Process for regulating and controlling sun-curing after-ripening of table vinegar by utilizing sunlight

Abstract

The invention relates to the technical field of table vinegar sun-curing, in particular to a process for regulating and controlling table vinegar sun-curing after-ripening by utilizing sunlight, which comprises the following steps: mixing vinegar mash and a composite photocatalyst, then carrying out light-catalyzed reaction through illumination, and filtering and storing after the reaction is finished. Wherein the composite photocatalyst comprises ferric oxide, titanium dioxide and zinc oxide. According to the method, the vinegar sun-curing after-ripening process is regulated and controlled through the photocatalytic reaction for the first time, and the sun-curing period is shortened by 30% or above. The traditional mode of vinegar sun-curing production is greatly improved, the sun-curing period can be remarkably shortened, the productivity is improved, the vinegar product quality is guaranteed, the shortages of the traditional vinegar sun-curing process are filled up, and the synergism and upgrading of the vinegar industry are promoted.

Description

Technical Field

[0001] The invention relates to the technical field of sun-drying of edible vinegar, in particular to a process for regulating the post-drying of edible vinegar by using sunlight. Background Art

[0002] Vinegar is one of my country's traditional fermented condiments, playing an important role in cooking, pickling, seasoning and other fields. my country is a major producer and consumer of vinegar. At present, my country's vinegar production capacity is about 4.61 million tons. With the upgrading of dietary and functional consumption of vinegar, the future market demand will be around 15 million tons. Sun drying is an important part of vinegar production, which is of great significance to the formation of vinegar flavor and the improvement of taste.

[0003] Sichuan sun-dried vinegar belongs to Sichuan bran vinegar, one of the "four famous vinegars" in my country. It uses bran and rice as the main raw materials and follows the brewing techniques of historical traditional secret recipes. It undergoes four major process flows: steaming, fermentation, sun drying (both the vinegar base and the finished vinegar are exposed to the sun), and aging. Therefore, it is referred to as "sun-dried vinegar". The process of sun-dried vinegar mash is mainly to cause the sugars and amino acids in it to undergo Maillard reaction, which deepens the color of the vinegar mash and makes its aroma prominent, thereby significantly improving the flavor and color of the poured vinegar. The product is dark brown in color, has no precipitation, and is fragrant. It has the characteristics of mellow sourness, slightly sweet and refreshing, long aftertaste, and long storage without corruption. However, the traditional sun-dried process has a long cycle (6-24 months), resulting in large investment in site and equipment in the early stage of vinegar production, high management costs, and low production efficiency. Therefore, accelerating the sun-dried aging process of vinegar has become a breakthrough for "improving quality and efficiency" in the vinegar production industry. Current research mainly focuses on the preparation process and formula of vinegar. There are few methods for accelerating sun-drying and even fewer studies on the effects of light on the sun-drying process. Sunlight, as a clean renewable energy source, is a key energy source for social development and industrial production. Although the traditional sun-drying process of vinegar involves the step of sun-drying, it is believed that the purpose of this step is to control the temperature. Therefore, the current vinegar sun-drying process has been optimized to be sealed sun-drying or to directly use modern industrial equipment to control the temperature. The effect of light itself on the ripening process has not been studied.

[0004] Therefore, the present application is committed to providing a vinegar sun-drying process that utilizes light scientifically and efficiently, so as to shorten the sun-drying cycle, increase production capacity, and ensure the quality of vinegar products. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a process for regulating the post-ripening of vinegar by sun-drying using sunlight, so as to at least shorten the sun-drying cycle, increase production capacity and ensure the quality of vinegar products.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A process for regulating the post-ripening of edible vinegar by sun-drying using sunlight comprises the following steps: mixing vinegar mash with a composite photocatalyst, then performing a photocatalytic reaction by irradiation with light, and filtering and storing after the reaction is completed.

[0008] Furthermore, the vinegar mash is obtained by boiling and fermenting the vinegar raw material;

[0009] And / or, the vinegar raw material includes at least one of bran, buckwheat and rice.

