US 4,181,748 AGranted

Combined dry-wet milling process for refining corn

AssigneeCPC International Inc.

InventorsVincent P. Chwalek, Richard M. Olson

Life of this patent

Estimating the term…

Loading patent…

Abstract

A continuous process for refining whole grain corn to obtain a prime corn starch fraction, an animal feed product and, optionally, corn oil. The process comprises dry milling corn kernels to provide an endosperm fraction, a germ fraction, a fiber (hull) fraction and a cleanings fraction, wet milling the endosperm fraction including using two distinct steeping steps, one upstream and the other downstream of an impact milling step, to provide a mill starch slurry. The process further comprises removing fine fiber tailings from the mill starch slurry, separating the slurry into a starch-rich fraction and protein-rich fraction, concentrating the protein-rich fraction, directly combining the fiber (hull), cleanings, fine fiber tailings and protein-rich concentrate without removing corn oil therefrom, with the germ fraction to provide a wet animal feed product, and drying the feed product. Optionally, corn oil is recovered from the germ fraction only.

Claims16

Dependent claims

A continuous corn refining process, which comprises:

(A) dry milling whole grain corn to provide
(a) an endosperm fraction,
(b) a germ fraction,
(c) a fiber (hull) fraction, and
(d) a cleanings fraction;
(B) wet milling the endosperm fraction of (A)(a) by sequentially
(i) steeping the endosperm fraction,
(ii) separating the larger wet endosperm particles from the smaller wet endosperm particles,
(iii) milling the larger wet endosperm particles to reduce their particle size,
(iv) recombining the wet endosperm particles of (ii) and (iii) into a single fraction, and
(v) steeping the endosperm fraction again to provide a mill starch slurry;
(C) separating fine fiber tailings from the mill starch slurry of (B)(v);
(D) separating the defibered mill starch slurry of (C) into a starch-rich fraction and a protein-rich fraction;
(E) concentrating the protein-rich fraction of (D);
(F) directly combining each of the fiber (hull) fraction and the cleanings fractions of (A), the fine fiber tailings fraction of (C) and the protein-rich concentrate of (E) without removing any corn oil therefrom, with the germ fraction of (A) to provide a wet animal feed product;
and
(G) drying the wet feed product of (F) to obtain a final animal feed product.

14 more elements

A continuous corn refining process, which comprises:

(A) dry milling whole grain corn to provide
(a) an endosperm fraction,
(b) a germ fraction,
(c) a fiber (hull) fraction, and
(d) a cleanings fraction;
(B) wet milling the endosperm fraction of (A)(a) by sequentially
(i) steeping the endosperm fraction in a solution of sulfur dioxide in water, the initial weight ratio of the process (steep) water to the endosperm particles being in the range of from about 6:1 to about 7:1,
(ii) separating the wet endosperm particles having a size of greater than about 50 microns from the smaller wet endosperm particles,
(iii) impact milling the wet endosperm particles having a size of greater than about 50 microns to reduce their particle size to about 50 microns or less,
(iv) recombining the wet endosperm particles of (ii) and (iii) into a single fraction, and
(v) steeping the endosperm fraction again in a solution of sulfur dioxide in water to provide a mill starch slurry, the total residence time of steeping steps (i) and (v) combined being in the range from about 2 to about 6 hours;
(C) separating the fine corn fiber tailings from the mill starch slurry of (B)(v);
(D) passing the defibered mill starch slurry of (C), having a specific gravity of from about 7.degree. to about 9.degree. Baume, through a plurality of hydroclones to provide an underflow stream comprising a starch-rich fraction and an overflow stream comprising a protein-rich fraction;
(E) concentrating the protein-rich fraction of (D);
(F) directly combining each of the fiber (hull) fraction and the cleanings fraction of (A), the fine fiber tailings fraction of (C) and the protein-rich concentrate of (E) without removing any corn oil therefrom, with the germ fraction of (A) to provide a wet animal feed product;
and
(G) drying the wet feed product of (F) to obtain a final feed product.

14 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/904,838Filed 11 May 1978
Granted: 1 Jan 1980
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

C08B 30/044
From cereals or grains: from corn or maize
A23J 1/12
Obtaining protein compositions for foodstuffs; Bulk opening of eggs and separation of yolks from whites: from cereals, wheat, bran, or molasses
A23K 10/30
Animal feeding-stuffs: from material of plant origin, e.g. roots, seeds or hay; from material of fungal origin, e.g. mushrooms
Y02P 60/87
Food processing, e.g. use of renewable energies or variable speed drives in handling, conveying or stacking: re-use of by-products of food…