Flexible and biodegradable bioplstics based on starch and gelatin

Orientadores: Fernanda Paula Collares Queiroz, Lucia Helena Innocentini MeiTese (doutorado) - Universidade Estadual dse Campinas, Faculdade de Engenharia de AlimentosResumo: O objetivo deste trabalho foi desenvolver um bioplástico flexível, biodegradável e comestível, à base de polímeros naturais de fontes renováveis (amido e gelatina) por processo de extrusão termoplástica seguido de sopro. Inicialmente, foi realizada a caracterização física e funcional de biofilmes à base de amido e gelatina elaborados pela técnica de solução (casting), visando a escolha das melhores formulações para serem utilizadas na produção destes bioplásticos por processo de extrusão e sopro. As soluções filmogênicas de amido de mandioca (nativo e modificado) e milho (nativo, ceroso, ceroso modificado e lipofílico) foram preparadas nas concentrações de 3 e 5% e a de gelatina, na concentração de 10%. Os biofilmes compostos de gelatina e amido (de mandioca ou de milho) foram elaborados nas proporções 4:1, 1:1 e 1:4, plastificadas com sorbitol ou glicerol, sendo 5% para as soluções de gelatina e 10% para as soluções de amido. Todos os biofilmes formados foram visualmente transparentes. A adição de gelatina provocou um aumento na espessura, na permeabilidade ao vapor de água (PVA) e na resistência à tração (RT), provocando também uma diminuição na opacidade dos mesmos. Posteriormente, diferentes ácidos graxos (palmítico, mirístico, cáprico, capróico e caprílico), nas concentrações de 5, 15, 25 e 50%, foram adicionados à mistura de amido lipofílico e gelatina. Esta adição causou, em geral, um aumento da opacidade, da espessura e da elongação, no entanto, ocorreu uma diminuição na RT e da PVA dos biofilmes formados. A melhor formulação de amido lipofílico, gelatina e plastificante (glicerol, sorbitol e ácido mirístico) foi utilizada para a produção de filmes por diferentes técnicas (prensados, prensados e soprados e extrudados). Bioplásticos prensados apresentaram menores valores de RT e maiores valores de solubilidade em água. Os filmes extrudados, obtidos nas mesmas concentrações de amido, gelatina e plastificante, apresentaram-se semi-rígidos, característica não desejável para o objetivo em questão. Com base nestes resultados, foram alteradas as concentrações dos componentes da mistura para permitir a obtenção de bioplásticos com propriedades adequadas pelo processo de extrusão termoplástica. Estes bioplásticos foram caracterizados quanto às propriedades físicas, fisico-químicas, morfológicas, mecânicas, de barreira e térmicas. Os bioplásticos elaborados foram flexíveis, apresentaram expansão durante o sopro e foram visualmente homogêneos, porém, os elaborados com sorbitol apresentaram-se quebradiços após o condicionamento. A adição de gelatina causou uma diminuição no valor de PVA, mas não influenciou a solubilidade em água nem a opacidade dos bioplásticos. A adição de lipídios ocasionou uma diminuição na RT dos bioplásticos, tanto no sentido transversal como no longitudinal em relação ao sentido de produção. Filmes compostos com 10 e 20% de gelatina, sem adição de ácido graxo apresentaram os menores valores de PVA e maiores valores de RTAbstract: The goal of this research was to develop a flexible, biodegradable and edible film using natural polymers (starch and gelatin) from renewable sources through a process of thermoplastic extrusion followed by blowing. The first step of the research consisted on a physical and functional characterization of starch and gelatin based biofilms produced using the casting technique. The purpose was to select the solutions to be used on the production of these biofilms by extrusion and blowing. The filmogenic solutions of manioc starch (native and modified) and corn (native, waxy, waxy modified and lipofilic) were prepared at concentrations of 3 and 5%. The filmogenic solution of gelatin was prepared at a concentration of 10%. The gelatin and (manioc and corn) starch based biofilms were prepared at ratios of 4:1; 1:1 and 1:4. They were plasticized with sorbitol or glycerol at 5% for the the gelatin solutions and 10% for the starch solutions. All the biofilms obtained were visually transparent. The addition of gelatin resulted in an increase of the film thickness, an increase of the water vapour permeability (WVP), an increase of the tensile strength (TS) and a decrease in the opacity. Different fatty acids (palmitic, miristic, capric, caproic and caprilic) were added to the lipofilic starch and gelatin solution at concentrations of 5, 15, 25 and 50%. These additions resulted in an increase on opacity, thickness and elongation. However, there was a decrease on WVP and TS. The best solution of lipofilic starch, gelatin and plasticizer (glycerol, sorbitol and miristic acid) was used in the production of films by different techniques (pressed, pressed and blowed and extruded). Pressed biofilms showed lower values of strain at break and higher values of water solubility. The extruded films, obtained at the same concentrations of starch, gelatin and plasticizer were found to be semi-rigid, a characteristic not aligned with the objective of theresearch. Based on the results of this first assessment, the concentrations of the components were adjusted with the purpose of obtaining extruded films with the desired properties. The resulting biofilms were characterized for their physical, physico-chemical, morphology, mechanical, barrier and thermical properties. Biofilms in general were flexible, showed expansion during blowing and were visually homogeneous. However, biofilms prepared with sorbitol were cracking very easily after storage. The addition of gelatin resulted in a reduction of the WVP but did not have any influence on the water solubility nor on the opacity of the biofilms. The addition of lipids resulted in a reduction of the TS of the biofilms both in longitudinal and transversal directions. Biofilms with 10 and 20% of gelatin and no fatty acid added showed lower values of WVP and higher values of TSDoutoradoDoutor em Tecnologia de Alimento

