Sweet potato starch

One of the more recent innovative approaches was to look for new micro-organisms and novel carbohydrate substrates. The early fermentations used sugar beet or cane molasses, various syrups, sweet potato starch or glucose itself and the micro-organism was always an Aspergillus spp. In the early 1930 s it was found that yeasts would produce dtric add from acetate. Since then a variety of yeasts, prindpally Candida spp., has been shown to convert glucose, w-alkanes or ethanol to dtric add with great effidency. 

Sweet potato flour contained 3.8% protein, the second highest amount of protein among starchy foods, and yet the protein appeared to be the poorest in nutritional quality. However, it should be noted that the sweet potatoes used in this study were dried at 60 C but were not cooked. Uncooked sweet potato starch is not completely digestable by rodents. As a consequence, maintenance requirements would increase. This is the most likely explanation for the increased requirement for bean flour, but there also may have been interference with digestion from protease inhibitors present in uncooked sweet potatoes. 

Horigome et al. (3J5) reported a PER of 1.9 for protein recovered from an industrial sweet potato starch facility. They were able to increase the PER to 2.5 by supplementing the diets with lysine and methionine. A portion of these amino acids were either destroyed or made biologically nonavailable by the processing operation. The possibility also exists that these amino acids were limiting in the cultivars studied. 

Chen, Z., Schols, H. A., Voragen, A. J. G. (2004). Differently sized granules from acetylated potato and sweet potato starches differ in the acetyl substitution pattern of their amylose populations. Carbohydr. Polym., 56, 219-226. 

Lee, J. J., Rhim, J. W. (2000). Characteristics of edible films based with various cultivars of sweet potato starch. Kor. J. Food Sci. TechnoL, 32(4), 834-842. 

Takeda, Y., Tokunaga, N., Takeda, C., andHizukuri, S. 1986. Physicochemical properties of sweet potato starches. Starch 38 345-350. 

Sweet potato starch (Plate IV, Fig. 27). This consists of granules of irregular form and size. The typical shape is rounded with four angles, somewhat like an egg or a kettle, and some granules are striated and exhibit a well-marked eccentric hilum. The mean size is 30 fx, but the largest granules may attain 65 fx. 

A wheat starch sample had an amylose that was the least branched, with only 27% of the molecules having a branch linkage. These branched amyloses had approximately five branch chains per molecule with an average DP of 270. The most highly-branched amylose was that obtained from sweet potato starch in which 70% of the molecules were branched, with 10 chains per molecule and an average DP of 335. 

Chemical and physical properties of sweet potato starch." Ind. Eng. Chem., 25 565-568. 

Liu C-S, Desai KGH, Meng X-H, Cheng X-G (2007) Sweet potato starch microparticles as controlled drag release carriers preaparation and in vitro drug release. Drying Technol 25 689-693... 

It is well known that starch-iron complexes are suitable for fortifying bread and flour with iron. The state of iron in flour, dough, and bread was investigated by Leichter and Joslyn.643 Iron salts influence the whiteness of sweet-potato starch, but this effect is variable.644 It was also reported645 that colloidal iron interacts with starch, a process which is used to fractionate starch into three portions The first portion (80% of the total amount) is formed by colloidal iron itself, the second (9% of the total) is formed by iron and electrolytes, and the third portion (11% of the total) is not precipitated at all. 

Cassava starch Sweet potato starch Waxy com starch... 

In this work, the profile of CD production by the action of CGTase from Bacillus clausii strain El 6 in soluble starch and maltodextrin was studied. Furthermore, the action of this CGTase in the presence of other starch botanical sources such as cassava starch, sweet potato starch, com starch, and waxy com starch were analyzed. 

The CGTase action was evaluated on cassava starch, sweet potato starch, com starch, and waxy com starch. Substrates concentrations were at 2.5%. Enz5mie, conditions, and quantity were conducted as described above, except that aliquot samples were withdrawn periodically until 24 h. In an independent experiment, starches were gelatinized by autoclave process. The percentage of starch converted into CDs was calculated by ratio of total grams of CDs formed divided per gram of starch and multiplied per 100. 

Soluble starch was a better substrate than maltodextrin for CD production, so other substrates were also used for CD production. The content and structural characteristics of amylose and amylopectin present in starches may vary depending of their botanical sources. So, it was interesting to investigate this parameter regarding to CD formation under CGTase action. Cassava starch, sweet potato starch, com starch and waxy com starch were used. 

Generally, starches contain about 20 to 30% of amylose and 70 to 80% of amylopectin, and these concentrations change with the botanical source of starch. Cassava starch, sweet potato starch, com starch, and waxy com starch showed, respectively, 17.0, 20.7, 25, and less than 1% of amylose (28,29, 30). The ratio amylose/amylopectin is an important factor to consider for CD production. The helicoidal stracture of amylose with loops of six to seven glucose imits can contribute with action of CGTase on a- and 3-CD formation (2). 

V. Sweet Potato Starch Utilization in Human Food Systems... 

V. SWEET POTATO STARCH UTILIZATION IN HUMAN FOOD SYSTEMS... 

FIG. 4 Scanning electron micrographs of sweet potato starch granules (Miller et al,... 

FIG. 5 Procedures for sweet potato starch production. (A) Sweet potato starch production by the sour-liquid method (Timmins and Matter, 1992). (B) Sweet potato starch isolation (Miller et al., 2003). 

FIG. 7 Overview of enzymatic hydrolysis of sweet potato starch into glucose syrup. LIQ = Liquefaction, SAC = Saccharification (Bovell-Benjamin et al., 2005). 

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