5 research outputs found

    Karakterisasi Sifat Fisikokimia dan Fungsional Fraksi Pati Uwi Ungu (Dioscorea Alata)

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    Size fractionation of yam starch granule could be achieved through dry sieving Retsch Siever with 400 and 500 mesh. Although the fractionation was not completely separate the granule size, however it could provide a significant difference in average size of the fractions. Starch granule morphology, size distribution, amylose and phosphorus contents, crystal structure, thermal properties, and rheological characteristic of the starch fraction were evaluated. In this study, based on the average value of the granule size, significant effects of fraction were obtained on phosphorus content and relative crystallinity of the starch. The size fraction differences did not give a significant impact on its gelatinization character, while in the pasta formations the effect of the fraction was found in peak and final viscosity. In the bigger size fraction, the phosphorus content increased but the relative crystallinity decreased. These differences made the large size fraction of starch granule had the advantage in paste profiling than starches and fractions against stirring, heating and cooling for its potential use in food processing as thickner

    Chemical Characterization of Flour Fractions From Five Yam (Dioscorea Alata) Cultivars in Indonesia

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    The purpose of this study was to investigate the influence of particle size on the chemical properties of yam flour in five cultivars, yellow/YY, orange/OY, light purple/LPY, purple/PY, and dark purple/DPY. With a mesh sieve, three flour fractions were separated according to particle size: small (128.6-139.7 µm), medium (228.7-257.9 µm), and large (475.4-596.3 µm). The content of moisture (6.81-11.26 %db) and lipids (4.48-9.85 %db) decreased with the increase of particle size, while proteins (4.48-9.85 %db) and carbohydrates (78.12-83.76 %db) were not influenced by particle size. Folin-Ciocalteu reagent and chlorogenic acid were used as standard to investigate the total phenolic compounds in the yam flour, and high-performance liquid chromatography (HPLC) was used to investigate the anthocyanin and carotene contents. It was found that there was no size influence on the content of phenolics (0.27-2.82%db), anthocyanin (2.25-15.27 mg/100g db) in LPY, PY, DPY or carotene (23.75-132.12 mg/100g db) in YY, OY. The differences in chemical composition were due to differences in particle size and heat treatment, but may also have been caused by the different composition of the milling process
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