Recombined freeze-dried tomato cubes and preparation method thereof

Abstract

The invention provides a recombinant freeze-dried tomato block and a preparation method thereof. The recombined freeze-dried tomato blocks are prepared from the following raw materials: diced tomato, tomato sauce, a coloring agent, compound colloid, D-sodium erythorbate, sodium citrate, starch, white sugar and RO water. The preparation method comprises the following steps: mixing the preparation raw materials according to the formula ratio, mixing the diced tomato and the tomato paste after primary stirring, and performing secondary stirring to obtain compound tomato paste; and sequentially carrying out traying treatment, quick-freezing treatment, cutting treatment, re-freezing treatment and vacuum freeze-drying treatment on the compound tomato paste to obtain the recombined freeze-dried tomato blocks. The preparation raw materials of the recombined freeze-dried tomato blocks are adjusted in a breakthrough manner, and the freeze-drying technology in the preparation method is optimized, so that the recombined freeze-dried tomato blocks are neat in appearance, solid in shape after rehydration, close to fresh tomatoes in taste and capable of being stored at normal temperature, the production requirements are well met, new food materials are provided for the instant food industry, and the recombined freeze-dried tomato blocks have good market prospects. Wide market prospects and market benefits are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and relates to a recombinant freeze-dried tomato block and a preparation method thereof, and particularly relates to a recombinant freeze-dried tomato block having a flavor close to that of fresh tomatoes after rehydration, and a preparation method thereof. Background Art

[0002] Tomato, also known as tomato, belongs to the Solanaceae family. It is an annual herb and perennial in tropical areas. It is native to tropical South American countries and has been cultivated for thousands of years. It is said that Columbus brought it back to Europe during his second voyage to America and began to cultivate it as an ornamental. It was not until the second half of the 18th century that it was cultivated as a vegetable in Italy. "Tomato" was recorded in the "Qunfangpu" in my country in the 17th century, but it was not cultivated as a vegetable until the early 20th century. It is now one of the main vegetables in my country.

[0003] Tomatoes are rich in nutrition, delicious, and bright red in color. They are one of the most popular and widely planted vegetable crops in the world. Tomatoes contain many nutrients, mainly including: protein, fat, carotene, lycopene, carbohydrates, niacin, VC, riboflavin, citric acid, malic acid, and some metal ions. These substances not only provide people with various nutrients needed by the human body, but also have multiple physiological functions. For example, niacin has the function of reducing capillary permeability, preventing capillary rupture and vascular sclerosis; the fine cellulose contained in tomatoes has an inestimable role in promoting the excretion of corrupt food in the intestines, lowering cholesterol, and preventing cancer; the sugar contained in tomatoes is mostly fructose and glucose, which are the easiest to digest and absorb, and have the effect of nourishing the heart and protecting the liver; the most important thing is the lycopene contained in tomatoes, which has a strong antioxidant property, 100 times that of vitamin E and more than twice that of beta-carotene; in addition, studies have also found that lycopene can effectively prevent prostate cancer, and its inhibitory effect on uterine cancer and lung cancer cells is significantly higher than that of beta- and alpha-carotene. Moreover, the content of lycopene in the human body is related to human life expectancy. Therefore, regular consumption of tomatoes and their products can not only provide people with a variety of vitamins, minerals and fiber, but also has a certain effect on strengthening the body, preventing and curing diseases.

[0004] Tomatoes have thin and juicy skins, with a water content of up to about 95%. They belong to the berry category, and fresh fruits are difficult to preserve for a long time. In addition, their harvest period is relatively short, and they are put on the market in a relatively concentrated manner. In order to adjust the supply demand of tomatoes in the off-season and peak season, they are processed into products such as tomato sauce, tomato juice, tomato powder, and diced tomatoes in the prior art. Most of the uses of such tomato products in the food industry are to make sauces, soup base bags, etc., and the tomatoes are all in the soup, which are tomatoes that can be eaten but not seen. There are also technologies such as vacuum freeze-drying fresh tomatoes, such as CN 108056155A, which discloses a method for preparing freeze-dried tomatoes and the prepared freeze-dried tomatoes. The method provided by the patent can effectively preserve nutrients, but is limited to fresh tomatoes and requires complex processes such as hot blanching and soaking in color-protecting liquid for pretreatment, so it is impossible to adjust the demand for tomatoes in the off-season and peak season, and the price is relatively high, so it cannot appear as an ingredient in fast food products.

[0005] Therefore, it is necessary to provide a preparation method that can get rid of the influence of production season and complex process, to ensure that the obtained tomato product has a real tomato texture when used in fast food products, to create a tomato that can be seen and eaten, and to bring consumers a new food experience. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a recombinant freeze-dried tomato block and a preparation method thereof. The present invention makes a breakthrough adjustment in the preparation raw materials of the recombinant freeze-dried tomato block, and optimizes the freeze-drying technology in the preparation method, so that the recombinant freeze-dried tomato block has a neat appearance, solid shape after rehydration, tastes close to fresh tomatoes, and can be stored at room temperature, which not only meets the production needs well, but also provides new ingredients for the convenience food industry, and has broad market prospects and market benefits.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a recombinant freeze-dried tomato block, wherein the raw materials for preparing the recombinant freeze-dried tomato block include: diced tomatoes, tomato paste, a colorant, a composite colloid, sodium D-isoascorbate, sodium citrate, starch, white sugar and RO water.

[0009] The present invention optimizes the raw material formula so that the recombinant freeze-dried tomato blocks still have the taste of fresh tomatoes after rehydration and can be stored at room temperature, which not only satisfies the production needs well, but also provides new food materials for the convenience food industry, and has broad market prospects and market benefits.