Effect of edible coatings on the shelf life of in natura guava (Psidium guajava L.) stored under refrigeration

Coberturas filmogênicas produzidas com gelatina, triacetina e ácido láurico foram aplicadas sobre goiabas brancas no estádio “verde maturo”. As frutas foram estocadas sob refrigeração, a 12°C, durante vinte dias, juntamente com frutas controle. Características físico-químicas indicadoras do amadurecimento incluindo pH, acidez titulável, o Brix, açúcares totais e redutores, dureza, cor e perda de massa foram medidas em intervalos de quatro dias. A avaliação da vida útil através de análise sensorial, incluindo aparência global, brilho, cor e intenção de compra, com a mesma periodicidade de retirada de amostras foi também efetuada. Análises sensoriais específicas para o sabor, aroma, textura e intenção de compra foram feitas após 9 dias de estocagem. As coberturas se mostraram efetivas na extensão da vida útil das goiabas em relação às frutas in natura sem cobertura, sendo bem aceitas pelos consumidores durante todo o período de duração do experimento e também para as análises sensoriais específicas. Entre as coberturas, a mistura de gelatina e triacetina mostrou-se a melhor, tanto sensorialmente quanto nas características físico-químicas estudadas. A incorporação de brilho, devido à adição das coberturas, teve um efeito favorável na aparência das amostras. Coberturas contendo ácido láurico, apesar de apresentarem aspectos positivos, influenciaram o sabor típico das goiabas. Entretanto, a lavagem das goiabas antes da degustação se mostrou suficiente para remover a presença de sabor estranho nas frutasPostprint (published version

Blackberry pulp microencapsulation with arrowroot starch and gum arabic mixture by spray drying and freeze drying

The objective of this research work was to obtain blackberry pulp powder (BL, without encapsulating agent) and microencapsulated blackberry pulp (ML, with encapsulating agent :mixture of starch arrowroot and gum arabic (1:1)) obtained by freeze drying and spray drying and evaluate their physico- chemical properties. The yield of blackberry freeze drying process was higher than the value found for spray drying process. The presence of encapsulating agent and drying method used for producing the powders influenced the average particle size, diameter, hygroscopicity, solubility, wettability and anthocyanin content of the powdersPostprint (published version

Effect of incorporation of blackberry particles obtained by freeze drying on physicochemical properties of edible films

