CN102698298B - Method for determining irradiation dose of product easy for breeding microorganisms - Google Patents

Abstract

The invention provides a method for determining the irradiation dose of a product easy for breeding microorganisms. The requirement of irradiation sterilization on a rapid microorganism breeding product cannot be met by the conventional irradiation sterilization method. In the method, the irradiation dose and irradiation time of a product can be determined according to the initial contaminating bacteria N0 at the end of product production, the irradiated time interval T after product production, the specific growth rate lambda of microorganisms at an index increasing period and the comprehensive D10 value of bacteria by using a provided calculation formula on the basis of preferably considering a microorganism breeding condition and the product tolerance dose. Due to the adoption of the method, the irradiation sterilization dose of the rapid microorganism breeding product is scientific and reasonable, the requirement of production sterilization can be met, the quality of the product can be ensured, and the scrapping risk of the product is avoided.

Description

A kind of method of irradiation dose of the product of determining easy propagate microorganisms

Technical field

The present invention relates to a kind of irradiance method, particularly, for the irradiance method of the product of easy propagate microorganisms, belong to biological irradiation sterilization technology field.

Technical background

Microorganism is produced, sold and used three aspects: to health-oriented products and is brought huge trouble, and the heavy losses that cause more and more cause people's attention.In October, 2011, " event is brought heavy blow to enterprise in miss " containing bacterium ".On December 7th, 2010, U.S. FDA issue 53-17 import early warning, carries out and automatically detains Imported Cosmetics owing to being subject to microbial contamination ..., on warning red inventory, have 13 of Chinese Enterprise.What microbial contamination affected is not only product safety, probably causes corresponding product recall event simultaneously or causes recovery calcellation to be processed, and even causes the financial crisis of company.Radiation sterilizing technology can solve health-oriented products from raw material, semi-finished product, packing until the microbiological pollution that finished product overall process exists, and compared with other method for disinfection, its application prospect is extremely wide.

Conventional radiation method for sterilizing is according to the comprehensive D of the initial contaminated bacteria after production, product microorganism ₁₀, according to mathematical model (formula 1), determine irradiation of product dosage D, formulate radiation sterilizing technique.

$D={\mathrm{<figure-callout\; id="10"\; label="D"\; filenames="HSA00000727387700012.png,HSA00000727387700022.png"\; state="\{\{state\}\}">D</figure-callout>}}_{10}\log \frac{N_0}{N}$ (formula 1)

In formula 1: D is for reaching the horizontal required dosage of sterilizing assurance (kGy), N ₀, N is respectively before irradiation sterilization in sample after initial contaminated bacteria number and sterilizing the survival number of contaminated bacteria in product, D ₁₀for the comprehensive D of antibacterial ₁₀value.

The low product of the suitable low water content of this conventional radiation method for sterilizing, nutritional labeling is as flavoring agent, dehydrated vegetables, Chinese crude drug etc.But the microniological proudcts of the easy breeding high for some moistures, nutritional labeling is abundant, as: the leisure fooies such as the baked chicken claw of cosmetics Salt roasted chicken wing, Yan such as facial film, eye sticker, cream frost, because predose product microbial reproduction is not very fast, the interval length that drops into irradiation after production has a strong impact on sterilization effect, and above-mentioned conventional method is difficult to reach sterilizing requirement.

The radiation sterilizing processing method of a kind of Conch Meretricis seu Cyclinae of the radiation method for sterilizing of its pet food of patent CN200610040128.6 and patent CN201110098354.0 is only for the radiation method for sterilizing of specific products, method is comparatively simple and unreasonable, in extensive actual irradiation processing, is difficult to realize.

The irradiation control method of its packaging for foodstuff of CN200810151223.2, the irradiation sterilization of consideration packaging material for food, packaging material for food is generally plastic components, does not support growth of microorganism, the method to be unwell to the radiation sterilizing of microorganism Fast-propagation product.Its food of CN200810151222.8 and Related product irradiation control method, considered product water content, pH value, oxidation-reduction potential, the initially impact of the factors such as physical state on radiation sterilizing of bacterium quantity, the place of production, shelf-life, protein content, sample.But in actual irradiation service process, the product after manufacturer produces is because the factors such as production cycle and logistics can not be sent to Radiation Center irradiation immediately, and Radiation Center is because the factors such as production capacity also can not can drop into irradiation.This practical situation brings all adverse effects to the radiation sterilizing of microorganism Fast-propagation product, it is longer interval time that product drops into irradiation, the quantity of microbial reproduction is more, is still difficult to guarantee radiation sterilizing effect and the product quality of microorganism Fast-propagation product according to the method for CN200810151222.8.

