Compound modifier, rice product and preparation method of rice product

Abstract

The invention discloses a compound modifier, a rice product and a preparation method of the rice product, the compound modifier comprises starch acetate, distarch phosphate and acetylated distarch phosphate, and the mass ratio of the starch acetate to the distarch phosphate to the acetylated distarch phosphate is 1: (0.5-2): (1-3). The starch acetate, the distarch phosphate and the acetylated distarch phosphate are all obtained by modifying cassava starch. After the compound modifier is used, the rice product is higher in curing efficiency and stable in gelatinization effect. By using multi-source ingredients and combining with a starch branched chain modification technology, the proportion of a double-helix crystalline region is increased while molecular chain arrangement in starch gel is adjusted, so that the gel quality is enhanced, and the industrial problem that the product quality is easy to deteriorate is solved.

Description

Technical Field

[0001] The invention relates to the technical field of grain deep processing, and in particular to a compound improver, a rice product and a preparation method thereof. Background Art

[0002] Rice noodles, also known as "can" in ancient times, are traditional rice products in my country. They occupy a large share in the rice product market and are one of the most popular noodle varieties. Rice noodles originated in China, and their invention can be traced back to the Western Jin Dynasty (266-316 AD) nearly 2,000 years ago. After centuries of practice and innovation, the production process of rice noodles has spread all over the world. Rice noodles originated from Guilin and Changde are the most popular in the entire Chinese market. Many other countries, especially Southeast Asian countries like Thailand and Vietnam, also occupy a considerable share in the international rice noodle market.

[0003] Rice noodles are rich in carbohydrates, vitamins, minerals and enzymes, and are cooked quickly and evenly, are refreshing and tender, and are easy to digest. In addition, rice protein is less allergenic than wheat protein, and as a gluten-free food, it can avoid the intense allergic reaction caused by gluten intake.

[0004] Rice noodle processing includes different methods. According to the raw material pretreatment method, rice noodles can be divided into fermented rice noodles and unfermented rice noodles. According to the subsequent processing method and the final performance of the product, they can be further divided into fresh rice noodles, dry rice noodles and convenient rice noodles. According to the molding process, it can be divided into sheared rice noodles (cut powder) and extruded rice noodles (pressed powder), etc. Dry rice noodles are rice noodles that have been dehydrated and dried. They usually need to be steamed for more than 20 minutes before they can be eaten and have a long storage period. Compared with dry rice noodles, fresh wet rice noodles have the advantages of being easy to eat, no need for drying and dehydration during the production process, saving energy, and reducing costs. They have huge development potential. In the future, fresh wet rice noodles will surely become a hot trend in food industry production.

[0005] The quality of rice noodles mainly depends on the physicochemical properties of rice starch, which helps it form a specific network structure. However, in actual industrial production, due to factors such as high-temperature cooking to extend the shelf life, fresh wet rice noodles have many problems such as easy to become mushy and easy to break, and have high cooking losses. Summary of the invention

[0006] The invention aims to provide a composite improver to solve the problems of fresh wet rice noodle products in the prior art, such as easy to become mushy, easy to break, and high cooking loss.

[0007] The second object of the present invention is to provide a rice product based on the composite improving agent.

[0008] The third object of the present invention is to provide a method for preparing the rice product.

[0009] The technical solution adopted to achieve the purpose of the present invention is:

[0010] In a first aspect, a composite improver for rice products comprises acetate starch, distarch phosphate and acetylated distarch phosphate, wherein the mass ratio of the acetate starch, distarch phosphate and acetylated distarch phosphate is 1:(0.5-2):(1-3), and the acetate starch, distarch phosphate and acetylated distarch phosphate are all modified from cassava starch.

[0011] In the above technical solution, the compound improving agent also includes food additives.

[0012] In the above technical solution, the compound improver includes, by weight: 20 to 40 parts of acetate starch, 20 to 40 parts of distarch phosphate and 40 to 60 parts of acetylated distarch phosphate.

