TWI626895B - Process for preparing puffed dried rice as an instant food product - Google Patents

Abstract

The preparation method of a swelled dry rice comprises the first drying of rice, adding a liquid modifier, stirring and mixing, so that the surface of the rice is coated with a liquid modifier, and then drying for a second time, and finally swelling with hot air. Drying, after cooling, instant rice with a bulk density of 0.2-0.6 g/mL is obtained.

Description

Method for preparing expanded dry rice as instant food product

The present invention relates to a method for preparing a bulging dry rice as a fast food product.

Taiwan Patent Application Publication No. 201446151 A (equivalent to JP2014-158423 A and CN105050424A) discloses a fast food food placed in a container, which is only infused with hot water or injected with hot water or water and then heated in a microwave oven. It is characterized in that the dried and dried rice which is submerged in water is contained in a container. In the case of the instant food, the water in the container can be visually observed by letting the dried and dried rice used to sink into the water. The preferred bulk density of the expanded dry rice submerged in water is 0.55 g/mL or more. The preparation method of the expanded dry rice disclosed in the previous case is as described in Comparative Example 1, and after the 700 g of stalked white rice is washed and drained, the following ratio is added to the refined white rice (emulsified fat 14 g/kg, sucrose fatty acid ester 3 g/kg, polymerization). Phosphate 0.3g/kg) and mix evenly. It was boiled for 15 minutes using a rice cooker (made in the forest, gas risotto RR-10KS) with a water content of 85% by mass. After steaming for 20 minutes, the water content after cooking is 50%. Cook rice. Allow the hair to cool and loosen. The loosely cooked rice was stored in a dry storage, and dried at a temperature of 3 to 4 m/s at 80 ° C for 3 minutes until the moisture content became 26% by mass. After drying for 30 minutes, it was placed on a sieve to remove severe tangles. Thereafter, it was flattened by passing between the rolls having a drum interval of 0.35 mm. The pressed rice after flattening was stored in a dry storage, and dried at a temperature of 3 to 4 m/s at 80 ° C for 15 minutes until the moisture content was 16%. After the second drying, the mixture was allowed to stand for 30 minutes, and then the secondary dried rice was stored in a high-temperature air flow dryer capable of high-speed jetting of a high-temperature air stream, and subjected to expansion and drying for 30 seconds at 190 ° C and a wind speed of 50 m/s. By swelling and drying, the rice is swollen, and the expanded rice having a moisture content of about 8% is obtained. The expanded dry rice is placed on a sieve to remove broken rice and unexpanded rice. The remaining expanded rice was found to have a false density of 0.43 g/mL. In the preparation method of the expanded dry rice disclosed in Example 1 of the previous case, in addition to adding more water during cooking, the moisture after the cooking is increased, and the temperature at the time of drying the hair is reduced to less than 160 ° C. The same operation as in Comparative Example 1 was carried out, except that the secondary dry rice was swollen and dried while blowing steam, to obtain a swelled dry rice having a pseudo density of 0.60 g/mL.

The previous method must be such that the first dried rice is flattened by the interval of the drum, which increases the fixing cost and takes time and labor.

A primary object of the present invention is to provide a method of preparing a bulging dry rice that does not require the flattening step of the prior art.

Another object of the present invention is to provide a method for preparing a bulging dry rice which has the advantages of good rehydration and good rice granules and good mouthfeel.

Still another object of the present invention is to provide a bulging dry rice which has the advantages of good rehydration and good rice granules and good mouthfeel.

A method for preparing a bulging dry rice according to the present invention comprises the steps of: drying the cooked rice for the first time to a water content of 25-40% by weight; and changing the first dried rice with a liquid The slurry is stirred and mixed so that the surface of the rice is coated with the liquid modifier; the rice coated with the liquid modifier is secondly dried to a water content of 3-12% by weight; for the second dried rice Performing hot air swelling, and after cooling, obtaining a swelled dry rice having a water content of 0.9 to 2.9 wt%, wherein 2.5 to 20 mL of the liquid modifier is added per 100 g of the first dried rice, The liquid modifier comprises: 0.5-5 g of polysaccharide per 100 mL; 0.5-10 g of emulsifier; 1-5 g of edible oil; and the balance of water, wherein when the emulsifier is a fatty acid glyceride, the liquid The modifying agent may not contain the edible oil.

Preferably, the polysaccharide is a plant polysaccharide.

Preferably, the polysaccharide is pullulan.

Preferably, the polysaccharide is carboxymethylcellulose-sodium.

Preferably, the polysaccharide is a modified starch.

Preferably, the emulsifier is an emulsifier having an HLB value of 3-6.

Preferably, the emulsifier is a sucrose ester, a fatty acid glyceride, a fatty acid sorbitan ester, or a fatty acid propylene glycol ester.

Preferably, the emulsifier is a sucrose ester.

Preferably, the emulsifier is a fatty acid glyceride.

Preferably, the edible oil is soybean oil.

Preferably, 5-10 mL of the liquid modifier is added per 100 grams of the first dried rice.

Preferably, the first drying is carried out with hot air at about 40 °C.

Preferably, the second drying is carried out with unheated or cold air.

Preferably, the hot air expansion is carried out by hot air at an outlet temperature of 300-550 ° C, and the temperature of the hot air when it is in contact with the second dried rice is 150-200 ° C.

Preferably, the hot air is carried out for a period of 6-12 seconds.

The present invention provides a bulging dry rice having a pseudo density of 0.2 to 0.6 g/mL and a porosity of 45 to 90%.

Preferably, the expanded dry rice has a whiteness of 75-80.

Preferably, the surface of the expanded dry rice has a plurality of channels, and the inside of the expanded dry rice has a porous structure.

Preferably, the expanded dry rice has a moisture content of 0.9 to 7.7%.

R101‧‧‧ fine white rice

R103‧‧‧ Cleaning

R105‧‧‧ soak

R107‧‧‧Drain

R109‧‧‧ steam steaming

R111‧‧‧Dispersed rice

R113‧‧‧ hot air drying

R115‧‧‧The first dried rice

R117‧‧‧Spray or spray modifier

R119‧‧‧ Cold air drying

R121‧‧‧Second dry rice

R123‧‧‧hot air bulging

R125‧‧‧Swelling dry rice

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram showing the flow of a method for preparing a bulging dry rice which is completed in accordance with a preferred embodiment of the present invention.

2(A) and 2(B) respectively show the bulging prepared according to Example 4 of the present invention A scanning electron microscope (SEM) photograph of the dried rice (R125) (A) and its surface before the swelling (R121) (B) was carried out at a magnification of 35X.

3(A) and 3(B) respectively show a scanning electron microscope of the expanded dry rice (R125) (A) prepared according to Example 4 and its cross section before the swelling (R121) (B) (scanning electron microscope, SEM) photograph, magnification 35X.

The invention discloses a novel preparation method of a swelled dry rice, which comprises the steps of mixing a liquid modifier with a first dried rice to uniformly apply the liquid modifier on the surface of the rice granule; The moisture content of the first dried rice is relatively low. The invention improves the surface of the rice granules, stabilizes the structure of the rice granules during the bulging, so that the internal moisture of the rice granules is blocked at the initial stage of the hot air swell and rapidly absorbs heat to form a water vapor swell, so the method of the invention can use low water. The second dried rice is subjected to hot air swelling to shorten the swelling time, and the obtained bulging dry rice has a completely gelatinized surface layer and a partially gelatinized and porous structure core, which has good rehydration. And the rice granules are complete and the taste is good.

The present invention provides a bulging dry rice having a false density of 0.2 to 0.6 g/mL and a whiteness of 75 to 80. The specific embodiment is that after the white rice is washed, the water is soaked to absorb 0.1 to 0.4 times of water, preferably 0.2 to 0.3 times; the water-absorbing rice grains are drained of excess water. The cooked rice is evenly spread on a stainless steel plate and dried for the first time with a hot air of 40 ° C. The wind speed is 50-250 m/min. The interval is 20~30 minutes until the water content of the rice is about 25-40%, and 2.5~20mL of a liquid modifier is added per 100g of the first dried rice, and the liquid modifier is used. 100mL comprises: 0.5 to 5 grams of polysaccharide; 0.5 to 10 grams of emulsifier; 1 to 5 grams of edible oil; and the balance of water, wherein when the emulsifier is fatty acid glyceride, the liquid modifier may not The edible oil is included, and then dried by cold air at 25 to 35 ° C, preferably 30 ° C. At this time, the treated rice grains can be obtained, and the moisture content thereof is about 3 to 12%, preferably 3 to 5%, which is low. The moisture rice grains are subjected to hot air swelling, the hot air outlet temperature is 300 to 550 ° C, the hot air temperature in contact with the material is 130 to 220 ° C, preferably 150 to 200 ° C, and the wind speed is 100 to 1000 m/min, preferably 300 m/min. The swelling time is 5 to 15 seconds, preferably 6 to 12 seconds, and the expanded dry rice of the present invention can be obtained by the operation, and the moisture content thereof is 0.9 to 7.7%, preferably 0.9 to 3%, and the pores thereof. The ratio is 45 to 90%, preferably 60 to 85%, and the false density is 0.2 to 0.6 g/mL, preferably 0.2 to 0.4 g/mL. The rice of the present invention may be white rice or colored rice such as purple rice, brown rice or the like.

