Patent GB-1203315-A (GB)
Title: Preparation of quick-cooking rice
Inventor: YASUMATSU KATSUHARU
IPC: A23L7/196
Filed: 1968-09-18
Abstract: 1,203,315. Preparing quick-cooking rice. TAKEDA YAKUHIN KOGYO K.K. 18 Sept., 1968 [22 Sept., 1967], No. 44269/68. Heading A2Q. Quick-cooking rice is produced by a method comprising the steps of (1) soaking raw white rice in an aqueous medium to increase its moisture content to between 25 per cent and 35 per cent, (2) steaming the soaked rice under atmospheric pressure for from 5 minutes to 1 hour to partially gelatinize the rice, (3) soaking the rice in an aqueous medium to raise its moisture content to between 45 per cent and 59 per cent and applying in this step from 0.03 per cent to 3 per cent of an edible oil, a surfactant or a mixture of the two to the rice (4) steaming the soaked rice under atmospheric pressure until it is completely gelatinized, (5) drying the rice grains with a stream of air at between 30C. and 100C. to a moisture content of between 8 per cent and 20 per cent, and (6) expanding the dried rice grains with a stream of air at between 200 and 400C. The aqueous medium in step (1) is either water or a mixture of water and flavouring agents or other additives, e.g. sodium chloride, monosodium glutamate, disodium 51-ribonucleotide or water-soluble vitamins, e.g. thiamine, sulphur-containing amino acids, e.g. cysteine and cystine, or/and a chelating agent such as citric acid, an edible salt thereof, or a molecularly dehydrated phosphoric acid, e.g. pyrophosphoric acid, poly-phosphoric acid or metaphosphoric acid or its edible salt in an amount from about 0-01 per cent to about 2 per cent. In step (3) the edible oil may be soya bean oil, cotton seed oil, sesame oil, corn oil, rice bran oil, lard, beef tallow and the like; the surfactant may be a glycerine fatty acid ester, a sorbitan fatty acid ester or a sucrose fatty acid ester. The preferred moisture content of the rice after soaking in water and oil and/or surfactant is about 50 per cent to 55 per cent while the amount of edible oil and/or surfactant absorbed on the rice is advantageously from about 0.1 per cent to about 1 per cent. In practice, the rice is directly soaked in an aqueous emulsion containing from about 0.1 per cent to about 10 per cent, preferably from about 0.3 per cent to about 3 per cent, of the edible oil and/or the surfactant for about 1 to 10 minutes at an elevated temperature of about 70C. Such additives as flavouring agents, water-soluble vitamins, sulphurcontaining amino acids or chelating agents may be used in the emulsion. The second steaming in step (4) is preferably for a period of from 15 minutes to 2 hours. The preferred drying temperature in step (5) is between 50C. and 90C., with agitation of the rice grains. The preferred moisture content of the dried grains is between 10 per cent and 19 per cent. The hot air employed in step (6) may be produced either by indirect heating or by the burning of a liquified gas e.g. propane or butane, or natural gas, coal gas or kerosene. The expansion is preferably conducted while the grains are suspended in the stream of hot air, e.g. by forcing the hot air through a perforated floor of a suitable apparatus such that as the grains expand they rise and are carried out of the apparatus.