Starch quality

Jansen, G., Flamme, W., Sehuler, K., Vandrey, M. (2001). Tuber and starch quality of wild and cultivated potato speeies and eultivars. Potato Research, 44,137-146. 

Little public information is known about the operating performance of the continuous steeping system, although it is generally recognized that at least one company has used the process successfully for more than 15 years. The major concern with using the continuous steeping process is starch quality. Problems could be encountered with... 

The concentration of lactic acid in the steep has been shown to affect both the yield of starch178 and the quality of the resulting starch.179 Starch yields increased with increasing lactic acid concentration up to —0.5%, and decreased when more than —2% lactic acid was used. Shandera and lackson179 tested starch quality when steeped at 57°C with either 0.2% or 1.5% lactic acid and 0.05% or 0.3% sulfur dioxide. The level of sulfur dioxide had a small effect on starch quality, but the level of lactic acid had a pronounced reduction effect on peak viscosity, shear thinning viscosity, set-back viscosity, pasting viscosity and starch water solubility. 

The hydrocyclone process is applicable for processing hard and soft wheat flours, and perhaps even wholemeal flour.92 In addition to its versatility in processing different wheat classes, other advantages of the hydrocyclone process compared to the Martin process include an increased yield of gluten, lower water and energy requirements, and manageable levels of effluent. To ensure the food safety of wheat starch, quality programs in many companies dictate the implementation of hazard analysis and critical control points in the hydrocyclone process.24... 

Although potato starch manufacturing is a mature technology, new developments will occur. The market is increasingly demanding a more defined starch quality. Starch production will move from a bulk production industry to a more commodity-oriented industry. This will result in different starch products from the potato process. For example, the Brabender or RVA viscosity or particle size distribution will have narrow specifications. 

It is conceivable that methodology such as that used to increase starch quantity could be used to influence starch quality by manipulation of starch synthase and branching isoforms. These new starches may have greater usefulness in food and industrial processes. The production of modified "specialty starches via molecular biology techniques is promising, and perhaps more beneficial and more economical than the chemical modification of starch for industrial purposes. 

In addition to altering quantity, starch quality could be changed via expression of the isoforms of starch synthase and branching enzymes in plants. These designer starches would be used in the food and other industries. One possible approach to modifying starch structure in a crop would be the replacement of the plant branching isozymes with other different properties. The foreign enzyme could be a chimeric construct. 

Miiller-Rdber, B. and Kossman, J. 1994. Approaches to influence starch quantity and starch quality in transgenic plants. Plant Cell Environ. 17, 601-613. 

In addition to plastics materials, many fibres, surface coatings and rubbers are also basically high polymers, whilst in nature itself there is an abundance of polymeric material. Proteins, cellulose, starch, lignin and natural rubber are high polymers. The detailed structures of these materials are complex and highly sophisticated in comparison the synthetic polymers produced by man are crude in the quality of their molecular architecture. 

In the Phadebas TM amylase test (72) (Pharmacia Labs) the substrate was a water insoluble cross-TTnked blue starch in tablet form which also contains some inert ingredients, sodium and potassium phosphate buffer salts and sodium chloride. This polymer was hydrolyzed by amylase into water soluble blue starch fragments. After centrifugation the absorbance of the blue supernatant was proportional to the activity of amylase present in the test samples. The day to day variation on a quality control serum had a coefficient of variation of 2.7% based on 30 days of data in our laboratory. The method is simple, reproducible and uses microquantities of serum. 

The desirability of damaged starch varies between products, in some products damaged starch is desirable while in others it is undesirable. Even in bread too high a starch damage is undesirable as product quality suffers. 

The corn wet milling process involves taking apart a corn kernel into its individual components. To take apart a com kernel for maximum and high-quality starch recovery, it is important to understand the structure and composition of the corn kernel. 

Lasseran, J.C. 1973. Incidences of drying and storing conditions of com (maize) on its quality for starch industry. Starch/Stdrke 25, 257-262. 

The binders vary quite widely—the most common being starch, soy protein and latexes in conjunction with other soluble polymers. Styrene-butadiene latexes have been the most popular but ethylene-vinyl acetate binders are also used. The method of polymer synthesis provides a way of modifying the properties of the latex. For example, adjustment of the ratio of styrene butadiene in the co-polymer gives rise to different degrees of softness or hardness. This property has a profound influence on the quality of the coating. It is also possible to co-polymerise monomers so as to introduce, for example, carboxy groups on to the surface of the latex particle which in turn assist in... 

Sweet potato flour contained 3.8% protein, the second highest amount of protein among starchy foods, and yet the protein appeared to be the poorest in nutritional quality. However, it should be noted that the sweet potatoes used in this study were dried at 60 C but were not cooked. Uncooked sweet potato starch is not completely digestable by rodents. As a consequence, maintenance requirements would increase. This is the most likely explanation for the increased requirement for bean flour, but there also may have been interference with digestion from protease inhibitors present in uncooked sweet potatoes. 

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