[0010] Furthermore, the composite colloid in the raw material is used for solidification and mouthfeel. The sodium D-isoascorbate is used for color protection and is also used together with sodium citrate to lower the pH value to avoid excessive use of sodium D-isoascorbate which makes the product taste bitter.

[0011] As a preferred technical solution of the present invention, the compound colloid includes agar and carrageenan.

[0012] Preferably, the mass ratio of agar to carrageenan is 1-5:0.1-1, for example, 1:0.1, 1:1, 2.5:0.1, 2.5:0.5, 5:0.1 or 5:1, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0013] In the present invention, agar and carrageenan are compounded to make the obtained reconstituted freeze-dried tomato blocks less prone to breakage after being frozen and cut, and the finished product has a more realistic taste and a firmer structure; the amount of agar added in the compound colloid is relatively high, and if the amount of agar added is relatively low, the freeze-dried tomatoes will be easily dispersed after being rehydrated.

[0014] Preferably, the coloring agent includes capsanthin and betaine.

[0015] Preferably, the starch comprises potato starch.

[0016] It is worth noting that the use of potato starch in the present invention can enhance the structure of the reconstituted freeze-dried tomato chunks, further making the tomato chunks solid after rehydration.

[0017] As a preferred technical solution of the present invention, the reconstituted freeze-dried tomato blocks include the following raw materials in parts by weight: 22 to 28 parts of diced tomatoes, 30 to 38 parts of tomato paste, 0.02 to 0.9 parts of capsanthin, 0.02 to 0.9 parts of beetroot red, 1 to 5 parts of agar, 0.1 to 1 parts of carrageenan, 1 to 5 parts of sodium D-isoascorbate, 1 to 5 parts of sodium citrate, 0.5 to 2 parts of potato starch, 1 to 7 parts of white sugar, and 25 to 45 parts of RO water.

[0018] Exemplarily, the weight proportion of diced tomatoes in the reconstituted freeze-dried tomato chunks is 22 to 28 parts, for example, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts or 28 parts, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0019] The weight proportion of the tomato paste is 30 to 38 parts, for example, 30 parts, 32 parts, 34 parts, 36 parts or 38 parts, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0020] The weight portion of the capsanthin is 0.02 to 0.9 parts, for example, 0.02 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.5 parts, 0.7 parts or 0.9 parts, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0021] The weight portion of the betalain is 0.02 to 0.9 parts, for example, 0.02 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.5 parts, 0.7 parts or 0.9 parts, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0022] The weight proportion of the agar is 1 to 5 parts, for example, 1 part, 2 parts, 3 parts, 4 parts or 5 parts, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0023] The weight portion of the carrageenan is 0.1 to 1 part, for example, 0.1 part, 0.2 part, 0.4 part, 0.6 part, 0.8 part or 1 part, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0024] The weight proportion of the sodium D-isoascorbate is 1 to 5 parts, for example, 1 part, 2 parts, 3 parts, 4 parts or 5 parts, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0025] The weight proportion of the sodium citrate is 1 to 5 parts, for example, 1 part, 2 parts, 3 parts, 4 parts or 5 parts, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0026] The weight portion of the potato starch is 0.5 to 2 parts, for example, 0.5 parts, 1 part, 1.5 parts or 2 parts, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0027] The weight proportion of the white sugar is 1 to 7, for example, 1, 2, 3, 4, 5, 6 or 7, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0028] The weight proportion of the RO water is 25 to 45 parts, for example, 25 parts, 30 parts, 35 parts, 40 parts or 45 parts, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] In the present invention, the main ingredients of the preparation raw materials of the recombinant freeze-dried tomato blocks include diced tomatoes and tomato paste. Lack of any one of them will result in insufficient tomato taste; if the amount of diced tomatoes is too low, the fresh taste of the tomatoes after rehydration will be weak; if the amount of diced tomatoes is too high, the vacuum freeze-drying treatment time in the preparation process will be prolonged, resulting in increased costs;

[0030] In addition, the potato starch has the function of strengthening the structure of the reconstituted freeze-dried tomato chunks. A high dosage will result in the central part of the reconstituted freeze-dried tomato chunks not being rehydrated, resulting in a fake taste, while a low dosage will result in an incomplete structure and easy collapse.

[0031] The sodium citrate is used to adjust the pH value of the raw materials. If the amount of sodium citrate is too high, the pH value will be too high, and if it is too low, the pH value will be too low. Both high and low pH values ​​will cause the reconstituted freeze-dried tomatoes to be easy to disperse after rehydration.

[0032] In a second aspect, the present invention provides a method for preparing the recombinant freeze-dried tomato chunks provided in the first aspect, the preparation method comprising the following steps:

[0033] (1) mixing a colorant, a compound colloid, sodium D-isoascorbate, sodium citrate, starch, and white sugar according to the formula amount, and then mixing RO water, stirring once, mixing diced tomatoes and tomato paste, and stirring twice to obtain a composite tomato paste;

[0034] (2) sequentially plating, quick freezing and cutting the composite tomato paste obtained in step (1) to obtain tomato chunks;

[0035] (3) refreezing and vacuum freeze-drying the tomato chunks obtained in step (2) to obtain the reconstituted freeze-dried tomato chunks.

[0036] In the present invention, firstly, the acidification process of the raw materials is realized by mixing sodium citrate (so that the pH value of the composite tomato paste is less than 5), and the mixing process is cold-treated throughout the process without heating, thereby avoiding the reproduction of microorganisms; then, quick freezing treatment is adopted to ensure that the product quickly passes through the -1 to 5° C. ice crystal zone and forms sufficiently small and dense ice crystals inside; and then, refreezing treatment and vacuum freeze-drying treatment are adopted to ensure that the obtained product has the taste and aroma of fresh tomatoes.

