Immobilization of beta-cyclodextrin in ethylene-vinyl alcohol copolymer for active food packaging applications

[EN] Current developments in active food packaging are focusing on incorporating agents into the polymeric package walls that will release or retain substances to improve the quality, safety and shelf-life of the food. Because cyclodextrins are able to form inclusion complexes with various compounds, they are of potential interest as agents to retain or scavenge substances in active packaging applications. In this study, beta-cyclodextrin (beta CD) was successfully immobilized in an ethylene-vinyl alcohol copolymer with a 44% molar percentage of ethylene (EVOH44) by using regular extrusion with glycerol as an adjuvant. Films with 10%, 20% and 30% of beta CD were flexible and transparent. The presence of the agent slightly increased the glass-transition temperature and the crystallinity percentage of the polymer, that is to say, it induced some fragility and a nucleating effect. The water vapor, oxygen and carbon dioxide barrier properties of the materials containing beta CD were determined and compared with those of the pure polymeric material. Permeability to these three permeants increased with the addition of beta CD due to the presence of discontinuities in the matrix and to the internal cavity of the oligosaccharide. Also the CO2/O-2 permselectivity increased with the addition of beta CD. Finally, the potential effect of the composites in the food aroma was analyzed. The materials with beta CD preferentially sorbed apolar compounds such as terpenes. This characteristic could be useful in active packaging applications for preferentially retaining undesired apolar food components like hexanal or cholesterol. (C) 2010 Elsevier B.V. All rights reserved.The authors acknowledge the financial support of the Spanish Ministry of Science and Innovation, projects AGL2006-02176 and Fun-C-Food CSD2007-00063, and the C. L-d-D fellowship (FPU program). Mary Georgina Hardinge provided assistance with the English language text.Lopez-De-Dicastillo, C.; Gallur, M.; Catala Moragrega, R.; Gavara Clemente, R.; Hernandez-Muñoz, P. (2010). Immobilization of beta-cyclodextrin in ethylene-vinyl alcohol copolymer for active food packaging applications. Journal of Membrane Science. 353(1-2):184-191. https://doi.org/10.1016/j.memsci.2010.02.049S1841913531-

Improving the Antioxidant Protection of Packaged Food by Incorporating Natural Flavonoids into Ethylene-Vinyl Alcohol Copolymer (EVOH) Films

This document is the unedited Author s version of a Submitted Work that was subsequently accepted for publication in Journal of Agricultural and Food Chemistry, copyright © American Chemical Society after peer review. To access the final edited and published work see https://doi.org/10.1021/jf1022324[EN] Ethylene-vinyl alcohol copolymer (EVOH) films containing catechin or quercetin as antioxidant agents were successfully produced by extrusion. The addition of these bioactive compounds did not modify greatly their water and oxygen permeabilities, T-g, or crystallinity but improved their thermal resistance. Exposure of the films to different food simulants showed that both compounds were released, although the extent and kinetics of release were dependent on the type of food. In aqueous and alcoholic food simulants their release was greater in the case of the catechin-containing samples. Exposure of the films to isooctane and ethanol 95% (fatty food simulants) provided controversial results; no release was observed in isooctane, whereas both bioactive compounds were extracted by ethanol due to their high solubility in alcohol and the plasticizing effect of ethanol on the polymer. Packaging applications of these films can improve food stability and provide a method for adding such bioactive compounds.Received for review June 10, 2010. Revised manuscript received August 24, 2010. Accepted September 16, 2010. We acknowledge the financial support of the Spanish Ministry of Science and Innovation, Projects AGL2006-02176, AGL2009-08776, and Fun-C-Food CSD2007-00063, and the C.L.-d.-D. fellowship (FPU program).Lopez-De-Dicastillo, C.; Alonso, JM.; Catala Moragrega, R.; Gavara Clemente, R.; Hernandez-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(20):10958-10964. https://doi.org/10.1021/jf1022324S1095810964582

Evaluation of Polyphenol Content and Antioxidant Capacity of Fruits and Vegetables Using a Modified Enzymatic Extraction

Fruits and vegetables are considered a good source of polyphenols and antioxidant capacities which are beneficial in protecting the human body against damage induced by reactive species. The objective of this work is to conduct an assessment of the polyphenol content and antioxidant activities of diff erent fruit (kiwi, pear, green apple, raspberry, blackberry, strawberry and blueberry) and vegetable (pumpkin, green and red pepper) extracts using both chemical extraction and a modified in vitro digestive enzymatic extraction in order to compare results. Polyphenol content and antioxidant capacity of different fruits, vegetables and fruit juices were determined by Folin-Ciocalteu and FRAP methods, respectively. It was observed that polyphenol content expressed as gallic acid equivalents of extracts obtained with the two extraction methods was signifi cantly (p<0.05) different (on average 310.3 and 231.8 mg per 100 g of fresh sample in enzymatic and methanolic extracts, respectively). Antioxidant capacity was also significantly (p<0.05) different in the extracts obtained by the two methods, with higher values in enzymatic extracts (1.91 mmol of Fe2+ per 100 g of fresh sample). Analyses of apple samples with and without skin also revealed important differences related to methodology and composition. Additionally, the original enzymatic extraction method was improved to avoid interferences caused by the presence of protein residues in the extract

Development of Active Polyvinyl Alcohol/beta-Cyclodextrin Composites To Scavenge Undesirable Food Components

[EN] Active food packaging systems based on the incorporation of agents into polymeric package walls are being designed to purposely release or retain compounds to maintain or even increase food quality. The objective of this work was to develop polyvinyl alcohol (PVOH)/ß-cyclodextrin (ßCD) composite films that can be applied to reduce undesirable component content such as cholesterol in foods through active retention of the compounds in the package walls during storage. Cyclodextrins were added to PVOH in a proportion of 1:1 and cross-linked with glyoxal under acidic media to reduce its water-soluble character. Three different cross-linking procedures were used: cross-linking of the polymer/polysaccharide mixture in solution and film casting, PVOH. ßCD*; cross-linking of the polymer, addition of ßCD, and casting of the mixture, PVOH*.CD; and casting of a PVOH film, addition of a ßCD/glyoxal solution onto the film, and cross-linking during drying, PVOH.CD*. Characterization studies showed that the PVOH*.CD and PVOH.CD* films provided the best physical characteristics with the lowest release values and the highest barrier properties. As a potential application, materials were tested as potential cholesterol-scavenging films. There was a significant reduction in the cholesterol concentration in milk samples when they were exposed to the materials developed.We acknowledge the financial support of the Spanish Ministry of Science and Innovation, Projects AGL2006-02176, AGL2009-08776, and Fun-C-Food CSD2007-00063, and the C.L.-d.-D.fellowship (FPU program).López De Dicastillo Bergamo, AC.; Jordá, M.; Catala Moragrega, R.; Gavara Clemente, R.; Hernandez-Munoz, P. (2011). Development of Active Polyvinyl Alcohol/beta-Cyclodextrin Composites To Scavenge Undesirable Food Components. Journal of Agricultural and Food Chemistry. 59(20):11026-11033. https://doi.org/10.1021/jf200749fS1102611033592