This research work aimed to evaluate the physicochemical properties of arrowroot starch films plasticized with glycerol and incorporated in film- forming solution directly (D) and by sprinkling (S) with 0%, 20%, 30%, 40% (mass blackberry solids / biopolymer mass) of blackberry pulp (BL) powder and freeze dried microencapsulated blackberry pulp (ML) using mixture of gum arabic and arrowroot starch (1: 1, mass / mass). Thickness, water solubility and water vapour permeability of the films significantly increased with increasing concentration of blackberry powder. Compared to arrowroot starch film (0%), the surface of films with BL and ML powder became irregular and roughPostprint (published version

Mechanical and moisture barrier properties of titanium dioxide nanoparticles and halloysite nanotubes reinforced polylactic acid (PLA)

Polylactic acid (PLA) has been larger used in biomedical field due to its low toxicity and biodegradability. The aim of this study was to produce PLLA nanocomposites, by melt extrusion, containing Halloysite nanotubes (HNT) and/or titanium dioxide (TiO2) nanoparticles. Immediately after drying, PLLA was mechanically homogenized with the nanofillers and then melt blended using a single screw extruder (L/D = 30) at a speed of 110 rpm, with three heating zones in which the following temperatures were maintained: 150, 150 and 160ºC (AX Plásticos model AX14 LD30). The film samples were obtained by compression molding in a press with a temperature profile of 235 ± 5ºC for 2.5 min, after pressing, films were cooled up to room temperature. The mechanical tests were performed according to ASTM D882-09 and the water vapor permeability (WVP) was measured according to ASTM E-96, in triplicate. The tensile properties indicated that the modulus was improved with increased TiO2 content up to 1g/100g PLLA. The Young's modulus (YM) of the PLA was increased from 3047 MPa to 3222 MPa with the addition of 1g TiO2/100g PLLA. The tensile strength (TS) of films increases with the TiO2 content. In both cases, the YM and TS are achieved at the 1% content of TiO2 and is due to the reinforcing effect of nanoparticles. Pristine PLA showed a strain at break (SB) of 3.56%, while the SB of nanocomposites were significant lower, for instance the SB of composite containing 7.5 g HNT/100g PLLA was around 1.90 %. The WVP of samples was increased by increasing the nano filler content. It should be expected that an increase of nanofiller content would decrease the mass transfer of water molecules throughout the samples due to the increase in the way water molecules will have to cross to permeate the material. However, this was not observed. Therefore, this result can be explained considering the molecular structure of both fillers, which contain several hydroxyl groups in the surface, making the end material more hydrophilicPostprint (published version

Use of rice on the development of plant-based milk with antioxidant properties: from raw material to residue

Given the consumer demand for new, savory products without allergenic impact on people, this work aimed to study the behavior of different rice types (white, red and black) during its hydration and development of plant-based milks. Verification of the pasteurization and sterilization on product's nutritional, chemical and physical characteristics was also conducted. Hydration kinetics of rice grains was carried out and the Peleg model was adjusted satisfactorily. Milk solutions submitted to sterilization showed solid texture, invalidating this treatment for the production of plant-based milks. Rice's, milks and residues were characterized. Products have shown high nutritional value, varying depending on the rice type. Not only phenolic compounds content (77.03 mg GAE/100 g), but also antioxidant activity (21.30 g/g DPPH• and 10.35 µM trolox/g in ABTS•+), were higher in products made from black rice. Furthermore, it was observed that the residues are suitable to be added in the enrichment of new food productsThis study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES – Finance code 001), and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq – 141413/2019–0). The author Farayde Matta Fakhouri is a Serra Hunter FellowPostprint (published version

Bioactive films based on starch from white, red, and black rice to food application

Packages from renewable sources have been the focus of many studies, due to the consumer needs for high-quality food, environmental concern related to the inadequate discard of packaging, low percentage of packaging recycling, and starch application by a viable method. Thus, this work aimed to develop bioactive packages based on white, red, and black rice starch and analyze the influence of macromolecule and plasticizer type, even its blends, on the characteristics of films. Films were characterized by color, opacity, thickness, water solubility, water vapor permeability, and bioactive properties. The use of rice starch in the development of edible and/or biodegradable films was feasible, with all the formulations tested presenting a homogeneous matrix and the films obtained varying in hue, to the naked eye, as a function of the starch used. Variation of the type of starch and plasticizer, as well as the concentrations of the same, resulted in films with differences in all studied properties. Films prepared with 5% of starch and 30% of sorbitol showed phenolic compounds and antioxidant capacity, using the DPPH and ABTS methods, indicating that these can be considered bioactive packages and also suitable for food application​This research was funded by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES—Finance code 001), and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq—141413/2019-0) ​Postprint (published version

