Starch isolation

Week-old poults fed a purified corn starch, isolated soy protein diet supplemented with 50 to 800 mg/kg ration for 3 weeks Dose-dependent increase in mortality and decrease in growth 10... 

Roushdi, M., Fahmy, A.A., and Mostafa, M. 1981a. Role of lactic acid in com steeping and its relation with starch isolation. Starch/Stdrke 33, 426-428. 

The protein concentration in the field pea proteinate was only 87.7% due to the presence of significant quantities of ash, lipid and carbohydrate (Table I). Both refined starches were relatively pure, the protein levels being only 0.5%. The merits of producing protein and starch isolates as opposed to concentrates by the dry process would depend on their relative functional properties and the requirements of the end-user. 

Starch is isolated from plant sources by various methods (Ratnayake and Jackson, 2003 Zobel, 1992). The method of starch isolation depends on the nature and composition of the raw material source. Most food starches are isolated and purified on a commercial scale and then used as ingredients by food manufacturers. Commercial food starches are generally classified based on both botanical origin and functionality. With the increasing availability of modified starches prepared for specific food applications, starch manufacturers tend to emphasize and market starch with a secondary focus on botanical source. In fact, for food... 

The detailed procedure of starch isolation from potato tubers is as follows. Potato tubers (10 kg) are washed, peeled, sliced into 2-3 cm cubes, and soaked in distilled water containing 20 mM sodium bisulfite and 10 mM citric acid for 2 hours to prevent darkening. The cubes are then disintegrated using a centrifugal juice extractor, the pulp is suspended in 6 L of distilled water and passed through the extractor again, and starch milk is collected. The milk is allowed to sediment for 30 minutes the supernatant and the suspended solids are removed by decantation, and the... 

Figure 10.4 RVA pasting curves of starches isolated from different New Zealand potato cultivars (source Singh et al., 2006).

Lim, S. T, Lee, J. H., Shin, D. H., Lim, H. S. (1999). Comparison of protein extraction solutions for rice starch isolation and effects of residual protein content on starch pasting properties. Starch, 51, 120-125. 

Probably the most important carbohydrate polymer in food, certainly from a nutritional standpoint, is starch, and Chapter E2 presents three units that can be used for starch isolation and characterization. UNITE2.1 condenses many different starch isolation methods into one scheme for starch isolation from virtually any plant source. In this protocol, the author notes the care that must be taken to prevent starch degradation during isolation. unite2.2 presents a simple enzymatic analysis method that can be used for estimation of starch in food. Finally, unit E2.3 describes a colorimetric method to determine starch amylose content. Again, different combinations of the units in this chapter can be used to characterize starch from any source. 

Figure E2.1.1 Basic steps in starch isolation from plant materials. Route A is for tubers, roots, and yams routes B-D are for grains route E is for wheat. See text for more details on individual steps.

Centrifugation is an important step in starch isolation that separates starch from fine fibers, insoluble or soluble protein, and gum or mucilage compounds. Centrifugation (usually 20 to 30 min at 5000 to 8000 x g, 20°C) settles the starch (a white layer) at the bottom of the centrifuge tube (Fig. E2.1.2). The water-insoluble contaminants (e.g., protein, fine fiber) form a dark or brown layer on top of the starch layer. This contaminant layer is normally removed manually by scraping with a spatula, being careful not to scrape away any of the starch layer. 

Grant, L.A. 1998. Effects of starch isolation, drying and grinding techniques on its gelatinization and retrogradation properties. Cereal Chem. 75 590-594. 

Air classification, starch isolation, 674-675 Aldehydes, see also Carbonyl compounds citrus oils, quantification meats, effect on flavor, 559 Alditol acetates... 

DNPH. see 2,4-Dinitrophenylhydrazine DOPA, conversion of, 395 Dough, washing, starch isolation, 675-676 DPH. see 1,6-Diphenyl-1,3,5-hexatriene Drip loss in solid foods, 319, 321-322. see also Water retention Droplet concentration in emulsions, 516, 594-596... 

FD. see Field desorption Fermentation, beer, 95 Ferrous oxidation/xylenol orange (FOX) method, lipid peroxide value (PV) basic protocol, 520-522, 526 characteristics of, 515, 526 modified, 527-528 FID. see Flame ionization detection Filtration, starch isolation, 676 Fish muscle, water retention examples, 320-323 (figs.) methods, 315-323... 

Hue, in color analysis, see also Color Hulled grains, starch isolation, 673 Human subjects/studies. see also specific studies... 

Mannuronic acid, determination of, 735 Manometer, measuring vapor pressure to determine water activity, 61 -66 Martin process, starch isolation, 675 Mass spectrometry (MS), see also specific MS methods... 

Pineapple oil, peel-oil content and aldehyde composition, see also Citrus oils Pin milling, starch isolation, 673, 677 Pipetting technique, 754-755 PL. see Pectic lyase... 

Slurrying, starch isolation, 674-676 Small-granule starches, centrifugation, 676 Smell chemicals, see Aroma compounds Smoke, interfacial properties, 609 (table) Sodium borohydride, 717 Sodium dodecyl sulfate, in SDS-PAGE. see Polyacrylamide gel electrophoresis Sodium thiosulfate, standardization, 519-520... 

Water slurrying, in starch isolation, 675 Water uptake ability (WUA) see also Water retention WHC... 

Western blot, see Immunoblot Wet grinding, starch isolation, 674-676 Wheat and wheat starch enzymatic quantification, 682 isolation, 676 moisture content, 22 Whole-grain wheat, enzymatic quantification, 682 Wijs reagent, 467-468, 475 Wine, see also Grapes WUA. see Water uptake ability... 

Starches isolated from different botanical sources display characteristic granule morphology.10-16 Starch granules vary in shape, including spherical, oval, polygonal, disk... 

Shibanuma et al.232 examined the molecular structures of starch isolated from three Japanese wheat varieties, one Australian standard white wheat and one US western white wheat. The data presented in Tables 10.9 and 10.10 again indicate that the properties and structural features of amylose and amylopectin are dependent on the starch source. The molecular sizes of amylose and amylopectin were larger in the US wheat compared to the corresponding starch fractions from the Australian and Japanese wheat starches. Among the five wheats, the two preferred for salt noodles in Japan, the Japanese variety Chihoku and the Australian standard white, contained a higher proportion of branched amylose and a lower number of chains per amylose... 

The loaf volumes of breads baked from wheat starch coming from different classes of wheat, be it hard red winter, hard red spring, soft red winter or soft white, were similar.436 By contrast, club wheat starch produced a larger loaf volume and durum wheat starch a smaller loaf volume. Other investigators found a range in the loaf volumes of breads baked from wheat starches isolated from different classes of wheat.437 Fractionation and reconstitution studies revealed that rye and barley starches can substitute for wheat starch in producing bread of satisfactory volume. Starches from... 

Rice starch is preferably prepared from broken rice for economic reasons, as discussed above. There are currently two commercial methods of rice starch isolation traditional and mechanical. The traditional method involves alkali solubilization of rice protein, while the mechanical method releases starch via a wet-milling process. 

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