Farayde Matta Fakhouri

Comparative study of processing methods for starch/gelatin films

In this work, the influence of processing methods on the properties of starch/gelatin films plasticized with glycerol and sorbitol is reported. Four different processing techniques: casting; pressing; pressing followed by blowing and extrusion followed by blowing were evaluated. Bioplastics prepared by casting were homogeneous and transparent with lower opacity and water vapor permeability (WVP) values when compared to films prepared by other techniques. Among the cast films studied, those with 3% lipophilic starch, in 1:1 proportions and plasticized with sorbitol, showed lower WVP values and higher tensile strength (TS). Films obtained by pressing and blowing showed little expansion during blow, had cracks in the surface, low TS and higher WVP. These films were the only samples to show crystallinity as determined by thermal analysis and X-ray diffraction. In conclusion, different processing techniques have significantly affected the properties of these films.

Filmes e coberturas comestíveis compostas à base de amidos nativos e gelatina na conservação e aceitação sensorial de uvas Crimson

Films based on gelatin and native starches from wheat, sorghum, potato and rice were produced separately and characterized as to their physical-chemical (water solubility and water vapor permeability), physical (thickness and opacity) and mechanical (resistance to traction and percentage elongation at rupture) properties. The same solutions were prepared and applied to Crimson grapes for sensory evaluation and determination of weight loss over 22 days. The sorghum and rice coatings were the most efficient in their extending shelf life (a ten day increase). However, with respect to sensory attributes, the grapes with the rice coating did not show a statistical difference when compared to the control, which presented the lowest scores for global appearance purchase. The sorghum coating presented a water vapor permeability of 5.40 g.mm.m-2.d.kPa, resistance to traction of 85.89 MPa, stretching of 6.61% and opacity of 40%. This film did not present the best characterization values, but was the best coating option. In the sensory evaluation, the coated grapes had a better or similar acceptance, when compared to the control, as to global appearance, shine, color and purchase. With respect to the eating characteristics of the grapes, none of the coatings significantly influenced aroma, flavor and texture, and were accepted by the consumers in every parameter.

Desenvolvimento de massa alimentícia fresca funcional com a adição de isolado protéico de soja e polidextrose utilizando páprica como corante

The trend of the current consumer is to use foods that are easy to prepare and that besides having nutritional quality provide health benefits. In this work, fresh food with functional characteristics was developed incorporating Soy Protein Isolate (SPI) and polidextrose using paprika as the coloring agent. The consumption of IPS could contribute to decrease cholesterol levels while polidextrose, acting as a fiber, could promote the reduction of risk of colon cancer. The optimization of the formulation was carried out using a 23 complete factorial design considering independent variables the following contents: i) SPI; ii) polidextrose; and iii) paprika. The effects of these variables on the quality of the food were evaluated through physical-chemical characteristics (color and cooking test), instrumental texture, and sensory analysis. Regarding the physical parameters, instrumental color of the raw pasta was affected only by the addition of paprika. The parameters cooking time (2.5 minutes), increase in mass (1.40 to 1.64%), and loss of solids (3.80 to 5.56%) were not influenced by the ingredients used. Elasticity (instrumental texture parameter) was reduced with the increase of polidextrose. Regarding sensory analysis of the raw food, an increase in the addition of SPI and a reduction in the addition of polidextrose positively affected global acceptance and purchase intention. An increases in SPI and paprika increased color acceptance. Regarding sensory analysis of the cooked food, SPI had a positive effect on texture while polidextrose and paprika negatively affected this parameter. Nevertheless, the ingredients used did not influence purchase intention of the cooked food. The ideal percentages of polidextrose, soy protein isolate, and paprika were 3.5, 8.0, and 1.5%, respectively.

Caracterização físico-química de filmes comestíveis de amido adicionado de acerola (Malphigia emarginata D.C.)

Edibles films are an alternative to synthetic materials used for packing food products. Barbados cherry is rich in vitamin C and carotenoids. The aim of this study was to characterize and develop films by casting from cassava starch, lyophilized Barbados cherry pulp and glycerol. The films were characterized with respect to thickness, water vapor permeability (WVP), water solubility, vitamin C, carotene and mechanical properties. The interaction of pulp and glycerol reduced film thickness. An increase in pulp concentration up to 60% increased WVP but beyond this concentration reduced both WVP and solubility leading to an increased level of vitamin C and β carotene in the films.

