Effect of an edible nanomultilayer coating by electrostatic self-assembly on the shelf life of fresh-cut mangoes

This work aims at evaluating the effect of an alginate-chitosan nanomultilayer coating, obtained by electrostatic layer-by-layer self-assembling, in the quality and shelf life of fresh-cut mangoes. Coated and uncoated fresh-cut mangoes were stored under refrigeration (8 °C) for 14 days. The changes in mass loss, titratable acidity, pH, ascorbic acid content, total soluble solids, malondialdehyde content, browning rate, and microbial count were evaluated during storage. At the end of the storage period, lower values of mass loss, pH, malondialdehyde content, browning rate, soluble solids, microorganisms proliferation, and higher titratable acidity were observed in the coated mangoes. The nanomultilayer coating did not improve the retention of vitamin C during storage of fresh-cut mangoes. Results suggest that chitosan-alginate nanomultilayer edible coating extends the shelf life of fresh-cut mangoes up to 8 days.Author Marthyna Pessoa de Souza thanks Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES/PDEE-Brazil) and Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE, Brazil) for granting her scholarships. The authors thank the Fundacao para a Ciencia e a Tecnologia (FCT) Strategic Project PEst-OE/EQB/LA0023/2013 and the Project "BioInd-Biotechnology and Bioengineering for improved Industrial and Agro-Food processes", REF. NORTE-07-0124-FEDER-000028, co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, and FEDER (Portugal)

The use of electric fields for edible coatings and films development and production: A review

Edible films and coatings can provide additional protection for food, while being a fully biodegradable, environmentally friendly packaging system. A diversity of raw materials used to produce edible coatings and films are extracted from marine and agricultural sources, including animals and plants. Electric fields processing holds advantage in producing safe, wholesome and nutritious food. Recently, the presence of a moderate electric field during the preparation of edible coatings and films was shown to influence their main properties, demonstrating its usefulness to tailor edible films and coatings for specific applications. This manuscript reviews the main aspects of the use of electric fields in the production of edible films and coatings, including the effect in their transport and mechanical properties, solubility and microstructure.Fundação para a Ciência e a Tecnologia (FCT), Portugal.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brasil

Effects of interactions between the constituents of chitosan-edible films on their physical properties

The main objective of this work was to evaluate the effect of chitosan and plasticizer concentrations and oil presence on the physical and mechanical properties of edible films. The effect of the film constituents and their in-between interactions were studied through the evaluation of permeability, opacity and mechanical properties. The effects of the studied variables (concentrations of chitosan, plasticizer and oil) were analysed according to a 2 3 factorial design. Pareto charts were used to identify the most significant factors in the studied properties (water vapour, oxygen and carbon dioxide permeability; opacity; tensile strength; elongation at break and Young's modulus). When addressing the influence of the interactions between the films' constituents on the properties above, results show that chitosan and plasticizer concentrations are the most significant factors affecting most of the studied properties, while oil incorporation has shown to be of a great importance in the particular case of transport properties (gas permeability), essentially due to its hydrophobicity. Water vapour permeability values (ranging from 1. 62 × 10 -11 to 4. 24 × 10 -11 g m -1 s -1 Pa -1) were half of those reported for cellophane films. Also the mechanical properties (tensile strength values from 0. 43 to 13. 72 MPa and elongation-at-break values from 58. 62% to 166. 70%) were in the range of those reported for LDPE and HDPE. Based on these results, we recommend the use of 1. 5% (w/w) chitosan concentration to produce films, where the oil and plasticizer proportions will have to be adjusted in a case-by-case basis according to the use intended for the material. This work provides a useful guide to the formulation of chitosan-based film-forming solutions for food packaging applications.The author MA Cerqueira is a recipient of a fellowship from Fundacao para a Ciencia e Tecnologia (FCT, SFRH/BD/23897/2005) and BWS Souza is a recipient of a fellowship from the Coordenacao Aperfeicoamento de Pessoal de Nivel Superior, Brazil (Capes, Brazil)

Influence of homogenization conditions on physical properties and antioxidant activity of fully biodegradable pea protein-alpha-tocopherol films

