A method for preparing a soft-packed white rice porridge can

Abstract

The application discloses a kind of soft package white rice gruel cans preparation method, belong to emergency support food processing technical field.The method with raw rice as raw material, by one-time completion of cooking and sterilization process in soft package, to retain the form and flavor of traditional rice gruel.Through system optimization, the application determines the suitable rice is the waxy rice with high amylose content, preferably the rice content is 10%, and adopts two-stage sterilization process: first 95 DEG C pretreatment 5 minutes, then 121 DEG C main sterilization 10 minutes.Aiming at the problem that flat soft package is prone to rice gruel knotting and bag sticking when static sterilization, the application further adopts rotary water bath sterilization mode, to ensure that product texture is uniform, form is complete.The white rice gruel cans obtained by the application reaches commercial sterile standard, has good taste, stable form and rich rice fragrance, and is suitable for long-term storage and direct consumption in emergency scenarios.

Description

Technical Field

[0001] This invention belongs to the field of emergency food processing technology, specifically relating to a method for preparing soft-packaged white rice porridge cans. Background Technology

[0002] Currently, emergency scenarios such as natural disasters, sudden incidents, and emergency rescue place stringent demands on food safety: food must be able to be stored stably for a long time, be easy to consume quickly, and possess good sensory quality and nutritional value. Canned foods, due to their commercial aseptic properties and long shelf life, have become an important component of emergency food safety systems. However, traditional canned porridge products often use pre-gelatinized rice or rice fragments as raw materials. After high-temperature sterilization, these products often suffer from problems such as soft, mushy rice grains, deteriorated taste, and separation of rice and water, failing to meet consumers' expectations for the "distinct rice grains and uniform consistency" of traditional rice porridge.

[0003] In existing technologies, some studies have attempted to improve the texture stability of canned porridge by adjusting the ingredient ratios or adding thickeners, such as using modified starch or colloidal substances to maintain the porridge's viscosity. However, these methods often result in distorted flavor and a sticky texture, and the use of additives conflicts with the "natural and pure" philosophy of emergency foods. Furthermore, some processes involve pre-cooking the porridge before filling and sterilizing, which is not only energy-intensive but also prone to causing excessive gelatinization of the rice grains during secondary heating, affecting the sensory quality of the final product.

[0004] For porridge products in flexible packaging, the choice of sterilization process has a particularly significant impact on product quality. While flat retort pouches offer advantages such as rapid heat transfer and convenient storage and transportation, during static sterilization, the high-starch porridge is prone to clumping and sticking to the pouch due to uneven heating in certain areas, severely compromising the product's uniformity and appearance. Existing sterilization technologies are mostly designed for liquid or semi-liquid foods with good flowability, lacking specific optimization for the textural characteristics of high-starch porridge, making it difficult to balance sterilization safety and product textural stability in industrial production.

[0005] Therefore, developing a method for preparing canned white rice porridge that can be cooked directly from raw rice in flexible packaging, achieving commercial sterility while maintaining good texture and flavor, has become a pressing technical challenge in this field. In particular, how to solve the clumping and sticking problem during the static sterilization process of flat flexible packaging through synergistic optimization of raw material selection, rice content control, and sterilization processes is of great significance for improving the industrial production level and product quality of emergency food supplies. Summary of the Invention

[0006] This invention provides a method for preparing soft-packaged white rice porridge, using raw rice as raw material. The rice is cooked and sterilized in a single step within the soft packaging, preserving the traditional porridge form. By optimizing the type of japonica rice, the 10% rice content, and a two-stage sterilization process (95℃ / 5min pretreatment combined with 121℃ / 10min main sterilization), a balance between commercial sterility and good taste is achieved. Addressing the issue of clumping caused by static sterilization in flat soft packaging, a rotary water bath sterilization method is employed to ensure uniform texture and intact shape, making the product suitable for long-term storage and direct consumption in emergency situations.

[0007] On the one hand, the present invention provides a method for preparing soft-packaged white rice porridge cans, which adopts the following technical solution: A method for preparing a soft-packaged canned white rice porridge includes the following steps: (1) Select japonica rice as raw material and determine its water absorption rate A, where A = mass of japonica rice after draining / mass of dry japonica rice; (2) Weigh out japonica rice and purified water according to a japonica rice content of 9%~11%, and put them into soft packaging bags. The mass of japonica rice = target total mass × japonica rice content × A, and the mass of purified water = target total mass - japonica rice mass. (3) Vacuum seal the flexible packaging bag; (4) A two-stage sterilization process is adopted for sterilization: first, pre-treatment at 95℃ for 5 minutes, and then main sterilization at 121℃ for 10 minutes; (5) The sterilization process adopts a rotary water bath sterilization method.

[0008] Preferably, the amylose content of japonica rice is 11% to 18%.