[0013] In a second aspect, a rice product comprises 0.5 to 25 wt % of the compound improver, calculated by weight percentage.

[0014] In the above technical solution, the rice product is rice noodles, rice jelly or rice freeze-dried powder.

[0015] In a third aspect, a method for preparing the rice product comprises the following steps:

[0016] Step 1, slurrying the soaked rice, adding a composite improver to obtain a prepared rice slurry;

[0017] Step 2, pre-gelatinizing the modulated rice slurry to obtain pre-gelatinized rice gel;

[0018] Step 3, post-treating the pregelatinized rice gel to obtain the rice product.

[0019] In the above technical solution, in step 2, the pre-gelatinization temperature is 70 to 90° C., and the pre-gelatinization time is 20 to 60 minutes.

[0020] In the above technical solution, when the rice product is rice noodles, the post-treatment in step 3 is to knead the pre-gelatinized rice gel into a ball and extrude it to obtain rice noodles;

[0021] When the rice product is freeze-dried rice powder, the post-treatment in step 3 is freeze-drying and crushing the pre-gelatinized rice gel to obtain the freeze-dried rice powder.

[0022] In the above technical solution, the preparation method further includes step 4, performing at least one of sterilization, aseptic packaging or brewing treatment on the rice.

[0023] In the above technical solution, the sterilization adopts UHT sterilization, the sterilization temperature is 130-140°C, and the time is 10-20s; or the sterilization adopts high temperature short time sterilization, and the sterilization condition is heating at 80-90°C for 10-20s;

[0024] The brewing temperature is controlled at 80-120°C, and the brewing time is 15-300s.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. After using the composite improver of the present invention, the cooking efficiency of rice products is higher and the gelatinization effect is stable. The composite improver of the present invention uses multi-source ingredients and combines starch branch modification technology to adjust the molecular chain arrangement in the starch gel while increasing the proportion of the double helix crystallization area to enhance the gel quality, thereby solving the industrial problem of easy deterioration of product quality.

[0027] 2. The composite improver of the present invention increases the raw material utilization rate of rice in rice products, and improves the cooking quality and gel strength of rice products: through multi-source ingredient preparation and design technology, cassava starch with high branched content is introduced to improve the gel strength of rice products.

[0028] 3. The preparation method of the present invention reduces the gelatinization temperature of the gel during the rice noodle processing, reduces the energy consumption of rice noodle processing, and improves production efficiency. The gelatinization temperature of the rice noodle in the preparation method of the present invention can be reduced to 75°C (only rice flour needs 88°C). The breaking rate and cooking loss of the rice noodle are reduced. The breaking rate of the rice noodle processed by this technology has a significant advantage over the rice noodle prepared only by rice slurrying.

[0029] 4. The present invention reduces the rehydration time of the finished rice noodle product from 5 to 15 minutes to within 60 seconds by modifying and modifying the key components of the staple food raw materials, thereby improving the edible efficiency of the product and providing a guarantee for the large-scale processing of the staple food.

[0030] 5. The rice noodles of the present invention have a lower digestion rate and an estimated glycemic index (eGI) value, which provides convenience for personalized customization of staple foods. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The microstructure diagram of the rice noodles of the present invention is shown, in which RF: rice noodles; CMS: compound improving agent.

[0032] Figure 2 Shown is a performance test diagram of pre-gelatinized rice gel, in which: Figure 2 a is the storage modulus (G'), Figure 2 b is the loss modulus (G″), Figure 2 c is tanδ(G″ / G′), Figure 2d is the viscosity.

[0033] Figure 3 Shown is a digestibility graph of fresh wet rice noodles. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] Unless otherwise specified, the experimental methods in the following examples are all conventional methods.

[0036] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0037] Example 1

[0038] The compound improver in this embodiment includes, by weight, 25 parts of acetate starch, 25 parts of distarch phosphate and 50 parts of acetylated distarch phosphate, wherein the acetate starch, distarch phosphate and acetylated distarch phosphate are all modified from cassava starch.

