Starch, complexes acids

The crude gum tragacanth is a mixture of the salt of a complex acid polysaccharide and a neutral polysaccharide composed principally of L-arabinose residues. Starch is also present in the gum. The acid character of this gum is due to units of D-galacturonic acid and not D-glucuronic acid and it is of interest to note that in its ability to form gels it resembles pectin and the plant mucilages, which also contain D-galacturonic acid. 

In starch chemistry and technology, extrusion is used for cooking as well as for preparation of starch complexes with such guest molecules as gluten6511 and lipids.651 Acylation of starch with cyclic anhydrides of dioic acids on extrusion has been demonstrated the reaction provides anionic starches.651... 

Iodates, III, 138, 157, 178 Iodic acid, as oxidant, III, 178 Iodine, adsorption by starch, I, 256 colors of products formed from starch by amylases, V, 261 as oxidant, III, 151, 169 solubility of, III, 136 Iodine starch complex, dichroism of flow of, I, 266... 

In some instances the carrier of the guest plays the role of emulsifier. For example, alcohols and lower fatty acids or their esters are used in the formation of fat-starch complexes.676 In this case, conditions for preparation of complexes resemble conditions for extraction, and unexpected results can accompany both processes. For example, it has been shown that extraction of lipids with 1-propanol from their surface complex with oat starch produced a helical lipid-starch complex that was absent prior to extraction.677... 

Starch complexes with aromas and flavoring agents are usually synthetic in origin. In nature, starch sometimes includes some aroma- and flavor-genic components that generate flavor and aroma on processing (see, for instance, ref. 678). Such agents include mainly aldehydes, ketones, and carboxylic esters however, hydrocarbons, alcohols, carboxylic acids, and haloalkanes have also been used. 

The preparation of starch-fatty acid complexes is based on the use of hydrophobic solvents, which in turn open the starch lattice for penetration by acids. Such solvent molecules can become guests of inclusion complexes and are subsequently displaced by fatty acids. Extrusion has been found useful for the synthesis of such complexes.748,749 Starch should be defatted prior to complexation by using methanol,739,740 Cellosolve, or 80% 1,4-dioxane.750-752 Table XXXV summarizes the results of a classical preparation.701 As shown in Fig. 47, the amount of complex formation by extrusion is not linearly proportional to the concentration of fatty acids added.749 In... 

X-ray diffraction analysis754 of a series of amylose complexes with lower and higher fatty acids revealed that the crystal structures depend on whether amylose was complexed in the dry or wet state. Both the 6, and 7i helical conformations of amylose were found in these complexes. The conformation appears to depend on the length of the hydrophobic moiety. Dry amylose forms crystalline complexes with a unit cell identical to that of the anhydrous 1-butanol-starch complex (lattice parameters a = b = 25.6 A). An orthorhombic unit cell was proposed for the 7i -helical structure of the wet complexes of monobasic acids (acetic, butanoic, pentanoic, hexanoic,... 

Inclusion protects unsaturated fatty acids from aging however, this protection is not perfect, as amylose itself also complexes oxygen753 756 (see Fig. 48). Unsaturated acids have a specific pattern of the carbon chain because at least two sp2-hybridized carbon atoms are present, causing geometrical isomerism. The frans-isomer does not fit perfectly into the cavity of amylose. Another report indicates that starch complexation with tannic acid has no effect on its activity against experimental ulcers in laboratory rats.757... 

It will be noted that this type of complex-formation is entirely different from that in which complexes are formed between amylose and certain polar, organic compounds. In contrast to the precipitates of the latter complexes (which are of a distinct, crystalline appearance), the starch-alkaline-earth hydroxide complexes are amorphous, curdlike flocculates. These complexes di,s.sociate on diluting them with water, and the starch redissolves. According to the patent description, the amylose complexes dissolve much more easily than the amylopectin complexes hence, fractionation must occur if water is added stepwise. Likewise, fractionation will take place if the starch complexes are partially neutralized, by the gradual addition of an acid. For obvious reasons, such acids as carbonic acid and sulfuric acid (which give insoluble calcium salts) are preferred. Furthermore, it is claimed that gradual addition of caustic alkali to a starch solu-... 

Crodatem. [Croda Food Prods. Ltd.] Diacetyl tartaric acid ester Antistaling agent, starch complexing agent, emulsifier for food industry. 

Figure 1.8 Chromatogram of iodide in seawater by size exclusion chromatography with UV detection. Iodide in seawater could be determined indirectly after it was converted to iodine-starch complex. Conditions column, Shim-pack DIOL-150 mobile phase, methanol-0.01 mol 1 aqueous phosphoric acid...

Chem. Descrip. Triglycerides of mixed edible fatty acids Uses Hardened bread fat for snack food coatings starch complexing agent in bread... 

Fanta, G.F., Shogren, R.L. and Saleh, J.H. (1999) Steam jet-cooking of high-amylose starch-fatty acid mixtures, an investigation of complex formation. Carbohydrate Polymers, 38, 1-6. 

Definition Monoester of glycerin and a blend of palmitic and stearic acids Empirical C63H116O12 Properties Nonionic Uses Emollient, stabilizer, emulsifier, dispersant for cosmetics food emulsifier starch complexer excipient in tablets lubricant, and binder in pharmaceuticals suspending agent thickener defoamer in... 

Stabilisation, 252,256 Staining reagents, 279 Staphylococcus species, 35, 542,478 Starch complexing, 226 Stearic acid and esters, see Octadecanoic acid Stearin, 171 Stearolic acid, 13 2-Stearodipalmitin, 370, 372 Stearoyl lactylates, 233 Stenachaenium macrocephalum, 20 Sterculia alata,13, 53 Sterculiafoetida, 53 Sterculic acid, 17, 53, 64 Sterculynic acid, 13,17,53 Stereomutation, 174,179,449,470... 

In the iodine clock reaction, a colorless solution suddenly changes to a blue-black iodine—starch complex in a predetermined amount of time (dependent upon the temperature and the concentrations of the reactants). The iodine is produced by the reaction of iodic acid and hydrogen iodide as represented in the following unbalanced equation. Identify the oxidiang and reducing agents in this reaction and balance the equation. 

Uses Antistaling agent, starch complexing agent in biscuits, cake mixes, gravy mix toffee emulsifier controls starch gelation in snack foods, pastas improves dispersibility of coffee whiteners emulsifies fat in meat prods. enables use of fat-sol,-only ingreds, in fatless flavor oil/color systems Properties Amber vise, liq, acid no, 110-130 iodine no. 70-80 sapon. no. 45-500 100% cone,... 

Uses Starch complexing agent, shelf-life extender for bread quality improver, volume improver in cakes controls/improves emulsification in coffee whiteners, filled milk stabilizer for mayonnaise aids fat dispersion In soups Properties Solid m.p. 53-58 C acid no. 3 max. iodine no. 2 max. sapon. no. 158-165 42% min. monoglyceride GMS Base [Clarkf]... 

Lassaigne s test is obviously a test also for carbon in the presence of nitrogen. It can be used therefore to detect nitrogen in carbon-free inorganic compounds, e.g., complex nitrites, amino-sulphonic acid derivatives, etc., but such compounds must before fusion with sodium be mixed with some non-volatile nitrogen-free organic compound such as starch... 

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