冷却猪肉中气单胞菌生长模型构建及货架期TTI的设计

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摘要

近年来，冷却肉因有着比鲜肉安全卫生，比冷冻肉营养丰富等特点，越来越

受消费者喜爱，已成为我国生鲜肉消费的主流之一。在低温冷藏条件下，冷却肉

中存在的绝大部分微生物生长受到抑制，但如果冷藏过程中温度控制不当，温度

升高，就会使得这些原本生长受到抑制的微生物变得活跃，开始迅速生长繁殖，

从而影响冷却肉的品质及其货架期。因此，研究不同贮藏温度条件下，冷却肉中

的微生物的生长繁殖规律，建立冷却肉中微生物的生长预测模型及冷却肉的货架

期预测模型对控制冷却肉腐败变质及确保冷却肉的安全性具有重要作用。

本论文重点研究既是冷却猪肉中特定腐败菌之一，又是致病菌的气单胞菌的

生长变化规律，通过预测微生物学方法，模拟不同贮藏温度下冷却猪肉中气单胞

菌的生长状况，建立气单胞菌生长预测模型及冷却猪肉货架期预测模型，为肉类

工业 HACCP 体系提供理论基础，同时在冷却猪肉货架期预测模型的基础上初步设

计一款电子式时间-温度指示器（TTI），给消费者提供货架期信息，为我国冷链监

控提供理论依据。

本研究的主要内容和结果如下：

（1）冷却猪肉中气单胞菌生长预测模型的构建

采用 Gompertz 方程和 Bělehrádek 平方根方程建立 0~35℃贮藏温度下气单胞菌

在冷却猪肉中的生长预测模型，应用 Origin8.0 分析软件对各贮藏温度下气单胞菌

的生长进行拟合，拟合度均大于 0.7，Bělehrádek 平方根方程对气单胞菌的最大生

长速率（µmax）及迟滞期（LPD）的判定系数 R2分别为 0.90 和0.95。同时选取 8℃

和20℃作为验证温度，计算准确因子（Af）和偏差因子（Bf）均在模型可接受范

围内。结果表明 Gompertz 方程和 Bělehrádek 平方根方程能够较好地描述 0~35℃贮

藏温度下气单胞菌在冷却猪肉中的生长规律。

（2）冷却猪肉货架期预测模型的构建

检测了贮藏在 0℃、4℃、7℃、10℃、15℃和 20℃条件下接种气单胞菌肉样

的感官特性、TVBN、TBA、pH 值及菌落数，分析得到气单胞菌在冷却猪肉中的

最小腐败限量为 6.33lg(CFU/g), 通过对 Gompertz 方程进行推导得到冷却猪肉的货

架期预测模型，以 8℃和 12℃作为验证温度，计算相对误差值分别为-8.5%和-9.3%，

均小于 10%，结果表明建立的冷却猪肉货架期预测模型具有较好的可靠性。

（3）电子式时间-温度指示器（TTI）的初步设计

在建立的冷却猪肉的货架期预测模型基础上，通过数字信号处理技术（即 DSP

技术），初步设计一款电子式时间-温度指示器（TTI），显示冷却猪肉的货架期信息。

同时为了解决 TTI 中初始值确定的问题，采用电阻抗法原理，通过测定气单胞菌

的菌落总数及其对应的电导率，得出菌落总数与电导率之间存在的关系，进而为

初始值的确定提供方法依据。结果表明，TTI 中货架期预测软件能够较好地计算冷

却猪肉的货架期。

综上所述，Gompertz 方程能够较好地描述在 0~35℃贮藏温度范围内气单胞菌

在冷却猪肉中的生长状况，同时在该贮藏温度范围内使用的 Bělehrádek 平方根方

程也较好地描述了温度对冷却猪肉中气单胞菌生长的影响，通过 Gompertz 方程推

导建立的 0~20℃范围内冷却猪肉的货架期预测模型在预测冷却猪肉的货架期时具

有一定的可靠性；初步设计的 TTI 能够通过货架期预测模型计算冷却猪肉的货架

期。本研究对冷却猪肉中的腐败微生物生长状况和货架期进行了基础理论研究，

对肉类工业有一定的指导意义。

关键词：冷却猪肉气单胞菌货架期预测模型电子式 TTI

ABSTRACT

Recently, chilled pork has become the mainstream of the fresh meat consumption

and become more and more popular, because it is more hygiene and safer than fresh

meat, also more nutrimental than frozen meat. During the cold storage, the growth of

the microorganisms contained in the chilled pork are mostly inhibited, however, if the

temperature is out of control and increases, these microorganisms will be active and

reproduce sharply, thus the characteristics and shelf life of chilled pork will be affected.

