Abstract Biomaterials developed with biopolymers contribute to the healing process of healthy or diabetic patients. The objective of the present study was to evaluate the effect of honey incorporation (0.3, 0.6, and 1.2 g/100 mL) in chitosan/collagen/glycerol composite films. The Ch/Coll/1.2H films revealed the greatest percentage of elongation (27.10%) and Young´s modulus (65.58 MPa). The barrier properties (WVTR and WVP) exhibited a significant increase when the honey was incorporated into the films. The absorption capacity, solubility, and enzymatic biodegradability were lower in films containing honey. The chemical interactions between the functional groups of the films were verified by FTIR. The morphology studied by SEM confirmed the mixture’s homogeneity. Finally, all formulations exhibited antibacterial properties against Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes, and Salmonella Typhimurium. The aforementioned properties of formulated dressings are suitable for their potential application in chronic wounds.

Abstract The papermaking potential of Opuntia ficus-indica (OFI) waste fibers was studied in this research. Alpha cellulose, lignin, hollocellulose, ethanol/benzene extractives and ash content were determined as 53.7±0.1%, 2.4±0.3%, 61.6±5.7%, 7.1±0.3% and 26.4±0.1%, respectively. The average fiber length, width, lumen, and cell wall thickness were found to be 1.1±0.3 mm, 18.8±6.1µm, 12.1±5.4 µm, and 4.3±1.0 µm. Soda pulping was conducted using 20 and 28% sodium hydroxide, cooking temperatures of 160 and 175 °C, cooking times of 60 and 120 min, and liquor- to fiber ratio of 9:1. Soda pulping with 28% sodium hydroxide, 175 °C and 120 min showed a lower Kappa number of 29.60±1.7 and a total yield of 32.2±1.6%. In general, tensile strength index (36.0±5.0 Nm/g), stretch (1.7±0.3%), breaking length (3.7±0.5 km), burst index (3.2±0.4 KPa.m2/g), tear index (7.3±0.0 mN.m2/g), folding endurance (166 times) and porosity (> 120 s) of OFI pulp were comparable with wood and non-wood pulps.

Resumen En esta investigación se estudió el potencial del uso de desechos de fibras de Opuntia ficus-indica (OFI) para elaborar papel. La estrategia metodológica que se siguió fue: caracterización de materia prima, análisis morfológico de las fibras, pulpeo soda mediante un diseño completamente al azar con un arreglo factorial 23, refinación de pulpa, formación y caracterización de hojas. El contenido de alfa-celulosa, lignina, holocelulosa, extractivos en etanol/benceno y cenizas fue de 53.7±0.1%, 2.4±0.3%, 61.6±5.7%, 7.1±0.3% y 26.4±0.1%, respectivamente. El promedio de la longitud de las fibras, ancho, lumen y espesor de la pared celular fue 1.1±0.3 mm, 18.8±6.1µm, 12.1±5.4 µm, 4.3±1.0 µm. Las condiciones de pulpeo fueron: 20 y 28% de hidróxido de sodio, 160 y 175 °C, durante 60 y 120 min y una relación licor/fibra de 9:1. El proceso de pulpeo con 28% de hidróxido de sodio, 175°C y 120 min mostró un menor número de Kappa (29.60±1.7) y un rendimiento total de 32.2±1.6%. En general el índice de tensión (36.0±5.0 Nm/g), deformación (1.7±0.3%), longitud de ruptura (3.7±0.5 km), índice de estallido (3.2±0.4 KPa.m2/g), índice de rasgado (7.3±0.0 mN.m2/g), resistencia al doblez (166 times) y porosidad (> 120 s) de la pulpa obtenida fueron comparables con valores reportados para pulpa de fibras maderables y no maderables.

Abstract The use of agroindustry waste is an option that benefits the environment. During the production of products with woven jute fibers (WJF) fragments are generated which do not have a specific use. In this work, we propose the use of WJF residues as a reinforcing material in laminates of polylactic acid (PLA) as an ecological and sustainable alternative to obtain low cost biodegradable biocomposites that can replace petroleum plastics. In order to improve the WJF and PLA compatibility, physicochemical treatments were used in fibers such as gamma irradiation (GI) and functionalization with maleic anhydride (MA). The results of PLA/WJF (MA) biocomposites revealed improvements in the mechanical and thermal properties compared to neat PLA; with an increase in elastic, flexural and storage modules of 48%, 6%, and 23%, respectively. This opens up the possible application of PLA/ WJF biocomposites in rigid containers, as well as the way to take advantage of other natural fibers used locally.

Resumen El aprovechamiento de residuos agroindustriales es una opción que beneficia al medio ambiente. Durante la elaboración de productos con fibras tejidas de yute (FTY) se generan fragmentos, los cuales no tienen un uso específico. En este trabajo, se propone la utilización de residuos de FTY como material de refuerzo en láminas de ácido poliláctico (PLA), como una alternativa ecológica y sustentable de obtener biocompuestos biodegradables a bajo costo que puedan sustituir a los plásticos provenientes del petróleo. Con el objetivo de mejorar la compatibilidad de las FTY y el PLA se utilizaron tratamientos fisicoquímicos en las fibras como la irradiación gamma (IG) y la funcionalización con anhídrido maleico (AM). Los resultados de los biocompuestos de PLA/ FTY (AM) revelaron mejoras en las propiedades mecánicas y térmicas comparadas con el PLA puro; con un incremento en los módulos elástico, de flexión y almacenamiento del 48%, 6% y 23 %, respectivamente. Esto entreabre la posible aplicación de los biocompuestos de PLA/FTY en envases rígidos, así como el camino para el aprovechamiento de otras fibras naturales usadas localmente.

Antecedentes: Uno de los principales objetivos del envasado de alimentos es protegerlo de factores que puedan afectar y causar una reducción en la calidad. El desarrollo de microorganismos en la superficie es uno de las causas principales del deterioro de los alimentos. Una opción es el empleo de envases con propiedades antimicrobianas. Objetivos: El objetivo del presente estudio fue evaluar el efecto de un envase antimicrobiano conteniendo eugenol en el desarrollo de Pseudomonas y bacterias mesofílicas aerobias (BMA) en piezas de pollo. Métodos: Tres lotes de película de polietileno de baja densidad (PEBD) conteniendo 0, 9.0 y 7.7 mg g-1 de eugenol (control, AAF1, AAF2, respectivamente) fueron obtenidas por extrusión-soplo utilizando un extrusor a nivel planta piloto. Se calculó la cinética de liberación del eugenol de la AAF1 hacia el aire a 5°C y 25°C. Se evaluó la capacidad antimicrobiana in vitro del eugenol sobre 10(8) UFC mL-1 de Pseudomona fluorescens utilizando discos de papel conteniendo 1.74, 0.87 y 0.36 mg de eugenol en agar Muller-Hinton. Las piezas de pollo fueron envueltas en la película AAF2 y almacenadas a 5°C evaluando a los 5 días el efecto de la película en el desarrollo de Pseudomonas y en BMA. Resultados: El eugenol mostró actividad antimicrobiana inhibiendo el crecimiento de P. fluorescens. Las películas conteniendo eugenol perdieron durante el proceso de extrusión 42.7% y 36.8% (AAF1 y AAF2 respectivamente) del total añadido mostrando un comportamiento fickiano con un coeficiente de difusión de 10-8 cm2 s-1. Las AAF2 mostraron un efecto moderado en la reducción del desarrollo de Pseudomonas (1.1 x 10(6) CFU g-1) comparadas con el control (6.0 x 10(6) CFU g-1) (P < 0.05). Las películas con eugenol (AAF2) fueron efectivas al reducir el desarrollo de las BMA (9.0 x 10(5) CFU g-1) comparadas con la película control (1.7 x 10(6) CFU g-1) (P < 0.05). Conclusiones: A pesar de las pérdidas del eugenol durante el proceso de extrusión para la obtención de las películas, estas mostraron un efecto antimicrobiano sobre las piezas de pollo. Por lo tanto, este estudio muestra el uso potencial del eugenol para la aplicación en envases antimicrobianos elaborados a base de PEBD.