The leisure fooies such as the cosmetics such as facial film, eye sticker, cream frost and the baked chicken claw of Salt roasted chicken wing, Yan, its actual production is subject to the impact of the conditions such as raw material, production technology and personnel's health, production product is very easily subject to the pollution of microorganism, this series products water content is high and contain abundant nutrient substance, if do not reduce in time microorganism, may amount reproduction even if exist in the situation of antiseptic also, cause product rejection (antiseptic can only delay the breeding of microorganism, and can not killing microorganisms).According to growth of microorganism rule, as product drops into irradiation interval time long (enter index idiophase after), may there is following unfavorable factor: first, according to conventional radiation method for sterilizing, be difficult to reach the bactericidal effect of expection.If repetitive irradiation, because of microbial reproduction, the dosage of secondary irradiation is difficult to determine, very easily causes product rejection.Secondly, if strengthen the dosage of radiation sterilizing, may destroy product quality.Cosmetics high dosage irradiation may occur following abnormal: change, the material glossiness of material viscosity are dimmed, material color changes, material becomes fragile.Leisure meat products high dosage irradiation may occur that taste changes and produces irradiation smell, affects quality.Finally, if antibacterial amount reproduction, antiseptic will be partially consumed, and cause following unfavorable factor: facial cream and so on cosmetics may be mouldy in consumer's use procedure; Salt roasted chicken wing may cause the shelf-life to shorten because antiseptic reduces.

Summary of the invention

The present invention is directed to the radiation sterilizing needs that above-mentioned conventional irradiation sterilization method can not meet microorganism Fast-propagation product (including but not limited to the leisure fooies such as the baked chicken claw of cosmetics Salt roasted chicken wing, Yan such as facial film, eye sticker, cream frost), patent of the present invention is being paid the utmost attention on the basis of product microbial reproduction situation, product tolerance dose, confirms effective and reasonable interval and the risk control time of after production, dropping into irradiation.Initial contaminated bacteria N while then, finishing according to production ₀, drop into irradiation after production interval T, microorganism at the specific growth rate λ of Exponential growth stage, the comprehensive D of antibacterial ₁₀value, confirms irradiation of product dosage according to mathematical model (formula 2), formulates rational irradiation technique.According to the inventive method, the radiation disinfection dosage of microorganism Fast-propagation product is scientific and reasonable, can meet the needs of product sterilization, can guarantee again product quality, has avoided the risk of product rejection.

Particularly, the method for the irradiation dose of a kind of product of determining easy propagate microorganisms of the present invention, described irradiation dose comprises D _max, D _min, it is characterized in that, described irradiation dose calculates acquisition according to mathematical modulo pattern 2,

Formula 2 is as follows:

As T < T ₀time: $D_{\min }={\mathrm{<figure-callout\; id="10"\; label="D"\; filenames="HSA00000727387700012.png,HSA00000727387700022.png"\; state="\{\{state\}\}">D</figure-callout>}}_{10}*\log \frac{N_0}{N};$ D _max＝D _min*U

As T>=T ₀time: $D_{\min }={\mathrm{<figure-callout\; id="10"\; label="D"\; filenames="HSA00000727387700012.png,HSA00000727387700022.png"\; state="\{\{state\}\}">D</figure-callout>}}_{10}*\log \frac{N_T}{N}={\mathrm{<figure-callout\; id="10"\; label="D"\; filenames="HSA00000727387700012.png,HSA00000727387700022.png"\; state="\{\{state\}\}">D</figure-callout>}}_{10}*\log \frac{N_0{e}^{\mathrm{\&lambda;}(T-T_0)}}{N};$ D _max＝D _min*U

Wherein: D _max: drop into the highest irradiation dose of exposure time point product, the highest irradiation dose must not exceed the maximum tolerated dose of product;

D _min: the minimum sterilizing dose that drops into exposure time point product;

λ: microorganism is at the specific growth rate of Exponential growth stage;

D ₁₀: the comprehensive D of antibacterial ₁₀value;

T: irradiation products does not drop into the interval of irradiation after producing, and this interval should be less than maximum time interval;

T ₀: not irradiation products produce after microbial reproduction lag time;

N ₀: irradiation products is not produced the Initial microorganisms quantity while finishing;

N: micro organism quantity in product after irradiation sterilization;

U: the dosage unevenness of irradiation of product.