[0039] A fresh wet rice noodle with improved quality is prepared by the following method:

[0040] Step 1, soak the rice at 4°C for 4 hours, and slurry the soaked rice according to the ratio of 60ml water / 100g rice, and add a composite improver at 5% of the weight of the rice to obtain a prepared rice slurry, and the water temperature is 30°C.

[0041] Step 2: Spread the prepared rice slurry on a plate and place it in a steamer for pre-gelatinization at a temperature of 85° C. for 30 min to obtain pre-gelatinized rice gel.

[0042] Step 3, kneading the pre-gelatinized rice gel into a dough, using a handheld extruder to obtain rice noodles, and sterilizing with boiling water to obtain fresh wet rice noodles, recorded as RF-5CMS, with a sterilization temperature of 98° C. and a time of 30 seconds.

[0043] The obtained fresh wet rice noodles have a smooth taste, are chewy and have a strong rice aroma. The compound improver gives it palatability and enhances the gel strength. After storage, the rehydration and ripening takes less than 1 minute, which greatly shortens the rehydration time. It has good water retention and the surface is still smooth after being placed for 5 minutes.

[0044] Example 2

[0045] The difference between this embodiment and embodiment 1 is that 10% of the mass of rice is added with a compound improver to obtain RF-10CMS.

[0046] Example 3

[0047] The difference between this embodiment and embodiment 1 is that 15% of the mass of rice is added with a compound improver to obtain RF-15CMS.

[0048] Example 4

[0049] The difference between this embodiment and embodiment 1 is that 20% of the mass of rice is added with a composite improver to obtain RF-20CMS.

[0050] Example 5

[0051] The difference between this embodiment and embodiment 1 is that 25% of the mass of rice is added with a composite improver to obtain RF-25CMS.

[0052] The main component of rice noodle gel is starch, followed by protein. After gelatinization, starch interacts with protein to form a unique network structure. The fresh wet rice noodles of Examples 1-5 and Comparative Example 1 were characterized microscopically. Figure 1 As shown in the figure, after adding the compound modifier, the network structure of the original starch-protein gel system changes. As the amount of addition changes, the pores of the gel change from large and loose to dense and uniform. This shows that the essence of the quality improvement after adding the compound modifier occurs at the gel structure level.

[0053] The fresh wet rice noodles obtained in Examples 1-5 and Comparative Example 1 were tested for mechanical properties. The results are as follows: Figure 2 a- Figure 2 As shown in Figure d, after adding the modifier, the gelatinized slurry behaves as a shear-thinning pseudoplastic non-Newtonian fluid. Adding the modifier can significantly improve the elasticity of the system and enhance its fluidity, which is beneficial to reducing feed blockage and wall loss during processing.

[0054] The fresh wet rice noodles obtained in Examples 1-5 and Comparative Example 1 were subjected to in vitro digestion tests. The results are as follows: Figure 3 As shown in Table 1, the results of the in vitro digestion experiment showed that the addition of the improver significantly reduced the digestibility of rice noodles and improved the effect. -1 and 1022 / 995cm -1 The FTIR spectrum is the analytical data, which reflects the degree of order of the structure. -1 The full width at half maximum also reflects the order of the starch chain. Generally speaking, the short-range order of the starch chain is consistent with the FTIR spectrum at 1047 / 1022cm -1 The ratio and Raman spectrum at 480cm -1 The half-height full width is proportional to the FTIR spectrum at 1022 / 995cm -1The addition of the compound improver can improve the short-range order of the starch chain, thereby making the rice noodles obtain a better gel structure, and this has a more obvious correlation with the addition amount.

[0055] Rice noodles are a fast-digesting food with a high postprandial blood sugar level, and long-term consumption may lead to the risk of chronic diseases. Reducing its digestibility will help meet the precise health needs of an aging society.