Examples 1-8 and Comparative Example 1:

After washing the raw white rice (R101) 1kg (R103) and soaking (R105) for 20 minutes, drain excess water (R107), put it in a steamer and cook at 100 °C for 20 minutes (R109) for about 2~2.3kg rice. . After the rice is slightly cooled, it is placed on the flat plate of the hot air drying oven, and the first drying (R113) is carried out with hot air at 40 ° C, the wind speed is 50 m/min, and the time is 20 to 30 minutes until the water content of the rice is about 25 to 40. %.

The modifier was formulated according to the formulation of Table 1.

Turn the first dried rice (R115) loose, spray or pour the table 1 modifier (R117), and immediately stir to make the surface of the rice evenly spread the modifier, and maintain for 5 to 10 minutes, so that the modifier is fully absorbed into the rice surface. The amount of the modifier (mL modifier/100 g of the first dried rice) is shown in Table 1.

About 1.3 to 1.5 kg of rice to which the modifier is attached is placed in a dryer for cold air drying (R119) at a wind speed of 50 m/min for 8 to 12 hours. The dried rice is the second dried rice (R121), and its water content is 3 to 5%. The surface of the dried rice to which the modifier is dried under these conditions is intact without cracks.

The second dried rice (R121) is put into a hair dryer for hot air swell (R123), wherein the input amount of rice is 50-150 g/batch, and the hot air outlet temperature is 300-550 ° C, preferably 450 ° C. When the material is in contact with the material, the temperature is preferably 150 to 200 ° C, the wind speed is 300 m/min, and the swelling time is 5 to 15 seconds per batch, preferably 6 to 12 seconds per batch. The more the above rice is input, the higher the hot air temperature is. The above-mentioned swelling time is adjusted according to the water content of the rice. The higher the water content, the longer the swelling time.

The properties before rehydration are listed in Table 2.1 and the time required for rehydration is listed in Table 2.2. As can be seen from Table 2.1, the water content is reduced from 3 to 12% of the second dried rice (R121) to 0.9 to 7.7%.

The hair-expanded dry rice (R125) to be cooled which was taken out from the hot air blasting machine had no scorch on the surface, which was Examples 1 to 8 and Comparative Example 1.

The pullulan in the Table 1 is manufactured by Plum Biotechnology Group Co., Ltd.; the sucrose stearate S-370F is manufactured by Mitsubishi Chemical Food Co., Ltd.; the sucrose stearate S-570 is manufactured by Mitsubishi Chemical Food Co., Ltd.; Sodium carboxymethyl cellulose is manufactured by CP KELCO; fatty acid glyceride is manufactured by KAO CORPORATION; sodium octylate sodium succinate is manufactured by National Starch and Chemical Co.

The cooled expanded rice was the instant rice of the present invention (Examples 1-8), and the properties before the rehydration and the swelling quality are listed in Table 2.1 and the time required for rehydration are listed in Table 2.2.

It can be seen from Table 2.1 that the expanded dry rice of the present invention has a smaller pseudo density than that of Comparative Example 1, and the range is from 0.22 to 0.53, which means that the volume is large after swelling; and in terms of porosity, Example 1 The porosity of ~8 ranged from 60.2% to 83.5%, which was higher than that of the control. It is shown that the expanded dry rice of the present invention has a porous structure and can reduce the rehydration time. It can also be seen from Table 2.2 that the expanded dry rice of the present invention requires a shorter period of time than the rehydration of Comparative Example 1.