[0037] As a preferred technical solution of the present invention, the temperature of the RO water in step (1) is 5-10°C, for example, 5°C, 6°C, 7°C, 8°C, 9°C or 10°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0038] Preferably, the stirring speed of the primary stirring in step (1) is 30 to 50 r / min, for example, 30 r / min, 35 r / min, 40 r / min, 45 r / min or 50 r / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] Preferably, the stirring time in step (1) is 5 to 10 minutes, for example, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0040] Preferably, the stirring speed of the secondary stirring in step (1) is 30 to 50 r / min, for example, it can be 30 r / min, 35 r / min, 40 r / min, 45 r / min or 50 r / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0041] Preferably, the secondary stirring time in step (1) is 2 to 5 minutes, for example, 2 minutes, 2.5 minutes, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes or 5 minutes, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0042] In the present invention, the raw materials are mixed at low temperature to prevent the growth of microorganisms and control the acoustic field speed of the microorganisms; combined with the added composite colloid and potato starch, small and dense holes are formed in the composite tomato paste and the low-temperature quick-freezing process, and a dense network structure is formed with the composite colloid and potato starch to fix the tomato paste and canned tomatoes, thereby forming a taste and authenticity like fresh tomatoes.

[0043] As a preferred technical solution of the present invention, the method for preparing diced tomatoes in step (1) comprises: chopping and blending canned diced tomatoes to obtain diced tomatoes.

[0044] The canned diced tomatoes of the present invention are purchased from Xinjiang Uygur Autonomous Region; the specification thereof is 19 mm×19 mm.

[0045] Preferably, the size of the diced tomatoes is 5-8mm×5-8mm, for example, 5mm×5mm, 5mm×6mm, 5mm×7mm, 5mm×8mm, 6mm×6mm, 8mm×5mm or 8mm×8mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0046] Preferably, the chopping time is 5 to 15 seconds, for example, 5 seconds, 7 seconds, 9 seconds, 11 seconds, 13 seconds or 15 seconds, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0047] Preferably, the chopping and mixing process includes high-speed chopping and low-speed stirring performed sequentially.

[0048] Preferably, the high-speed chopping speed is 1480-2960 rpm, for example, it can be 1480 rpm, 1500 rpm, 1800 rpm, 2100 rpm, 2400 rpm, 2700 rpm or 2960 rpm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0049] Preferably, the rotation speed of the low-speed stirring is 7 to 16 rpm, for example, it can be 7 rpm, 9 rpm, 11 rpm, 13 rpm, 15 rpm or 16 rpm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0050] As a preferred technical solution of the present invention, the plate-laying process in step (2) comprises: pouring the composite tomato paste obtained in step (1) into a mold, and then performing a shaping process using a scraper.

[0051] Preferably, the temperature of the quick freezing treatment in step (2) is -35 to -45°C, for example, it can be -35°C, -37°C, -39°C, -41°C, -43°C or -45°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0052] Preferably, the time for the quick freezing treatment in step (2) is 4 to 7 hours, for example, it can be 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours or 7 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0053] In the present invention, the temperature of the quick freezing treatment is -35 to -45°C. If the temperature is too low, it will lead to an increase in cost, and if the temperature is too high, the ice crystals formed during the quick freezing process will be larger and the overall structure will be uneven.

[0054] As a preferred technical solution of the present invention, the temperature of the refrozen treatment in step (3) is -18 to -10°C, for example, it can be -18°C, -17°C, -16°C, -15°C, -14°C, -13°C, -12°C, -11°C or -10°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0055] Preferably, the refrozen treatment time in step (3) is 30 to 60 min, for example, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0056] In the present invention, the temperature of the refrozen treatment is -18 to -10°C. If the temperature is too low, it will lead to increased costs, and if the temperature is too high, it will lead to incomplete refrozen, and the surface will easily collapse during the subsequent vacuum freeze-drying treatment.

[0057] As a preferred technical solution of the present invention, the vacuum freeze-drying treatment in step (3) includes: heating to a first temperature at a constant rate, lowering to a second temperature after one insulation treatment, and lowering to a third temperature after two insulation treatments for three insulation treatments.

[0058] Preferably, the vacuum degree of the vacuum freeze-drying treatment is 30-100 Pa, for example, 30 Pa, 50 Pa, 70 Pa, 90 Pa or 100 Pa, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0059] Preferably, the constant rate is 1.5-2.5°C / min, for example, it can be 1.5°C / min, 1.7°C / min, 1.9°C / min, 2.1°C / min, 2.3°C / min or 2.5°C / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0060] Preferably, the first temperature is 60-70°C, for example, 60°C, 62°C, 64°C, 66°C, 68°C or 70°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0061] Preferably, the time for the single insulation treatment is 4.5 to 5.5 h, for example, 4.5 h, 4.7 h, 4.9 h, 5.1 h, 5.3 h or 5.5 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0062] Preferably, the second temperature is 50-55°C, for example, 50°C, 51°C, 52°C, 53°C, 54°C or 55°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0063] Preferably, the time of the secondary insulation treatment is 6.5 to 7.5 h, for example, 6.5 h, 6.7 h, 6.9 h, 7.1 h, 7.3 h or 7.5 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0064] Preferably, the third temperature is 40-45°C, for example, 40°C, 41°C, 42°C, 43°C, 44°C or 45°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0065] Preferably, the time for the three insulation treatments is 4.5 to 5.5 h, for example, 4.5 h, 4.7 h, 4.9 h, 5.1 h, 5.3 h or 5.5 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0066] It is worth noting that the temperature during the vacuum freeze-drying process of the present invention is not higher than 70° C., so as to ensure the nutrition and color of the recombinant freeze-dried tomato pieces and ensure that the finished product has the taste and aroma of fresh tomatoes.

[0067] As a preferred technical solution of the present invention, the second aspect of the present invention provides a method for preparing the recombinant freeze-dried tomato chunks according to the first aspect, comprising the following steps:

[0068] (1) mixing a colorant, a compound colloid, sodium D-isoascorbate, sodium citrate, starch, and white sugar according to a formula amount, and then mixing RO water at 5 to 10° C., stirring once at a stirring speed of 30 to 50 r / min for 5 to 10 min, and then mixing diced tomatoes and tomato paste, and stirring twice at a stirring speed of 30 to 50 r / min for 2 to 5 min to obtain a composite tomato paste;

[0069] The method for preparing diced tomatoes comprises: chopping and stirring canned diced tomatoes for 5 to 15 seconds to obtain diced tomatoes; the chopping and stirring comprises sequentially performing high-speed chopping at a rotation speed of 1480 to 2960 rpm and low-speed stirring at a rotation speed of 7 to 16 rpm;

[0070] (2) pouring the composite tomato paste obtained in step (1) into a mold, shaping it with a scraper to achieve a plate-like process, and then performing a quick freezing process at -35 to -45°C for 4 to 7 hours, and cutting it after demolding to obtain tomato chunks;

[0071] (3) refreezing the tomato chunks obtained in step (2) at -18 to -10°C for 30 to 60 minutes; and then performing vacuum freeze drying at a vacuum degree of 30 to 100 Pa to obtain the reconstituted freeze-dried tomato chunks;

[0072] The vacuum freeze-drying process includes: heating to 60-70°C at a constant rate, maintaining the temperature for 4.5-5.5 hours, then reducing the temperature to 50-55°C, maintaining the temperature for 6.5-7.5 hours, then reducing the temperature to 40-45°C, and maintaining the temperature for 4.5-5.5 hours.

[0073] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0074] The system refers to an equipment system, a device system or a production device.

[0075] Compared with the prior art, the present invention has the following beneficial effects:

[0076] (1) The present invention optimizes the raw material formula and preparation method of recombinant freeze-dried tomatoes, so that the prepared recombinant freeze-dried tomatoes have a neat appearance, are solid after rehydration, have a taste close to that of fresh tomatoes, and can be stored at room temperature. This not only satisfies production needs well, but also provides new ingredients for the convenience food industry, and has broad market prospects and market benefits.

[0077] (2) The preparation method of the recombinant freeze-dried tomato provided by the present invention is operated at low temperature throughout the process, the process is simple and easy to operate, and the growth and reproduction of microorganisms are effectively reduced, which is safe and controllable;

[0078] (3) The recombinant freeze-dried tomato blocks provided by the present invention are prepared from canned diced tomatoes as raw materials, thus getting rid of the influence of the production season;

[0079] (4) The recombinant freeze-dried tomato chunks provided by the present invention have a shelf life of 10 months, which is relatively long and is conducive to large-scale production and sales. DETAILED DESCRIPTION

[0080] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0081] The tomato sauce used in the following examples and comparative examples was purchased from Uni-President Enterprises; the canned diced tomatoes were purchased from COFCO Group.

[0082] Example 1

[0083] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 25 parts of diced tomatoes, 34 parts of tomato paste, 0.4 parts of paprika, 0.6 parts of beetroot red, 2.5 parts of agar, 0.5 parts of carrageenan, 3 parts of sodium D-isoascorbate, 3 parts of sodium citrate, 1.75 parts of potato starch, 4 parts of white sugar, and 35 parts of RO water.

[0084] The preparation method of the recombinant freeze-dried tomato chunks comprises the following steps:

[0085] (1) mixing a colorant, agar, carrageenan, sodium D-isoascorbate, sodium citrate, potato starch, and white sugar according to the formula amount, and then mixing with RO water at 8° C., stirring once at a stirring speed of 40 r / min for 8 minutes, and then mixing diced tomatoes and tomato paste, and stirring twice at a stirring speed of 40 r / min for 3 minutes to obtain a composite tomato paste;

[0086] The method for preparing diced tomatoes comprises: chopping and stirring canned diced tomatoes for 12 seconds to obtain diced tomatoes; the chopping and stirring comprises sequentially performing high-speed chopping at a rotation speed of 2000 rpm and low-speed stirring at a rotation speed of 12 rpm;

[0087] (2) pouring the composite tomato paste obtained in step (1) into a mold, shaping it with a scraper to achieve a plate-like process, and then performing a quick freezing process at -40°C for 5.5 hours, and cutting it after demolding to obtain tomato chunks;

[0088] (3) refreezing the tomato chunks obtained in step (2) at -15°C for 40 minutes; and then performing vacuum freeze-drying at a vacuum degree of 80 Pa to obtain the reconstituted freeze-dried tomato chunks;

[0089] The vacuum freeze-drying process includes: heating to 65°C at a constant rate, maintaining the temperature for 5 hours, then reducing the temperature to 52.5°C, maintaining the temperature for 6 hours, then reducing the temperature to 42.5°C, and maintaining the temperature for 5 hours three times.

