Recent advances and perspectives on starch nanocomposites for packaging applications

Starch nanocomposites are popular and abundant materials in packaging sectors. The aim of this work is to review some of the most popular starch nanocomposite systems that have been used nowadays. Due to a wide range of applicable reinforcements, nanocomposite systems are investigated based on nanofiller type such as nanoclays, polysaccharides and carbonaceous nanofillers. Furthermore, the structures of starch and material preparation methods for their nanocomposites are also mentioned in this review. It is clearly presented that mechanical, thermal and barrier properties of plasticised starch can be improved with well-dispersed nanofillers in starch nanocomposites

Genotoxicity evaluation of carvacrol in rats using a combined micronucleus and comet assay

11 páginas.-- 6 figuras.-- 1 tabla.-- referenciasGenotoxic data of substances which could be incorporated into food packaging are required by the European Food Safety Authority. Due to its antioxidant and antibacterial properties carvacrol is one of these compounds. This work aims to study for the first time the in vivo genotoxic effects produced in rats orally exposed to 81, 256 or 810 mg cavacrol/kg body weight (bw) at 0, 24 and 45 h. A combination of the micronucleus assay (OECD 474) in bone marrow and the standard (OECD 489) and enzyme-modified comet assay was used to determine the genotoxicity on cells isolated from stomach and liver of exposed animals. In addition, a histopathological study was performed on the assayed tissues, and also in the lungs due to the volatility of carvacrol. Direct analytical pyrolysis was used to search for carvacrol in viscera and to ensure that the compound reaches stomach and liver cells. Results from MN-comet assay revealed that carvacrol (81-810 mg/kg bw) did not induce in vivo genotoxicity or oxidative DNA damage in any of the tissues investigated. Moreover, no histopathological changes were observed. Altogether, these results suggest lack of genotoxicity of carvacrol and therefore its good profile for its potential application as food preservative.The authors wish to thank the Spanish Ministry of Science and Innovation (AGL2012-38357-C02-01) co-financed by FEDER funds and Junta de Andalucía (AGR-7252) for the financial support for this study, the Microscopy Service of CITIUS and the animal housing from the Faculty of Pharmacy in the Universidad de Sevilla. María Llana-Ruiz-Cabello also gratefully acknowledges Junta de Andalucía for her predoctoral grant associated to the AGR7252 project.Peer Reviewe

Effect of an active bio-package extruded with oregano essential oil in lettuce nutrient profile

Due to its bioactive properties, oregano essential oil (OEO) is being included in new food packaging materials. However, due to essential oils (EOs) high volatility, ageing and conditions of films preparation may cause losses and diminish the activity, Analytical pyrolysis (Py-GC/MS) is a tool providing fingerprinting and precise information about composition, quality and additives in active packages made with biogenic polymers, In a previous work, we used Py-GC/MS combined with d13C analysis to ensure that no appreciable EO losses occurred when our polylactic acid (PLA) polybutylene succinate (PBS) (95:5) films containing OEO were developed. We confirmed that the OEO remained in adequate quantities and bioactive after the extrusion process. In a subsequent study, the effect of this bio-package in lettuce shelf life and its effect in the chemical composition of the food that contains was evaluated, and specifically in the conservation of specific compounds with dietetic value. In this work we describe a detailed Py-GC/MS study performed to detect changes in the relative contents of polyunsaturated fatty acids (PUFAs) and phytosterols in iceberg lettuce after 1, 4 and 8 days packaged in PLAlPBS (95:5) films containing different quantities of OEO (O , 2, 5 and 10%). Our results indicate that films containing any quantity of OEO, used in packages with a proportion of 5.5 9 of film/kg lettuce, allow maintaining the profile of lettuce PUFAs and phytosterols during the shelf life of the packed food.Projects AGL2012-38357-C02-01 and CGL2012-38655-C04-01, cofinanced by FEDER. María Llana-Ruiz-Cabello acknowledges Junta de Andalucia predoctoral grant associated to AGR7252 project.Peer Reviewe

Dissimilar tendencies of innovative green clay organo-modifier on the final properties of poly(ε-caprolactone) based nanocomposites

Composites based on poly(ε-caprolactone) (PCL) were prepared by melt blending the polymer with natural and modified bentonite. Soy lecithin (SL), a natural and nontoxic biosurfactant, was used as modifier agent. Three organoclays with different SL contents were employed as fillers and composites containing 1 and 2 wt% of each clay, were prepared. Thermal (by thermogravimetric analysis, and differential scanning calorimetry), morphological (by X-ray diffraction (XRD) and melt rheology), mechanical (by tensile tests) and barrier properties (by means of water vapor permeability tests) of matrix and composites were studied as a function of clay type and content. Morphological analysis by XRD showed nanocomposites with intercalated-exfoliated structures while melt rheology suggests thermal degradation of PCL matrix catalyzed by SL bentonite modifier. Thermal and mechanical properties were consistent with this assumption, due to the slight increment in crystallinity percentage and detriment in the Young?s modulus of the nanocomposites in comparison with the neat matrix. On the other hand, water vapor permeability of PCL significantly decreased in composites, as is expected for polymer/clay nanocomposites, favoring its potential application as food packaging. Thus, dissimilar tendencies were found in the final properties of the nanocomposites that were attributed to the matrix molecular weight degradation catalyzed by the novel green clay organo-modifier.Fil: Merino, Danila. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Ludueña, Leandro Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Alvarez, Vera Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin