Tomy J. Gutiérrez

Eco-friendly films prepared from plantain flour/PCL blends under reactive extrusion conditions using zirconium octanoate as a catalyst

Plantain flour (Musa ssp., group AAB, sub-group clone Harton)/poly(ε-caprolactone) (PCL) blends, containing glycerol as a plasticizer, were prepared by reactive extrusion (REx) in a twin-screw extruder using zirconium octanoate (Zr(Oct)4) as a catalyst, followed by thermo-compression molding for film development. The films were then characterized in terms of their: infrared (FTIR) spectra, water solubility, thermogravimetric (TGA) curves, differential scanning calorimetry (DSC) thermograms, and X-ray diffraction (XDR) diffractograms, as well as their microstructural, mechanical and antimicrobial properties in order to (1) compare the effects of PCLs with two different molecular weights (Mw) on the characteristics of the plantain flour/PCL blends, and (2) determine whether using Zr(Oct)4 in the production of active composite polymer materials improves their properties. The plantain flour/PCL blends were all developed successfully. The higher Mw PCL gave more hydrophobic and thermally stable films with improved mechanical properties. The addition of the Zr(Oct)4 catalyst to the plantain flour/PCL blends also resulted in films with similar characteristics to those described above, due to the cross-linking of the polymers. In addition, the films containing the catalyst showed antimicrobial activity against Escherichia coli O157:H7 and Staphylococcus aureus indicating a dual effect of Zr(Oct)4, and making it an attractive alternative for the development of active films.

Structural properties and in vitro digestibility of edible and pH-sensitive films made from guinea arrowroot starch and wastes from wine manufacture

A non-conventional starch obtained from guinea arrowroot tubers (Calathea allouia) grown in the Amazon was used as a polymeric matrix for the development of edible films. The films were manufactured by blending/thermo molding and plasticized with glycerol. Agro-industrial wastes from wine manufacture (grape waste flour and grape waste extract) were used as natural fillers of the thermoplastic starch (TPS) matrices. The results showed that the natural fillers caused cross-linking in the TPS matrix. This led to the production of films with higher resistant starch (RS) content, especially RS type 4 (RS4), although the DSC results showed that the films developed also contained RS type 3 (RS3). As expected, the presence of RS reduced the in vitro digestibility rate. Films made with the natural fillers were also less hydrophilic, had a greater thermal resistance, and tended towards ductile mechanical behavior. Finally, the edible film containing grape waste flour as a natural filler proved to be pH-sensitive, although this material disintegrated under alkaline conditions.

Data on physicochemical properties of active films derived from plantain flour/PCL blends developed under reactive extrusion conditions

The data given below relates to the research paper entitled: “Eco-friendly films prepared from plantain flour/PCL blends under reactive extrusion conditions using zirconium octanoate as a catalyst”, recently published by our research group [1]. This article provides information concerning the physicochemical properties of the above-mentioned film systems: thickness, density, opacity, moisture content and surface moisture.

Bionanocomposite Films Prepared from Corn Starch With and Without Nanopackaged Jamaica ( Hibiscus sabdariffa ) Flower Extract

Active and pH-sensitive nano-fillers were prepared from natural and modified montmorillonite (Mnt) and nanopackaged with anthocyanins extracted from the Jamaica (Hibiscus sabdariffa) flower. These were then used to reinforce corn (Zea mays) starch-based films plasticized with glycerol, and processed by extrusion and thermo-molding. Seven film systems were investigated for their potential as “active and intelligent” (A&I) bionanocomposite films with improved properties. The thermal and mechanical properties of the bionanocomposite films obtained were enhanced largely due to the added modified clay nano-fillers, and the nanopackaging of the anthocyanins between the nano-clay layers. Unfortunately, however, the bionanocomposite films failed as A&I materials, despite the supposed effect of the nano-clays as protective nano-encapsulating materials for the active and pH-sensitive compound (anthocyanins). The results obtained suggest that the exfoliation of the nano-fillers as a consequence of the shear forces inside the extruder led to the exposure of the anthocyanins during extrusion. Because of this, we consider the large-scale development of A&I biodegradable films incorporating natural pigments very unlikely being processed by extrusion/thermo-molding, since there are several significant processes involved in the techniques currently available in the food and polymer industries that leave the active and pH-sensitive compounds unprotected.

