Starch potato, properties

Similar materials are available based on potato starch, eg, PaseUi SA2 which claims DE below 3 and has unique properties based on its amylose—amylopectin ratio pecuhar to potato starch. The product contains only 0.1% proteia and 0.06% fat which helps stabilize dried food mixes compounded with it. Another carbohydrate raw material is waxy-maize starch. Maltodextrias of differeat DE values of 6, 10, and 15, usiag waxy-maize starch, are available (Staley Co.). This product, called Stellar, is offered ia several physical forms such as agglomerates and hoUow spheres, and is prepared by acid modification (49). Maltodextrias based oa com starch are offered with DEs of 5, 10, 15, and 18 as powders or agglomerates (Grain Processing Corp.). 

Compared to native starches, monophosphate esters have a decreased gelatinization temperature range and swell in cold water at a DS of 0.07. Starch phosphates have increased paste viscosity and clarity and decreased retrogradation. Their properties are in many ways similar to those of potato starch, which naturally contains phosphate groups. 

Starches remain a popular glidant, in particular those with the larger grain sizes such as potato starch, possibly because of their additional value as a disin-tegrant in the formulation. Concentrations up to 10% are common, but it should be appreciated that excess may result in exactly the opposite effect of that desired (i.e., flow properties may worsen). Talc is also widely used and has the advantage that it is superior to starches in minimizing any tendency for material to stick... 

Not all modified starches are suitable for removal by aqueous dissolution alone. Such modifications of natural starches are carried out to reduce solution viscosity, to improve adhesion and ostensibly to enhance aqueous solubility. Commercial brands vary [169], however, from readily soluble types to those of limited solubility. Indeed, some may be as difficult to dissolve as potato starch if they have been overdried. It is thus very important to be sure of the properties of any modified starch present. If there are any doubts about aqueous dissolution, desizing should be carried out by enzymatic or oxidative treatment. Even if the size polymer is sufficiently soluble, it is important to ensure that the washing-off range is adequate. Whilst the above comments relate to modified starches, other size polymers such as poly(vinyl acetate/alcohol) and acrylic acid copolymers vary from brand to brand with regard to ease of dissolution. 

The sorption of water by excipients derived from cellulose and starch has been considered by numerous workers, with at least three thermodynamic states having been identified [82]. Water may be directly and tightly bound at a 1 1 stoichiometry per anhydroglucose unit, unrestricted water having properties almost equivalent to bulk water, or water having properties intermediate between these two extremes. The water sorption characteristics of potato starch and microcrystalline cellulose have been determined, and comparison of these is found in Fig. 11. While starch freely adsorbs water at essentially all relative humidity values, microcrystalline cellulose only does so at elevated humidity values. These trends have been interpreted in terms of the degree of available cellulosic hydroxy groups on the surfaces, and as a function of the amount of amorphous material present [83]. 

FIGURE 5.4 Potato starch granules viewed under polarized light (magnification, x400). Reprinted from Encyclopedia of Food Sciences and Nutrition (Second Edition), Jackson (2003b), Starch - Structure, properties and determination. Pages 5561-5567, with permission from Elsevier. 

Potato starch, and tuberous starch in general, has some unique properties as compared to cereal starches. The most important ones include long amylopectin chains forming hydrated and ordered B-type crystallites and the presence of phosphate esters. The clusters of potato amylopectin are comparatively small, comprising 5-10 short chains. The internal part ofthe clusters is organized into branched building blocks mainly found in the amorphous lamellae of the... 

Noda, T., Takigawa, S., Matsuura-Endo, C., Kim, S. -J., Hashimoto, N., Yamauchi, H., Hanashiro, I., Takeda, Y. (2005). Physicochemical properties and amylopectin structures of large, small, and extremely small potato starch granules. Carbohydr. Polym., 60,245-251. 

Eliasson, A. C, Kim, H. R. (1992). Changes in rheological properties of hydroxypropyl potato starch pastes during freeze-thaw treatments I. A rheological approach for evaluation of freeze-thaw stability. J. Texture Stud, 23, 279-295. 

Suzuki, A., Shibanuma, K., Takeda, Y, Abe, J. and Hizukuri, S. (1994). Structures and pasting properties of potato starches from Jaga Kids Purple 90 and Red 90. Oyo Toshitsu Kagaku, 41,425-432. 

An understanding of physicochemical and structural properties of starch will offer the possibility to control the quality of potato and potato products (e.g. digestibility), and to produce new potato starches with added value. As a result, it is critical to understand and apply advanced analytical techniques to characterize and evaluate the quality of potatoes and potato starch. In this chapter, the advanced analytical techniques to evaluate the quality of potatoes and potato starch are introduced and discussed in detail. 

Most potato starches are composed of a mixture of two polysaccharides, a linear fraction, amylose, and a highly branched fraction, amylopectin. The content of amylose is between 15 and 25% for most starches. The ratio of amylose to amylopectin varies from one starch to another. The two polysaccharides are homoglucans with only two types of chain linkage, a-(l 4) in the main chain and a-(l 6)-linked branch chains. Physicochemical properties of potato and its starch are believed to be influenced by amylose and amylopectin content, molecular weight, and molecular weight distribution, chain length and its distribution, and phosphorus content (Jane and Chen, 1992). 

Potato starch usually contains 0.01-0.6% (w/w) phosphorus. Although phosphorus is present at very low levels, it has a significant effect on the physicochemical properties of starch. Phosphorus is in part responsible for the high swelling power, paste stability, and resistance to enzyme hydrolysis of potato starch. Potato starches contain significant amounts of monophosphate esters... 

Eerlingen, R. C., Jacobs, H., Block, K., Delcour,J. A. (1997). Effects of hydrothermal treatments on the rheological properties of potato starch. Carbohydrate Research, 297, 347-356. 

Cottrell, J. E., Dulfus, C. M., Paterson, L., George, R. M. (1995). Properties of potato starch Effects of genotype and growing eonditions. Phytochem.,40,1057-1064. 

Physically modified potato starch is preferred in processed foods because of its improved functional properties over those of its native counterpart. Moreover, this modified strach can be safely used in different food products and other industrial applications. Different physical... 

OPT is a new method of physical modification, in which potato starch is suspended in solution saturated with a salt such as sodium sulfate and heated (autoclaved) at temperatures above 100° C for different times. This treatment has been reported to have the same effects on the starch properties as HMT but the starch modified using OPT exhibits better homogeneity (Pukkahuta et al., 2007). 

Physico-chemical properties of derivatized potato starch... 

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