[0010] Furthermore, stirring is performed continuously during the illumination process to ensure that the vinegar mash and the composite photocatalyst are fully mixed.

[0011] Furthermore, the stirring rate of the stirring is 20-80 r / min.

[0012] Furthermore, the composite photocatalyst includes iron oxide, titanium dioxide and zinc oxide.

[0013] Furthermore, the composite photocatalyst includes 1 to 3 parts of iron oxide, 1 to 5 parts of titanium dioxide and 1 to 5 parts of zinc oxide in parts by weight.

[0014] Furthermore, the added amount of the composite photocatalyst is 0.01 to 0.5% of the weight of the vinegar mash.

[0015] Furthermore, the wavelength of the light is 180-750nm.

[0016] Furthermore, the energy intensity of the illumination is 0.01-2 mw / cm 2 .

[0017] Furthermore, the light irradiation is performed once every 5 to 15 days, for a total of 3 to 5 times, and the duration of a single irradiation is 5 to 20 hours.

[0018] It is worth noting that photocatalysis is a process of breaking the chain of organic matter. A one-time strong photocatalysis will cause the aroma components to decompose too quickly. Therefore, a moderate catalytic reaction plus a moderate static aging will help to generate more aroma components, thereby accelerating the effect.

[0019] Furthermore, the irradiation temperature of the light is below 40°C.

[0020] The illumination first utilizes sunlight for photocatalytic treatment, and when the light intensity is insufficient, supplementary lighting measures are used to meet the light intensity.

[0021] It is worth noting that the process of vinegar sun-making and aging is a process in which the flavor substances are richer and smoother, mainly the changes and reactions of aroma components such as lipids and aldehydes, and they are more tightly combined with water molecules. Under normal circumstances, the reaction process takes a very long time, and sunlight plays the role of illumination and warming in this process. Illumination stimulates a series of reactions, but the energy in sunlight that can stimulate reactions is relatively weak. Therefore, this technology supplements the light source separately and controls the intensity of illumination, which not only overcomes the disadvantage of slow reaction, but also controls the reaction that is too fast to induce a strong oxidation reaction and destroy the flavor. The present invention uses a composite photocatalyst as a metal oxide of iron, titanium and zinc. Iron oxide and zinc oxide are easy to react with acidic substances, and can promote the reaction under the catalysis of light.

[0022] The beneficial effects of the present invention are:

[0023] 1. The present invention uses photocatalytic reaction to regulate the post-ripening process of vinegar for the first time, shortening the drying cycle by more than 30%, reducing the investment in production equipment and site, and efficiently utilizing sunlight to achieve green and low-carbon production in this link, while providing reference experience for the innovative application of food processing and drying processes. Taking the annual production of 30,000 tons of vinegar as an example, the implementation and application of this project can achieve an additional production capacity of 6,000 to 10,000 tons under the same drying site area. Photocatalytic oxidation technology can effectively shorten the material drying cycle, improve drying efficiency, and expand production capacity.

[0024] 2. The sun drying process is a process of improving product quality through illumination. It is green, energy-saving and low-carbon, and is a typical means of rationally utilizing natural energy in traditional processes in the food manufacturing process. The implementation and application of the technology of the present invention uses catalysts to significantly improve the efficiency of sunlight, while ensuring product quality, increasing the production capacity per unit sun drying area, intensively reducing production inputs, and increasing management costs, which has good green and low-carbon production demonstration.

[0025] 3. The lighting condition of the present invention is a means of supplementary lighting for sun drying. In the production process, sunlight is first used for photocatalytic treatment. When the light intensity is insufficient, supplementary lighting measures are used to meet the light intensity. The application of the technology of the present invention will greatly improve the traditional mode of sun-dried vinegar production, significantly shorten the drying cycle, increase production capacity, ensure the quality of vinegar products, fill the gaps in the traditional sun-dried vinegar process, and promote the efficiency and upgrading of the vinegar industry. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is described in further detail below, but the protection scope of the present invention is not limited to the following.

