Potato protein properties

Lokra, S., Helland, M. H., Claussen, I. C., Straetkvern, K. O., Egelandsdal, B.10.1016/j.lwt.2007.07.006 (2007). Chemical characterization and functional properties of a potato protein concentrate prepared by large-scale expanded bed adsorption chromatography. LWT - Food Sci. Technol. 

Chem. Descrip. Organic defoamer Uses Defoamer for protein and starch, potato processing Properties Liq. sp.gr. 0.966 vise. 400 cps flash pt. (PMCC) > 300 F Mazu DF 204 [BASF]... 

Because composition and nutritional properties of the major food legumes and oilseeds have been reported in numerous technical journals and books (listed above), the section devoted to composition and chemistry highlights lesser-known but potentially important sources of plant protein that have not received the same attention. Some of these food crops have been cultivated for many years so that they are not "new" sources. Such crops as winged bean, sweet potato, tropical seeds, fruits and leaves, yams and cucurbits are potential sources of protein in areas where they are grown. These are discussed in greater detail in the remaining five chapters. 

His first work in the Laboratory of Biological Chemistry was on the purification and properties of potato phosphorylase, but he soon changed his subject to the study of amino-containing sugars. It was not well understood at that time whether there were impurities in the products of separation and purification of proteins. Consequently, Onodera made up his mind to devote his whole life to identifying the chemical nature of amino-containing sugars. 

Jorgensen, M., Bauw, G., Welinder, K. G. (2006). Molecular properties and activities of tuber proteins from starch potato cv. Kuras. J. Agric. Food Chem., 54, 9389-9397. 

Potato BEII was first characterized and found to be a granule-bound protein in tuber starch.256 In potato, BEII appears to be less abundant than BEL Both potato tuber BEI and BEII were cloned and expressed in E. coli,257 258 and the properties of... 

Tortillas prepared from mixtures of com with wheat, broadbean, rice, chickpea, and/or potato were studied. These mixes resulted in tortillas of very similar mechanical and sensory properties as those prepared from corn alone. However, the contents of protein and available lysine were in many cases higher (see Table XIII). Such mixtures provide an efficient way to improve the quantity and quality of protein in tortillas. 

Specific interactions between starch and proteins were observed as early as the beginning of the twentieth century. Berczeller996 noted that the surface tension of aqueous soap solutions did not decrease with the addition of protein (egg albumin) alone, but it did decrease when starch and protein were added. This effect was observed to increase with time. Sorption of albumin on starch is inhibited by bi- and trivalent ions and at the isoelectric point. Below the isoelectric point, bonding between starch and albumin is ionic in character, whereas nonionic interactions are expected above the isoelectric point.997 The Terayama hypothesis998 predicts the formation of protein complexes with starch, provided that starch exhibits the properties of a polyelectrolyte. Apart from chemically modified anionic starches (such as starch sulfate, starch phosphate, and various cross-linked starch derivatives bearing ionized functions), potato starch is the only variety that behaves as a polyelectrolyte. Its random phosphate ester moieties permit proteins to form complexes with it. Takeuchi et a/.999-1002 demonstrated such a possibility with various proteins and a 4% gel of potato starch. 

If, on the other hand, either the intestinal phosphatase at pH 9.0 or the potato enzyme at pH 5.6 are added to ovalbumin, the reaction is more complex. The protein is rapidly dephosphorylated until 46 % of the phosphorus is released (Fig. 2a). Here, Ai is again converted into a protein with the properties of A2. Dephosphorylation, however, continues and a new component, A3, appears which moves more slowly than A2 and is a phosphorus-free ovalbumin (line 4, Fig. 25). 

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