Conversion of konjac powder into glucomannan-oligosaccharides, mannose, and glucose by hydrolysis facilitated by microwave heating and HCl catalyst

AbstractThe reaction conditions to hydrolyze konjac powder (KP) were investigated by using a combination of microwave radiation heating and HCl as a catalyst to explore the possibility of glucomannan-oligosaccharides, mannose, and glucose extractions from the polysaccharides of KP. Selective reaction conditions to produce glucomannan-oligosaccharides, mannose, and glucose were determined. The highest yield for glucomannan-oligosaccharides production, at 19.2%, was achieved under the reaction conditions of 110°C, 15 min, 2 M HCl and 10:1 (mL/g) ratio of reaction volume to KP mass. The highest yield for both mannose and glucose production, at 35.8% and 30.2%, respectively, was achieved under the reaction conditions of 110°C, 15 min, 1.2 M HCl and    10:1 (mL/g) ratio of reaction volume to KP mass. Only a small amount of 5-HMF at 0.3% was formed and a low level of UV absorbance (284 nm) of hydrolyzed products (HP) at 1.7 was found under these conditions. The combination of microwave radiation (MCR) heating and HCl effectively hydrolyzed konjac powder selectively into glucomannan-oligosaccharides and/or monosaccharides in a relatively short reaction time

The production of hydrolysates from industrially defatted rice bran and its surface image changes during extraction

BACKGROUND This research employed mild-subcritical alkaline water extraction (SAW) technique to overcome the difficulty of active compounds extractability from an industrially defatted rice bran (IDRB). Mild-SAW (pH 9.5, 130 °C, 120 min) treatment, followed by enzymatic hydrolysis (Protease G6) were applied to produce rice bran hydrolysate (RBH). Response surface methodology was used to identify proteolysis conditions for maximizing protein content and ABTS radical scavenging activity (ABTS-RSA). The microstructural changes during the extraction occurring in the IDRB were monitored. The selected RBH was characterised for protein recovery, yield, antioxidant activities, phenolic profile and hydroxymethylfufural (HMF) content. RESULTS Optimal proteolysis conditions were at 20 mL kg-1 IDRB (E/S) for 6 h. Under these conditions, the yield, ABTS-RSA, Ferric reducing antioxidant power and the total phenolic content of the RBH were 46.1%, 294.22 μmol trolox g-1, 57.72 μmol FeSO4 g-1, and 22.73 mg gallic acid g-1, respectively, with relatively low HMF level (0.21 mg g-1). The protein recovery was 4.8 times greater than the recovery obtained by conventional alkaline extraction. Its major phenolic compounds were p-coumaric and ferulic acids. The microstructural changes of IDRB confirmed that the mild-SAW/Protease G6 process enhanced the release of active compounds. CONCLUSION The process of mild-SAW followed by proteolysis promotes the release of active compounds from IDRB

Impact of in vitro gastrointestinal digestion on peptide profile and bioactivity of cooked and non-cooked oat protein concentrates

Oat (Avena sativa) is one of the most cultivated and consumed cereals worldwide. Recognized among cereals for its high protein content (12% to 24%), it makes it an excellent source of bioactive peptides, which could be modified during processes such as heating and gastrointestinal digestion (GID). This work aims to evaluate the impact of heat treatment on the proteolysis of oat proteins and on the evolution of antioxidant peptide release during in vitro static GID, in terms of comparative analysis between cooked oat protein concentrate (COPC) and non-heated oat protein concentrate (OPC) samples. The protein extraction method and cooking procedure used showed no detrimental effects on protein quality. After GID, the proportion of free amino acids/dipeptides (40% for both samples (OPC and COPC), thus producing peptides with low molecular weight and enhanced bioactivity. Furthermore, during GID, the amino acid profile showed an increase in essential, positively-charged, hydrophobic and aromatic amino acids. At the end of GID, the reducing power of OPC and COPC increased >0.3 and 8-fold, respectively, in comparison to the non-digested samples; while ABTS•+ and DPPH• showed a >20-fold increase. Fe2+ chelating capacity of OPC and COPC was enhanced >4 times; similarly, Cu2+ chelation showed a >19-fold enhancement for OPC and >10 for COPC. β-carotene bleaching activity was improved 0.8 times in OPC and >9 times in COPC; the oxygen radical antioxidant capacity assay increased 2 times in OPC and >4.7 times in COPC, respectively. This study suggests that OPC after cooking and GID positively influenced the nutritional and bioactive properties of oat peptides. Thus, COPC could be used as a functional food ingredient with health-promoting effects, as hydrothermal treatment is frequently used for this type of cereals