The method of the irradiation dose of above-mentioned a kind of product of determining easy propagate microorganisms, described T ₀determine according to mathematical modulo pattern 3 with λ,

Formula 3 is as follows:

$N_T={\mathrm{<figure-callout\; id="0"\; label="K\; T\; N"\; filenames="HSA00000727387700011.png,HSA00000727387700022.png"\; state="\{\{state\}\}">K</figure-callout>}}_T{N}_{}{}_0=e^{\mathrm{\&lambda;}(T-T_0)}{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="HSA00000727387700011.png,HSA00000727387700022.png"\; state="\{\{state\}\}">N</figure-callout>}}_0$

Wherein: K _t: microbial reproduction multiple when the resting period is not T after irradiation products production;

N _t: micro organism quantity when the resting period is not T after irradiation products production;

N ₀: irradiation products is not produced the Initial microorganisms quantity while finishing;

λ: microorganism is at the specific growth rate of Exponential growth stage;

T: irradiation products does not drop into the interval of irradiation after producing, and this interval should be less than maximum time interval;

T ₀: not irradiation products produce after microbial reproduction lag time.

Preferably, the microorganism D of described irradiation of product ₁₀range of variables is 2.0～5.0kGy;

Preferably, after described production completes, the maximum time interval variable 1～10 day of input irradiation, is preferably 24 hours;

Preferably, the irradiation dose unevenness U of described product is less than 1.8;

Preferably, described product suitable exposure dose range of variables 3.0～9.0kGy;

Preferably, described product is cosmetics and leisure food, and described cosmetics are facial film, eye sticker or cream frost, the described baked chicken claw of leisure food Wei Salt roasted chicken wing Huo Yan.

Compared with prior art, the present invention has following outstanding technical advantage:

First, according to the art of this patent, utilize mathematical modulo pattern 2, consider initial contaminated bacteria, the product of product after producing and dropped into exposure time interval, product microorganism time reproduction curve and product bactericidal effect, for supporting growth of microorganism product that the irradiation sterilization solution of system is provided, guarantee that product different time after production completes drops into irradiation and all can obtain suitable irradiation dose, science and the reasonability of irradiation of product have been improved, avoid the risk of product secondary irradiation, improve irradiation of product quality.

Secondly, the art of this patent, according to small lot test confirmation product maximum tolerated dose, avoids product high dosage irradiation to cause product rejection; This patent confirms that according to mathematical model product drops into the largest interval time of irradiation, effectively reduces irradiation dose, guarantees the success rate of irradiation sterilization.

Finally, by the mathematical modulo pattern 2 of patent of the present invention, can determine the mathematical model of a certain series products, the irradiation dose of later like product only needs the essential informations such as the initial contaminated bacteria after production, can directly calculate the accurate dosage that drops into irradiation, increases work efficiency.

Accompanying drawing explanation

In order to be illustrated more clearly in example of the present invention or technical scheme of the prior art, to the accompanying drawing of required use in example or description of the Prior Art be briefly described below, apparently, accompanying drawing in the following describes is only examples more of the present invention, for those of ordinary skills, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings other accompanying drawing.

Fig. 1 is that mask product provided by the invention is deposited the microbial growth curve schematic diagram behind different time interval (2,3,4,5,6,7,8 days);

Fig. 2 is the graph of a relation of mask product survival total plate count provided by the invention and irradiation dose;

Fig. 3 is that Salt roasted chicken wing product provided by the invention is deposited the microbial growth curve schematic diagram behind different time interval (1-5 days);

Fig. 4 is the graph of a relation of Salt roasted chicken wing product survival total plate count provided by the invention and irradiation dose;

The specific embodiment

Following content is in conjunction with concrete preferred implementation further description made for the present invention, can not assert that specific embodiment of the invention is confined to these explanations.For general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, can also make some simple deduction or replace, all should be considered as belonging to protection scope of the present invention.

Example one: definite method of facial film irradiation dose and exposure time

1, determine irradiation products N ₀, N and U

Initial contaminated bacteria N when production finishes ₀: 5100cfu/g;

The irradiation sterilization effect N:500cfu/g of customer requirement;

The packing specification of product: 45 × 30 × 30cm;

The weight of single case product: 10kg/ case;

The value 1.45 of this example dosage unevenness U.

2, determine microbial reproduction T lag time ₀with the specific growth rate λ of microorganism at Exponential growth stage

2.1 monitoring mask product are deposited the micro organism quantity behind different time interval (2,3,4,5,6,7,8 days), obtain microbial growth curve as shown in Figure 1.

2.2 according to microbial growth curve, draws following parameter:

Microorganism is at the specific growth rate λ of Exponential growth stage: 0.6;

Irradiation products is not produced rear microbial reproduction T lag time ₀: 2d.

3, determine comprehensive D ₁₀with product maximum tolerated dose

3.1 pairs of products carry out the test of small lot dosage, 5 sample irradiation 0kGy, 2.0kGy, 4.0kGy, 6.0kGy, 8.0kGy respectively;

3.2 pairs of above-mentioned 5 samples carry out microorganism testing, and the relation that obtains total plate count and irradiation dose is as following table:

Take irradiation dose (kGy) as abscissa, the logarithm value of total plate count is vertical coordinate, obtains relation curve as shown in Figure 2.

3.3 according to upper curve, draws the comprehensive D of antibacterial in facial film ₁₀value is 3.5kGy;

3.4 above-mentioned irradiation sample is carried out to physics and chemistry, outward appearance and sensory test, confirms product maximum tolerated dose D _max=8.0kGy.

4, set up irradiation of product dosage (D _min, D _max) mathematical model

As T < T ₀time:

$D_{\min }={\mathrm{<figure-callout\; id="10"\; label="D"\; filenames="HSA00000727387700012.png,HSA00000727387700022.png"\; state="\{\{state\}\}">D</figure-callout>}}_{10}*\log \frac{N_0}{N}$

D _max＝D _min.U

As T>=T ₀time:

$D_{\min }={\mathrm{<figure-callout\; id="10"\; label="D"\; filenames="HSA00000727387700012.png,HSA00000727387700022.png"\; state="\{\{state\}\}">D</figure-callout>}}_{10}*\log \frac{N_T}{N}={\mathrm{<figure-callout\; id="10"\; label="D"\; filenames="HSA00000727387700012.png,HSA00000727387700022.png"\; state="\{\{state\}\}">D</figure-callout>}}_{10}*\log \frac{N_0{e}^{\mathrm{\&lambda;}(T-T_0)}}{N}$

D _max＝D _min.U

Wherein:

D _min: the minimum sterilizing dose that drops into exposure time point product;

D _max: drop into the highest irradiation dose of exposure time point product, the highest irradiation dose of product must not exceed the maximum tolerated dose of product, and this example like product maximum tolerated dose is 8.0kGy;

λ: microorganism is at the specific growth rate of Exponential growth stage, and the microorganism of this example like product is 0.6 at the specific growth rate of Exponential growth stage;

T ₀: not irradiation products produce after microbial reproduction lag time, like product microbial reproduction 2d lag time that this example value is confirmed;

D ₁₀: comprehensive D ₁₀value, this example value like product confirmation value 3.5kGy;

T: irradiation products does not drop into the interval of irradiation after producing; This interval should be less than maximum time interval;

N ₀: Initial microorganisms quantity 5100cfu/g when production finishes;

N: micro organism quantity 500cfu/g in product after irradiation sterilization;

U: the empirical value 1.45 of the dosage unevenness value like product of irradiation of product.

5, by software, characterize above-mentioned mathematical model.

6, by the relevant information of computer input product to be irradiated, can automatically obtain:

The largest interval time that product drops into irradiation is 4.2 days;

It is 5.4kGy that product making time is spaced apart the minimum sterilizing dose of product of 4 days;

It is 7.8kGy that product making time is spaced apart the highest irradiation dose of product of 4 days.