Consequently, in order to control the decaying and transformation of chilled pork and to

assure the safety of chilled pork, it is important to study the variation of the

microorganisms in the chilled pork at various storage temperatures and to establish the

predictive growth model of the microorganisms and the shelf life predictive model of

the chilled pork.

The emphasis of this paper was to study the growth rule of Aeromonas spp., one of

the specific spoilage and pathogenic bacteria. According to the predictive microbiology

theory, the growth of Aeromonas spp.at different storage temperatures were simulated,

meanwhile the predictive growth models of the microorganisms in the chilled pork and

the shelf life predictive models of the chilled pork were modeled, respectively. This

study provided theoretical reference to the Hazard Analysis and Critical Control Point

(HACCP) in the meat industry. Meanwhile, according to the shelf life predictive model

of the chilled pork, a kind of electronic time-temperature indicator (TTI) was designed

to provide the consumers with the information of shelf life and to provide theoretical

reference to the cold chain control in our country.

The main contents and results are following:

（1）The establishment of growth predictive models of Aeromonas spp.in the

chilled pork.

The Gompertz model and the Bělehrádek model were used to establish the growth

model of Aeromonas spp.in the chilled pork in 0~35℃. Origin 8.0 software was used to

simulate the growth of Aeromonas spp.at different temperatures, and the

goodness-of-fit were all above 0.7. The determination coefficient (R2) of maximum

growth rate (µmax) and lag phase (LPD) derived by Bělehrádek model were 0.90 and

0.95 respectivly. Moreover, the temperature 8 ℃and 20 ℃were chosen as the

validation temperature at the same time, and both the accuracy factor（Af）and the bias

factor

（Bf）

were in the acceptable domain. The results showed that the Gompertz model

and the Bělehrádek model could predict the growth of Aeromonas spp.in the chilled

pork in 0~35℃.

（2）The establishment of the shelf life models for the chilled pork.

In this part, the attributes of sensory evaluation, TVBN, TBA, pH values and

bacterial amount of the pork sample inoculated with Aeromonas spp.were detected,

respectively, at different storage temperatures (0℃, 4℃, 7℃, 10℃, 15℃and 20℃).

The analysis showed that the minimum of the spoilage limit was 6.33 lg(CFU/g). Then

the temperature conditions 8℃and 12℃were chosen for validation. The shelf life

models for the chilled pork were established which derived by the Gompertz model with

the relative error value -8.5% and -9.3%, respectively The results indicated that the shelf

life models for the chilled pork would be reliable and applicable in practice.

（3）The design of the electronic time-temperature indicator（TTI）.

Based on the establishment of the shelf life models for the chilled pork, an

electronic time-temperature indicator（TTI）was designed by digital signal processor

（DSP）to predict the shelf life of chilled pork. Meanwhile, the theory of impedance

was used to solve the problem of the primary value determination of bacterial amount.

The relationship between the amount of colony and impedance was obtained through

the determination of the amount of Aeromonas spp.colony and its corresponding

impedance values, and then the measurement of the primary bacterial amount could be

realized. As a result, the TTI designed in this paper could calculate the shelf life of the

chilled pork well.

In conclusion, the Gompertz model could describe the growth of Aeromonas spp.

in the chilled pork in 0~35℃well. At the same time, the Bělehrádek model could also

describe the effect of temperature on the growth of Aeromonas spp.in this temperature

range well. The predictive shelf life models of the chilled pork under 0~20℃, which

were derived by the Gompertz model, prove to be reliable. The TTI designed based on

above models could predict the shelf life of the chilled pork. This study provided basic

theoretical reference for the meat industry to control the growth of the spoilage

microorganisms in the chilled pork, and also the designed TTI would be meaningful for

the quality control in practice.

Key Words: chilled pork, Aeromonas spp., predictive microbiological

model, shelf life, TTI

中文摘要

ABSTRACT

第一章绪论 .................................................................................................................. 1

§1.1 冷却肉的概念及腐败机理 .......................................................................................1

§1.1.1 冷却肉及其特点 .............................................................................................1

§1.1.2 肉的腐败机理 .................................................................................................1

§1.1.3 气单胞菌的选用 .............................................................................................3

§1.1.4 影响肉腐败变质的因素 ...............................................................................3

§1.1.5 衡量肉制品腐败的品质指标 .......................................................................4

§ 1.2 预测微生物学的应用 .............................................................................................5

§1.2.1 预测微生物学的概念及意义 .........................................................................5

§1.2.2 预测微生物学的研究进展 .............................................................................6

§1.2.3 预测模型的分类 ...........................................................................................6

§1.2.4 微生物生长的数学模型 ...............................................................................7

§1.2.5 食品货架期的研究进展 .................................................................................9

§1.3 立题意义 ................................................................................................................12