Plantain flours as potential raw materials for the development of gluten-free functional foods

Plantain flour (Musa ssp., group AAB, sub-group clone Harton) was modified by acetylation, carboxymethylation, methylation, oxidation and phosphation, in order to determine which of these modifications produce a material with potential for the development of gluten-free products with improved nutritional properties. The structural, rheological and nutritional properties of the modified flours were investigated. The phosphated plantain flour, cross-linked with sodium trimetaphosphate (STMP), had a lower in vitro digestibility rate associated with resistant starch (RS) types RS2, RS4 and RS5. This latter was confirmed by the formation of the amylose-lipid complex as determined by XRD. All the flours tested had a C-type structure with the exception of the methylated plantain flour which produced a large quantity of reaction by-product (BaSO4). The phosphated plantain flour represents a raw material with great potential for the development of gluten-free food (bread and cookie) with functional properties, i.e. health benefits.

Polymers for Food Applications: News

Polymers usually are found every day in a myriad of applications, but special importance has the polymers for food applications. In particular, edible polymers are of great importance for human subsistence. Edible polymers from the nutritional point of view have been classified as carbohydrates, proteins, fiber and lipids, i.e. they are considered as macronutrients. The study of edible polymers still booming because of the great demand for healthier and more convenient foods, as well as the development of new food products with better sensory properties, which may have a prolonged shelf life. Many edible polymers being modified have allowed the development of functional or medical foods. Obtaining new products from modified edible polymers has also led to the manufacture of more stable foods, and even that can be administered to people with special dietary regimens such as celiac, phenylketonuric, diabetic, lactose intolerant, among others. The edible polymers have had a positive impact on different sectors of the food industry, from food packaging to the detection of toxic food substances. The edible polymers in essence lead to the production of edible films and membranes, foamed foods, snack, micro- and nanoencapsulated, hydrogels, prebiotics and oligomers, as well as food colloids and emulsions. More recently, edible polymers have also given way to the development of printed and electrospinned foods. This chapter aims to be preamble to the study and analysis of polymers for food applications that will be addressed in the course of this book, which has the contribution of important researchers with extensive experience, which in some cases are editors of major international journals in the field of food science and technology.

Composite Foams Made from Biodegradable Polymers for Food Packaging Applications

Polymeric foams are cell structures (porous microstructures) that have been frequently made from synthetic polymers for use in the development of food packaging. Due to the problems concerning the environmental impact caused by polymers from the petrochemical industry, the foams have been more recently studied from biodegradable polymers. However, the polymer materials obtained are usually susceptible to moisture, thus conditioning the collapse of the porous structure of the material. As an alternative, the composite foams have been investigated from nanofillers such as clays, cellulose, nanoparticles, among others. This chapter aims to analyze the recent advances in the studies of composite foams.

Biological Macromolecule Composite Films Made from Sagu Starch and Flour/Poly(ε-Caprolactone) Blends Processed by Blending/Thermo Molding

Non-conventional starch sources (starch and flour) obtained from sagu (Canna edulis Kerr) rhizomes grown in the Venezuelan Amazon were used as biological macromolecule matrices. Biological macromolecule composite films prepared from sagu starch and flour/poly(ε-caprolactone) (PCL) blends were then obtained by blending/thermo molding. The use of flours as a rich source of starch has attracted much attention as they are cheaper than starch, thus making them commercially more competitive. The PCL-containing films proved to be less stable in an alkaline medium and less dense (0.60–0.66xa0g/cm3), and were also thinner (1.15–1.17xa0mm), rougher, more crystalline (20.5–27.1%) and opaque (1.45–1.52) than the films without added PCL. Films made from the flour/PCL blend showed a greater phase separation than the starch/PCL films. The use of flour as a starchy source is interesting. However, the results of attenuated total reflectance Fourier transform infrared spectroscopy and water activity suggest that the films prepared from sagu starch-glycerol had stronger hydrogen bonding interactions than those made from flour-glycerol. This led to the sagu starch-based film being less susceptible to moisture and more stable under alkaline conditions.