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DOCUMENTATION_FORMAT: VOLATILE
SAMPLE_ID: Starch, corn Argo GDS549
MATERIAL_TYPE: Sugar; Polysaccharide; Starch; Plant Carbohydrate
MATERIAL: Starch
FORMULA: (C6H10O5)n
FORMULA_HTML: (C6H10O5)n
COLLECTION_LOCALITY: Purchased from grocery store. Corn starch Argo brand.
COLLECTION_LATITUDE: Not Available # degrees and decimal minutes (N or S)
COLLECTION_LONGITUDE: Not Available # degrees and decimal minutes (W or E)
DATUM: Not Available # coordinate datum
ORIGINAL_DONOR: Raymond F. Kokaly
CURRENT_SAMPLE_LOCATION: USGS Spectroscopy Lab, Denver, CO
ULTIMATE_SAMPLE_LOCATION:USGS Spectroscpy Lab, Denver, CO
SAMPLE_DESCRIPTION:
This starch sample, a white powder, was purchased from a grocery store. It is a corn-derived product of Argo brand (ACH Food Companies, Inc.; Ankeny, Iowa).
Starch is a carbohydrate polymer of glucose units joined together by O-glycosidic bonds. It consists of two types of molecules: the linear and helical amylose and the branched amylopectin. Amylose consists of repeating α-1,4-D-glucans (isomeric with the celluose structure of β-1,4-D-glucans). Branching in amylopectin takes place with α(1-6) bonds occurring every 24 to 30 glucose units, resulting in a soluble molecule that can be quickly degraded. In contrast, amylose contains very few of these branches, which causes it to be hydrolyzed more slowly but have higher density and be insoluble. Depending on the plant, starch generally contains 20 to 25% amylose and 75 to 80% amylopectin by weight.
IMAGE_OF_SAMPLE:
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
END_XRD_ANALYSIS.
COMPOSITIONAL_ANALYSIS_TYPE: None.
COMPOSITION_TRACE: None
COMPOSITION_DISCUSSION:
END_COMPOSITION_DISCUSSION.
MICROSCOPIC_EXAMINATION:
END_MICROSCOPIC_EXAMINATION.
SPECTROSCOPIC_DISCUSSION:
END_SPECTROSCOPIC_DISCUSSION.
SPECTRAL_PURITY: 1a2a3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns