Potato starch separators

Separation of potato starch and two fractions (nb/lcb, scb) of potato starch... 

FIGURE 16.16 Nonbranched/long chain branched glucans of potato starch dissolved in hot water-steam and 0.1 M NaOH 1.2 ml of the 18-mg/ml solution was separated on Sepharose CL 2B (88 X 1.6 cm) 3-ml fractions were collected for further analysis normalized (area = 1.0) eluogram profiles (ev) constructed from an off-line determined mass of carbohydrates of each of the fractions flow rate 0.15 ml/min V. , = 70 ml, = 180 ml eluent 0.01 tA NaOH. 

In Fig. 16.32, application of a TSK PW SEC system consisting of a combination of precolumn + PWM + 6000 + 5000 + 4000 + 3000 demonstrates a possibility for analytical purposes to change from DMSO-dissolved glucans to an aqueous solution. An initially DMSO-dissolved potato starch sample was applied to the TSK PW system and because separated with an aqueous... 

Starches can be separated into two major components, amylose and amylopectin, which exist in different proportions in various plants. Amylose, which is a straight-chain compound and is abundant in potato starch, gives a blue colour with iodine and the chain assumes a spiral form. Amylopectin, which has a branched-chain structure, forms a red-purple product, probably by adsorption. 

The variation between the starch from different plants is considerable. The percentage of amylose varies from 27% in maize starch through 22% in potato starch to 17% in tapioca starch. The waxy maizes are unusual in that they are almost pure amylopectin. This is extremely convenient because it avoids the need to separate amylopectin from amylose chemically. 

Amylodextrins from waxy-maize starch (A type) and potato starch (B type) retain the same diffraction pattern as that of the parent starch. On separation of a starch to give an amylodextrin, the... 

Figure 10.1 Scanning electron micrographs (SEM) of starches separated from different sources (a) rice, (b) wheat, (c) potato, (d) maize (bar= 10 mm) (source Singh et al., 2003).

Maize starch may be separated after irradiation into several fractions, based on solubility in alcohol and aqueous alcohol. The size of the fractions and their composition depends on the radiation dose, as shown in Table X which also shows the distribution of organic products of destruction (aldehydes and carboxylic acids) in particular fractions.118 The relations presented in this Table are S-shaped. Under irradiation with increasing doses, the destruction of starch obviously increases. The nature of the increase of acidity in com starch has also been studied by Athanassiades and Berger.119 Thollier and Guilbot120 have conducted similar studies on potato starch, and Raffi et al99 have extended their studies to more varieties of starch. The results expressed as free and total acidities, as well as the quantity of formic acid at equilibrium water content, are given in Table XI. These data vary rather nonlinearly with increase of the irradiation dose and water content. 

Starch for use in papermaking has to meet specific purity requirements in residual oil, protein, bran and ash content. Industrial starches have a protein content (N X 6.25), ranging from about 0.05% for potato starch to 0.3-0.6% for com starch, depending on separation efficiency during production. Excess protein content will induce foaming in dispersions of starch and affect the quality and strength of the coated surface. Starch for use in the paper industry should not contain more than 0.4% protein. Oxidized starches tend to have the lowest protein content. Residual oil will cause retrogradation due to complex formation with amylose. 

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