Characterization of composite biofilms of wheat gluten and cellulose acetate phthalate

The objective of this research was to develop and characterize composite biofilms produced using wheat gluten and cellulose acetate phthalate. Biofilms act as barriers to moisture and oxygen diffusion through the film. The films were prepared with different thicknesses and component concentrations and were analyzed for water vapor and oxygen permeabilities, water and acid solubilities and mechanical properties. Results showed that the mixture improved film characteristics more than each of the individual components alone. The 1:1 mixture had properties of better permeability to water and oxygen. The composite films were completely soluble in water and acid, with the exception of the film with the highest gluten concentration, which was 50% soluble in water and acid. An increase in gluten concentration in the composite films resulted in a decrease in tensile strength. There was no significant difference in elongation at break between the composite films. No difference in thickness was detected either. Results showed that the mixture improved the characteristics more than of the individual components alonePostprint (published version

Development and characterization of multilayer films based on polyhydroxyalkanoates and hydrocolloids

New biodegradable polymeric materials have been developed in order to minimize the environmental impact caused bythe traditional packaging found in the market. Polyhydroxyalkanoates (PHAs) are biopolymers with important features such as biode-gradability and biocompatibility; however, the costs associated with PHAs production and the limited mechanical properties reducetheir application. Whey is a residual product from dairy industry and gelatin is a biopolymer with good processing characteristics. Inthis context, a filmogenic solution based on these two biopolymers was incorporated into pure PHA films to improve their optical,mechanical, and structural properties. The filmogenic solution was prepared from gelatin, cheese whey and PHAs, using glycerol asplasticizer agent. The multilayers films (gelatin concentrations at 3 and 5%, w/v) showed higher values for all properties when com-pared with the PHA standard film. In this sense, the addition of this solution was responsible for the improvement of the film prop-erties. The 5% gelatin multilayers films added of cheese whey and PHAs showed better results when compared with the multilayersfilms with gelatin at 3%. The film composed of gelatin 5% and cheese whey showed a water vapor permeability ranging from 0.45 gmm/m2/d/kPa, elongation of 2.18%, and opacity of 14.5%. However, the results of the morphological analysis showed that both filmspresented a homogeneous surface without cracks. Moreover, the results of the thermal analysis of both films indicate polymeric misci-bility. Thus, the choice of the best film will depend on its applicabilityPostprint (published version

Effect of applying edible films to in nature guavas (Psidium guajava). I. Development and characterization of edible films from gelatin, triacetin and fatty acids

Filmes de gelatina com a adição de triacetina e ácidos graxos, compostos e de dupla camada, foram produzidos e caracterizados quanto às propriedades de barreira ao vapor de água, ao oxigênio e mecânicas. Filmes simples de gelatina e triacetina apresentaram baixa permeabilidade ao vapor de água, ao oxigênio e alta resistência mecânica. A adição de ácido láurico à gelatina produziu filmes menos permeáveis ao vapor de água comparado àqueles com ácidos esteárico e palmítico. As análises das micrografias por microscopia eletrônica de varredura, mostraram o ácido láurico fortemente incorporado à matriz filmogênica. O aumento da concentração de ácidos provocou uma diminuição da resistência à tração e aumento da elongação. A partir das melhores concentrações dos ácidos e de triacetina foram produzidos filmes compostos e de dupla camada contendo gelatina, triacetina e ácido graxo. Os filmes compostos apresentaram melhores propriedades mecânicas e de barreira que os de dupla camada. Nas concentrações estudadas, a adição de ácidos graxos e de triacetina não comprometeu a transparência dos filmes de gelatinaPostprint (published version