Utilização de coberturas comestíveis para redução de absorção de gordura em produtos estruturados pré-fritos congelados de mandioca

Este estudo objetivou avaliar o efeito de coberturas comestiveis como barreira a incorporacao de oleo durante o processo de fritura em produtos estruturados pre-fritos congelados, produzidos com raiz de mandioca. Foram utilizados tres diferentes hidrocoloides em seis formulacoes de coberturas, sendo tres coberturas compostas por pectina e proteina de soro de leite, e outras tres compostas por hidroxipropil-metil celulose e proteina de soro de leite nas proporcoes de 1:4, 1:1 e 4:1, respectivamente. Foram tambem produzidos filmes nas mesmas relacoes utilizadas para as coberturas e, nestes filmes, foram avaliadas a permeabilidade ao vapor de agua, a solubilidade em agua e a espessura, alem das propriedades mecânicas (resistencia a tracao e elongacao). Nos produtos de mandioca, foram avaliados os teores de umidade e lipidios, cor e textura instrumental, e atributos sensoriais. A concentracao de proteina de soro de leite influenciou as propriedades dos filmes, provocando diminuicao da solubilidade, aumento da espessura, aumento no valor da permeabilidade para os filmes compostos de pectina e reducao significativa para os filmes compostos de hidroxopropil-metil celulose e proteina de soro de leite. As coberturas a base de hidroxipropil-metil celulose proporcionaram maiores teores de umidade e menores teores de lipidios nos produtos de mandioca, sendo que a combinacao de 1:4 proporcionou uma reducao de 32,3% no teor de absorcao de lipidios. A cobertura de hidroxipropil-metil celulose na combinacao de 1:4 proporcionou ao produto maior crocância, alem de coloracao dourada, desejavel neste tipo de produto. Sensorialmente, os produtos apresentaram diferencas estatisticas somente em relacao aos atributos textura e crocância. A partir destes resultados, pode-se concluir entao que esta interacao, hidroxipropil-metil celulose e proteina de soro de leite na proporcao 1:4, quando aplicada em produtos estruturados de mandioca pre-fritos congelados, proporciona menor retencao de lipidios, alem de crocância e textura interna adequadas.

Effect of incorporation of blackberry particles on the physicochemical properties of edible films of arrowroot starch

ABSTRACT This research work evaluated the physicochemical properties of arrowroot starch films plasticized with glycerol and incorporated directly and by sprinkling with 0, 20, 30, and 40% (blackberry solids mass/biopolymer mass) blackberry particles obtained by spray drying. The films were characterized by thickness, color, water activity, moisture content, water solubility, water vapor permeability, mechanical properties, anthocyanins content, and antioxidant properties. Films incorporated with blackberry particles showed an increase in thickness, water solubility, water vapor permeability, and elongation at break as well as decrease tensile strength compared to the control film. The incorporation of blackberry particles to films transferred bioactive compounds and antioxidant capacity, as well as color to resulting films.

Bioactive films of arrowroot starch and blackberry pulp: Physical, mechanical and barrier properties and stability to pH and sterilization

The influence of the incorporation of blackberry pulp on properties of arrowroot starch films has been studied. The blackberry pulp transferred bioactive compounds, antioxidant capacity and color to arrowroot starch films. Increasing the concentration of blackberry pulp (from 0 to 40%, mass/mass of dry starch) in the film resulted in increased thickness (from 0.065 to 0.133 mm), increased elongation (from 3.18 to 13.59%), decreased tensile strength (from 22.71 to 3.97 MPa), increased water vapor permeability (from 3.62 to 4.60 g.mm/m2.day.kPa) and solubility in water (from 14.18 to 25.46%). The films were stable to different media, maintaining the same initial diameter dimensions after immersion in acidic, neutral and alkaline solutions, but their color intensity was reduced, probably due to the release of anthocyanins to the solutions. The films with blackberry pulp presented darkness after sterilization process.

