Graft copolymerization onto starch. III. Grafting of acrylonitrile to gelatinized potato starch by manganic pyrophosphate initiation

Starch is arranged in a crystalline manner within its storage granules and should thus give sharp X-ray diagrams. Unfortunately most of the common starch granules have sizes between 1 and 100μm, making them too small for an X-ray study on individual grains. There is only one instance where an oriented X-ray diagram could be obtained on one sector of an individual giant starch granule. Despite their small size, starch granules are still too thick to be studied by electron diffraction with a transmission electron microscope. The only reported study on starch ultrastructure using electron diffraction on frozen hydrated material was made on small fragments. The present study has been realized on thin sectioned granules previously litnerized to improve the signal to noise ratio.Potato starch was hydrolyzed for 10 days in 2.2N HCl at 35°C, dialyzed against water until neutrality and embedded in Nanoplast. Sectioning was achieved with a commercially available low-angle “35°” diamond knife (Diatome) after a very carefull trimming and a pre-sectioning with a classical “45°” diamond knife. Sections obtained at a final sectioning angle of 42.2° (compared with the usual 55-60°) and at a nominal thickness of 900Å were collected on a Formvar-carbon coated grid. The exact location of the starch granules in their sections was recorded by optical microscopy on a Zeiss Universal polarizing microscope (Fig. 1a). After rehydration at a relative humidity of 95% for 24 hours they were mounted on a Philips cryoholder and quench frozen in liquid nitrogen before being inserted under frozen conditions in a Philips EM 400T electron microscope equipped with a Gatan anticontaminator and a Lhesa image intensifier.

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Composition of White Potato Starch (Ipomea batatas L.) with Avocado Seed Starch (Persea americana Mill) and Glyserol Concentration in Edible Film

Serambi Journal of Agricultural Technology ◽

10.32672/sjat.v2i2.2415 ◽

2020 ◽

Vol 2 (2) ◽

Author(s):

Musdar Musdar ◽

Lukmanul Hakim ◽

Juliani Juliani ◽

Jailani Jailani

Keyword(s):

Sweet Potato ◽

Potato Starch ◽

Persea Americana ◽

Edible Film ◽

Glycerol Concentration ◽

White Potato ◽

Ipomea Batatas ◽

Sweet Potato Starch ◽

Local Plants ◽

Avocado Seed

White sweet potato starch (Ipomea batatas L.) and avocado seed starch (Parsea americana Mill) derived from local plants have the potential to be developed as agricultural products. Starch is a hydrocolloid compound as a potential local resource to be utilized. Glycerol function as an anti-freezing which is hygroscopic. This study aims to determine the ratio of white sweet potato starch with avocado seed starch and the concentration of glycerol for making edible film. This study was an experiment using a completely randimized factorial design with 2 (two) main factor consisting of a comparison of white sweet potato starch and avocado seed with 3 levels: P1 = 35%:65%., P2=50%:50%., P3=65%:35% and glycerol concentration with 3 levels: G1=1%., G2=2%., G3=3%. The best result reasearch were content of 23.03% (tratment P1G1), solubility of 55.57% (treatment P3G2)., swelling test of 9.83% (treatment P2g3)., elongation of 8.18% (treatment P3G2)

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Influence of gelatin on the properties of edible films and coatings on the basis of potato starch

Polymer materials and technologies ◽

10.32864/polymmattech-2017-3-3-64-70 ◽

2017 ◽

Vol 3 (3) ◽

pp. 64-70

Author(s):

O.S. Shulga ◽

O.A. Petrusha

Keyword(s):

Potato Starch ◽

Edible Films

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