[0009] Preferably, the content of japonica rice is 10%.

[0010] Preferably, the flexible packaging bag is a flat aluminum-plastic composite bag.

[0011] Preferably, the rotation speed of the rotary water bath sterilization is 1.5~2.5 r / min.

[0012] Preferably, the target total mass in step (2) is 300~400 grams.

[0013] Preferably, a top gap is left during filling in step (2) to ensure a sealing effect.

[0014] Preferably, the sterilization intensity F0 value of the two-stage sterilization process in step (4) reaches more than 10 minutes.

[0015] On the other hand, the present invention also provides a soft-packaged canned white rice porridge, which adopts the following technical solution: A soft-packaged canned white rice porridge prepared according to the above preparation method.

[0016] Preferably, the canned food meets commercial aseptic standards, the rice grains are intact, the porridge is uniform, and there is no clumping or sticking to the bag.

[0017] In summary, the beneficial effects of the present invention are as follows: This invention effectively solves the problems of soft and mushy rice grains, separation of rice water, and deterioration of taste that are common in traditional canned porridge products after high-temperature sterilization by precisely controlling the rice type (japonica rice with a suitable high amylose content), rice content (10%), and a two-stage sterilization process (pretreatment at 95℃ combined with main sterilization at 121℃). The resulting product has intact rice grains, uniform porridge, and a rich rice aroma, significantly improving the edible quality and sensory acceptance of emergency food.

[0018] This invention addresses the issues of clumping and sticking of contents during static sterilization of flat, flexible packaging. It innovatively employs a rotating water bath sterilization method, ensuring uniform heating and dynamic dispersion of the porridge during sterilization. This fundamentally solves the technical bottleneck of texture deterioration in high-starch porridge, achieving commercial aseptic safety while guaranteeing good texture stability and appearance integrity of the product. It provides a reliable technical solution for the industrial production of flexible packaged porridge products. Attached Figure Description

[0019] Figure 1 Image of canned white rice porridge made for preliminary rice variety selection; Figure 2 This is a schematic diagram of the installation of the test support for the orthogonal experiment. Figure 3 A schematic diagram showing the placement of rice porridge bags in sterilization baskets and autoclaves for an orthogonal experiment. Figure 4 An orthogonal experiment was conducted to investigate the clumping phenomenon of rice porridge in soft-packaged rice porridge. Figure 5 L and b values ​​were generated for six orthogonal experimental combinations to prepare canned white rice porridge. Figure 6 Texture test values ​​for canned white rice porridge were prepared for six orthogonal experimental combinations. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the embodiments.

[0021] Example Example 1 The specific steps for screening rice varieties in a preliminary test of soft-packaged white rice porridge are as follows: S1. Raw material preparation: Four types of rice samples were selected: japonica rice A1, A2, A3 and porridge rice. Their basic physicochemical indicators (moisture, total starch, amylose, crude protein content) were recorded. The basic information of japonica rice A1, A2 and A3 is shown in Table 1.

[0022] Table 1 Basic Information on Rice Varieties

[0023] S2. Water absorption rate determination: Weigh each type of dry rice m1, wash and drain it, and weigh it again m2. Calculate the water absorption rate A = m2 / m1.

[0024] S3. Bagging Ratio: Calculate the required mass of each type of rice according to the formula in Table 2, and pack them into 300g aluminum-plastic composite bags. Each group has two treatments: 75℃ hot water filling and room temperature water filling.

[0025] Table 2. Weight of rice varieties used in the preliminary screening test

[0026] S4. Exhaust and seal: Leave an appropriate headspace during filling and use a can sealing machine to perform vacuum sealing to ensure that the packaging is completely isolated from external microorganisms.

[0027] S5. Sterilization treatment: Sterilization was carried out using a DTS sterilizer with sterilization conditions of 95℃ / 5min followed by 121℃ / 5min. Two sterilization methods were compared: rotary (2.5r / min) and static water bath sterilization.

[0028] S6. Finished Product Evaluation: Observe the fluidity, gelatinization degree, and rice grain integrity of each sample of finished product, compare the effects of different rice varieties and different canning water temperatures on the sensory quality of white rice porridge, and preliminarily screen suitable rice varieties for further optimization.

[0029] like Figure 1 As shown, rice varieties 2 and 3 have good flowability, with rice variety 2 being superior to rice variety 3. Rice variety 1 has the highest gelatinization degree. For glutinous rice, it is the best for porridge. Rice aroma is subjective; compared to rice packaged in 75°C cans with room temperature water, the aroma of white rice porridge made in 75°C cans is slightly stronger, but no significant difference was perceived. Porridge rice has a stronger aroma, and rice packaged in 75°C water is more viscous than rice packaged in room temperature water, with rice variety 2 showing the most pronounced difference. The reason for using room temperature water is to maintain the integrity of the rice grains.