La réforme juridique de la régulation de la communication audiovisuelle et des télécommunications en Thaïlande

En Thaïlande, les communications audiovisuelle et les télécommunications sont soumises depuis longtemps au régime du monopole étatique, mais la démarche réformatrice de la communication en Thaïlande est déjà lancée. L'ensemble de l'étude porte sur la politique de la communication et l'évolution des événements, ainsi que des dispositions juridiques en droit thaïlandais qui permet de comprendre la genèse de la réforme et de constater les complications et les problèmes persistants. Puisque chaque pays a engagé des réformes législatives avec des motifs et des convictions propres, la réforme de la régulation de la communication audiovisuelle et des télécommunications en Thaïlande porte à la fois sur les deux secteurs de la communication, celui de l'audiovisuel et des télécommunications.L'évolution technique et la réforme des nouvelles autorités régulatrices en Thaïlande trouvent leur racine dans les expériences étrangères, notamment en droit français. Il est courant d'observer les pratiques et les conceptions du droit français, afin de comprendre, ou bien de comparer certaines conceptions ou certaines expériences, celles qui sont susceptibles d'influencer le droit de la communication thaïlandaise. Les difficultés et les problématiques thaïlandaises qui sont parfois distinctes des françaises ont permis de préciser les aspects de l'esprit, la politique de la culture juridique thaïe qui peuvent surprendre les occidentaux. Cela tend à exprimer la volonté de réforme, non seulement des droits relatifs à la régulation, mais aussi le paysage des communications audiovisuelles et des télécommunications qui sont en voie d'amélioration progressive.Telecommunications and broadcasting in Thailand have been monopolized by the government for many decades ; however there has been starting to reform the telecommunications and broadcasting activity in Thailand. In general, this study relates on policy of telecommunication and broadcasting, and evolution of circumstances and regulation of telecommunications and communications law in Thailand. This will lead to understanding of the causes reformation and concerning complexity of the problems, which is existing in Thailand. Each country has an individual approach to reform legislations with its objectives and attitude. Reformation of the regulation system of telecommunication and broadcasting in Thailand comprises of Radio Broadcasting and Telecommunications. The technical evolution and the reformation of the new regulating authorities in Thailand are originally from the foreign experiences, in particular in the French law. It actually observe the practices and the concepts of French law, in order to understand, or to compare a certain designs or certain experiments, those, which are likely to influence the human right in communication in Thailand. The difficulties and the problems, which may be different from French, can specify the determination, the policy and the culture in Thai law. This distinctive point can surprise the Westerners, but it represents the willing to reform the regulations law as well as the overview of communications and telecommunications, which is gradually progressing in a positive way

La réforme juridique de la régulation de la communication audiovisuelle et des télécommunications en Thaïlande

En Thaïlande, les communications audiovisuelle et les télécommunications sont soumises depuis longtemps au régime du monopole étatique, mais la démarche réformatrice de la communication en Thaïlande est déjà lancée. L'ensemble de l'étude porte sur la politique de la communication et l'évolution des événements, ainsi que des dispositions juridiques en droit thaïlandais qui permet de comprendre la genèse de la réforme et de constater les complications et les problèmes persistants. Puisque chaque pays a engagé des réformes législatives avec des motifs et des convictions propres, la réforme de la régulation de la communication audiovisuelle et des télécommunications en Thaïlande porte à la fois sur les deux secteurs de la communication, celui de l'audiovisuel et des télécommunications.L'évolution technique et la réforme des nouvelles autorités régulatrices en Thaïlande trouvent leur racine dans les expériences étrangères, notamment en droit français. Il est courant d'observer les pratiques et les conceptions du droit français, afin de comprendre, ou bien de comparer certaines conceptions ou certaines expériences, celles qui sont susceptibles d'influencer le droit de la communication thaïlandaise. Les difficultés et les problématiques thaïlandaises qui sont parfois distinctes des françaises ont permis de préciser les aspects de l'esprit, la politique de la culture juridique thaïe qui peuvent surprendre les occidentaux. Cela tend à exprimer la volonté de réforme, non seulement des droits relatifs à la régulation, mais aussi le paysage des communications audiovisuelles et des télécommunications qui sont en voie d'amélioration progressive.Telecommunications and broadcasting in Thailand have been monopolized by the government for many decades ; however there has been starting to reform the telecommunications and broadcasting activity in Thailand. In general, this study relates on policy of telecommunication and broadcasting, and evolution of circumstances and regulation of telecommunications and communications law in Thailand. This will lead to understanding of the causes reformation and concerning complexity of the problems, which is existing in Thailand. Each country has an individual approach to reform legislations with its objectives and attitude. Reformation of the regulation system of telecommunication and broadcasting in Thailand comprises of Radio Broadcasting and Telecommunications. The technical evolution and the reformation of the new regulating authorities in Thailand are originally from the foreign experiences, in particular in the French law. It actually observe the practices and the concepts of French law, in order to understand, or to compare a certain designs or certain experiments, those, which are likely to influence the human right in communication in Thailand. The difficulties and the problems, which may be different from French, can specify the determination, the policy and the culture in Thai law. This distinctive point can surprise the Westerners, but it represents the willing to reform the regulations law as well as the overview of communications and telecommunications, which is gradually progressing in a positive way