[0056] Table 1 Parameters of rice flour starch hydrolysis, FTIR and Raman spectroscopy analysis

[0057]

[0058]

[0059] Note: In the same column, different letters indicate significance when P < 0.05.

[0060] Equilibrium concentration D ∞ It is an indicator that reflects the degree of digestion, K is the kinetic constant, HI is the hydrolysis index, and eGI is the estimated glycemic index.

[0061] Equilibrium concentration D ∞ It indicates the limit of the hydrolysis reaction, that is, the maximum degree of digestion, which means that the digestion and hydrolysis limit of rice noodles has been significantly improved after adding the compound improver.

[0062] The kinetic constant K indicates the speed of the reaction, and the addition of compound improvers does not significantly change the digestion rate of rice noodles.

[0063] The hydrolysis index has a similar meaning to the equilibrium concentration and mainly indicates the limit of the hydrolysis reaction.

[0064] eGI is a commonly used in vitro digestion evaluation index in academia. It can be seen that adding compound improvers can help delay the rise of blood sugar after meals.

[0065] The 13C NMR helical conformation of starch in fresh wet rice noodles was analyzed. The results are shown in Table 2. The addition of compound improvers can increase the proportion of single helical and double helical crystals and reduce the proportion of amorphous regions, indicating that the addition of compound improvers can make the structure of rice noodle gel more orderly, which is consistent with other results, and together proves the effect of adding compound improvers on improving the quality of rice gel.

[0066] Table 2 Starch 13 C NMR helical conformation

[0067] Double helix (%) Single helix (%) Amorphous phase (%) Comparative Example 1 <![CDATA[53.72±0.14 c ]]> <![CDATA[4.08±0.26 c ]]> <![CDATA[14.87±0.43 b ]]> Example 2 <![CDATA[54.15±0.22 b ]]> <![CDATA[4.78±0.18 b ]]> <![CDATA[15.82±0.56 a ]]> Example 4 <![CDATA[54.76±0.18 a ]]> <![CDATA[5.76±0.23 a ]]> <![CDATA[15.24±0.38 ab ]]>

[0068] Comparative Example 1

[0069] Fresh wet rice noodles without being treated with a compound improver are prepared by the following steps:

[0070] Step 1, soaking rice at 4°C for 4 hours, and slurrying the soaked rice according to the ratio of 60ml water / 100g rice to obtain rice slurry, and the water temperature is 30°C.

[0071] Step 2, the obtained rice slurry is spread on a plate and placed in a steamer for pre-gelatinization, the treatment temperature is 85° C., the treatment time is 30 min, and pre-gelatinized rice gel is obtained.

[0072] Step 3, kneading the pre-gelatinized rice gel into a dough, using a handheld extruder to obtain rice noodles, and sterilizing with boiling water to obtain fresh wet rice noodles, recorded as RF, with a sterilization temperature of 98° C. and a time of 30 seconds.

[0073] The fresh wet rice noodles had a moderate taste and a strong rice aroma. A large number of broken noodles appeared during sterilization and rehydration and steaming. A lot of broken rice noodles appeared when gently stirred, and the steaming water became turbid. After storage, rehydration and ripening required 5 to 15 minutes. The water holding capacity was average, and the surface was slightly rough after 5 minutes.

[0074] Comparative Example 2

[0075] Fresh wet rice noodles modified with only acetate starch were prepared by the following method:

[0076] Step 1, soaking rice at 4°C for 4 hours, slurrying the soaked rice according to the ratio of 60 ml water / 100 g rice, and adding cassava acetate starch at 5% of the weight of the rice to obtain a prepared rice slurry, and the water temperature is 30°C.

[0077] Step 2, the obtained rice slurry is spread on a plate and placed in a steamer for pre-gelatinization, the treatment temperature is 85° C., the treatment time is 30 min, and pre-gelatinized rice gel is obtained.