§1.4 研究内容 ................................................................................................................12

第二章冷却猪肉中气单胞菌生长模型的构建 .......................................................... 14

§2.1 引言 ........................................................................................................................14

§2.2 材料与方法 .............................................................................................................14

§2.2.1 材料与设备 ...................................................................................................14

§2.2.2 气单胞菌菌悬液制备及猪肉接种 ...............................................................15

§2.2.3 冷却猪肉中气单胞菌计数 ...........................................................................15

§2.2.4 冷却猪肉中气单胞菌生长模型的建立及验证 ...........................................16

§2.3 结果与讨论 ............................................................................................................16

§2.3.1 气单胞菌生长一级模型的建立 ...................................................................16

§2.3.2 气单胞菌生长二级模型的建立 .................................................................19

§2.3.3 模型的验证 ...................................................................................................19

§2.3.4 讨论 ...............................................................................................................21

§2.4 本章小结 ................................................................................................................21

第三章冷却猪肉货架期预测模型的构建 .................................................................. 23

§3.1 引言 ........................................................................................................................23

§3.2 材料与方法 ............................................................................................................23

§3.2.1 材料及前处理 ...............................................................................................23

§3.2.2 试剂与设备 ...................................................................................................23

§3.2.3 冷却猪肉感官评定 .......................................................................................24

§3.2.4 气单胞菌菌落总数的测定 ............................................................................24

§3.2.5 挥发性盐基氮（TVBN）的测定 .................................................................24

§3.2.6 脂肪氧化（TBA）测定 ................................................................................24

§3.2.7 pH 值测定 ...................................................................................................24

§3.2.8 气单胞菌生长模型的构建 .........................................................................24

§3.2.9 冷却猪肉货架期预测模型的构建及验证 ...................................................24

§3.3 结果与讨论 ............................................................................................................25

§3.3.1 贮藏过程中冷却猪肉的感官变化 ...............................................................25

§3.3.2 贮藏过程中各温度下接种肉样中的气单胞菌菌落总数值 .......................26

§3.3.3 贮藏过程中各温度下接种气单胞菌猪肉的 TVB-N 值.............................27

§3.3.4 贮藏过程中各温度下接种气单胞菌猪肉的 TBA 值.................................28

§3.3.5 贮藏过程中各温度下接种气单胞菌猪肉的 pH 值...................................29

§3.3.6 各贮藏温度对接种猪肉 TVBN、TBA、pH 和气单胞菌菌落总数影响 .. 30

§3.3.7 接种猪肉特定腐败菌最小腐败水平的确定 ...............................................34

§3.3.8 气单胞菌生长模型的构建 ...........................................................................34

§3.3.9 冷却猪肉货架期预测模型的构建及验证 ...................................................35

§3.3.10 讨论 .............................................................................................................35

§3.4 本章小结 ................................................................................................................36

第四章基于 DSP 的电子式 TTI 的设计 .................................................................... 37

§4.1 引言 ........................................................................................................................37

§4.2 电子式 TTI 的设计装置及工作原理 ................................................................... 37

§4.2.1 电子式 TTI 的结构装置 ...............................................................................37

§4.2.2 电子式 TTI 的工作原理 ...............................................................................38

§4.2.3 电子式 TTI 的软件编写 ...............................................................................38

§4.3 TTI 软件初始值的确定 ......................................................................................... 40

§4.3.1 试验材料与方法 ...........................................................................................41

§4.4 结果与讨论 ............................................................................................................41

§4.4.1 气单胞菌菌落总数与电导率之间的关系 ...................................................41

§4.4.2 讨论 ..................................................................................................................... 42

§4.5 本章小结 ................................................................................................................43

第五章结论与展望 ...................................................................................................... 44

§5.1 研究结论 ................................................................................................................44

§5.2 展望 ........................................................................................................................45

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摘要：

摘要近年来，冷却肉因有着比鲜肉安全卫生，比冷冻肉营养丰富等特点，越来越受消费者喜爱，已成为我国生鲜肉消费的主流之一。在低温冷藏条件下，冷却肉中存在的绝大部分微生物生长受到抑制，但如果冷藏过程中温度控制不当，温度升高，就会使得这些原本生长受到抑制的微生物变得活跃，开始迅速生长繁殖，从而影响冷却肉的品质及其货架期。因此，研究不同贮藏温度条件下，冷却肉中的微生物的生长繁殖规律，建立冷却肉中微生物的生长预测模型及冷却肉的货架期预测模型对控制冷却肉腐败变质及确保冷却肉的安全性具有重要作用。本论文重点研究既是冷却猪肉中特定腐败菌之一，又是致病菌的气单胞菌的生长变化规律，通过预测微生物学方法，模拟不同贮藏温...

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