Starch ethers applications

Commercially available cationic starches for wet end application are quaternary and tertiary products. These products have been available since about the mid 1950 s and no new basic chemistry has been developed since that time. The development in the late 1940 s and early 1950 s of starch ethers and esters made in the original granule form led to a torrent of starch derivatives for industrial use. Very few of these became commercial. This is possibly because the functions that were required by the industrial and food markets were far... 

Starches have been chemically modified to improve their solution and gelling characteristics for food applications. Common modifications involve the cross linking of the starch chains, formation of esters and ethers, and partial depolymerization. Chemical modifications that have been approved in the United States for food use, involve esterification with acetic anhydride, succinic anhydride, mixed acid anhydrides of acetic and adipic acids, and 1-octenylsuccinic anhydride to give low degrees of substitution (d.s.), such as 0.09 [31]. Phosphate starch esters have been prepared by reaction with phosphorus oxychloride, sodium trimetaphosphate, and sodium tripolyphosphate the maximum phosphate d.s. permitted in the US is 0.002. Starch ethers, approved for food use, have been prepared by reaction with propylene oxide to give hydroxypropyl derivatives [31]. 

Another group of compounds made by a. are hy-droxyethyl cellulose and - hydroxypropyl cellulose. Starch is modified also by ethoxylation (- starch ethers), and - alginic acid is propoxy-lated for some food applications. 

Starch, cooked in the paper mill or supplied as - pregelatinized starch, is used also. Modified starches (- oxidized starch, - cationic starch or - starch ethers) are common in that application. Sodium - carboxymethyl cellulose is also effective, but as an anionic polymer, it requires a retention aid such as alum. 

Application of ethylene-,4C to plants resulted in only a 2.4% conversion into soluble carbohydrates, 11% into ether-soluble materials, 6.9% into phytol, 31.7% into cellulose and lignin, and 9.6% into soluble protein and non-protein material, mainly phosphates. 9 Treatment of detached fruit (such as apples, bananas, peaches, figs, and pears) with synthetic auxins, especially (2,4,5-trichlorophenoxy) acetic acid, speeded up ripening, as indicated by color, taste, softness, and starch breakdown. 7 Other fruits have been similarly ripened, 8 and the treatments are effective both on climacteric and non-climacteric fruit. 

Carbohydrase (Aspergillus oryzae var.) Produced as an off white to tan, amorphous powder or a liquid by controlled fermentation using Aspergillus oryzae var. Soluble in water (the solution is usually light yellow to dark brown), but practically insoluble in alcohol, in chloroform, and in ether. Major active principles (1) a-amylase, (2) glucoamylase (amyloglucosidase), and (3) lactase. Typical applications used in the preparation of starch syrups, alcohol, beer, ale, bakery products, and dairy products. 

---