[0078] Step 3, kneading the pre-gelatinized rice gel into a dough, using a handheld extruder to obtain rice noodles, and sterilizing with boiling water to obtain fresh wet rice noodles, the sterilization temperature is 98° C., and the time is 30 seconds.

[0079] The fresh wet rice noodles have a hard texture and a noodle texture, without a strong rice aroma. Only some of them break during sterilization and rehydration and steaming. They break when stirred but are not easy to break. The turbidity of the steaming water is small. After storage, rehydration and ripening require 3 to 5 minutes. The water holding capacity is poor, and the surface becomes rough after 5 minutes.

[0080] Comparative Example 3

[0081] Fresh wet rice noodles modified only with distarch phosphate were prepared by the following method:

[0082] Step 1, soaking rice at 4°C for 4 hours, slurrying the soaked rice according to the ratio of 60 ml water / 100 g rice, and adding 5% of the mass of rice cassava phosphate distarch to obtain a modulated rice slurry, the water temperature is 30°C.

[0083] Step 2, the obtained rice slurry is spread on a plate and placed in a steamer for pre-gelatinization, the treatment temperature is 85° C., the treatment time is 30 min, and pre-gelatinized rice gel is obtained.

[0084] Step 3, kneading the pre-gelatinized rice gel into a dough, using a handheld extruder to obtain rice noodles, and sterilizing with boiling water to obtain fresh wet rice noodles, the sterilization temperature is 98° C., and the time is 30 seconds.

[0085] The obtained fresh wet rice noodles have a smooth and chewy texture and a strong rice aroma. Only some of the noodles are broken during sterilization and rehydration cooking, and they are not easily broken when stirred. The turbidity of the cooking water is small, and it takes 5 to 8 minutes to rehydrate and ripen after storage. It has good water retention and the surface is still smooth after being placed for 5 minutes.

[0086] Comparative Example 4

[0087] Fresh wet rice noodles modified only with acetylated distarch phosphate were prepared by the following method:

[0088] Step 1, soaking rice at 4°C for 4 hours, slurrying the soaked rice according to the ratio of 60 ml water / 100 g rice, and adding 5% of the mass of rice acetylated distarch phosphate of cassava to obtain a prepared rice slurry, the water temperature being 30°C.

[0089] Step 2, the obtained rice slurry is spread on a plate and placed in a steamer for pre-gelatinization, the treatment temperature is 85° C., the treatment time is 30 min, and pre-gelatinized rice gel is obtained.

[0090] Step 3, kneading the pre-gelatinized rice gel into a dough, using a handheld extruder to obtain rice noodles, and sterilizing with boiling water to obtain fresh wet rice noodles, the sterilization temperature is 98° C., and the time is 30 seconds.

[0091] The fresh wet rice noodles have a hard texture and a noodle texture, with a strong rice aroma. They are almost unbroken during sterilization and rehydration and cooking, and are not easily broken when stirred, but the turbidity of the cooking water is small. After storage, rehydration and maturation require 3 to 5 minutes. The water holding capacity is good, and the surface is smooth after being placed for 5 minutes.

[0092] The texture and cooking characteristics of the fresh wet rice noodles obtained in Examples 1-5 and Comparative Examples 1-4 were tested. The results are shown in Tables 3 and 4.

[0093] Table 3 Texture of fresh wet rice noodles

[0094]

[0095] Table 4 Cooking characteristics of fresh wet rice noodles

[0096] CLR(%) WAR(%) Turbidity Example 1 11.32±0.04 19.48±1.28 1.25±0.0053 Example 2 9.47±0.07 23.78±6.08 1.47±0.0156 Example 3 6.58±0.18 26.49±2.94 0.55±0.0004 Example 4 5.84±0.59 28.62±0.90 0.47±0.0040 Example 5 4.23±0.20 25.48±1.64 0.19±0.0004 Comparative Example 1 13.82±0.60 19.86±1.07 1.84±0.0551 Comparative Example 2 11.32±0.50 19.49±1.56 1.48±0.0192 Comparative Example 3 12.37±0.37 20.57±1.32 0.63±0.0310 Comparative Example 4 10.20±1.14 21.82±1.36 0.27±0.0010

[0097] Example 6

[0098] The freeze-dried rice powder treated with a compound improver is prepared by the following method:

[0099] Step 1, soak the rice at 4°C for 4 hours, and slurry the soaked rice according to the ratio of 60ml water / 100g rice, and add a composite improver at 5% of the weight of the rice to obtain a prepared rice slurry, and the water temperature is 30°C.

