CN101406269B - Method for producing fresh-keeping instant rice - Google Patents

Abstract

The invention provides a method for preparing fresh-keeping instant cooked rice, belongs to the technical field of agricultural product deep processing and food industry, and mainly relates to application of the ultrasonic treatment technique and the enzyme preparation in the instant cooked rice. In the method, the refined rice is used as a raw material, and the ultrasonic treatment technique and the enzyme preparation are utilized to control the aging and fresh-keeping of the instant cooked rice. The preparation method of the instant cooked rice comprises the following steps: the refined rice is washed, soaked in water, water-drained, pre-boiled, and then subjected to enzyme liquid soak and ultrasonic treatment, drainage, enzymolysis, acid soak, water drainage, packaging, sealing and sterilization to obtain the finished production of the fresh-keeping instant cooked rice. The fresh-keeping instant cooked rice prepared by the method has the advantages of low cost, convenient use and convenient eating, and can be eaten instantly or after heated; and if the hot food is needed, the rice bag is heated in boiled water or a microwave oven over medium-high heat for 1 to 2 minutes.

Description

A kind of production method of instant preserved rice

Technical field

A kind of production method of instant preserved rice the present invention relates to a kind of method of utilizing ultrasound-assisted enzymolysis to prepare instant preserved rice, specifically belongs to deep processing of farm products and food industrial technical field.

Background technology

Along with people's rhythm of life is constantly accelerated, the production of instant food is developed rapidly, and the cereal convenience food will occupy critical role in the food industry of new century.The cereal instant food is to be the food that primary raw material is made with cereal, and it comprises a plurality of kinds such as bread, biscuit, dilated food, instant noodles, instant-rice, convenient rice flour noodles bar.Wherein, instant-rice also claims to cook quickly rice, and it is on the scientific and technical basis of modernization, in order to adapt to a kind of novel foodstuff that people's staple food life socialization needs arise at the historic moment.

The domestic market increases day by day to the demand of instant food in recent years, impels the very strong sales of food such as instant noodles, but it is actually rare to have suitable consumer's convenient and instant rice product.And convenient and instant rice has just appearred in states such as the U.S., Japan many years ago, as Japanese convenient and instant rice more than 20 style is arranged, more than 20 ten thousand tons of year sales volumes.

Though China has begun the research that instant-rice (need use the boiling water rehydration when eating) is produced in the seventies in 20th century, after this also constantly there is research report to occur, and at 20th century the mid-80, existing instant-rice launch products, but generally speaking, edible quality is not good, kind is few, output is little, lacks the market competitiveness, and this is extremely unbecoming with China's food demand that with rice is staple food.It is many-sided influencing instant-rice factor of competitiveness on market, and as product variety, quality, cost, price etc., but topmost problem is the quality of product.Compare with instant-rice, instant preserved rice has instant, instant bagged, and without rehydration, the rice palatability is better, and also eutrophy more also can carry out seasoning according to different consumers' hobby, will have vast market.

During World War II, for adapting to the war needs, the U.S. has succeeded in developing αization rice, but, American-European countries mainly is staple food with bread, and is therefore, also few to the research of rice food, in limited research, main energy is also placed on the paste property and gelling properties of instant congee, dehydrated cooked rice and rice starch.Japan's research in this respect is just more deep, the beginning of the seventies, Japan develops a kind of edible freshness-keeping instant rice more easily, therefore advantages such as this rice has can keep that original local flavor, nutritive loss are less substantially, the peculiar taste of no metal can, normal temperature are guaranteed the quality, are easy to carry develop very fast.Development so far, a greater variety of instant-rices have appearred in Japan, roughly can be divided into two big classes, be dehydrated cooked rice and dehydrated cooked rice not, dehydrated cooked rice is not soft rice or instant rice again, instant rice is according to the difference of packing and storage method, and it is several to be divided into canned rice, freezing rice, retort pouch rice, refrigeration rice and sterile filling rice etc.

In numerous kinds, most convenient be exactly sterile filling rice, be about to method that cooked rice adopts aseptic packaging and pack in container or the bag, pack.In process of production, in order to suppress microorganism, the rice pH value before will packing is sometimes adjusted to about 5, encloses deoxidier simultaneously when packing.The production technology of initial aseptic packaging rice, only be the extension of traditional serialization rice processing technology, promptly after common serialization rice processing, beginning rice enters senior dust-free workshop from cooking rice over a slow fire, under the administration of health of strictness, finish loose meal, the metering coating-dividing sealing of rice.Therefore, operating personnel require to wear tight dustproof clothes, and the management of whole technology, operation all have a very big difficulty, and running, production cost are high relatively.Japan had had successfully researched and developed a kind of new production process of taking the course of its own in 1996.This technology is in whole process, only need very little space is arranged as dustless space, the requirement of remaining production process state and normal food job shop does not have too big difference, and go into container from the rice splendid attire and discharge to final sealing, all need not artificial intervention, when realizing the production automation, saved labour cost, and improved the processing wholesomeness of rice, be one of advanced production technology of instant rice so far.But also there is a problem in sterile filling rice, promptly easily brings back to life in storage, and this is affected with regard to making product quality or edible convenience.