[0090] Example 2

[0091] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 22 parts of diced tomatoes, 30 parts of tomato paste, 0.02 parts of capsanthin, 0.9 parts of betaine, 1 part of agar, 0.1 parts of carrageenan, 1 part of sodium D-isoascorbate, 1 part of sodium citrate, 0.5 parts of potato starch, 7 parts of white sugar, and 25 parts of RO water.

[0092] The preparation method of the recombinant freeze-dried tomato chunks comprises the following steps:

[0093] (1) mixing a colorant, agar, carrageenan, sodium D-isoascorbate, sodium citrate, potato starch, and white sugar according to the formula amount, and then mixing with RO water at 5° C., stirring once at a stirring speed of 30 r / min for 10 min, and then mixing diced tomatoes and tomato paste, and stirring twice at a stirring speed of 30 r / min for 5 min to obtain a composite tomato paste;

[0094] The method for preparing diced tomatoes comprises: chopping and stirring canned diced tomatoes for 5 seconds to obtain diced tomatoes; the chopping and stirring comprises sequentially performing high-speed chopping at a rotation speed of 2960 rpm and low-speed stirring at a rotation speed of 16;

[0095] (2) pouring the composite tomato paste obtained in step (1) into a mold, shaping it with a scraper to achieve a plate-like process, and then performing a quick freezing process at -35°C for 7 hours, and cutting it after demolding to obtain tomato chunks;

[0096] (3) refreezing the tomato chunks obtained in step (2) at -10°C for 60 minutes; and then performing vacuum freeze-drying at a vacuum degree of 30 Pa to obtain the reconstituted freeze-dried tomato chunks;

[0097] The vacuum freeze-drying process includes: heating to 60°C at a constant rate, keeping warm for 5.5 hours, then reducing to 50°C, keeping warm for 7.5 hours, then reducing to 40°C and keeping warm for 5.5 hours three times.

[0098] Example 3

[0099] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 28 parts of diced tomatoes, 38 parts of tomato paste, 0.9 parts of capsanthin, 0.02 parts of betaine, 5 parts of agar, 1 part of carrageenan, 5 parts of sodium D-isoascorbate, 5 parts of sodium citrate, 2 parts of potato starch, 7 parts of white sugar, and 45 parts of RO water.

[0100] The preparation method of the recombinant freeze-dried tomato chunks comprises the following steps:

[0101] (1) mixing a colorant, agar, carrageenan, sodium D-isoascorbate, sodium citrate, potato starch, and sugar according to the formula, and then mixing with RO water at 10° C., stirring once at a stirring speed of 50 r / min for 5 min, and then mixing with diced tomatoes and tomato paste, and stirring twice to obtain a composite tomato paste;

[0102] The method for preparing diced tomatoes comprises: chopping and stirring canned diced tomatoes for 15 seconds to obtain diced tomatoes; the chopping and stirring comprises sequentially performing high-speed chopping at a rotation speed of 1480 rpm and low-speed stirring at a rotation speed of 7 rpm;

[0103] (2) pouring the composite tomato paste obtained in step (1) into a mold, shaping it with a scraper to achieve a plate-like process, and then performing a quick freezing process at -45°C for 4 hours, and cutting it after demolding to obtain tomato chunks;

[0104] (3) refreezing the tomato chunks obtained in step (2) at -18°C for 30 minutes; and then performing vacuum freeze-drying at a vacuum degree of 100 Pa to obtain the reconstituted freeze-dried tomato chunks;

[0105] The vacuum freeze-drying process includes: heating to 70°C at a constant rate, keeping warm for 4.5 hours, then reducing the temperature to 55°C, keeping warm for 6.5 hours, then reducing the temperature to 45°C and keeping warm for 4.5 hours three times.

[0106] Example 4

[0107] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 25 parts of diced tomatoes, 34 parts of tomato paste, 0.4 parts of paprika, 0.6 parts of beetroot red, 2.5 parts of agar, 0.5 parts of carrageenan, 3 parts of sodium D-isoascorbate, 3 parts of sodium citrate, 1.75 parts of potato starch, 4 parts of white sugar, and 35 parts of RO water.

[0108] The preparation method of the recombinant freeze-dried tomato chunks is different from that of Example 1 only in that:

[0109] In this embodiment, the temperature of the RO water in step (1) is adjusted to 25°C.

[0110] Example 5

[0111] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 25 parts of diced tomatoes, 34 parts of tomato paste, 0.4 parts of paprika, 0.6 parts of beetroot red, 2.5 parts of agar, 0.5 parts of carrageenan, 3 parts of sodium D-isoascorbate, 3 parts of sodium citrate, 1.75 parts of potato starch, 4 parts of white sugar, and 35 parts of RO water.

[0112] The preparation method of the recombinant freeze-dried tomato chunks is different from that of Example 1 only in that:

[0113] In this embodiment, the temperature of the quick freezing treatment in step (2) is adjusted to -30°C.

[0114] Example 6

[0115] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 25 parts of diced tomatoes, 34 parts of tomato paste, 0.4 parts of paprika, 0.6 parts of beetroot red, 2.5 parts of agar, 0.5 parts of carrageenan, 3 parts of sodium D-isoascorbate, 3 parts of sodium citrate, 1.75 parts of potato starch, 4 parts of white sugar, and 35 parts of RO water.

[0116] The preparation method of the recombinant freeze-dried tomato chunks is different from that of Example 1 only in that:

[0117] In this embodiment, the temperature of the quick freezing treatment in step (2) is adjusted to -50°C.

[0118] Example 7

[0119] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 25 parts of diced tomatoes, 34 parts of tomato paste, 0.4 parts of paprika, 0.6 parts of beetroot red, 2.5 parts of agar, 0.5 parts of carrageenan, 3 parts of sodium D-isoascorbate, 3 parts of sodium citrate, 1.75 parts of potato starch, 4 parts of white sugar, and 35 parts of RO water.

