment criteria.[ES] Gracias a las nuevas tecnologías, cada vez hay disponibles más herramientas que facilitan la labor del profesor como guía en el proceso de aprendizaje de los estudiantes. En este contexto, tener la oportunidad de poder acceder a la explicación realizada sobre una determinada tarea varias veces mejora sustancialmente su ejecución. Asimismo, de las correcciones de los errores cometidos en las pruebas de evaluación, se afianzan muchos conocimientos. Por ello, es importante conocer las razones por las que se ha fallado en cada caso. Así, el objetivo de este artículo es presentar dos innovaciones docentes aplicadas en la asignatura de Tecnología Postcosecha en el ámbito universitario. Concretamente, se han incorporado presentaciones con audio (screencast) para apoyar las explicaciones llevadas a cabo para la realización de las prácticas y por otro lado se ha utilizado la herramienta de exámenes online de la plataforma PoliformaT programándola para mostrar comentarios en las preguntas incorrectas. Los estudiantes han agradecido estas iniciativas en la metodología docente y el rendimiento en su trabajo ha sido notable. Además, se ha incorporado la evaluación participativa de las prácticas se ha llevado a cabo tanto por parte del profesorado como de los estudiantes, consensuando los criterios de valoración previamente.Castelló Gómez, ML.; Cháfer Nácher, MT.; Conesa Domínguez, C.; Ortolá Ortolá, MD. (2014). USO DEL SCREENCAST Y LA e-EVALUACIÓN EN LAS PRÁCTICAS DE LA ASIGNATURA ¿TECNOLOGÍA POSTCOSECHA¿ EN LA UNIVERSITAT POLITÈCNICA DE VALÈNCIA. Editorial Universitat Politècnica de València. 251-259. http://hdl.handle.net/10251/168640S25125

A preliminary study on the use of coatings based on chitosan and efficient microorganisms for postharvest control of the blue mold of oranges

[SPA] Se analizó el efecto antifúngico de recubrimientos a base de quitosano, así como de una mezcla de microorganismos denominados “eficaces” (EM), como posibles tratamientos alternativos a los fungicidas sintéticos para el control de la podredumbre azul de naranjas, evaluándose además los principales aspectos de calidad de las naranjas durante dos semanas de almacenamiento a 25ºC y 85% de humedad relativa. Para ello, se planificaron dos series experimentales. En la primera serie, se evaluó la capacidad antifúngica de la disolución madre de EM y de los siguientes recubrimientos comestibles: quitosano (1% p/p), quitosano (Q)+ metilcelulosa (MC) (1% y 1% p/p), y MC + EM (1% y 5% p/p). Como controles se utilizaron muestras no tratadas (C) y muestras tratadas con tiabendazol (TBZ) al 0.1% (p/p). Para ello, las naranjas (variedad Lane-Late) fueron inoculadas con Penicillium italicum a una dosis de 105 esporas·mL-1, evaluándose la evolución de la infección durante el almacenamiento en condiciones óptimas para el desarrollo fúngico. En la segunda serie experimental, se caracterizaron, al principio y final del almacenamiento, los principales parámetros de calidad de las naranjas tras aplicar los tratamientos con mayor efecto antifúngico. Los resultados mostraron que todos los tratamientos redujeron el crecimiento fúngico en comparación con las muestras no tratadas (C). Por otro lado, sólo las muestras tratadas con la disolución madre de EM y las muestras recubiertas con MC-EM al 5% mejoraron o igualaron, respectivamente, la capacidad antifúngica del TBZ. No se observaron diferencias significativas entre los distintos tratamientos en la pérdida de peso, color (tono y croma) y tasa respiratoria de las naranjas durante el almacenamiento. [ENG] The antifungal effect of coatings based on chitosan and a mixture of efficient microorganisms (EM) was analysed in order to obtain an alternative treatment to synthetic fungicides for the postharvest control of the blue mold decay of oranges. Moreover, fruit quality was evaluated after ten days of storage at 25ºC and 85% relative humidity. Two experimental trials were performed. Firstly, the antifungal effect of a EM commercial stock solution and the following coatings: chitosan (1 wt%), chitosan+methylcellulose (1 wt % and 1 wt%) and methylcelullose (MC) + EM (1% and 5% wt) was evaluated. Control samples were those non-treated samples (C) and treated with thiabendazole (TBZ) at 0.1 wt%. The antifungal effect of these formulations was evaluated in oranges (cv. Lane-Late) that were inoculated with Penicillium italicum spores (105 spores·mL-1) and stored under the optimal fungal growth conditions. In the second trial, fruit quality was analysed in stored oranges that were treated with the formulations that showed antifungal effect. Results showed that all treatments reduced fungal development in comparison with non-treated samples (C). On the other hand, only samples treated with EM stock solution and samples coated with MC-EM at 5% increased or showed the same antifungal effect as the ones treated with TBZ, respectively. After ten days of storage, no significant differences among the treatments were found in terms of weight loss, colour (hue and chroma) and respiration rate of oranges.Las autoras agradecen a la Universidad Politécnica de Valencia la ayuda concedida a través de la Acción Especial (200660345) “Aplicación de la tecnología de los microorganismos eficaces (EM) en la conservación de frutas y hortalizas”

Antifungal films based on starch-gelatin blend, containing essential oils

[EN] The antimicrobial activity of essential oils (EO) is very well-known and it has been reported that incorporating them into edible films based on biopolymers extends the food's shelf-life. In this study, cinnamon, clove and oregano EO, at 25% with respect to the polymer, were incorporated into glycerol plasticized starch-gelatin blend films (ratio 1:1) in order to elucidate their effect on the physical (barrier, mechanical and optical), structural and antifungal properties of the films. Whereas EOs exhibited no significant effect on tensile behavior in the case of casting films conditioned at 53% relative humidity and 25 degrees C, the EO compounds did significantly reduce the water vapor and oxygen permeability of the films. Likewise, the EOs increased the films' transparency but reduced their gloss. Despite the fact that about 60% of the incorporated EOs were lost during the film drying step, they exhibited antifungal activity against the two tested fungal species, Colletotrichum gloesporoides (CG) and Fusarium oxysporum (FOG), as revealed by the in vitro agar diffusion method. (C) 2016 Elsevier Ltd. All rights reserved.The authors acknowledge the financial support provided by the Ministerio de Economia y Competitividad-Spanish Government (AGL2013-42989-R).Acosta-Davila, SC.; Chiralt, A.; Santamarina Siurana, MP.; Rosello Caselles, J.; González Martínez, MC.; Cháfer Nácher, MT. (2016). Antifungal films based on starch-gelatin blend, containing essential oils. Food Hydrocolloids. 61:233-240. doi:10.1016/j.foodhyd.2016.05.008S2332406