Development of Multilayer Films Obtained From Epoxidized Methyl Esters, Polyhydroxyalkanoates and Their Combinations

The aim of this work was the production and characterization of films prepared from starch, gelatin and methyl esters of epoxidized macauba (Acrocomia aculeata), corn (Zea mays), pacu (Piaractus mesopotamicus), pintado (Pseudoplatystoma corruscans) and soybean (Glycine max) and also multilayer films of polyhydroxyalkanoates (PHA) conjugated with two of the epoxides that presented the best results in characterizations. The two types of films EEF (Epoxidized esters films) and EEFPHA (Epoxidized esters and PHA conjugated films) were both characterized for their visual aspects, solubility in water and acid, width, color, opacity, water vapor permeability, tensile strength and elongation. EEFPHA were also characterized by differential scanning calorimetry, scanning electron microscopy and X-ray diffraction analyses. The epoxidation reaction was successfully carried out; with the GC-MS analysis indicating the formation of epoxidized esters derived from linoleic and oleic acids. The addition of the epoxidized esters to the EEF films caused an increase in film thickness, opacity, solubility in water, tensile strength and elongation, while the solubility in acid presented the same value as compared to the blank sample. In the EEFPHA samples, addition of filmogenic solution of epoxidized esters from corn and macauba presented a value exceeding the standard in the thickness, opacity, water solubility, water vapor permeability and tensile strength analyses. In the analysis of solubility in acid these samples showed results below the standard, and the elongation test showed values very close. DSC, SEM and XRD results showed that there was a polymeric incorporation between the starch and the PHA.

Microencapsulation of blackberry pulp with arrowroot starch and gum arabic mixture by spray drying

Abstract This research work aimed to obtain blackberry pulp powder by spray drying and, by an experimental design, evaluated the effect of inlet air temperature (100–150 °C) and blackberry pulp solids:arrowroot starch/gum arabic solids ratio of 1:0.5–1:2 on the physicochemical properties of the powders. Arrowroot starch and gum arabic present glass transition temperature (Tg) values above 100 °C; hence it was possible to employ them as carriers in blackberry pulp spray drying in order to increase Tg of the system. Powder yield and solubility increased with increasing blackberry pulp solids:arrowroot starch/gum arabic solids ratio of 1:0.5–1:2, whereas hygroscopicity decreased. Yield, solubility and hygroscopicity of the powders increased and water activity decreased, with increasing inlet air temperature. The powders presented low moisture content and water activity. Temperature of 143 °C and blackberry pulp solids:arrowroot starch/gum arabic solids ratio of 1:1.78 were the optimal conditions to obtain high yield and blackberry powders that are soluble in water and less hygroscopic.AbstractThis research work aimed to obtain blackberry pulp powder by spray drying and, by an experimental design, evaluated the effect of inlet air temperature (100–150 °C) and blackberry pulp solids:arrowroot starch/gum arabic solids ratio of 1:0.5–1:2 on the physicochemical properties of the powders. Arrowroot starch and gum arabic present glass transition temperature (Tg) values above 100 °C; hence it was possible to employ them as carriers in blackberry pulp spray drying in order to increase Tg of the system. Powder yield and solubility increased with increasing blackberry pulp solids:arrowroot starch/gum arabic solids ratio of 1:0.5–1:2, whereas hygroscopicity decreased. Yield, solubility and hygroscopicity of the powders increased and water activity decreased, with increasing inlet air temperature. The powders presented low moisture content and water activity. Temperature of 143 °C and blackberry pulp solids:arrowroot starch/gum arabic solids ratio of 1:1.78 were the optimal conditions to obtain hig...

Chapter 9 – Cellulose Nanocrystals Functionalization by Grafting

Abstract In recent years, the environmental concern has directed the research, through the modification of natural polymers such as cellulose to increase their functionality and consequently their use. Cellulose nanocrystals (CNC) can be obtained by means of acid hydrolysis, isolated from cellulosic structures. In comparison with cellulose fibers, CNC exhibit higher elastic modulus and also changes in optical, electrical, and magnetic properties. Moreover, CNC can be modified through grafting to acquire different properties, such as antimicrobial activity, which is extremely important in combating the existence and dissemination of resistant microorganisms. In this chapter, some graft modifications applied to CNC are described.