Starch-cellulose matrix

Other systems have been designed that respond, for example, to calcium, such as in the case of a starch-cellulose matrix that contains a-amylase, and whose degradation is produced in the presence of calcium, which allows the release of the drugs incorporated in... 

In the homogenous mixture of Starch and Polyvinyl alcohol (PVA), 30 % of plasticizer was mixed to make Pure blend. Then 10 % cellulose was mixed into above mixture followed by removal of extra water gave Cellulose-Reinforced starch-PVA blends. The different proportions of Fly ash were mixed into mixture of Cellulose-Reinforced starch-PVA blends to get various fly ash inserted Cellulose-Reinforced starch-PVA blends. Solubility, swelling behaviour and water absorption studies of Fly ash blends were measured at different time intervals at relative humidity of 50-55%. The insertion of Cellulose into starch-PVA blend decreases the solubility of blends due to the hydrophobicity of cellulose, but the solubility further increases by insertion of Fly ash into starch-PVA matrix that indicating the mechanical stability enhancement of blends. The water absorption behaviour of fly ash blends increases rapidly upto 150 min and then no change. The optimum concentration of Fly ash into Cellulose-Reinforced starch-PVA blend was 4%. 

Recently, bacterial cellulose, produced by Acetobacter Xylinum, was used as reinforcement in composite materials with a starch thermoplastic matrix [230]. The composites prepared with bacterial cellulose displayed better mechanical properties than those with vegetable cellulose fibers. 

CMSt were further added to a glycerol plasticized corn starch thermoplastic matrix. In order to obtain starch-cellulose composite materials, different cellulose fillers were... 

Highly oxidizable oils such as fish oils can be protected by a process known as microencapsulation, which coats the oil with a matrix of protein (gelatin, casein), carbohydrates (starch, cellulose, carboxymethylcellulose or cellulose derivatives) and lecithin. Microencapsulation provides protection against oxidation and imparts oxidative stability. The use of carboxymethylcellulose and cyclodextrins as coatings is claimed to provide better protection of oils by improved oxygen barrier properties. For special applications as nutritional supplements, fish oils enriched in n-3 PUFA are microencapsulated, in the presence of antioxidants, into a powder that is relatively stable at ambient temperatures. However, encapsulated fish oils can impart undesirable fishy taste when incorporated into food emulsions. More research and development is needed to evaluate potential applications and benefits of active packaging to increase the shelf life of fish oils and other highly oxidizable oils in foods. 

Several publications reported these effects. In the works of (Cao et al. 2008a), cellulose crystals, prepared by acid hydrolysis of flax fiber (F-CN), were added to a potato starch (PS) matrix, the nanocomposite films exhibited a significant increase in tensile strength and Young s modulus from 3.9 to 11.9 MPa and from 31.9 to 498.2 MPa, respectively, with increasing F-CN content from 0 to 30 wt%. 

The presence of natural fillers causes a slightly increased water resistance and could improve the apphcation property of these composite films. This behavior could be due to the presence of hydrogen bonding interactions between starch polymer matrix and crystaUine part of wood and fir tree needles fillers (which comprise cellulose in their chemical composition). The hydrogen bonds network occurred within the composite films tends to stabilize the starch polymer matrix when it is subjected to high moisture content environment. 

Natural fillers used in this study are not water soluble (two of them contain significant amounts of cellulose in their chemical composition) and randomly disperse within the starch plasticized matrix, and appears as a discontinuous phase after composite films drying (as evidenced by the scanning electron microscopy SEM investigation presented below). Therefore, these natural fillers provide more interfacial area within the composite films stmcture. As a result, light diffusion is enhanced, thus generating a reduced transparency property for the composite films. Overall, plasticized starch-based composite films exhibit some relative transparency mainly at low amount values for natural fillers in composite formulations. 

Kaushik and collaborators [37] obtained cellulose nanofibers from the wheat straw fibers using steam explosion (NaOH 10-12% solution and fiber/solution of 1 10), bleaching with 8% (v/v) solution, acid hydrolysis with 10% HCl (IN) and mechanical treatment. After the treatment it was possible to obtain mechanical defibrillation of cellulose nanofibers, which presented diameters between 10 and 60nm. The addition of these nanofibers to the starch thermoplastic matrix improved the barrier and mechanical properties of the nanocomposites. 

Biopolymers have diverse roles to play in the advancement of green nanotechnology. Nanosized derivatives of polysaccharides like starch and cellulose can be synthesized in bulk and can be used for the development of bionanocomposites. They can be promising substitutes of environment pollutant carbon black for reinforcement of rubbers even at higher loadings (upto SOphr) via commercially viable process. The combined effect of size reduction and organic modification improves filler-matrix adhesion and in turn the performance of polysaccharides. The study opens up a new and green alternative for reinforcement of rubbers. 

Chase and Long (1997) propose that this conundrum can be eliminated by the use of Zero Reference Materials (ZRMs) in analytical methods development to fully evaluate the method. A ZRM is a product matrix that lacks those nutrient components that are to be assayed, i.e. a blank matrix. The use of a ZRM in method development can and will give a true indication as to how the method will perform as the spiked nutrient levels approach zero. For example, two products. Corn Starch (NIST RM 8432) and Microcrystalline Cellulose (NIST RM 8416), contain very low elemental concentrations and could conceivably serve as real sample blanks or ZRMs in some analytical procedures. 

Oxygen Availability in Degrading Films. A major difference between natural materials and starch-plastic or cellulose-plastic blends is that the hydrophilic and relatively permeable matrix of materials like wood and hydrated polysaccharide films allows diffusion of O2 and release of nutrients from sites at a distance from the invasion site. As colonization proceeds, pore enlargement occurs when the pore walls are degraded (8) or as the polymer matrix of amylose or PVA films is hydrolyzed (10.12). In contrast, the LDPE matrix supplies no nutrients, hinders diffusion of water and O2, and the pore diameter cannot be increased. The consequence of impermeability is that the sole means of obtaining O2 and nutrients is by diffusion through water-filled pores. 

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