阅读说明：本技术 一种微波协同真空预处理加工燕窝罐头的工艺 (Process for processing bird's nest can through microwave and vacuum pretreatment ) 是由 张怡 范力艺 郑宝东 曾红亮 胡嘉淼 于 2021-06-30 设计创作，主要内容包括：本发明公开了一种微波协同真空预处理加工燕窝罐头的工艺,将燕窝原料装进罐头瓶中放在微波真空减菌室内,设定真空度为-0.08～-0.1MPa、微波强度20W/g左右,温度105～115℃,微波真空减菌处理燕窝原料12～15min,处理后灌装糖液,再通过121℃饱和蒸汽杀菌5-10mins,使得燕窝罐头货架存放期保持在6-12个月；本发明通过微波协同真空减菌预处理,达到单一微波或者单一真空条件减菌无法达到的效果；并且微波真空预处理协同传统热杀菌对燕窝罐头品质的破坏远远小于传统罐头热杀菌对食品物料的破坏,此方法极大地保护了产品品质,适宜进一步推广应用。(The invention discloses a process for processing a bird's nest can by microwave-assisted vacuum pretreatment, which comprises the steps of filling bird's nest raw materials into a can bottle, placing the can bottle in a microwave vacuum sterilization chamber, setting the vacuum degree to be-0.08 to-0.1 MPa, the microwave intensity to be about 20W/g, the temperature to be 105 to 115 ℃, carrying out microwave vacuum sterilization on the bird's nest raw materials for 12 to 15min, filling sugar liquor after treatment, and carrying out saturated steam sterilization at 121 ℃ for 5 to 10mins to keep the shelf life of the bird's nest can at 6 to 12 months; according to the invention, the effect that the sterilization cannot be achieved by single microwave or single vacuum condition is achieved through microwave synergistic vacuum sterilization pretreatment; and the damage of microwave vacuum pretreatment and traditional heat sterilization to the quality of the cubilose can is far less than the damage of traditional heat sterilization to food materials, so that the method greatly protects the product quality and is suitable for further popularization and application.)

1. A technology for processing a cubilose can by microwave-assisted vacuum pretreatment is characterized by comprising the following steps:

1) filling the dry cubilose raw material into a can bottle, and then carrying out microwave vacuum sterilization for 15min under the conditions of-0.08 to-0.1 MPa, 105 to 115 ℃ and 800W microwave power;

2) filling sugar liquor into the can bottle filled with the dry cubilose raw material after microwave vacuum sterilization, then covering a bottle cap, and sterilizing at 121 ℃ for 5-10 mm.

2. The process of claim 1, wherein each can is filled with 40g of dry edible bird's nest.

3. The process for processing the cubilose can through microwave and vacuum pretreatment in cooperation with the claim 1, wherein the temperature is increased to 105-115 ℃ within 30-40 seconds in the microwave vacuum sterilization process in the step 1).

Technical Field

The invention relates to the technical field of food processing, in particular to a process for processing a cubilose can by microwave-assisted vacuum pretreatment.

Background

The bird's nest is a nest formed by mixing and bonding saliva and down feather secreted by several swiftlets of the family Ranidae. Mainly produced in southeast Asia countries such as Malaysia, Indonesia, Thailand, Burma and the like, and Fujian and Guangdong coastal zones of China. The cubilose is rich in saccharides, organic acids, free amino acids and a characteristic substance, namely sialic acid.

The edible bird's nest needs to be sterilized and disinfected in the filling process, and the conventional common sterilization and disinfection methods mainly comprise a microwave sterilization method, a high-temperature water circulation sterilization method and a steam and compressed air mixed circulation gas sterilization method; the sterilization modes have the defects that the microwave sterilization of materials can only kill common microorganisms, and the sterilization effect of the can indicator namely Geobacillus stearothermophilus is small; the high-temperature water circulation sterilization mode is to heat packaged food to 121 ℃ for sterilization and disinfection, and has the following defects: the nutritional ingredients of the food are greatly damaged and lost at 121 ℃, the texture characteristics of the canned food are greatly changed at a high temperature for a long time, and a large amount of heat energy is consumed; the sterilization mode of the mixed circulating gas of the steam and the compressed air is to heat the packaged food to 121 ℃ through a hot ventilation steam sterilizer for sterilization, and the defects are as follows: when circulation is insufficient, sterilization dead corners can occur, the requirement for placing articles is strict, nutrient components of the food are greatly damaged and lost at 121 ℃, and the texture characteristics of the canned food are greatly changed; while also consuming a large amount of heat energy.