Background: One of the aims of food packaging is to protect the product from environmental factors that can cause a reduction in quality. Surface growth of microorganism is one of the leading causes of food spoilage. One option is to use antimicrobial packaging to provide an increased margin of safety and quality. Objectives: The aim of this study was evaluate the effect of active packaging with eugenol on growth of Pseudomonas and aerobic mesophilic bacteria in fresh chicken pieces. Methods: Three batches of low-density polyethylene (LDPE) film, containing 0, 9.0 and 7.7, mg g-1 eugenol (control, AAF1 and AAF2, respectively), were extruded in a pilot-plant scale blown-extrusion machine. The films with eugenol lost 42.7% and 36.8% (AAF1 and AAF2, respectively) of eugenol during processing and absorbed UV-visible light at 300-261 nm. The kinetics of eugenol release from the AAF1 into the air at 5°C and 25°C displayed Fick’s behavior, and a diffusion coefficient of 10-8 cm² s-1 was calculated. Results: Eugenol showed antimicrobial activity on in vitro, using paper discs with 1.74, 0.87 and 0.36 mg eugenol on 108 CFU mL-1 of Pseudomonas fluorescens in Muller-Hinton agar. Chicken thighs were wrapped in the AAF2 film, and the effects on the growth of Pseudomonas and aerobic mesophilic bacteria (AMB) were evaluated after storage for 5 d at 5°C. The AAF2 showed a moderately antimicrobial effect in reducing the growth of Pseudomonas (1.1 x 10(6) CFU g-1) relative to growth in the control film (6.0 x 10(6) CFU g-1) (P < 0.05). The film with eugenol was effective in reducing the growth of AMB (9.0 x 10(5) CFU g-1) relative to growth in the control film (1.7 x 10(6) CFU g-1) (P < 0.05). Conclusions: Despite the high losses of eugenol during the extrusion of the films, they showed an antimicrobial effect during contact with fresh chicken under commercial conditions. This study shows the potential use of eugenol for application in LDPE antimicrobial packaging film.

Fresh blue shrimp (Litopenaeus stylirostris) muscle was stored with antioxidants under different conditions: ANTIOX 2%, packed in bilayer film of polyamide-low density polyethylene film (PA-LDPE) with 2% α-tocopherol; ANTIOX 4%, packed in PA-LDPE film with 4% α-tocopherol; and ANTIOX-GLAZED, samples stored glazed with 2% α-tocopherol. Shrimps packed in PA-LDPE without α-tocopherol were used as CONTROL. All samples were stored at –20 °C for 120 days. As compared to the CONTROL, the shrimp stored with the antioxidant showed lower lipid oxidation (0.10-0.14 vs 1.58 mgMA/kg of muscle), lost less firmness and astaxanthin content. ANTIOX 2% and ANTIOX-GLAZED showed the lowest concentrations of formaldehyde (0.081-0.083 μM/g). There were no significant differences in color and sensory properties, but differences in the integrity of the muscle fibers were observed. The treatments with α-tocopherol maintained the shrimp muscle quality during frozen storage. However, no significant differences were found between these treatments.

Rancidity development during frozen storage (–20 °C) of sierra fish (Scomberomorus sierra) was studied. Fillets were packed in low-density polyethylene films with and without butylated hydroxytoluene added (BHT-LDPE and LDPE respectively). Fillets stored with no package were used as control. Special attention was given to the effect of previous ice storage (0, 3, 6, 9 and 15 days) on the quality of the frozen fish. Physical (pH and texture) and chemical (peroxide value, PV and thiobarbituric acid index, TBA-i) analyses were carried out. Lipid oxidation increased with ice storage time in fish muscle without film packing, being greater than the film packed muscle (with and without antioxidant). An effect of previous ice storage time was observed on the frozen product (in all treatments). However, fish muscle with film packing containing antioxidant showed less lipid deterioration. Under the conditions applied in this study, the plastic films with antioxidant prevented the lipids oxidation during the cold handling of the sierra muscle.