In this study, antioxidant biodegradable films based on pea protein and alpha-tocopherol were successfully developed by solution casting. The effect of both the homogenization conditions (rotor stator and microfluidizer) and the relative humidity (RH) on the microstructure and physical properties (transparency, tensile, oxygen and water vapour barrier properties) of pea protein/alpha-tocopherol-based films was evaluated. The addition of alpha-tocopherol produced minimal changes in the films transparency, while providing them with antioxidant properties and improved water vapour and oxygen barrier properties (up to 30 % in both water vapour and oxygen permeability) when films were at low and intermediate RH. The addition of alpha-tocopherol in microfluidized films gave rise to an increase in their resistance to break and extensibility (up to 27 % in E values) at intermediate and high RH. These results add a new insight into the potential of employing pea protein and alpha-tocopherol in the development of fully biodegradable antioxidant films which are of interest in food packagingThe authors acknowledge the financial support from the Spanish Ministerio de Educacion y Ciencia throughout the project AGL2010-20694, co-funded by FEDER. Author M.J.Fabra is a recipient of a Juan de la Cierva contract from the Spanish Ministerio de Economia y Competitividad.Fabra, MJ.; Jiménez, A.; Talens Oliag, P.; Chiralt, A. (2014). Influence of homogenization conditions on physical properties and antioxidant activity of fully biodegradable pea protein-alpha-tocopherol films. Food and Bioprocess Technology. 7(12):3569-3578. https://doi.org/10.1007/s11947-014-1372-0S35693578712ASTM (1995). Standard test methods for water vapor transmission of materials. Standards Desingnations: E96-95. 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H. (2001). Physical and mechanical properties of pea–protein-based edible films. Journal of Food Science, 66, 319–322.Choi, W. S., & Han, J. H. (2002). Film-forming mechanism and heat denaturation effects on the physical and chemical properties of pea-protein-isolate edible films. Journal of Food Science, 67, 1399–1406.Fabra, M. J., Talens, P., & Chiralt, A. (2009). Microstructure and optical properties of sodium caseinate films containing oleic acidebeeswax mixtures. Food Hydrocolloids, 23, 676–683.Fabra, M. J., Talens, P., & Chiralt, A. (2010). Water sorption isotherms and phase transitions of sodium caseinate–lipid films as affected by lipid interactions. Food Hydrocolloids, 24, 384–391.Fabra, M. J., Hambleton, A., Talens, P., Debeaufort, F., & Chiralt, A. (2011). Effect of ferulic acid and α-tocopherol antioxidants on properties of sodium caseinate edible films. Food Hydrocolloids, 25, 1441–1447.Fabra, M. J., Talens, P., Gavara, R., & Chiralt, A. (2012). Barrier properties of sodium caseinate films as affected by lipid composition and moisture content. Journal of Food Engineering, 109, 372–379.Frankel, E. N., Huang, S. W., Kanner, J., & German, J. B. (1994). Interfacial phenomena in the evaluation of antioxidants: bulk oils vs emulsions. Journal of Agriculture and Food Chemistry, 42(5), 1054–1059.Gómez-Estaca, J., Giménez, B., Montero, P., & Gómez-Guillén, M. C. (2009). Incorporation of antioxidant borage extract into edible films based on sole skin gelatin or a commercial fish gelatin. Journal of Food Engineering, 92, 78–85.Huang, S. W., Frankel, E. N., & German, J. B. (1994). Antioxidant activity of alpha.- and.gamma.-tocopherols in bulk oils and in oil-in-water emulsions. Journal of Agriculture and Food Chemistry, 42(10), 2108–2114.Hutchings, J. B. (1999). Food and colour appearance (2nd ed.). Gaithersburg: Chapman and Hall Food Science Book, Aspen Publication.Jiménez, A., Fabra, M. J., Talens, P., & Chiralt, A. (2010). Effect of lipid self-association on the microstructure and physical properties of hydroxypropylmethylcellulose edible films containing fatty acids. Carbohydrate Polymers, 82(3), 585–593.Jiménez, A., Fabra, M. J., Talens, P., & Chiralt, A. (2013). Physical properties and antioxidant capacity of starch-sodium caseinate films containing lipids. Journal of Food Engineering, 116(3), 695–702.Jung, M. Y., & Min, D. B. (1990). Effects of alpha-. γ-, and δ-tocopherols on oxidative stability of soybean oil. Journal of Food Science, 55(5), 1464–1465.López-de-Dicastillo, C., Alonso, J. M., Catalá, R., Gavara, R., & Hernández-Muñoz, P. (2010). Improving the antioxidant protection of packaged food by incorporating natural flavonoids into ethylene-vinyl alcohol copolymer (EVOH) films. Journal of Agricultural and Food Chemistry, 58, 10958–10964.Ma, W., Tang, C.-H., Yin, S.-W., Yang, X. Q., Qi, J. R., & Xia, N. (2012). Effect of homogenization conditions on properties of gelatin-olive oil composite films. Journal of Food Engineering, 113(1), 136–142.Mauer, L. J., Smith, D. E., & Labuza, T. P. (2000). Water vapor permeability, mechanical, and structural properties of edible β-casein films. International Dairy Journal, 10(5–6), 353–358.Mc Hugh, T. H., Avena-Bustillos, R., & Krochta, J. M. (1993). Hydrophobic edible films:modified procedure for water vapor permeability and explanation of thickness effects. Journal of Food Science, 58(4), 899–903.McHugh, T. H., & Krochta, J. M. (1994). Dispersed phase particle size effects on water vapour permeability of whey protein–beeswax emulsion films. Journal of Food Processing and Preservation, 18, 173–188.Ozkan, G., Simsek, B., & Kuleasan, H. (2007). Antioxidant activities of Satureja cilicica essential oil in butter and in vitro. Journal of Food Engineering, 79, 1391–1396.Pereira de Abreu, D. A., Paseiro Losada, P., Maroto, J., & Cruz, J. M. (2011). Natural antioxidant active packaging film and its effect on lipid damage in frozen blue shark (Prionace glauca). Innovative Food Science and Emerging Technologies, 12, 50–55.Re, R., Pellegrini, N., Proteggente, A., Pannala, A., Yang, M., & Rice-Evans, C. (1999). Antioxidant activity applying an improved ABTS radical cation decoloration assay. Free Radical Biology and Medicine, 26, 1231–1237.Roos, Y. H. (1995). Phase transitions in food. San Diego: Academic Press.Salgado, P. R., Molina Ortiz, S. E., Petruccelli, S., & Mauri, A. N. (2010). Biodegradable sunflower protein films naturally activated with antioxidant compounds. Food Hydrocolloids, 24(5), 525–533.Salgado, P. R., Fernández, G. B., Drago, S. R., & Mauri, A. N. (2011). Addition of bovine plasma hydrolysates improves the antioxidant properties of soybean and sunflower protein-based films. Food Hydrocolloids, 25, 1433–1440.Samaranayaka, A. G. P., & Li-Chan, E. C. Y. (2008). Autolysis-assisted production of fish protein hydrolysates with antioxidant properties form Pacific hake (Merluccius productus). Food Chemistry, 107, 768–776.Souza, B. W. S., Cerqueira, A., Casariego, A., Lima, A. M. P., Teixeira, J. A., & Vicente, A. A. (2009). Effect of moderate electric fields in the permeation properties of chitosan coatings. Food Hydrocolloids, 23, 2110–2115