When the existing common sterilization and disinfection method is adopted to sterilize the cubilose can, the sterilization effect is poor, and meanwhile, the nutrient components in the cubilose are easily damaged and lost greatly.

Disclosure of Invention

Aiming at the technical problems, the invention provides a process for processing a cubilose can by microwave-assisted vacuum pretreatment.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a process for processing a cubilose can by microwave-assisted vacuum pretreatment comprises the following steps:

1) filling the dry cubilose raw material into a can bottle, and then carrying out microwave vacuum sterilization for 15min under the conditions of-0.08 to-0.1 MPa, 105 to 115 ℃ and 800W microwave power;

2) filling sugar liquor into the can bottle filled with the dry cubilose raw material after microwave vacuum sterilization, then covering a bottle cap, and sterilizing at 121 ℃ for 5-10 mm.

Further, each can was filled with 40g of dry bird's nest.

Further, the temperature is raised to 105-115 ℃ within 30-40 s in the microwave vacuum sterilization process in the step 1).

Compared with the prior art, the invention has the following beneficial effects:

the process for processing the bird's nest can by microwave-vacuum pretreatment provided by the invention can greatly protect the texture characteristics and the nutritional value of the bird's nest can product while killing bacteria. The effect of killing Geobacillus stearothermophilus by microwave synergistic vacuum sterilization is far better than that of a single microwave sterilization technology, and the microwave sterilization technology is suitable for further popularization and application.

Drawings

FIG. 1 is a process flow diagram of a canned bird's nest;

FIG. 2 is a schematic diagram of Weibull model of Geobacillus stearothermophilus for bird's nest raw material for microwave vacuum pretreatment sterilization with different parameters;

FIG. 3 is a graph showing the results of measuring the heat resistance of Geobacillus stearothermophilus in bird's nest soup;

FIG. 4 is a DNA gel electrophoresis chart of Geobacillus stearothermophilus as raw material of bird's nest after microwave vacuum pretreatment and sterilization;

FIG. 5 is a schematic diagram showing the texture of the product after microwave vacuum pretreatment and high-temperature high-pressure sterilization.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

A process for processing a cubilose can by microwave-assisted vacuum pretreatment comprises the following steps:

(1) preparation of pretreatment: filling 40g of dry edible bird's nest raw material subjected to microwave vacuum pretreatment and sterilization into a can bottle, then putting the can bottle into an inner frame, and pushing the inner frame into a microwave vacuum sterilization chamber;

(2) vacuumizing: starting a vacuum pump to extract air in the cavity, and controlling the vacuum degree to be-0.08 to-0.1 MPa; experiments show that the sterilization effect is remarkably improved along with the increase of the vacuum degree, but the too high vacuum degree can lead the water to be evaporated too fast, so that the cubilose sample is damaged, and the vacuum degree is preferably between-0.08 and-0.1 MPa.

(3) Microwave vacuum sterilization: setting the set temperature of a control panel at 105-115 ℃, the microwave power at 800W, and the temperature in a microwave vacuum sterilization room to be raised to the set temperature within 30-40 s and keeping for 15 min; tests show that the larger the microwave intensity is, the better the sterilization effect is, but the too large microwave intensity can cause the sample to be damaged, and the too low microwave intensity has a general sterilization effect, so that the preferable microwave power is 800W, and the microwave vacuum sterilization time is 15 min.

(4) And (3) air is introduced and stopped: closing the microwave vacuum sterilization, and opening the air inlet valve to feed air.

(5) High-temperature high-pressure sterilization at 121 ℃: taking out the can bottle filled with the dry bird's nest raw material, filling sugar liquid, covering a cover, and placing the can bottle in a sterilization kettle for sterilization at 121 ℃ for 5-10 min; after the sterilization is carried out by microwave vacuum pretreatment, the product enters a sterilization kettle for short-time sterilization, thus meeting the commercial sterile requirement and keeping the edible taste of the product.

