Corn starch blends

Matthey, F. P. and Hanna, M. A. (1997). Physical and functional properties of twin-screw extruded whey protein concentrate-corn starch blends. LWT Food Sci. Technol. 30,359-366. 

Figure 4 Differential scanning calorimetry endotherms (DSC model 2910, TA Instruments, New Castle, DE) of cowpea protein-corn starch blends in different ratios (R) at pH 7 and scanning rate 5°C min-1. (Courtesy of Okechukwu and Rao, 1996b.)...

When PE-y-MA is added to low density poly(ethylene) (LDPE)/ corn starch blends, the tensile strength and elongation at break of the blends are improved and the improvement was more pronounced at higher starch contents. 

M.A. Araiijo, A.M. Cunha, M. Mota, Changes on surface morphology of corn starch blend films. Journal of Biomedical Materials Research — Part A 94 (3) (2010) 720-729. 

The case of contradictory findings for the analysis of dietary fiber are due to differences among analytical methods employed. The AO AC total dietary fiber method measures all compounds not digested by amylase and protease and insoluble in 80% aqueous ethanol. While cellulose, pectin, hemicelluloses, gums and lignin do meet these criteria, extrusion-modified starches and proteins could also be measured as fiber. Sites formerly accessible to digestion by enzymes may be involved in new bonds or physically-hindered. Many materials used to add dietary fiber to foods contain far less than 100% fiber. Artz and co-workers (1990) found no difference in X-ray diffraction patterns of corn fiber-corn starch blends after extrusion, which was expected since very little crystalline cellulose was present. The com bran isolate used as a fiber source actually contained only 16.6% cellulose. Amorphous hemicelluloses comprised the remainder of the dietary fiber fraction. 

Pre-Extrusion Blending. Based on the moisture contents of the corn starch and various protein sources, blends of 0,5,15,30, and 50% (dry weight) of each protein source were made by first dry mixing for 10 minutes in a Paterson-Kelly Model LB-P-8 twin shell blender followed by the appropriate amount of 20°C tap water to obtain a total moisture content of either 15 or 25% (wet basis). The moistened mixtures were then blended for an additional 20 minutes followed by overnight equilibration at room temperature in air-tight bags. 

Among the world s leading suppliers are Novamont (Mater-Bi products) and its licensees (about 80,000 t per year), Rodenburg (Solanyl products, 40,000 t per year). Com Products, Japan Corn Starch, Chisson, Biotec, Supol, Starch Technology, VTT Chemical, Groen Granulaat and Plantic. The price of the blends of starch with polyesters is about US 5 kg-, while the price of the modified starch is about US 1.0 -1.5 kg. ... 

Fig. 6. FTIR second derivative spectrum of corn starch a, cystalline b, gelatinized c, blended with EVOH (129).

Zhang et aimed to overeome the lower erystallisation rate and large crystal size of the P(3HB-co HB) copolymer by blending the P(3HB-co-4HB) copolymer with corn starch. Besides that, the high production cost of P(3HB-CO-4HB) had also led to the limitation of the applications. Therefore, corn starch, which is a polysaccharide found in nature, was selected as a raw material in the blending. The blends were fabricated by melt mixing and injection molding. 

Guohua Z., Ya L., CuUan R, Min Z., Caiqiong Z., Zongdao C. Water resistance, mechanical properties and biodegradabihty of methylated-corn starch/poly(vinyl alcohol) blend film, Polym. Deg. Stab. 91 (2006)703. 

Corn starch was gelatinized to a high degree even at low temperatures resulting in good dispersion qualities for nitrogen at recipe I. Therefore, starch can be used as a binder added as native powder to the dry blend. 

Figure 6.9 Droplet-like structure of thermoplastic corn starch/EVOH blend in film from, after disagregation in boiling water [118].

Figure 6.11 FTIR second derivative spectra of corn starch (a) cystalline (b) gelatinized (c) blended with EVOH [118].

To disintegrate PP/starch blends within 6-9 months in a marine environment it is desirable to bring about chemical degradation of PP by using certain metal catalysts like aluminum stearate/Co(III) acetylacetonate (within the sample or in seawater) and auto-oxidants like corn oil or fatty acids, in addition to the possible biodegradation of the starch filler [71]. 

The biocompatibility of two different blends of corn-starch, SEVA and starch/cellulose acetate (SCA), and their respective composites with HAp, were studied by Marques et al. [274]. Researchers found that both types of starch-based polymers exhibit a cytocompatibility that might allow for their use as biomaterials Eurthermore SEVA blends were found to be less cytotoxic for the tested cell line, although cells adhere better to SCA surface. Considering the overall behaviour of SEVA, SCA and their composites with HAp, it can be expected that their cytocompatibility will allow for their use in the future in applications such as bone replacement/fixation and/or tissue engineering scaffolding. 

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