CN103120277A - Method for preparing zinc nutrient fortified rice - Google Patents

Abstract

The invention relates to a method for preparing zinc nutrient fortified rice. The method comprises the following steps of: grinding broken rice which serves as the raw material, and mixing the ground broken rice with a zinc fortifier, wherein 8-20mg of zinc fortifier is added to every 1kg of broken rice according to the content of zinc; adjusting to ensure that the materials contain 25-45% of wet-basis moisture; adding the materials into an extruder; mixing and preheating the materials in a first area, extruding and conveying in a second area, pre-gelatinizing in a third area, gelatinizing and shearing in a fourth area and melting at a high temperature in a fifth area by adopting the improved extruding technology; cutting rotationally, granulating and forming; ageing the product for about 2-4 hours at the temperature of 35-50 DEG C and the relative humidity of 60-80%; and drying the product at the temperature of 35-65 DEG C until the product contains 11-13% of moisture. The zinc nutrient fortified rice prepared by adopting the method is small in zinc loss, is high in zinc retention rate (more than 96%) after being washed and steamed, is similar to the commercially available late indica rice in texture and quality and can meet the demand on zinc of people.

Description

A kind of zinc nutrition is strengthened the preparation method of rice

Technical field

The present invention relates to a kind of zinc nutrition and strengthen the preparation method of rice, belong to agricultural byproducts fine finishining and food nutrition field.

Background technology

Trace element zinc is one of nutrient of wanting of body weight for humans, has in vivo important physiological function and trophism.At first Prasad in 1961 finds in Iranian rural area that anaemia, hepatosplenomegaly, human body of short and small stature, sexual hypofunction lack zinc disease, after the zinc treatment, obtains remarkable result, and the research of Zinc Nutrition Status and some disease relationship causes people's concern day by day.There is stronger catholicity and seriousness in China resident's zinc deficiency situation, prove according to the investigation to more than 30 provinces，municipalities and autonomous regions in the whole nation, the preschool child lacks the zinc rate up to 40%-70%, cause immunologic hypofunction, apocleisis, growth retardation, many moving, intelligence development is bad; It is also quite general that the elderly lacks zinc, and relevant with the morbidity of cancerous swelling, coronary heart disease; The pregnant woman lacks zinc except the health that affects itself, and baby's physique of its childbirth is bad, often cause congenital malformation and the day after tomorrow many disadvantages.For the zinc deficiency situation, the measures such as people can take that food is reasonably combined, Food fortification and additional zinc preparation replenish the zinc element.Wherein food is strengthened and can just can be obtained good result in a short time with less expense under the prerequisite that does not change people's eating habit, is highly suitable for China and carries out penetration and promotion.The product of China's zinc reinforcement at present is mainly zinc enriched soy sauce and zinc fortified flour, and the Zn fortified rice is rarely had report.

The main nutritional labeling of paddy concentrates in cortex, aleurone, perisperm and embryo, and the endosperm main component is starch.After paddy is processed into highed milled rice, cortex is peelled off with a rice embryo, the degree of depth of milling reaches aleurone and inferior aleurone deeply, even reach perisperm and albuminous cell tissue, a large amount of nutriment losses, along with machining accuracy improves, its ideal nutrient composition is mainly starch, be secondly mass percent less than 7% protein, vitamin, mineral element, fat, dietary fiber etc. have been minute quantity.Long-term edible highed milled rice might cause occurring the nutrient deficiency diseases such as athlete's foot, canker sore disease, Wound healing difficulty.People are more and more higher to outward appearance and the mouthfeel requirement of rice, and the nutritional deficiency that this and rice fine finishining cause becomes day by day serious contradiction.Therefore, the rice fortification has become China's rice processing industry problem demanding prompt solution.

In recent years, the fortification of rice has become study hotspot both domestic and external.China's Eleventh Five-Year Plan clearly proposes to carry out the plan that staple food is strengthened, developed enriched rice, realizes that with this nutrient replenishes this Major Strategic target.The method of at present rice fortification is enforced the law in roughly can being summarized as, crop spraying process and outer addition.In enforce the law and comprise: (1) preboiled rice: make rice bran layer nutriment be transferred to rice inside by humid heat treatment.(2) rice germ: will be rich in the nutrient plumule by special milling and keep, be i.e. rice with remained germ.(3) Return Law: in extraction chaff and plumule, nutritional labeling adds method in the grain of rice again.Though in enforce the law and can replenish some nutriments, generally speaking, because the zinc content of paddy own is lower, in the enforce the law zinc content strengthened be difficult to satisfy zinc deficiency crowd's needs.

Crop foliar spray method is more advanced fortification method, as the patent No.: 200410084878.4, a kind of Nutritive Rice that is rich in Organic Selenium, zinc, the organic intercalating agent solution with zinc, respectively in minute evil phase, boot stage and pustulation period of paddy rice, spray on the blade face, absorb, transform the rice rich in zinc that produces by rice leaf, zinc content is respectively 12-25mg/kg.The patent No.: 200610086308.8, a kind of organic selenium-zinc enriched nutrition rice, zinc content are 0.5-1.5mg/kg, and its production method is also diversity phase, boot stage and the pustulation period in paddy rice, and Spraying Se-fertilizer and zinc fertilizer obtain during three.