Perspectives on utilization of edible coatings and nano-laminate coatings for extension of postharvest storage of fruits and vegetables

It is known that in developing countries, a large quantity of fruit and vegetable losses results at postharvest and processing stages due to poor or scarce storage technology and mishandling during harvest. The use of new and innovative technologies for reducing postharvest losses is a requirement that has not been fully covered. The use of edible coatings (mainly based on biopolymers) as a postharvest technique for agricultural commodities has offered biodegradable alternatives in order to solve problems (e.g., microbiological growth) during produce storage. However, biopolymer-based coatings can present some disadvantages such as: poor mechanical properties (e.g., lipids) or poor water vapor barrier properties (e.g., polysaccharides), thus requiring the development of new alternatives to solve these drawbacks. Recently, nanotechnology has emerged as a promising tool in the food processing industry, providing new insights about postharvest technologies on produce storage. Nanotechnological approaches can contribute through the design of functional packing materials with lower amounts of bioactive ingredients, better gas and mechanical properties and with reduced impact on the sensorial qualities of the fruits and vegetables. This work reviews some of the main factors involved in postharvest losses and new technologies for extension of postharvest storage of fruits and vegetables, focused on perspective uses of edible coatings and nano-laminate coatings.María L. Flores-López thanks Mexican Science and Technology Council (CONACYT, Mexico) for PhD fellowship support (CONACYT Grant Number: 215499/310847). Miguel A. Cerqueira (SFRH/BPD/72753/2010) is recipient of a fellowship from the Fundação para a Ciência e Tecnologia (FCT, POPH-QREN and FSE Portugal). The authors also thank the FCT Strategic Project of UID/ BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the project ‘‘BioInd Biotechnology and Bioengineering for improved Industrial and AgroFood processes,’’ REF. NORTE-07-0124-FEDER-000028 Co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico – FUNCAP, CE Brazil (CI10080-00055.01.00/13)

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

Ultrasound-assisted chitosan-surfactant nanostructure assemblies: towards maintaining postharvest quality of tomatoes

A novel ultrasound-assisted chitosan–surfactant nanostructure assembly was developed to allow better delivery of chitosan particles into intact fruit tissues for extension of postharvest life. Three solutions of 1 % chitosan–surfactant nanostructure assembly with micelle sizes of 400, 600 and 800 nm were prepared and applied as an edible coating on tomatoes. The fruits were stored at 15 ± 2 °C and 70–80 % relative humidity for 20 days. The indicators of tomato ripening, which included loss of firmness, decline of titratable acidity, decline of chlorophyll content and increase in soluble solid content, were delayed in the treated fruits in comparison to the control (p  0.05)