[0120] The preparation method of the recombinant freeze-dried tomato chunks is different from that of Example 1 only in that:

[0121] In this embodiment, the temperature of the refrozen treatment in step (3) is adjusted to -25°C.

[0122] Example 8

[0123] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 25 parts of diced tomatoes, 34 parts of tomato paste, 0.4 parts of paprika, 0.6 parts of beetroot red, 2.5 parts of agar, 0.5 parts of carrageenan, 3 parts of sodium D-isoascorbate, 3 parts of sodium citrate, 1.75 parts of potato starch, 4 parts of white sugar, and 35 parts of RO water.

[0124] The preparation method of the recombinant freeze-dried tomato chunks is different from that of Example 1 only in that:

[0125] In this embodiment, the temperature of the refrozen treatment in step (3) is adjusted to -5°C.

[0126] Example 9

[0127] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 25 parts of diced tomatoes, 34 parts of tomato paste, 0.4 parts of paprika, 0.6 parts of beetroot red, 2.5 parts of agar, 0.5 parts of carrageenan, 3 parts of sodium D-isoascorbate, 3 parts of sodium citrate, 1.75 parts of potato starch, 4 parts of white sugar, and 35 parts of RO water.

[0128] The preparation method of the recombinant freeze-dried tomato chunks is different from that of Example 1 only in that:

[0129] In this embodiment, the thawing process described in step (3) is omitted.

[0130] Example 10

[0131] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 25 parts of diced tomatoes, 34 parts of tomato paste, 0.4 parts of paprika, 0.6 parts of beetroot red, 2.5 parts of agar, 0.5 parts of carrageenan, 3 parts of sodium D-isoascorbate, 3 parts of sodium citrate, 1.75 parts of potato starch, 4 parts of white sugar, and 35 parts of RO water.

[0132] The preparation method of the recombinant freeze-dried tomato chunks is different from that of Example 1 only in that:

[0133] In this embodiment, the first temperature during the vacuum freeze-drying process in step (3) is adjusted to 75°C.

[0134] Embodiment 11

[0135] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 25 parts of diced tomatoes, 34 parts of tomato paste, 0.4 parts of paprika, 0.6 parts of beetroot red, 2.5 parts of agar, 0.5 parts of carrageenan, 3 parts of sodium D-isoascorbate, 3 parts of sodium citrate, 1.75 parts of potato starch, 4 parts of white sugar, and 35 parts of RO water.

[0136] The preparation method of the recombinant freeze-dried tomato chunks is different from that of Example 1 only in that:

[0137] In this embodiment, the vacuum freeze-drying process of step (3) is adjusted as follows: the temperature is raised to 65° C. at a constant rate, and the temperature is kept at this temperature for 5 hours, then the temperature is lowered to 52.5° C., and the temperature is kept at this temperature for a second time for 6 hours.

[0138] Example 12

[0139] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 25 parts of diced tomatoes, 34 parts of tomato paste, 0.4 parts of paprika, 0.6 parts of beetroot red, 2.5 parts of agar, 0.5 parts of carrageenan, 3 parts of sodium D-isoascorbate, 3 parts of sodium citrate, 1.75 parts of potato starch, 4 parts of white sugar, and 35 parts of RO water.

[0140] The preparation method of the recombinant freeze-dried tomato chunks is different from that of Example 1 only in that:

[0141] In this embodiment, the vacuum freeze-drying process of step (3) is adjusted as follows: the temperature is raised to 65° C. at a constant rate, kept warm for 5 hours, then lowered to 42° C., and kept warm for a second time for 5 hours.

[0142] Example 13

[0143] The present embodiment provides a reconstituted freeze-dried tomato block, which comprises the following raw materials in parts by weight: 25 parts of diced tomatoes, 34 parts of tomato paste, 0.4 parts of paprika, 0.6 parts of beetroot red, 2.5 parts of agar, 0.5 parts of carrageenan, 3 parts of sodium D-isoascorbate, 3 parts of sodium citrate, 1.75 parts of potato starch, 4 parts of white sugar, and 35 parts of RO water.

[0144] The preparation method of the recombinant freeze-dried tomato chunks is different from that of Example 1 only in that:

[0145] In this embodiment, the vacuum freeze-drying process of step (3) is adjusted as follows: the temperature is raised to 55° C. at a constant rate, and the temperature is kept at this temperature for 5 hours, then the temperature is lowered to 42° C., and the temperature is kept at this temperature for a second time for 5 hours.

[0146] Embodiment 14

[0147] This embodiment provides a recombinant freeze-dried tomato chunk, which is different from that of embodiment 1 only in that:

[0148] In this embodiment, the mass ratio of agar to carrageenan in the composite colloid is adjusted to 1:5.

[0149] The preparation method of the recombinant freeze-dried tomato chunks is the same as that in Example 1.

[0150] Embodiment 15

[0151] This embodiment provides a recombinant freeze-dried tomato chunk, which is different from that of embodiment 1 only in that:

[0152] In this embodiment, the compound colloid is adjusted to xanthan gum and gelatin in a mass ratio of 1:1.

[0153] The preparation method of the recombinant freeze-dried tomato chunks is the same as that in Example 1.

[0154] Example 16

[0155] This embodiment provides a recombinant freeze-dried tomato chunk, which is different from that of embodiment 1 only in that:

[0156] In this embodiment, the potato starch is adjusted to corn starch.