As the product making time interval of input is greater than 4.2 days, software system gives warning prompt.

7, by minimum sterilizing dose and the maximum tolerated dose irradiation products confirmed, and with radiacmeter, irradiation process is monitored; Irradiation finishes rear radiacmeter to be measured, and finally determines the actual irradiation processing dosage of mask product.

Example two: definite method of Salt roasted chicken wing irradiation dose and exposure time

1. determine the parameter N of irradiation Salt roasted chicken wing product ₀, N and U

Initial contaminated bacteria N when production finishes ₀: 8500cfu/g;

Micro organism quantity N:1000cfu/g in product after irradiation sterilization;

The packing specification of product: 40 × 35 × 30cm;

The weight of single case product: 8.0kg/ case.

2. microbial reproduction T lag time ₀, microorganism determines the value-added coefficient λ's of Exponential growth stage

Monitor same production batch Salt roasted chicken wing product and deposit the micro organism quantity behind different time interval (1 to 5 day), obtain microbial growth curve as shown in Figure 3.

According to microbial growth curve, draw following parameter:

Microorganism is at the specific growth rate λ of Exponential growth stage: 0.75;

Irradiation products is not produced rear microbial reproduction T lag time ₀: 1d.

3. comprehensive D ₁₀with determining of product maximum tolerated dose

3.1 pairs of products carry out the test of small lot dosage, 5 sample irradiation 0kGy, 2kGy, 4.0kGy, 6.0kGy, 8.0kGy respectively;

3.2 pairs of the said goods irradiation samples carry out microorganism testing, and the relation that obtains total plate count and irradiation dose is as following table:

Take irradiation dose (kGy) as abscissa, the logarithm value of total plate count is vertical coordinate, obtains the relation curve of total plate count and irradiation dose as shown in Figure 4.

3.3 according to upper curve, draws the comprehensive D of antibacterial in Salt roasted chicken wing ₁₀value is 3.9kGy.

3.4 above-mentioned irradiation sample is carried out to physics and chemistry, outward appearance and sensory test, confirms product maximum tolerated dose D _max=8.0kGy;

4. set up irradiation of product dosage (D _min, D _max) mathematical model

As T < T ₀time:

$D_{\min }={\mathrm{<figure-callout\; id="10"\; label="D"\; filenames="HSA00000727387700012.png,HSA00000727387700022.png"\; state="\{\{state\}\}">D</figure-callout>}}_{10}*\log \frac{N_0}{N}$

D _max＝D _min.U

As T>=T ₀time:

$D_{\min }={\mathrm{<figure-callout\; id="10"\; label="D"\; filenames="HSA00000727387700012.png,HSA00000727387700022.png"\; state="\{\{state\}\}">D</figure-callout>}}_{10}*\log \frac{N_T}{N}={\mathrm{<figure-callout\; id="10"\; label="D"\; filenames="HSA00000727387700012.png,HSA00000727387700022.png"\; state="\{\{state\}\}">D</figure-callout>}}_{10}*\log \frac{N_0{e}^{\mathrm{\&lambda;}(T-T_0)}}{N}$

D _max＝D _min.U

Wherein:

D _min: the minimum sterilizing dose that drops into exposure time point product;

D _max: drop into the highest irradiation dose of exposure time point product, the highest irradiation dose of product must not exceed the maximum tolerated dose of product, and this example like product maximum tolerated dose is 8.0kGy;

λ: microorganism is at the specific growth rate of Exponential growth stage, and the microorganism of this example like product is 0.75 at the specific growth rate of Exponential growth stage;

T ₀: not irradiation products produce after microbial reproduction lag time, like product microbial reproduction 1d lag time that this example value is confirmed;

D ₁₀: comprehensive D ₁₀value, this example value like product confirmation value 3.9kGy;

T: irradiation products does not drop into the interval of irradiation after producing; This interval should be less than maximum time interval.

N ₀: Initial microorganisms quantity 8500cfu/g when production finishes;

N: micro organism quantity 1000cfu/g in product after irradiation sterilization.