La réforme juridique de la régulation de la communication audiovisuelle et des télécommunications en Thaïlande

En Thaïlande, les communications audiovisuelle et les télécommunications sont soumises depuis longtemps au régime du monopole étatique, mais la démarche réformatrice de la communication en Thaïlande est déjà lancée. L'ensemble de l'étude porte sur la politique de la communication et l'évolution des événements, ainsi que des dispositions juridiques en droit thaïlandais qui permet de comprendre la genèse de la réforme et de constater les complications et les problèmes persistants. Puisque chaque pays a engagé des réformes législatives avec des motifs et des convictions propres, la réforme de la régulation de la communication audiovisuelle et des télécommunications en Thaïlande porte à la fois sur les deux secteurs de la communication, celui de l'audiovisuel et des télécommunications.L'évolution technique et la réforme des nouvelles autorités régulatrices en Thaïlande trouvent leur racine dans les expériences étrangères, notamment en droit français. Il est courant d'observer les pratiques et les conceptions du droit français, afin de comprendre, ou bien de comparer certaines conceptions ou certaines expériences, celles qui sont susceptibles d'influencer le droit de la communication thaïlandaise. Les difficultés et les problématiques thaïlandaises qui sont parfois distinctes des françaises ont permis de préciser les aspects de l'esprit, la politique de la culture juridique thaïe qui peuvent surprendre les occidentaux. Cela tend à exprimer la volonté de réforme, non seulement des droits relatifs à la régulation, mais aussi le paysage des communications audiovisuelles et des télécommunications qui sont en voie d'amélioration progressive.Telecommunications and broadcasting in Thailand have been monopolized by the government for many decades ; however there has been starting to reform the telecommunications and broadcasting activity in Thailand. In general, this study relates on policy of telecommunication and broadcasting, and evolution of circumstances and regulation of telecommunications and communications law in Thailand. This will lead to understanding of the causes reformation and concerning complexity of the problems, which is existing in Thailand. Each country has an individual approach to reform legislations with its objectives and attitude. Reformation of the regulation system of telecommunication and broadcasting in Thailand comprises of Radio Broadcasting and Telecommunications. The technical evolution and the reformation of the new regulating authorities in Thailand are originally from the foreign experiences, in particular in the French law. It actually observe the practices and the concepts of French law, in order to understand, or to compare a certain designs or certain experiments, those, which are likely to influence the human right in communication in Thailand. The difficulties and the problems, which may be different from French, can specify the determination, the policy and the culture in Thai law. This distinctive point can surprise the Westerners, but it represents the willing to reform the regulations law as well as the overview of communications and telecommunications, which is gradually progressing in a positive way

Arthrospira platensis Mutagenesis for Protein and C-Phycocyanin Improvement and Proteomics Approaches

Arthrospira (Spirulina) platensis is known for its use as a food supplement, with reported therapeutic properties including antiviral, anti-inflammatory and antioxidant activity. Arthrospira is also an excellent source of proteins and C-phycocyanin. The latter is a light-harvesting pigment-protein complex in cyanobacteria, located on the outer surface of the thylakoid membrane and comprising 40 to 60% of the total soluble protein in cells. Random mutagenesis is a useful tool as a non-genetically modified mutation method that has been widely used to generate mutants of different microorganisms. Exposure of microalgae or cyanobacteria to chemical stimuli affects their growth and many biological processes. Chemicals influence several proteins, including those involved in carbohydrate and energy metabolisms, photosynthesis and stress-related proteins (oxidative stress-reactive oxygen species (ROS) scavenging enzymes). Signal transduction pathways and ion transportation mechanisms are also impacted by chemical treatment, with changes causing the production of numerous biomolecules and stimulation of defence responses. This study compared the protein contents of A. platensis control and after mutagenesis using diethyl sulphate (DES) under various treatment concentrations for effective mutation of A. platensis. Results identified 1152 peptides using proteomics approaches. The proteins were classified into 23 functional categories. Random mutagenesis of A. platensis by DES was found to be highly effective for C-phycocyanin and protein production