[0157] The preparation method of the recombinant freeze-dried tomato chunks is the same as that in Example 1.

[0158] Comparative Example 1

[0159] This comparative example provides a reconstituted freeze-dried tomato chunk, which differs from Example 1 only in that:

[0160] In this comparative example, 25 portions of diced tomatoes are adjusted to 25 portions of tomato sauce, that is, the diced tomatoes are omitted in this comparative example.

[0161] The preparation method of the recombinant freeze-dried tomato chunks is the same as that in Example 1.

[0162] Comparative Example 2

[0163] This comparative example provides a reconstituted freeze-dried tomato chunk, which differs from Example 1 only in that:

[0164] In this comparative example, the composite colloid is adjusted to 3.0 parts of agar.

[0165] The preparation method of the recombinant freeze-dried tomato chunks is the same as that in Example 1.

[0166] Comparative Example 3

[0167] This comparative example provides a reconstituted freeze-dried tomato chunk, which differs from Example 1 only in that:

[0168] In this comparative example, the compound colloid is adjusted to 3.0 parts of carrageenan.

[0169] The preparation method of the recombinant freeze-dried tomato chunks is the same as that in Example 1.

[0170] Performance testing:

[0171] (1) The recombinant freeze-dried tomato chunks provided in the above examples and comparative examples were subjected to colony detection, and the results are shown in Table 1;

[0172] The colony detection is carried out in accordance with GB4789 "National Food Safety Standard for Food Microbiology Examination of Total Colony Count";

[0173] (2) The recombinant freeze-dried tomatoes provided in the above examples and comparative examples were rehydrated and subjected to sensory tests. The results are shown in Table 1.

[0174] The rehydration treatment comprises: taking 5 g of the reconstituted freeze-dried tomatoes and then brewing them with 200 mL of boiling water.

[0175] Table 1

[0176]

[0177] According to Table 1, we can know the following points:

[0178] (1) Comprehensive analysis of Examples 1-3 shows that the raw material for preparing the recombinant freeze-dried tomatoes provided by the present invention is not affected by the production season, and the total colony count thereof is ≤10 cfu / g, which is safe and controllable; and the taste of the recombinant freeze-dried tomatoes after rehydration is close to that of fresh tomatoes, which not only satisfies the production needs well, but also provides new ingredients for the convenience food industry, and has broad market prospects and market benefits;

[0179] (2) Comprehensive analysis of Example 1 and Example 4 shows that when the temperature of RO water is adjusted to room temperature, although it will not affect the color and taste of the product, it will cause the growth of microorganisms during the preparation process, which will cause the obtained product to fail to meet the national safety standards;

[0180] (3) Comprehensive analysis of Example 1 and Examples 5-6 shows that the temperature of the quick freezing process affects the taste. When the temperature of the quick freezing process is too high, the ice crystals formed will be too large and the structure will be uneven, affecting the final taste. On the contrary, when the temperature of the quick freezing process is too low, the cost will be high and the color, taste and smell will have little effect.

[0181] (4) Comprehensive analysis of Example 1 and Examples 7-9 shows that the refreezing process affects the taste and smell. When the temperature of the refreezing process is too high, the surface layer will melt during vacuum drying, and the tomato pieces will be hard and collapsed, and have the smell of rotten tomatoes. On the contrary, when the temperature of the refreezing process is too low, it will lead to high costs.

[0182] When the refrozen process is omitted, the block will melt and the freeze-dried tomato blocks will not be formed;

[0183] (5) Comprehensive analysis of Example 1 and Examples 10-13 shows that the vacuum freeze-drying process affects the color, taste and smell of the product;

[0184] When the first temperature in the vacuum freeze-drying process is too high, the freshness of the tomatoes will disappear and they will have a roasted sweet potato smell; when the first cooling process or the second cooling process is omitted in the vacuum freeze-drying process, the center of the tomato pieces will not be frozen dry and will contain ice, which will easily return to moisture, affecting rehydration and taste;

[0185] (6) Comprehensive analysis of Example 1, Examples 14-16, and Comparative Examples 2-3 shows that when the agar content in the composite colloid in the preparation raw material is low (such as Example 14), the freeze-dried tomato pieces will be easily dispersed after rehydration;

[0186] When the compound colloid in the raw materials is adjusted to xanthan gum and gelatin, the frozen cuts will not be formed, the crushing rate is high, the structure is poor, and it will fall apart when washed;

[0187] When either agar or carrageenan is omitted from the composite colloid in the preparation of raw materials, it will cause the frozen cuts to be fragile and the taste will be poor after rehydration;

[0188] When the potato starch in the preparation raw material is adjusted to corn starch, the gelatinization degree is insufficient and the molding property is poor;

[0189] (7) Comprehensive analysis of Example 1 and Comparative Example 1 shows that when the diced tomatoes in the preparation raw material are adjusted to tomato paste, the freshness and real taste of the reconstituted freeze-dried tomato blocks after rehydration will be poor.

[0190] In summary, the present invention makes a breakthrough in adjusting the raw materials for preparing the recombinant freeze-dried tomato chunks and optimizes the freeze-drying technology in the preparation method, so that the recombinant freeze-dried tomato chunks have a neat appearance, are solid after rehydration, have a taste close to that of fresh tomatoes, and can be stored at room temperature. This not only satisfies production needs well, but also provides new ingredients for the convenience food industry, and has broad market prospects and market benefits.

[0191] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A recombinant freeze-dried tomato chunk, characterized in that: The raw materials for preparing the recombinant freeze-dried tomato blocks include: diced tomatoes, tomato paste, colorant, compound colloid, sodium D-isoascorbate, sodium citrate, starch, white sugar and RO water.