U: the empirical value 1.35 of the dosage unevenness value like product of irradiation of product

5. by software, characterize above-mentioned mathematical model.

6. by the relevant information of computer input product to be irradiated, can automatically obtain:

The largest interval time that product drops into irradiation is 2.8 days;

It is 4.9kGy that product making time is spaced apart the minimum sterilizing dose of product of 2 days;

It is 6.6kGy that product making time is spaced apart the highest irradiation dose of product of 2 days.

As the product making time interval of input is greater than 2.8 days, software system gives warning prompt.

7, by minimum sterilizing dose and the maximum tolerated dose irradiation products confirmed, and with radiacmeter, irradiation process is monitored; Irradiation finishes rear radiacmeter to be measured, and finally determines the actual irradiation processing dosage of Salt roasted chicken wing.

Claims (8)

1. a method of determining the irradiation dose of the product of easy propagate microorganisms, described irradiation dose comprises D _max, D _min, it is characterized in that, described irradiation dose calculates acquisition according to mathematical modulo pattern 2,

Formula 2 is as follows:

Work as T<T ₀time: $D_{\min }=D_{10}*\log \frac{N_0}{N};$ D _max=D _min*U

As T>=T ₀time: $D_{\min }=D_{10}*\log \frac{N_T}{N}=D_{10}*\log \frac{N_0{e}^{\mathrm{\&lambda;}(T-T_0)}}{N};$ D _max=D _min*U

Wherein: D _max: drop into the highest irradiation dose of exposure time point product, the highest irradiation dose must not exceed the maximum tolerated dose of product;

D _min: the minimum sterilizing dose that drops into exposure time point product;

λ: microorganism is at the specific growth rate of Exponential growth stage;

D ₁₀: the comprehensive D of antibacterial ₁₀value;

T: irradiation products does not drop into the interval of irradiation after producing, and this interval should be less than maximum time interval;

T ₀: not irradiation products produce after microbial reproduction lag time;

N ₀: irradiation products is not produced the Initial microorganisms quantity while finishing;

N: micro organism quantity in product after irradiation sterilization;

U: the dosage unevenness of irradiation of product.

2. the method for the irradiation dose of a kind of product of determining easy propagate microorganisms as claimed in claim 1, is characterized in that described T ₀determine according to mathematical modulo pattern 3 with λ,

Formula 3 is as follows:

$N_T=K_T{N}_0=e^{\mathrm{\&lambda;}(T-T_0)}{N}_0$

Wherein: K _t: microbial reproduction multiple when the resting period is not T after irradiation products production;

N _t: micro organism quantity when the resting period is not T after irradiation products production;

N ₀: irradiation products is not produced the Initial microorganisms quantity while finishing;

Enter: microorganism is at the specific growth rate of Exponential growth stage;

T: irradiation products does not drop into the interval of irradiation after producing, and this interval should be less than maximum time interval;

T ₀: not irradiation products produce after microbial reproduction lag time.

3. the method for the irradiation dose of a kind of product of determining easy propagate microorganisms as claimed in claim 1, is characterized in that the microbiological comprehensive D of described irradiation of product ₁₀range of variables is 2.0～5.0kGy.

4. the method for the irradiation dose of a kind of product of determining easy propagate microorganisms as claimed in claim 1, is characterized in that, after production completes, the maximum time interval of input irradiation is 1～10 day.

5. the method for the irradiation dose of a kind of product of determining easy propagate microorganisms as claimed in claim 4, is characterized in that, after described production completes, the maximum time interval of input irradiation is 24 hours.

6. the method for the irradiation dose of a kind of product of determining easy propagate microorganisms as claimed in claim 1, is characterized in that, the irradiation dose unevenness U of product is less than 1.8.

7. the method for the irradiation dose of a kind of product of determining easy propagate microorganisms as claimed in claim 1, is characterized in that described irradiation of product dosage D _min～D _maxscope be 3.0～9.0kGy.

8. the method for the irradiation dose of a kind of product of determining easy propagate microorganisms as described in as arbitrary in claim 1-7, it is characterized in that, described product is cosmetics and leisure food, and described cosmetics are facial film, eye sticker or cream frost, the described baked chicken claw of leisure food Wei Salt roasted chicken wing Huo Yan.

Images