[0030] Example 2 Based on the principles of orthogonal experimental design, the specific steps for the research and development of porridge (3 factors: rice type, rice content, and sterilization process; 2 types of rice; 3 levels of rice content and sterilization process) are as follows: S1. Set up 6 groups of experiments according to Table 3. The combination factors include: (1) Types of rice (A): A2 (japonica rice 2), A3 (japonica rice 3).

[0031] (2) Rice content (B): B1: 9%, B2: 10%, B3: 11%.

[0032] (3) Sterilization process (C): C1: Two-stage sterilization (95℃ / 5min, 121℃ / 5min); C2: Two-stage sterilization (95℃ / 5min, 121℃ / 10min); C3: High-temperature sterilization (121℃ / 15min).

[0033] Table 3. Orthogonal array for the preparation of canned white rice porridge in orthogonal experiments.

[0034] S2. Weigh the mass m1 of each type of dried rice, rinse, drain, and weigh the drained rice m2; calculate m2 / m1, represented by the letter A. The weighed masses of rice and purified water are shown in Table 4. Table 4. Orthogonal array for the preparation of canned white rice porridge in orthogonal experiments.

[0035] S3, such as Figure 2 As shown, a hole is made at the bottom of the retort pouch used for heat penetration testing to install a wireless temperature probe and probe holder, ensuring the probe is located at the cold spot of the contents. An appropriate top gap is left during filling, and the pouch is vacuum-sealed using a can sealing machine.

[0036] S4, such as Figure 3 As shown, static water bath sterilization (rotation speed 2r / min) was carried out in groups according to sterilization process. Experiments with the same sterilization process were sterilized in batches: Experiments 3 and 5 were a batch (C1 process), Experiments 1 and 6 were a batch (C2 process), and Experiments 2 and 4 were a batch (C3 process). Each sterilization basket contained 15-20 bags, and a total of 60 bags were filled with 4 layers (30 bags per group). Figure 3 The red dot indicates the location of the temperature probe.

[0037] S5. To address the clumping phenomenon that occurs during static sterilization, a comparative verification experiment was added, namely, 95℃ / 5min-121℃ / 10min, rotary sterilization. The following sets of experiments were conducted: 400g flat bags with 10% rice content. At the same time, the following were tried for comparative verification under the same sterilization conditions: ① 2.8% japonica rice; ② 6.10% japonica rice; ③ 2.10% japonica rice in 300g stand-up pouches.

[0038] S6. Conduct multi-dimensional testing and analysis on the finished product, including: heat penetration curve and sterilization intensity F0 value determination, sensory evaluation (color, taste, rice aroma, texture), physicochemical index analysis (pH value, moisture content, solid content, color, textural characteristics), and flavor substance GC / MS analysis. The quality evaluation indicators and methods are shown in Table 5.

[0039] Table 5. Quality evaluation indicators and methods for orthogonal experiments on soft-packaged white porridge

[0040] For low-acid foods, F0 > 3 min, and the F0 value is significantly correlated with the sterilization process. Rice porridge prepared under all three sterilization processes met food safety requirements. Some rice porridge adhered to the bag wall and clumped (see...). Figure 4 The above phenomenon did not occur when the 300g stand-up pouches were sterilized statically. Therefore, it is speculated that this is due to the flat shape of the pouches and the static state during sterilization. Sensory scores, thermal sterilization F0 value, and pH value are shown in Table 6 below: Table 6 Sensory evaluation, thermal sterilization F0 value, and pH value of soft-packaged white porridge in orthogonal experiment

[0041] The comparison and verification in step S5 are shown in Table 7: Table 7 Sensory evaluation, thermal sterilization F0 value, and pH value of soft-packaged white porridge in orthogonal experiment

[0042] As shown in Table 8, when the rice content is the same (9% or 11%), the white rice porridge made from japonica rice 2 has a higher moisture content than that made from japonica rice 3. This is related to the higher moisture content of japonica rice 2 compared to japonica rice 3. However, when the rice content is 10%, the white rice porridge made from japonica rice 2 has a slightly lower moisture content than that made from japonica rice 3. This may be due to the slight moisture loss caused by the unstable sealing during the heat sterilization process of japonica rice 2 at 10% rice content (121℃ / 15 minutes). When the sterilization conditions and rice type are different, comparing the white rice porridge made from 11%, 10%, and 9% rice content reveals that the higher the rice content, the lower the moisture content of the white rice porridge. When there is a 95℃ pretreatment and a short sterilization time, increasing the rice content has a more significant impact on the results. This is because as the sterilization time is extended, a large number of hydroxyl groups are exposed in the starch molecular chains, which form hydrogen bonds with water molecules. They are not easily evaporated during the drying process, so the initial rice content no longer has a significant impact on the moisture content of the final product.

