Daniel Weingart Barreto

Acetilação da fibra de bucha (Luffa cylindrica)

In this work the effect of a new chemical surface treatment on the structure and surface morphology of loofah fibers (Luffa cylindrica) was analyzed, using infrared spectroscopy and scanning electron microscopy. The chemical treatment is aimed at increasing loofah compatibility with the polymeric matrices commonly used in composites. It was shown that the treatment used caused a reduction on the polarity of cellulose molecules, and removed the outer surface layer of loofah fibers, exposing their internal fibrillar structure. As a consequence the treatment promoted an increase on the surface area available to adhesion.

Effects of derivatization on sponge gourd (Luffa cylindrica) fibres

A derivatization treatment aimed to reduce the hydrophilic behaviour of sponge gourd (Luffa cylindrica) fibres is described. The effect of the treatment on the chemical composition, surface morphology and thermal stability of the fibres was analysed. FT-IR results show that the polarity of the fibres was reduced, although the acetylation reaction did not go to completion. SEM analysis showed that the surface roughness of the fibres was increased by the treatment due to the removal of the outer surface layer of the fibres, and the thermal analysis showed variations in the fibre thermal behaviour caused by the chemical treatment. In particular, a significant reduction in weight loss was noted in temperatures lower than 100 °C, indicating that the fibres became more hydrophobic after treatment.

Effect of a Two Step Fiber Treatment on the Flexural Mechanical Properties of Sisal-polyester Composites

Sisal fibers were chemically treated with a two-step treatment (first sodium sulfide aqueous solution and then acetic anhydride/acetic acid mixture) to promote better adhesion to a polyester resin matrix. The flexural behaviour of the composites was analyzed as a function of the time of immersion in distilled water, and there was an improvement for short times of immersion. The long term behaviour of the treated composites was, however, no better than that of the untreated ones. This could be because of the controlling role of plasticization of both the fibers and the resin matrix for the longer times of immersion.

Enzyme-enhanced extraction of phenolic compounds and proteins from flaxseed meal.

Flaxseed (Linum usitatissimum) meal, the main byproduct of the flaxseed oil extraction process, is composed mainly of proteins, mucilage, and phenolic compounds. The extraction methods of phenolics either commonly employed the use of mixed solvents (dioxane/ethanol, water/acetone, water/methanol, and water/ethanol) or are done with the aid of alkaline, acid, or enzymatic hydrolysis. This work aimed at the study of optimal conditions for a clean process, using renewable solvents and enzymes, for the extraction of phenolics and proteins from flaxseed meal. After a screening of the most promising commercial preparations based on different carbohydrases and proteases, a central composite rotatable design and a mixture design were applied, achieving as optimal results a solution containing 6.6 and 152 g kg−1  meal of phenolics and proteins, respectively. The statistical approach used in the present study for the enzyme-enhanced extraction of phenolics and proteins from the major flaxseed byproduct was effective. By means of the sequential experimental design methodology, the extraction of such compounds was increased 10-fold and 14-fold, when compared to a conventional nonenzymatic extraction.

An ethanol-based process to simultaneously extract and fractionate carotenoids from Mauritia flexuosa L. Pulp

Mauritia vinifera (buriti) e uma palmeira nativa de diferentes regioes do Brasil, particularmente na regiao Amazonica. O oleo de buriti e rico em carotenoides, especialmente em β-caroteno. A demanda por fontes naturais de β-caroteno tem contribuido para aumentar a industrializacao do fruto de buriti pelas usinas de extracao de oleos vegetais. O processo mais adotado baseia-se em tecnologias convencionais envolvendo as etapas de despolpamento, secagem e prensagem da polpa para extracao do oleo, seguida da separacao dos carotenoides em uma fase liquida usando solventes orgânicos. Neste trabalho, foi avaliado o uso do etanol comercial para extracao e fracionamento simultâneo de carotenoides a partir da polpa de buriti. A materia-prima foi misturada com etanol, na proporcao 1:4 solvente/substrato, e mantida em banho termostatizado a 60oC, por 1 hora, sob agitacao constante de 30 rpm. A mistura foi filtrada sob vacuo e resfriada a 10oC resultando na formacao de duas fases. A composicao de carotenoides foi determinada por CLAE e indicou uma concentracao de β-caroteno 12 vezes maior na fase mais densa que na fase leve. O perfil de carotenoides foi similar ao obtido no oleo bruto de buriti, porem a concentracao de carotenoides totais foi 40% maior, indicando que o processo tecnologico avaliado e particularmente promissor para aplicacao industrial.

