Oxidation of potato starch with different sodium hypochlorite concentrations and its effect on biodegradable films

AbstractThe objective of this study was to evaluate the effects of oxidation with sodium hypochlorite at different concentrations of active chlorine (0.5, 1.0 and 1.5 g/100 g) on the physicochemical, morphological, pasting, thermal and gel texture properties of potato starch. The native and oxidized starches were used in different concentrations (3.0, 4.0 and 5.0 g starch/100 mL) for the preparation of biodegradable films using glycerol as plasticizer. The films were evaluated for their mechanical properties, color, water solubility and permeability of water vapor. The degree of oxidation potato starches was more intense as there was an increased concentration of active chlorine in the reaction. Films made with oxidized starch with the highest level of active chlorine had lower tensile strength when compared to native starch films. Also, these films had a lower water solubility and water vapor permeability as compared to the native starch films

Structural, morphological, and physicochemical properties of acetylated high-, medium-, and low-amylose rice starches

AbstractThe high-, medium-, and low-amylose rice starches were isolated by the alkaline method and acetylated by using acetic anhydride for 10, 30, and 90min of reaction. The degree of substitution (DS), the Fourier-transformed infrared spectroscopy (FTIR), the X-ray diffractograms, the thermal, morphological, and pasting properties, and the swelling power and solubility of native and acetylated starches were evaluated. The DS of the low-amylose rice starch was higher than the DS of the medium- and the high-amylose rice starches. The introduction of acetyl groups was confirmed by FTIR spectroscopy. The acetylation treatment reduced the crystallinity, the viscosity, the swelling power, and the solubility of rice starch; however, there was an increase in the thermal stability of rice starch modified by acetylation

Filmes biodegradáveis à base de proteínas miofibrilares de pescado

O objetivo deste trabalho foi estudar as propriedades físicas, mecânicas e de barreira dos filmes produzidos a partir de diferentes concentrações de proteínas miofibrilares de pescado de baixo valor comercial. O pescado utilizado foi a corvina (Micropogonias furnieri), que foi eviscerada e filetada. As proteínas miofibrilares foram obtidas do músculo, em sucessivas lavagens com água destilada. Os filmes foram produzidos com 3, 4 e 5% de proteínas miofibrilares pelo método de casting. Os filmes foram analisados nos seguintes aspectos: espessura, solubilidade, opacidade, resistência à tração, elongação e permeabilidade ao vapor de água (PVA). O aumento da concentração de proteínas miofibrilares atribuiu aos filmes maior espessura, opacidade, resistência à tração e PVA; no entanto, conferiu menor elongação na ruptura dos mesmos.The objective of this work was to study the physical, mechanical and barrier properties of the films produced from different concentrations of myofibrillar proteins of fish. The fish used was croaker (Micropogonias furnieri), which was gutted and filleted. The myofibrillar proteins were obtained through the muscle with successive washes with distilled water. The films were made with 3, 4 and 5% of myofibrillar proteins by the method of casting. The films were analyzed by thickness, solubility, opacity, tensile strength, elongation and water vapor permeability (PVA). The increase of myofibrillar proteins concentration in the films increased thickness, opacity, tensile strength and water vapor permeability and reduced elongation at break of the film

Filmes biodegradáveis à base de proteínas miofibrilares de pescado Biodegradable films based on myofibrillar proteins of fish

O objetivo deste trabalho foi estudar as propriedades físicas, mecânicas e de barreira dos filmes produzidos a partir de diferentes concentrações de proteínas miofibrilares de pescado de baixo valor comercial. O pescado utilizado foi a corvina (Micropogonias furnieri), que foi eviscerada e filetada. As proteínas miofibrilares foram obtidas do músculo, em sucessivas lavagens com água destilada. Os filmes foram produzidos com 3, 4 e 5% de proteínas miofibrilares pelo método de casting. Os filmes foram analisados nos seguintes aspectos: espessura, solubilidade, opacidade, resistência à tração, elongação e permeabilidade ao vapor de água (PVA). O aumento da concentração de proteínas miofibrilares atribuiu aos filmes maior espessura, opacidade, resistência à tração e PVA; no entanto, conferiu menor elongação na ruptura dos mesmos.<br>The objective of this work was to study the physical, mechanical and barrier properties of the films produced from different concentrations of myofibrillar proteins of fish. The fish used was croaker (Micropogonias furnieri), which was gutted and filleted. The myofibrillar proteins were obtained through the muscle with successive washes with distilled water. The films were made with 3, 4 and 5% of myofibrillar proteins by the method of casting. The films were analyzed by thickness, solubility, opacity, tensile strength, elongation and water vapor permeability (PVA). The increase of myofibrillar proteins concentration in the films increased thickness, opacity, tensile strength and water vapor permeability and reduced elongation at break of the film

Development of oxidised and heat–moisture treated potato starch film

Submitted by Taís Renata Pereira Amorim ([email protected]) on 2014-08-15T19:39:44Z No. of bitstreams: 1 27- Development of oxidised and heat–moisture treated potato starch film.pdf: 254878 bytes, checksum: 2fb04d09ae8fc77f97d8740eb490a416 (MD5)Approved for entry into archive by Paula Gautério ([email protected]) on 2014-08-22T18:54:05Z (GMT) No. of bitstreams: 1 27- Development of oxidised and heat–moisture treated potato starch film.pdf: 254878 bytes, checksum: 2fb04d09ae8fc77f97d8740eb490a416 (MD5)Made available in DSpace on 2014-08-22T18:54:05Z (GMT). No. of bitstreams: 1 27- Development of oxidised and heat–moisture treated potato starch film.pdf: 254878 bytes, checksum: 2fb04d09ae8fc77f97d8740eb490a416 (MD5) Previous issue date: 2012This study investigated the effects of sodium hypochlorite oxidation and a heat–moisture treatment of potato starch on the physicochemical, pasting and textural properties of potato starches in addition to the water vapour permeability (WVP) and mechanical properties of potato starch films produced from these starches. The carbonyl contents, carboxyl contents, swelling power, solubility, pasting properties and gel texture of the native, oxidised and heat–moisture treated (HMT) starches were evaluated. The films made of native, oxidised and HMT starches were characterised by thickness, water solubility, colour, opacity, mechanical properties and WVP. The oxidised and HMT starches had lower viscosity and swelling power compared to the native starch. The films produced from oxidised potato starch had decreased solubility, elongation and WVP values in addition to increased tensile strength compared to the native starch films. The HMT starch increased the tensile strength and WVP of the starch films compared to the native starch