[0100] Step 2, the obtained rice slurry is spread on a plate and placed in a steamer for pre-gelatinization, the treatment temperature is 85° C., the treatment time is 30 min, and pre-gelatinized rice gel is obtained.

[0101] Step 3, precooling the obtained rice gel at -4°C for 30 minutes, prefreezing at -20°C for 30 minutes, and freezing at -80°C for 4 hours to obtain frozen rice gel.

[0102] Step 4, placing the frozen rice gel in a freeze dryer and drying for 48 hours to obtain freeze-dried rice gel.

[0103] Step 5, passing the freeze-dried rice gel through a powder grinder to obtain freeze-dried rice powder.

[0104] The obtained freeze-dried rice powder has a strong rice aroma, well retains the aroma of rice, has high whiteness, uniform color and texture, is not easy to harden, is rich in rice nutrition, can be stored at room temperature for more than 2 years, and can be used as a plant-based food ingredient in industrial production.

[0105] The above is only a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A composite improver for rice products, characterized in that: The invention comprises acetate starch, phosphate distarch and acetylated distarch phosphate, wherein the mass ratio of the acetate starch, phosphate distarch and acetylated distarch phosphate is 1:(0.5-2):(1-3), and the acetate starch, phosphate distarch and acetylated distarch phosphate are all obtained by modifying cassava starch.

2. The compound improving agent according to claim 1, characterized in that The compound improver also includes food additives.

3. The composite improver according to claim 1, characterized in that The compound improver comprises, by weight, 20 to 40 parts of acetate starch, 20 to 40 parts of distarch phosphate and 40 to 60 parts of acetylated distarch phosphate.

4. A rice product, characterized in that: Calculated by mass percentage, it comprises 0.5-25wt% of the compound improving agent as described in any one of claims 1-3.

5. The rice product according to claim 4, characterized in that The rice product is rice noodles, rice jelly or rice freeze-dried powder.

6. A method for preparing a rice product according to any one of claims 4 to 5, characterized in that: The following steps are involved: Step 1, slurrying the soaked rice, adding a composite improver to obtain a prepared rice slurry; Step 2, pre-gelatinizing the modulated rice slurry to obtain pre-gelatinized rice gel; Step 3, post-treating the pregelatinized rice gel to obtain the rice product.

7. The preparation method according to claim 6, characterized in that: In the step 2, the pre-gelatinization temperature is 70 to 90° C., and the pre-gelatinization time is 20 to 60 minutes.

8. The preparation method according to claim 6, characterized in that: When the rice product is rice noodles, the post-treatment in step 3 is to knead the pre-gelatinized rice gel into a ball and extrude it to obtain rice noodles; When the rice product is freeze-dried rice powder, the post-treatment in step 3 is freeze-drying and crushing the pre-gelatinized rice gel to obtain the freeze-dried rice powder.

9. The preparation method according to claim 6, characterized in that: The preparation method further comprises step 4, performing at least one of sterilization, aseptic packaging or brewing treatment on the rice.

10. The preparation method according to claim 9, characterized in that: The sterilization adopts UHT sterilization method, the sterilization temperature is 130-140°C, and the time is 10-20s; or the sterilization adopts high temperature short time sterilization, and the sterilization condition is heating at 80-90°C for 10-20s; The brewing temperature is controlled at 80-120°C, and the brewing time is 15-300s.

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