[0043] Table 8. Moisture content of canned white rice porridge produced by orthogonal experiment

[0044] As shown in Table 9, when the sterilization process is 95°C / 5 min, 121°C / 5 min and 95°C / 5 min, 121°C / 10 min, the solid content is relatively high. This is because during the heating process, the rice grains absorb water, the starch granules expand and increase in volume, and subsequently the granules break down, releasing starch molecules into the water. These starch molecules form a gel network with water molecules through hydrogen bonds and van der Waals forces, gradually giving the porridge a thick texture, viscosity, and stickiness, thus increasing the solid content. The higher rice content and the longer sterilization time at 121°C amplify this effect. However, when the sterilization process is continuous sterilization at 121°C for 15 minutes, the starch molecular structure is destroyed, making it unable to effectively retain water. Local clumping and water precipitation occur, resulting in a decrease in the solid content. This is particularly evident in the 2.9% rice content of japonica rice under this sterilization process, which may be due to the higher amylopectin content in japonica rice 2, making its structure more easily destroyed under long-term, high-temperature conditions.

[0045] Table 9. Solid content of canned white rice porridge prepared by orthogonal experiment

[0046] Colorimetric test results as follows Figure 5 As shown, the longer the sterilization time, the more brown substances are produced by the Maillard reaction between amino acids and reducing sugars in the rice, resulting in a lower brightness (L value). Rice porridge made from Japonica rice 3, under conditions of 9% rice content and 121℃ / 15min, has a higher L value than rice porridge made from Japonica rice 2 with a rice content of 10% under the same sterilization conditions. This may be due to the lower content and protein content of Japonica rice 3, leading to a lower degree of Maillard reaction. Yellowness (b value) is related to the pigments contained in the rice variety and can be further studied.

[0047] Texture test results as follows Figure 6 As shown, firmness reflects the hardness of the rice porridge, thickness reflects the overall viscosity of the porridge, cohesiveness reflects the internal binding force of the porridge, and viscosity reflects the surface adhesion characteristics of the porridge. White rice porridge made from japonica rice type 3 with a rice content of 11% has a higher firmness; white rice porridge made from japonica rice type 2 with a rice content of 11% has higher thickness, cohesiveness, and viscosity. This is because during the heat sterilization process, the starch in the rice gelatinizes under the influence of hydrogen bonds formed between molecular chains and van der Waals forces between molecules, resulting in a dense, tightly intertwined molecular network with strong internal binding force. The effect is more pronounced when the rice type is japonica rice type 3 with a high proportion of amylose and when the rice content is higher. However, when sterilized at high temperatures for a prolonged period (121℃ / 15min), the structural destruction is more thorough, and obvious clumping is observed. Therefore, the recommended optimal sterilization conditions are 95℃ / 5min and 121℃ / 10min.

[0048] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a soft-packaged canned white rice porridge, characterized in that, Includes the following steps: (1) Select japonica rice as raw material and determine its water absorption rate A, where A = mass of japonica rice after draining / mass of dry japonica rice; (2) Weigh the japonica rice and purified water according to the content of japonica rice of 9%~11%, and put them into a soft packaging bag. The mass of japonica rice = target total mass × japonica rice content × A, and the mass of purified water = target total mass - japonica rice mass. (3) Vacuum seal the flexible packaging bag; (4) A two-stage sterilization process is adopted for sterilization: first, pre-treatment at 95℃ for 5 minutes, and then main sterilization at 121℃ for 10 minutes; (5) The sterilization process adopts a rotary water bath sterilization method.

2. The preparation method according to claim 1, characterized in that, The amylose content of the japonica rice is 11% to 18%.

3. The preparation method according to claim 1, characterized in that, The content of japonica rice is 10%.

4. The preparation method according to claim 1, characterized in that, The flexible packaging bag is a flat aluminum-plastic composite bag.

5. The preparation method according to claim 1, characterized in that, The rotation speed of the rotary water bath sterilization is 1.5~2.5 r / min.

6. The preparation method according to claim 1, characterized in that, The total target mass mentioned in step (2) is 300~400 grams.

7. The preparation method according to claim 1, characterized in that, Leave a top gap during filling in step (2) to ensure a sealing effect.

8. The preparation method according to claim 1, characterized in that, The sterilization intensity F0 value of the two-stage sterilization process described in step (4) reaches more than 10 minutes.

9. A soft-packaged white rice porridge canned food prepared according to any one of claims 1-8.

10. The soft-packaged white rice porridge canned food according to claim 9, characterized in that, The canned food meets commercial aseptic standards, with intact rice grains, uniform porridge consistency, and no clumping or sticking to the bag.

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