Test of

1. Verification of microwave vacuum pretreatment bacteria reduction effect

1.1 spore suspension preparation

Activated Geobacillus stearothermophilus (ATCC 7953) was inoculated into nutrient agar medium, spread with sterilized curved bars, and cultured at 55 ℃. Culturing at room temperature after 5 days, and scraping off spores by using a sterilizing spoon when the spore rate reaches more than 90%. Filtering with sterilized absorbent cotton, removing scraped agar, breaking chains in a test tube by shaking with a small steel ball, and dispersing Geobacillus stearothermophilus into single spores. Geobacillus stearothermophilus was centrifuged at 7000rpm for 15min, the supernatant was decanted, resuspended in distilled water, and then centrifuged, and repeated 2 times. Keeping in 90 deg.C water bath for 10min to kill propagules. Then centrifuged at 7000 rpm. Diluting the spores into bacterial liquid with the concentration of 10-8 by using distilled water, and subpackaging the bacterial liquid into a centrifuge tube for later use.

1.2 preparation of bird's nest raw material bacteria carrier

Weighing 40g of picked bird's nest, grinding for 90s to obtain powder, subpackaging in 15 test tubes (2 g/tube), sealing with kraft paper and rubber band, sterilizing in a pressure sterilization container at 121 ℃ for 15min, and forming the sterilized bird's nest powder into regular blocks in the test tubes again to serve as bacteria carriers. 0.1mL of spore suspension prepared in the step 1.1 is sucked by a 1mL liquid transfer gun and inoculated on the plane of the edible bird's nest in the test tube, and the inoculated edible bird's nest is used as an edible bird's nest raw material bacteria carrier.

1.3 microwave vacuum pretreatment of bird's nest raw material Geobacillus stearothermophilus sterilization kinetics study

FIG. 2a shows the residual rate of the bacteria-reducing thermophilic bacteria of the bird's nest raw material bacteria carrier prepared in 1.2 under the non-vacuum condition and different microwave powers. The results in FIG. 2a show that the sterilization effect of the microwave on Geobacillus stearothermophilus under the non-vacuum condition is very poor, and even the sterilization effect after 20min under the maximum power of 1600W is only about 1.5 log values.

FIG. 2b shows the residual rate of the bacteria-reducing thermophilic bacteria in different vacuum degrees under 400w microwave power for the bird's nest raw material bacteria carrier prepared in 1.2. The results in FIG. 2b show that the vacuum degree was changed at a lower microwave power (400W) to have little bactericidal effect on Geobacillus stearothermophilus, even the growth of microorganisms occurred. It was found by monitoring that the temperature of the material did not rise to the limit temperature of 121 ℃ under low power conditions, and thus the temperature did not reach a temperature for killing geobacillus stearothermophilus, thereby making the sterilization effect poor, and also promoting the germination and growth of geobacillus stearothermophilus due to the long-term heat preservation.

FIG. 2c shows the residual rate of the bacteria in the edible bird's nest raw material bacteria prepared in 1.2 under the rated vacuum degree of-0.1 MPa and different microwave powers. The results in FIG. 2c show that the bactericidal effect on Geobacillus stearothermophilus is increased with the increase of the microwave power under the rated vacuum degree of-0.1 MPa.

FIG. 2d shows the residual rate of the bacteria-reducing thermophilic bacteria in different vacuum degrees under the condition of the rated power of 800W for the bird's nest raw material bacteria carrier prepared in 1.2. The results of fig. 2d show that the sterilization effect is remarkably improved with the increase of the vacuum degree under the condition of the rated power of 800W. This is probably due to the rapid decrease in water activity of the bacterial spores under vacuum conditions, which leads to increased heat sensitivity and thus enhanced bactericidal effect. Therefore, the vacuum negative pressure mechanism can have a significant effect on microwave sterilization and dry heat sterilization.

2. Compared with the traditional heat sterilization process

2.1 Process for preparing canned bird's nest

The process steps are shown in figure 1, wherein the microwave power of the microwave vacuum pretreatment is 800W (20W/g), the temperature is 105-115 ℃, and the vacuum degree is-0.08 to-0.1 MPa; the temperature of the traditional heat sterilization (sterilization temperature of a sterilization pot) is 114 ℃ or 121 ℃.

2.2 detection of Heat resistance of Geobacillus stearothermophilus in cubilose soup

Referring to fig. 3, the total sterilization number of 6 log values required by the can product is determined by measuring the heat resistance of geobacillus stearothermophilus in the bird's nest soup, the microwave vacuum pretreatment is matched with the traditional heat sterilization for the following corresponding time parameters, 2 log values of geobacillus stearothermophilus are killed after the microwave vacuum pretreatment (the treatment time is 12.14min), and 4 log values of geobacillus stearothermophilus are killed after the microwave vacuum pretreatment is matched with the traditional heat sterilization (the sterilization time is 13.32 min); after microwave vacuum pretreatment, 4 log values of Geobacillus stearothermophilus are killed (the treatment time is 14.71min), 2 log values of Geobacillus stearothermophilus are killed by matching with traditional heat sterilization (the sterilization time is 6.66min), the D value of the Geobacillus stearothermophilus in the cubilose soup is 3.33min, and the Z value is 10.5 as shown in figure 4.