After outer addition refers to nutrition fortifier is mixed with solution, then join in ground rice extrusion forming or be coated in and improve the rice nutritive value on grain of rice face, it can selectively add according to the amount of required additional nutrient.For example soak the suction method, spraying process, extruding reinforcement.Soak the suction method too low for the utilization rate of nutrition fortifier, the enriched rice that spraying process is produced nutrient loss in eluriating digestion process is larger.And the extruding reinforcement is a kind of will the mixing with nutrition fortifier after the raw material Crushing of Ultrafine, is undertaken modifiedly by the effect of steam and water, then enters extruder and again granulates, and final drying obtains the method for enriched rice.This method can make nutrition fortifier be evenly distributed on rice inside, and in process, loss is less.

The conventional extruded method be mainly by the high-temperature high-pressure swelling mode change material (as starch) thus structure realizes the improvement of its character, in extrusion process, material usually the Study of Volume Expansion of three, four times can occur.And the improvement extrusion is to reduce the novel method of extrudate expansion rate on the conventional extruded method by the improvement to equipment.Longer through the screw extruder spiro rod length after improving, barrel zone temperature is lower, and rotating speed is slower, and rice mould and supporting cutting tool that conventional extruder does not have are housed at the die head place, make the expansion rate of extrudate lower by low temperature and high pressure, and texture characteristic is near highed milled rice.

Summary of the invention

The objective of the invention is to make up traditional rice zinc and contain quantity not sufficient, adopt the improvement extrusion technique, prepare a kind of zinc nutrition and strengthen rice, after its elutriation boiling, the retention rate of zinc is high, and edible quality is good, and texture characteristic is near late long-grained nonglutinous rice.

The present invention is achieved by the following technical solutions: with the accessory substance Broken rice as its raw material of refining rice, add nourishment intensifying agent with zinc, through the mixing of materials modulation, the moulding of improvement extrusion technique, the circumgyration incision granulation, aging, dry, cooling packing and preparing, nutriment also has a large amount of albumen except starch, B family vitamin and mineral element.

Concrete technology step of the present invention is:

(1) mixing of materials modulation: water intaking dissolubility nourishment intensifying agent with zinc is dissolved in the water, fully mix in mixer with the powder of cracking rice after pulverizing, maybe will be insoluble in the nourishment intensifying agent with zinc of water and the powder abundant mixing in mixer of cracking rice after pulverizing, more slowly add entry, fully mix; Every 1kg cracks rice, and the addition of nourishment intensifying agent with zinc is calculated as 8-20mg by the zinc constituent content in powder, and the wet basis moisture of material is between 25-45%;

Described water-soluble nourishment intensifying agent with zinc is zinc sulfate, zinc gluconate, zinc lactate, ethylenediamine tetra-acetic acid zinc sodium, zinc methionine, zinc acetate, zinc malate, zinc citrate, glycine zine, one or more in zinc chloride; The nourishment intensifying agent with zinc that is insoluble in water is zinc oxide, zinc stearate, zinc succinate, one or more in trbasic zinc phosphate and zinc pyrophosphate;

(2) improvement extrusion modling: the material after step (1) mixing is joined in single-screw extrusion machine, and rate of feeding is 20-40 kg/min, and material is respectively through district mixing preheating, temperature is 30-60 ℃, and the extruding of 2nd district is carried, and temperature is 50-80 ℃, the pre-gelatinization in 3rd district, temperature is 80-120 ℃, and the gelatinization of 4th district is sheared, and temperature is 90-120 ℃ and five district's high-pressure smeltings, pressure is 13-19 MPa, temperature is 75-100 ℃, screw speed 14-34rpm, then circumgyration incision granulating and forming;

(3) aging: it is 35-50 ℃ that step (2) product is placed in temperature, and humidity is aging 2-4 h under the constant-temperature constant-humidity environment of 60-80%;

(4) drying: with step (3) product as for dry under 35-65 ℃, until moisture is between 11-13%.

The invention has the beneficial effects as follows: the present invention is with Broken rice as its raw material, adopt the improvement extrusion technique to prepare zinc nutrition and strengthen matter structure rice, zinc content can be adjusted according to demand, the zinc element is evenly distributed in the inside of matter structure rice, after eluriating boiling, the zinc retention rate is greater than 96%, and product has the similar texture quality of commercially available late long-grained nonglutinous rice, has certain market prospects.

The specific embodiment

Example 1:

Take 8kg and crack rice, pulverize.Get the water-soluble solution of 1.5kg 1.4g zinc sulfate, fully mixing.Cracking rice after pulverizing poured in mixer, slowly pour solution of zinc sulfate into, stir with mixer, pour in the feeding chamber of extruder.Adopt the improvement extrusion technique, shear and five district's high-pressure smelting processes through district mixing preheating, the extruding conveying of 2nd district, the pre-gelatinization in 3rd district, the gelatinization of 4th district, wherein this 5th districts temperature is set to respectively 50 ℃, 60 ℃, 90 ℃, 105 ℃ and 95 ℃, screw speed is 25rpm, this moment, die pressure was 14.8 MPa, then circumgyration incision moulding.Product is aging 3 h of constant temperature and humidity under 35 ℃, the environment of relative humidity 70%.Then under 50 ℃ drying until moisture in about 11-13%.Be cooled to room temperature, packaging into products.