[0027] The vinegar mash preparation method adopted in the following examples is as follows:

[0028] The bran is boiled with water to obtain vinegar mother liquor (vinegar porridge), which is then poured into a fermentation tank to cool down, and acetic acid bacteria and vinegar koji are added for natural fermentation. The vinegar mash is obtained by coarse filtration.

[0029] Example 1 Lighting Condition Comparison

[0030] Take equal amounts of vinegar mash into 5 groups and prepare vinegar raw material liquid according to the following method:

[0031] S1: adding 0.1% of a photocatalyst to the vinegar mash and mixing, and then continuously stirring, wherein the photocatalyst is prepared by mixing iron oxide, titanium dioxide and zinc oxide in a ratio of 1:1:1;

[0032] S2: Different illumination conditions were used for photocatalytic reaction in each group, as follows: Group 1 was irradiated only once, with a single irradiation time of 20 hours; Group 2 was irradiated 3 times, with a single irradiation time of 7 hours; Group 3 was irradiated 2 times, with a single irradiation time of 12.5 hours; Group 4 was irradiated 5 times, with a single irradiation time of 5 hours; Group 5 was irradiated 4 times, with a single irradiation time of 6 hours. Each irradiation interval was 10 days for each group. The light intensity of 365nm wavelength was controlled to be 0.02mw / cm 2 The total sunlight exposure time is 300 hours, and the overall average light intensity is 0.3mw / cm 2 , the temperature was controlled at 40°C. (The above irradiation was performed within one day)

[0033] The method for controlling the light intensity is as follows: a light intensity sensor is used to detect the light intensity in real time, and then a fill light device is used to fill light so that the light intensity reaches a rated value.

[0034] S3: After the reaction, samples of the materials obtained from each group are filtered and tested. If the raw material liquid product does not meet the standards, step S2 is repeated until the raw material liquid product meets the standards.

[0035] In addition, two groups of vinegar mash were taken to set up two control groups that were sun-dried using conventional methods. In control group 1, the vinegar jars were opened and exposed to natural light, while in control group 2, the vinegar jars were kept sealed and protected from light. The cumulative sunlight exposure time was 300 hours.

[0036] Starting from 60 days, samples will be taken for testing every day until the resulting raw liquid product meets the standards.

[0037] The above detection method is: using GC-MS to determine the flavor substances, using ethyl hexanoate, 3-hydroxy-2-butanone, isooctyl acetate, etc. as indicators for judgment.

[0038] Table 1

[0039]

[0040]

[0041] It can be seen that by controlling the photocatalytic reaction, the drying process that originally took 5-6 months can be shortened to nearly 50 days.

[0042] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A process for regulating the ripening of vinegar by sun-drying using sunlight, characterized in that: The following steps are involved: The vinegar mash and the composite photocatalyst are mixed, and then a photocatalytic reaction is carried out by irradiation with light. After the reaction is completed, the mixture is filtered and stored to obtain the product.

2. The process according to claim 1, characterized in that: The vinegar mash is obtained by boiling and fermenting the vinegar raw material.

3. The process according to claim 2, characterized in that: The vinegar raw material includes at least one of bran, buckwheat and rice.

4. The process according to claim 1, characterized in that: The composite photocatalyst comprises iron oxide, titanium dioxide and zinc oxide.

5. The process according to claim 4, characterized in that: In parts by weight, the composite photocatalyst includes 1 to 3 parts of iron oxide, 1 to 5 parts of titanium dioxide and 1 to 5 parts of zinc oxide.

6. The process according to claim 1, characterized in that: The added amount of the composite photocatalyst is 0.01-0.5% of the weight of the vinegar mash.

7. The process according to claim 1, characterized in that: The wavelength of the light is 180-750nm.

8. The process according to claim 1, characterized in that: The energy intensity of the light is 0.01-2mw / cm 2 .

9. The process according to claim 1, characterized in that: The light irradiation is performed once every 5 to 15 days, for a total of 3 to 5 times, and the duration of a single irradiation is 5 to 20 hours.

10. The process according to claim 1, characterized in that: The irradiation temperature of the light is below 40°C.

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