APPLICATION OF FOAM COLUMN AS GREEN TECHNOLOGY FOR CONCENTRATION OF SAPONINS FROM SISAL (Agave sisalana) AND JUÁ (Ziziphus joazeiro)

Abstract - Saponins, molecules classified as triterpenic or steroidal glycosides, are metabolites distributed in all the plant kingdom that can be used for the production of foods, cosmetics, and pharmaceuticals, as well as in soil bioremediation. Saponins are normally extracted from natural resources with water, ethanol and/or methanol, and then concentrated by liquid-liquid partitioning with n-butanol. An alternative concentration method is with a foam column, by which the saponins can be concentrated via preferential adsorption at a gas-liquid interface. Therefore, the objective of this work was the use of a foam column for the concentration of saponins from jua and sisal, evaluating parameters such as: initial working volume in the column, saponin concentration in the extracts from jua and sisal, air flow rate, pH, Raschig rings loading and operation time. When a gradient air flow rate and 25 g of Raschig rings were used, 82.6% of the jua saponins loaded onto the system were recovered in a 3.46-fold concentrated solution after 9 h of operation. Regarding sisal saponins, a concentration factor of 1.98 was observed with 90.5% of saponin recovery during 4.5 h of operation.

Obtenção de extratos de guaraná ricos em cafeína por processo enzimático e adsorção de taninos

Summary Guarana-flavoured beverages are very popular in Brazil and have shown an excellent sales potential on foreign markets. According to Brazilian law, each 100 mL of guarana-flavoured beverages must contain between 0.02 g and 0.2 g of guarana seed or its equivalent. These levels are normally obtained by adding a concentrated hydroalcoholic extract or sugar syrup containing guarana extract, directly to the beverage. However, the use of more concentrated extracts is limited by the presence of tannins, which imparts astringency and a dark colour to the final product. In this work the development of an enzymatic process to obtain non-alcoholic guarana extracts with low tannin concentrations and high caffeine contents was studied using an experimental design and adsorption processes. By way of a fractional factorial design the quantities of 0.25% (v/v) pectinase and 0.1% (v/v) glucoamylase were determined, which were maintained in the central composite design, obtaining as the optimal conditions: 0.23% (v/v) cellulase, 0.86% (v/v) hemicellulase, 1% (v/v) alpha-amylase, 5.5 h extraction time, 200 rpm and 50 °C, producing a caffeine/tannin ratio of 1.65. Using a magnesium oxide adsorption process at 10% (w/v), a caffeine/tannin ratio of 7.3 was obtained.

FSSC 22000 Packaging Implementation: a Plastics Industry Research

This paper presents the outcomes of an exploratory research carried out in companies, which are located in Brazil. They are FSSC-22000-certified food plastic packaging manufacturers. In order to identify the key aspects of the implementation process and certification, a questionnaire was developed and sent to twenty certified organizations. Out of them, eleven of which participating companies responded in a collaborative way. Based on the data obtained, improving competitiveness and customer retention were the reasons, which led the companies to seek the certification. However, the greatest difficulties were related to personnel, which presented technical and behavioral issues. In addition, it was noted that an overall satisfaction, derived from after-certification benefits, has been arisen in the companies. For instance, enhanced employee awareness, improved company’s image and winning new customers, significantly contributing to their competitiveness, are some of the benefits found in this process.