The difference of zinc content before and after the texture characteristic of contrast zinc nutrition reinforcement rice and commercially available rice and elutriation boiling, result is as shown in table 1 and table 2.The zinc nutrition of the present invention's preparation is strengthened rice matter structure near the matter structure of commercially available rice as shown in Table 1.Zinc nutrition is strengthened rice zinc content far above rice zinc content as shown in Table 2, and after the elutriation boiling, the retention rate of zinc is 96.4%.

Table 1 zinc nutrition is strengthened rice and rice texture characteristic

Sample	Hardness/g	Adhesion/gs	Elasticity	Cohesion
					Zinc nutrition is strengthened rice	6161	571	0.70	0.60
Commercially available rice	6078	550	0.69	0.59

Table 2 rice and zinc nutrition are strengthened rice zinc content

Sample	Eluriate the front zinc content (mg/kg) of boiling	Zinc content (mg/kg) after the elutriation boiling
			Rice	4.7	3.1
Zinc nutrition is strengthened rice	19.6	18.9

Example 2

Take 8kg and crack rice, import in mixer after pulverizing.Add the 2.5g zinc pyrophosphate, fully mixing.Slowly pour 2kg water into, stir with mixer, pour in the feeding chamber of extruder.Adopt the improvement extrusion technique, shear and five district's high-pressure smelting processes through district mixing preheating, the extruding conveying of 2nd district, the pre-gelatinization in 3rd district, the gelatinization of 4th district, wherein this 5th districts temperature is set to respectively 40 ℃, 70 ℃, 95 ℃, 110 ℃ and 85 ℃, screw speed is 30rpm, this moment, die pressure was 15.3 MPa, then circumgyration incision moulding.Product is aging 3 h of constant temperature and humidity under 35 ℃, the environment of relative humidity 70%.Then under 50 ℃ drying until moisture in about 11-13%.Be cooled to room temperature, packaging into products.

The difference of zinc content before and after the texture characteristic of contrast zinc nutrition reinforcement rice and commercially available rice and elutriation boiling, result is as shown in table 1 and table 2.The zinc nutrition of the present invention's preparation is strengthened rice matter structure near the matter structure of commercially available rice as shown in Table 1.Zinc nutrition is strengthened rice zinc content far above rice zinc content as shown in Table 2, and after the elutriation boiling, the retention rate of zinc is 96.2%.

Table 3 zinc nutrition is strengthened rice and rice texture characteristic

Table 4 rice and zinc nutrition are strengthened rice zinc content

Sample	Eluriate the front zinc content (mg/kg) of boiling	Zinc content (mg/kg) after the elutriation boiling
			Rice	7.21	6.94
Zinc nutrition is strengthened rice	18.6	17.9

Claims (1)

1. a zinc nutrition is strengthened the preparation method of rice, it is characterized in that:

(1) mixing of materials modulation: water intaking dissolubility nourishment intensifying agent with zinc is dissolved in the water, fully mix in mixer with the powder of cracking rice after pulverizing, maybe will be insoluble in the nourishment intensifying agent with zinc of water and the powder abundant mixing in mixer of cracking rice after pulverizing, more slowly add entry, fully mix; Every 1kg cracks rice, and the addition of nourishment intensifying agent with zinc is calculated as 8-20mg by the zinc constituent content in powder, and the wet basis moisture of material is between 25-45%;

Described water-soluble nourishment intensifying agent with zinc is zinc sulfate, zinc gluconate, zinc lactate, ethylenediamine tetra-acetic acid zinc sodium, zinc methionine, zinc acetate, zinc malate, zinc citrate, glycine zine, one or more in zinc chloride; The nourishment intensifying agent with zinc that is insoluble in water is zinc oxide, zinc stearate, zinc succinate, one or more in trbasic zinc phosphate and zinc pyrophosphate;

(2) improvement extrusion modling: the material after step (1) mixing is joined in single-screw extrusion machine, and rate of feeding is 20-40 kg/min, and material is respectively through district mixing preheating, temperature is 30-60 ℃, and the extruding of 2nd district is carried, and temperature is 50-80 ℃, the pre-gelatinization in 3rd district, temperature is 80-120 ℃, and the gelatinization of 4th district is sheared, and temperature is 90-120 ℃ and five district's high-pressure smeltings, pressure is 13-19 MPa, temperature is 75-100 ℃, screw speed 14-34rpm, then circumgyration incision granulating and forming;

(3) aging: it is 35-50 ℃ that step (2) product is placed in temperature, and humidity is aging 2-4 h under the constant-temperature constant-humidity environment of 60-80%;

(4) drying: with step (3) product as for dry under 35-65 ℃, until moisture is between 11-13%.