In the first to third embodiments, the bubbles generated during brewing were small, and the whiteness of the rice was high. In the examples 4 to 6, there were many bubbles generated during brewing, and the whiteness of the rice was slightly lower than that of the examples 1 to 3. The bubbles in the examples 7 to 8 were moderate, and the whiteness of the rice was lower than that of the examples 1 to 3. The aforementioned whiteness (WI) is measured by the spectrophotometer method to measure the L value, the a value and the b value, and then calculated by the following formula:

The expanded dry rice of Examples 1-8 and Comparative Example 1 was measured for hardness and viscosity by a texture analyzer (TA-XT2) after rehydration for 3 minutes, and the measured hardness was shown in Table 3. The hardness of the example 2 is similar to that of the white rice, the mouthfeel is less sticky, the rice grains are more easily cut, and the hardness of the examples 1, 3, 4 and 5 is higher; in addition, the appearance of the rice of the examples 1-8 is comparatively controlled. Example 1 is uniform.

The pseudo-dried rice prepared according to Example 4 has a pseudo density as shown in Table 2.1, and the range is 0.22 g/mL, but the pseudo-density before the hot air expansion in the hair expander is 0.63 to 0.67 g/mL. The raw density of the white rice material used is 0.80 to 0.84 g/mL. Furthermore, the expanded dry rice prepared according to Example 4 had a whiteness of 76.48, and the result was close to the white rice raw material used was 72.19. Whiteness, and the whiteness of the second dried rice before the swelling in the hot air extruder was only 63.91.

2 shows a scanning electron microscope (SEM) photograph of the expanded dry rice (R125) (A) prepared in accordance with Example 4 and its surface before the swelling (R121) (B). Magnification 35X. Figure 3 is a scanning electron microscope (SEM) photograph of the expanded dry rice (R125) (A) prepared according to Example 4 and its cross section before (F121) (B). Magnification 35X. It can be seen from Fig. 2 that the dried rice (R121) (B) before the bulging has a smooth surface and a small passage with respect to the swelled dry rice (R125) (A); and the swelled dry rice (R125) of the present invention ( The surface of A) has many channels, and the liquid can enter smoothly when rehydrating. It can be seen from Fig. 3 that the dry rice before the bulging (R121) (B) is solid with respect to the expanded dry rice (R125) (A); and the expanded dry rice (R125) (A) of the present invention The surface is rough and the interior has a porous structure. The SEM photographs of Figs. 2 and 3 show that the expanded dry rice (R125) prepared by the method of the present invention has a structure in which liquid can be smoothly entered and reconstituted easily.

Claims (15)

The invention relates to a method for preparing a swelled dry rice, which comprises first drying the cooked rice to a water content of 25-40% by weight; mixing the first dried rice with a liquid modifier to make the surface of the rice coated The liquid modifying agent is disposed; the rice coated with the liquid modifier is subjected to a second drying to a water content of 3-12% by weight; the second dried rice is subjected to hot air swelling, and after cooling, a swelled dry rice having a water content of 0.9 to 2.9 wt% and a pseudo density of 0.2 to 0.6 g/mL, wherein 2.5 to 20 mL of the liquid modifier is added per 100 g of the first dried rice, The liquid modifier comprises: 0.5-5 g of polysaccharide per 100 mL; 0.5-10 g of emulsifier; 1-5 g of edible oil; and the balance of water, wherein when the emulsifier is a fatty acid glyceride, The liquid modifier may not contain the edible oil. The method of claim 1, wherein the polysaccharide is a plant polysaccharide. The method of claim 2, wherein the polysaccharide is pullulan. The method of claim 2, wherein the polysaccharide is carboxymethylcellulose-sodium. The method of claim 1, wherein the polysaccharide is a modified starch. The method of any one of claims 1 to 5, wherein the emulsifier is an emulsifier having an HLB value of 3-6. The method of claim 6, wherein the emulsifier is a sucrose ester, a fatty acid glyceride, a fatty acid sorbitan ester, or a fatty acid propylene glycol ester. The method of claim 7, wherein the emulsifier is a sucrose ester. The method of claim 7, wherein the emulsifier is a fatty acid glyceride. The method of claim 8, wherein the edible oil is soybean oil. The method of claim 6, wherein 5-10 mL of the liquid modifier is added per 100 grams of the first dried rice. The method of claim 6, wherein the first drying is performed with hot air at about 40 °C. The method of claim 6, wherein the second drying is carried out at a temperature of from 25 ° C to 35 ° C. The method of claim 6, wherein the hot air swell is performed at a hot air having an outlet temperature of 300 to 550 ° C, and the hot air is in contact with the second dried rice at a temperature of 150 to 200 ° C. The method of claim 14, wherein the hot air blasting is performed for a period of 6-12 seconds.