Summary of the invention

The objective of the invention is to solve instant rice in the process of storing, the aging of starch taken place easily, influence the problem of product quality and shelf life.In order better to address this problem, the present invention mainly will adopt the method for ultrasound-assisted enzymolysis, at first adopt ultrasonic technology to handle in the rice of pre-boiling, utilize cavitation effect of ultrasonic waves, make endonuclease capable be deep into the inside of rice pellets, increase the effective function scope, improve the action effect of enzyme, finally play anti-aging preferably effect.

Technical scheme of the present invention: a kind of production method of instant preserved rice, by utilizing the aging of ultrasonic technology and enzyme preparation control instant rice, the production process of instant preserved rice is: soak, drain the pre-boiling in back after selected rice is eluriated, soak and ultrasonic wave is handled, drained, pack, seal and sterilization behind the enzymolysis, acid soak, draining through enzyme liquid then, obtain the instant preserved rice of finished product;

(1) eluriate, soak: selected rice is eluriated the back soak, soak time is 1～3 hour, and the immersion water temperature is a room temperature; Rice is fully absorbed water, so that fully gelatinization of starch during boiling

(2) pre-boiling: soaked rice is drained away the water atmospheric cooking 10～30min;

(3) enzyme liquid soaks and the ultrasonic wave processing: the rice after the pre-boiling is carried out this processing;

Selected enzyme is the complex enzyme of maltogenic amylase and zytase, and the mass ratio of maltogenic amylase and zytase is 9:1;

Described maltogenic amylase, its enzyme are lived and are that it is 2500FXU/g that 1000U/g-20000U/g, the enzyme of zytase live;

The used complex enzyme liquid of described immersion, enzyme liquid concentration is 20～200mg/L;

Enzyme liquid carries out ultrasonic wave simultaneously when soaking handles, and the power that ultrasonic wave is handled is 200～800w, and immersion and ultrasonic treatment time are 10～30min; Operative temperature is 40～50 ℃; Drain then;

(4) enzymolysis: the rice after immersion of enzyme liquid and the ultrasonic wave processing is carried out enzymolysis, and hydrolysis temperature is 50～60 ℃, and enzymolysis time is 1～2h;

(5) acid soak: the rice that enzymolysis is good soaks with δ-glucolactone, soaks pH2～5, soak time 2～3min;

(6) pack behind the draining, seal, sterilization, sterilization temperature is 105 ℃-121 ℃, sterilizing time is 3-10min; Promptly obtain the instant preserved rice of finished product.

The present invention produces best soak time 1～2h in the instant rice process, about best pre-digestion time 20min.

The used hyperacoustic the best use of condition of the present invention: ultrasonic power is 500～600w, and be 20～30min action time, and operative temperature is 40～50 ℃.

The complex enzyme that the used best enzyme preparation of the present invention is maltogenic amylase and zytase, wherein the maltogenic amylase enzyme is lived and is that it is 2500FXU/g that 1000U/g～20000U/g, the enzyme of zytase live; Best enzyme liquid concentration is 20～200mg/L.

Optimum enzymolysis condition of the present invention: 50～60 ℃ of hydrolysis temperatures, enzymolysis time 1～2h

Best acidleach condition of the present invention: selecting δ-glucolactone for use is acidity regulator, best pH3～5, best soak time 2～3min.

Beneficial effect of the present invention:

Improve the production technology of high temperature sterilization instant-rice, rice is carried out acid mediate reason (with δ-glucolactone solution immersion 2～3min of pH2～5, the acidity that makes product is between the 1.3-1.4) after, adopt comparatively gentle sterilization conditions just can reach the expection bactericidal effect and also can keep normal matter structure of rice and taste, rice is stored more than 6 months at normal temperatures never degenerated.Overcook when so not only having solved long-time high temperature sterilization preferably and the mouthfeel decline problem that causes, and avoid import manufacture of aseptic equipment, reduced production cost of products.

At present, the aseptic packaging instant-rice need adopt heating using microwave, if the not enough rice of degree of heat has half-cooked mouthfeel, makes troubles for the edible of product.For improving this weak point, rice is carried out enzyme handle, suppress product wearing out when storing, improve the edible quality of product, heating just can have mouthfeel preferably to make product heat not even slightly.

