Organic compounds -- part of the class 532-570 series – Organic compounds – Carbohydrates or derivatives
Patent
1997-01-17
1999-07-27
Prats, Francisco
Organic compounds -- part of the class 532-570 series
Organic compounds
Carbohydrates or derivatives
435101, 435274, 435275, 127 71, 127 65, C08B 3004, C12P 1904
Patent
active
059292318
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The subject of this invention is separation and purification of fine-granuled and modified starches from oat or rice groats.
Cereal crops used for manufacturing of starch have been so far mainly corn and wheat. As compared to these crops, use of rice for starch manufacture is less common. When used, the raw material consists usually for economical reasons of mechanically or enzymatically damaged kernels of rice. Despite the properties of rice starch deviate from other cereal starches, its industrial use has remained smaller as compared to other cereal starches. This is partly due to its higher price, partly due to fluctuations in quality deriving of the problems in the quality of raw material said above. Barley and rye have been used in the manufacture of starch mainly for finding demand for surplus crops. These starches have no such special properties that would give them an advantage over other cereal starches.
Unlike most other cereal starches, oat starch has a small granule size. The primary granules are usually 3 to 5 .mu.m in dimensions and the shape is globular or angular. In the kernels of oats and rice, the starch is for its main part in compound granules. In the endosperm of rice, the starch is totally in compound granules, whereas in oats also individual granules occur. The small granule size makes it possible to use oat starch technologically for several purposes for which rice starch has been used so far. Also the gelatinization properties of native oat starch deviate from other cereal starches, due at least partly to the amount and composition of lipids in the starch granules.
BACKGROUND OF THE INVENTION
Recovery of oat starch has been earlier presented mainly as a by-product in the preparation of protein or fibre concentrates. In most of these methods, separation is not presented further than until oat flour, or for the removal of starch for enriching the main products. Thus the U.S. Pat. No. 4,028,468 describes a process, where oat gum, starch and protein are separated from the bran by wet milling in sodium carbonate solution. Starch is separated by an effective centrifugation of the viscous solution, but any further separation of starch nor the purity of the recovered starch is given. The granule size of starch is said to be 5 to 10 .mu.m. Similarly, the Canadian Patent 1,133,446 describes separation of the endosperm from milled oats, but purification of starch only for testing purposes using laboratory methods. U.S. Pat. No. 4,211,801 describes separation in an organic solvent, whereby of oat flour free of oat gum is prepared, but separation of starch from it is not described.
Separation and purification of starch are described in detail in the European Patent Application 89.200321.1, and in the corresponding Finnish application 900508. The method is based on wet milling in a solution containing sulfur dioxide, and subsequent sieving and hydrocyclone operations. For achieving the separation of starch from cell walls, enzymes degrading cell wall components such as cellulose, hemicellulose and .beta.-glucan are used. The particle size distribution of the starch obtained using this method is according to the patent specification within limits 4-15 .mu.m.
Enzymatic steps are also included in processes where starch is further hydrolysed to maltodextrin, as in the U.S. Pat. Nos. 4,996,063 and 5,082,673. These methods are, however, not intended for separation of unhydrolyzed starch. In a method according to the Canadian Patent 1,179,189, hull-less oat groats are soaked in sulfur dioxide containing water for 24-28 hours at 50.degree. C. The inherent enzymatic activity of the kernel decomposes cell wall material, and the endosperm containing starch is separated from the bran by squeezing. In this method, too, no description of starch separation is included.
In the method described in the Finnish Patent 84,775 and in the corresponding European Patent 379,499, oat endosperm is treated in sodium hydroxide solution to decrease the protein content. The patent specification does not
REFERENCES:
patent: 3368903 (1968-02-01), Johnson et al.
patent: 3488256 (1970-01-01), High et al.
patent: 3537893 (1970-11-01), Hauser et al.
patent: 4916064 (1990-04-01), Derez et al.
Juliano, "Rice Starch: . . . ," Chapter XVI of Starch: Chemistry and Technology, 2nd ed, Whistler et al eds., 1984, pp. 507-528.
STN International, File FSTA, Fsta accession No. 86(09):L0077, Gough, B.M. et al. "On the interaction of sodium dodecyl sulphate with starch granules", (1985) pp. 99-108. (Abstract only).
Malkki Yrjo
Myllymaki Olavi
Tuomela Risto
Exavena OY
Prats Francisco
LandOfFree
Method for preparing fine-granuled and modified starches does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for preparing fine-granuled and modified starches, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for preparing fine-granuled and modified starches will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-880004