2. The recombinant freeze-dried tomato chunks according to claim 1, characterized in that: The composite colloid comprises agar and carrageenan; Preferably, the mass ratio of agar to carrageenan is 1-5:0.1-1; Preferably, the coloring agent includes capsanthin and betalain; Preferably, the starch comprises potato starch.

3. The reconstituted freeze-dried tomato chunks according to claim 2, characterized in that: The reconstituted freeze-dried tomato chunks include the following raw materials in parts by weight: 22-28 parts of diced tomatoes, 30-38 parts of tomato paste, 0.02-0.9 parts of capsanthin, 0.02-0.9 parts of beetroot red, 1-5 parts of agar, 0.1-1 parts of carrageenan, 1-5 parts of sodium D-isoascorbate, 1-5 parts of sodium citrate, 0.5-2 parts of potato starch, 1-7 parts of white sugar, and 25-45 parts of RO water.

4. A method for preparing the recombinant freeze-dried tomato chunks according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: (1) mixing a colorant, a compound colloid, sodium D-isoascorbate, sodium citrate, starch, and white sugar according to the formula amount, and then mixing RO water, stirring once, mixing diced tomatoes and tomato paste, and stirring twice to obtain a composite tomato paste; (2) sequentially plating, quick freezing and cutting the composite tomato paste obtained in step (1) to obtain tomato chunks; (3) refreezing and vacuum freeze-drying the tomato chunks obtained in step (2) to obtain the reconstituted freeze-dried tomato chunks.

5. The preparation method according to claim 4, characterized in that: The temperature of the RO water in step (1) is 5-10°C; Preferably, the stirring speed of the first stirring in step (1) is 30 to 50 r / min; Preferably, the stirring time in step (1) is 5 to 10 minutes; Preferably, the stirring speed of the secondary stirring in step (1) is 30 to 50 r / min; Preferably, the secondary stirring time in step (1) is 2 to 5 minutes.

6. The preparation method according to claim 4 or 5, characterized in that: The method for preparing diced tomatoes in step (1) comprises: chopping and blending canned diced tomatoes to obtain diced tomatoes; Preferably, the size of the diced tomatoes is 5-8×5-8 mm; Preferably, the chopping and mixing process takes 5 to 15 seconds; Preferably, the chopping and mixing process includes high-speed chopping and low-speed stirring performed sequentially; Preferably, the high-speed chopping speed is 1480-2960 rpm; Preferably, the rotation speed of the low-speed stirring is 7 to 16 rpm.

7. The preparation method according to any one of claims 4 to 6, characterized in that: The plate-laying process in step (2) comprises: pouring the composite tomato paste obtained in step (1) into a mold, and then performing a shaping process using a scraper; Preferably, the temperature of the quick freezing treatment in step (2) is -35 to -45°C; Preferably, the quick freezing treatment time in step (2) is 4 to 7 hours.

8. The preparation method according to any one of claims 4 to 7, characterized in that: The temperature of the refrozen treatment in step (3) is -18 to -10°C; Preferably, the thawing time in step (3) is 30 to 60 minutes.

9. The preparation method according to any one of claims 4 to 8, characterized in that: The vacuum freeze-drying treatment in step (3) comprises: heating to a first temperature at a constant rate, cooling to a second temperature after a heat preservation treatment, cooling to a third temperature after a second heat preservation treatment, and performing heat preservation treatment three times; Preferably, the vacuum degree of the vacuum freeze-drying process is 30-100 Pa; Preferably, the constant rate is 1.5-2.5°C / min; Preferably, the first temperature is 60-70°C; Preferably, the time of the heat preservation treatment is 4.5 to 5.5 hours; Preferably, the second temperature is 50-55°C; Preferably, the secondary heat preservation treatment time is 6.5 to 7.5 hours; Preferably, the third temperature is 40-45°C; Preferably, the three heat preservation treatments are performed for 4.5 to 5.5 hours.

10. The preparation method according to any one of claims 4 to 9, characterized in that: The preparation method comprises the following steps: (1) mixing a colorant, a compound colloid, sodium D-isoascorbate, sodium citrate, starch, and white sugar according to a formula amount, and then mixing RO water at 5 to 10° C., stirring once at a stirring speed of 30 to 50 r / min for 5 to 10 min, and then mixing diced tomatoes and tomato paste, and stirring twice at a stirring speed of 30 to 50 r / min for 2 to 5 min to obtain a composite tomato paste; The method for preparing diced tomatoes comprises: chopping and stirring canned diced tomatoes for 5 to 15 seconds to obtain diced tomatoes; the chopping and stirring comprises sequentially performing high-speed chopping at a rotation speed of 1480 to 2960 rpm and low-speed stirring at a rotation speed of 7 to 16 rpm; (2) pouring the composite tomato paste obtained in step (1) into a mold, shaping it with a scraper to achieve a plate-like process, and then performing a quick freezing process at -35 to -45°C for 4 to 7 hours, and cutting it after demolding to obtain tomato chunks; (3) refreezing the tomato chunks obtained in step (2) at -18 to -10°C for 30 to 60 minutes; and then performing vacuum freeze drying at a vacuum degree of 30 to 100 Pa to obtain the reconstituted freeze-dried tomato chunks; The vacuum freeze-drying process includes: heating to 60-70°C at a constant rate, maintaining the temperature for 4.5-5.5 hours, then reducing the temperature to 50-55°C, maintaining the temperature for 6.5-7.5 hours, then reducing the temperature to 40-45°C, and maintaining the temperature for 4.5-5.5 hours.

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