Parboiled rice production and graded soaking method

Abstract

The invention discloses a parboiled rice production and graded soaking method.The method is technically characterized in that cleaned unhulled rice is subjected to graded soaking two times.The cleaned unhulled rice is soaked in a solution of citric acid with the concentration being 1% and cellulose enzyme (enzyme activity is 5000 u / g and concentration is 0.010-0.015%) for the first time, soaking temperature is 45-55 DEG C, soaking pressure is 300-400 kpa, and soaking time is 1-2 h.The unhulled rice soaked for the first time is subjected to filtration so that soaking liquid can be filtered out, second time of normal pressure soaking is performed, and soaking is performed for 2-3 h in a selenium solution with the concentration being 60 micron mol / L at the temperature of 30-45 DEG C.After the unhulled rice is processed, water content is controlled to be 40-42%, the unhulled rice is conveyed into a cooking vessel through a conveying device, the cooking vessel is closed, 120 DEG C saturated steam is introduced, and starch of unhulled rice endosperms is fast gelatinized.The cooked unhulled rice is gradually dried till the water content is 14%, the temperature of the unhulled rice is gradually lowered through a tempering technology after each drying procedure, and it is guaranteed that temperature and water of various portions of the unhulled rice are uniform; the dried unhulled rice is hulled, ground and packaged, and parboiled rice finished products are made.

Description

technical field [0001] The invention belongs to the technical field of grain processing, and specifically relates to a production process of parboiled rice, in particular to a steaming method in which secondary soaking is performed during the production process of parboiled rice. Grading soaking technology for rice production. Background technique [0002] Parboiled rice, commonly known as "semi-cooked rice" in the international market, is a rice product produced with rice as raw material, after cleaning, soaking, cooking, drying and other hydrothermal treatments, and then according to conventional rice milling processing methods. It has the characteristics of high rice rate, high oil yield, long storage period, and short cooking time. Parboiled rice processing preserves more nutrients than white rice processing, but some nutrients are still dissolved in water during the soaking process, and most of them are water-soluble micronutrients, resulting in the loss of rice nutrie...

AI Technical Summary

Problems solved by technology

One-time immersion has the disadvantages of immersion pressure, fixed immersion temperature, high temperature, high pressure, short immersion time, fast water absorption rate, high nutrient loss rate, and high crack rate during subsequent processing.

If the soaking temperature is low and the pressure is small, the soaking time will be long, which will affect the production efficiency

No soaking process is used in the production process, which can reduce the loss of rice nutrients, but nutrients such as selenium in rice cannot be enriched, and direct cooking due to high cooking temperature will lead to a high crack rate in the product and affect the quality of the finished product

[0003] The soaking process directly affects the effect of husking and rice milling in the subsequent processing. Soaking in general soaking liquid will cause the rice grains to become more compact after absorbing water, which will increase the difficulty of husking and rice milling.