Adopt ultrasound-assisted enzymolysis to produce instant rice, pass through cavitation effect of ultrasonic waves, make maltogenic amylase and zytase can be deep into the inside of rice pellets, solved the problem that enzymolysis under the general condition can not be deep into starch inside preferably, made the whole rice pellets identical matter structure all be arranged.Solved the easily problem of the half-cooked mouthfeel of generation of instant rice, made rice when storing 6 months, still have mouthfeel preferably.

Adopt 6 months the quality of instant rice normal temperature such as the following table of this explained hereafter:

Table 1 self-control sample and commercially available sample physical and chemical index are relatively

Description of drawings

Fig. 1 process chart of the present invention.

The different amylase of Fig. 2 are to the influence of instant preserved rice gelatinization degree.1, the sample that makes through AMS and the compound immersion of zytase, 2, the sample that makes through beta amylase and the compound immersion of zytase, 3, the sample that makes through maltogenic amylase and the compound immersion of zytase, 4, be blank.

The specific embodiment

Embodiment 1: the production technology of instant preserved rice to specifications, get pre-well-done rice 500g, the AMS and zytase mixed enzyme, beta amylase and zytase mixed enzyme, maltogenic amylase and zytase mixed enzyme (mass ratio of amylase and zytase the is 9:1) aqueous solution that add the 200mg/L of 1000mL respectively, soak 20min, drain 55 ℃ of following enzymolysis 1h.Make be placed on behind the sample 4 ℃ down refrigeration survey its gelatinization degree after 14 days, the high more explanation degree of aging of gelatinization degree is more little.Concrete outcome is seen Fig. 2

Embodiment 2: the production technology of instant preserved rice to specifications, get pre-well-done rice 500g, the maltogenic amylase and the zytase mixed enzyme (mass ratio of maltogenic amylase and zytase is 9:1) that add 1000mL50mg/L, carry out ultrasonic wave and handle, ultrasonic power 400w, action time 25min, drain, respectively enzymolysis 30,60,90 and 120min, make be placed on behind the sample 4 ℃ down refrigeration survey its gelatinization degree and matter structure after 21 days, concrete outcome sees Table 2

Table 2 enzymolysis time is to the influence of instant preserved rice gelatinization degree and matter structure

Embodiment 3: the production technology of instant preserved rice to specifications, get pre-well-done rice 500g, the maltogenic amylase and the zytase mixed enzyme (mass ratio of maltogenic amylase and zytase is 9:1) that add 1000mL50mg/L, carry out ultrasonic wave and handle, ultrasonic power is respectively 200w, 400w, 600w, 800w, action time 25min, drain, enzymolysis 60min, make be placed on behind the sample 4 ℃ down refrigeration survey its gelatinization degree and matter structure after 21 days, concrete outcome sees Table 3

Table 3 ultrasonic power is to the influence of instant preserved rice gelatinization degree and matter structure

Claims (1)

1. the production method of an instant preserved rice, it is characterized in that: by utilizing the aging of ultrasonic technology and enzyme preparation control instant rice, the production process of instant preserved rice is: soak, drain the pre-boiling in back after selected rice is eluriated, soak and ultrasonic wave is handled, drained, pack, seal and sterilization behind the enzymolysis, acid soak, draining through enzyme liquid then, obtain the instant preserved rice of finished product;

(1) eluriate, soak: selected rice is eluriated the back soak, soak time is 1～3 hour, and the immersion water temperature is a room temperature;

(2) pre-boiling: soaked rice is drained away the water atmospheric cooking 10～30min;

(3) enzyme liquid soaks and the ultrasonic wave processing: the rice after the pre-boiling is carried out this processing;

Selected enzyme is the complex enzyme of maltogenic amylase and zytase, and the mass ratio of maltogenic amylase and zytase is 9: 1;

Described maltogenic amylase, its enzyme are lived and are that it is 2500FXU/g that 1000U/g-20000U/g, the enzyme of zytase live;

The used complex enzyme liquid of described immersion, enzyme liquid concentration is 20～200mg/L;

Enzyme liquid carries out ultrasonic wave simultaneously when soaking handles, and the power that ultrasonic wave is handled is 200～800w, and immersion and ultrasonic treatment time are 10～30min; Operative temperature is 40～50 ℃; Drain then;

(4) enzymolysis: the rice after immersion of enzyme liquid and the ultrasonic wave processing is carried out enzymolysis, and hydrolysis temperature is 50～60 ℃, and enzymolysis time is 1～2h;

(5) acid soak: the rice behind the enzymolysis is soaked with δ-glucolactone, pH2～5 of control acid solution, soak time is 2～3min;

(6) pack behind the draining, seal, sterilization, sterilization temperature is 105 ℃-121 ℃, sterilizing time is 3-10min; Promptly obtain the instant preserved rice of finished product.

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