2.3 Effect of microwave vacuum Sterilization on Geobacillus stearothermophilus DNA

Referring to FIG. 4, the concentration is 10^-80.1mL of the Geobacillus stearothermophilus spore liquid is absorbed by cfu/mL and inoculated to the cubilose raw material to prepare the cubilose can, and the cubilose can is treated according to different sterilization processes. No. 1 was processed according to the method of example 1, namely, a canned bird's nest sample subjected to microwave vacuum pretreatment (treatment time 14.71min) and then combined with conventional heat sterilization (121 ℃, 6.66min), a canned bird's nest sample subjected to No. 2 non-sterilization treatment, and a canned bird's nest sample subjected to 3 conventional heat sterilization (121 ℃, 19.98 min). The Geobacillus stearothermophilus DNA is extracted, PCR amplification primers are 16S and 1942R, and the obvious deletion of a sample band of the No. 1 sample subjected to microwave vacuum sterilization pretreatment and the slight darkening of a sample band of the No. 3 sample subjected to heat sterilization can be obviously found (as shown in figure 4). Therefore, compared with the traditional heat sterilization, the microwave vacuum sterilization pretreatment combined with the short-time heat sterilization has stronger destructive effect on Geobacillus stearothermophilus DNA. Therefore, the microwave vacuum sterilization pretreatment is combined with the short-time traditional heat sterilization, and the effect is better than that of the traditional long-time sterilization by combining the non-heat effect.

2.4 influence of microwave vacuum pretreatment in cooperation with traditional heat sterilization on microorganism and quality of bird's nest can

Referring to fig. 5, three sample processing modes are as follows: after the sample is subjected to microwave vacuum pretreatment under the condition that the vacuum degree of 800W is-0.1 MPa to complete 0 log value, 2 log values and 4 log value sterilization, the sterilization with the total number reaching 6 log values is completed by using a traditional sterilization method, wherein the sample a is subjected to microwave vacuum pretreatment to kill 2 log values of Geobacillus stearothermophilus firstly (the treatment time is 12.14min) and then is subjected to traditional heat sterilization to complete 4 log value sterilization (the treatment time is 13.32 min); the sample b is prepared by killing 4 log Geobacillus stearothermophilus by microwave vacuum pretreatment (the treatment time is 14.71min), and then completing 2 log sterilization by traditional heat sterilization (the treatment time is 6.66 min); sample c was a sample that had undergone only 6 log conventional heat sterilization without microwave vacuum pretreatment (treatment time 19.98 min). It was found that samples a and b all had better Hardness (Hardness), Chewiness (Chewiness), and resiliency (Resilience) than sample c, and lower tackiness (tackiness) than sample c. This shows that microwave vacuum pretreatment sterilization is combined with short-time traditional heat sterilization, which can better protect the product quality.

In conclusion, Geobacillus stearothermophilus is an indicator bacterium in can sterilization, and the invention combines practical conditions that vacuum degree of-0.08-0.1 Mpa and power of 800W (20W/g) are used for pretreating raw materials, and then short-time high-temperature high-pressure sterilization is combined, so that the aims of killing microbes and ensuring product texture characteristics and nutrient substances can be achieved.

The spoilage rate of the canned food is controlled to one ten thousandth, and the Geobacillus stearothermophilus is killed by using a value of 6D, and the D value of the Geobacillus stearothermophilus in the cubilose soup is measured to be 3.33 min. Therefore, the traditional can sterilization needs to be carried out at 121 ℃ for 19.98mins, most of manufacturers producing cubilose at present carry out sterilization according to the strength, but the quality of cubilose can products is greatly damaged by using the sterilization method with the strength. The process for processing the bird's nest can through microwave-assisted vacuum pretreatment provided by the invention can greatly protect the texture characteristics and the nutritional value of bird's nest can products while killing geobacillus stearothermophilus. From experimental results, the effect of microwave synergistic vacuum sterilization on killing Geobacillus stearothermophilus is far superior to that of a single microwave sterilization technology, and the technology is not used in the field of sterilization and is not used in the field of bird's nest cans.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.