FOOD90023 · Food MicrobiologyFOOD90023 · 食品微生物学
The microbes that spoil, ferment and poison food — and the lab science used to detect and control them.让食物腐败、发酵或致病的微生物,以及检测与控制它们的实验科学。FOOD90023 is a 12.5-point graduate subject at the University of Melbourne (Parkville) covering microbial growth in food, foodborne pathogens, spoilage and preservation, predictive microbiology and a hands-on laboratory program. This page is built from 140 real FOOD90023 materials in the AskSia Library — including the lab manual, weekly lectures and a past example exam — and summarises what the subject actually teaches and how the handbook says it is assessed.
FOOD90023 是墨尔本大学(Parkville 校区)一门 12.5 学分的研究生课程,内容涵盖食品中的微生物生长、食源性致病菌、腐败与保藏、预测微生物学,以及配套的实验室操作课程。本页基于 AskSia Library 中 140 份真实 FOOD90023 材料(含实验手册、每周讲义及一份往年样卷)整理,梳理这门课真正教什么、官方 handbook 规定如何评分。
What FOOD90023 is aboutFOOD90023 讲什么
FOOD90023 Food Microbiology is a graduate subject at the University of Melbourne that introduces the fundamentals of food microbiology and their practical applications in the food industry. It covers the important microorganisms found in foods, microbial metabolism and growth in food, the action of microbes on food components, predictive microbiology, microorganisms used in food production, and those of food-safety concern, including genetically modified microorganisms. The subject is supported by a practical laboratory program emphasising modern and instrumental microbiological techniques for identifying spoilage and disease-causing organisms.
FOOD90023 食品微生物学是墨尔本大学的一门研究生课程,介绍食品微生物学的基本原理及其在食品工业中的实际应用。内容包括食品中重要微生物的概览、微生物代谢与在食品中的生长、微生物对食品成分的作用、预测微生物学、用于食品生产的微生物,以及具食品安全隐患的微生物(含转基因微生物)。课程配有实验室操作环节,侧重现代及仪器化微生物学技术,用于鉴定腐败菌和致病菌。
The FOOD90023 syllabus, topic by topicFOOD90023 大纲 · 逐个主题
Overview of important microorganisms in foods食品中重要微生物概览
Introduces the bacteria, yeasts, moulds and viruses that matter in food, with their classification and identification. Sets the vocabulary used throughout the subject.
介绍食品中具重要意义的细菌、酵母、霉菌和病毒,及其分类与鉴定,建立全课程通用的术语体系。
Microbial metabolism微生物代谢
How microorganisms obtain energy and metabolise substrates. Underpins later topics on fermentation, spoilage and growth prediction.
微生物如何获取能量并代谢底物,是后续发酵、腐败与生长预测内容的基础。
Nature of microbial growth in food食品中微生物的生长特性
Bacteria multiply by binary fission, giving exponential growth described by N = N0·2^n and N = N0·e^(µt), where µ is the specific growth rate and generation (doubling) time g = ln2/µ. Covers the four batch-culture phases (lag, log/exponential, stationary, death) — generation time is defined in the log phase, where cells are most metabolically active and most sensitive to heat. Intrinsic factors (pH, water activity a_w, nutrients, redox potential) and extrinsic factors (temperature, atmosphere) control the rate; psychrotrophs like Listeria still grow at fridge temperature, so chilling is not a kill step.
细菌通过二分裂繁殖,呈指数增长,由 N = N0·2^n 和 N = N0·e^(µt) 描述,其中 µ 为比生长速率,世代(倍增)时间 g = ln2/µ。涵盖分批培养的四个阶段(迟滞期、对数/指数期、稳定期、衰亡期)——世代时间在对数期定义,此时细胞代谢最活跃、对热最敏感。内在因素(pH、水分活度 a_w、营养、氧化还原电位)与外在因素(温度、气体环境)共同决定生长速率;像李斯特菌这类嗜冷菌在冰箱温度下仍能生长,故冷藏并非杀灭步骤。
Action of microorganisms on food components微生物对食品成分的作用
How microbes break down proteins, carbohydrates and fats in food, producing the changes seen in spoilage and in deliberate fermentation.
微生物如何分解食品中的蛋白质、碳水化合物和脂肪,从而引发腐败现象或被用于有意发酵。
Predictive microbiology预测微生物学
Quantitative microbiology that summarises microbial responses to environmental factors as mathematical models, organised in a three-level hierarchy: primary models describe number-vs-time under fixed conditions (e.g. Gompertz, Baranyi, logistic fits giving µ and lag); secondary models describe how those parameters change with temperature, pH and a_w (e.g. the square-root/Ratkowsky model); and tertiary models are software packages such as ComBase that combine the two. Used to predict shelf life and pathogen risk and to support HACCP — but only valid within the range of conditions used to build them, so extrapolation is not allowed.
一种定量微生物学,把微生物对环境因素的响应总结为数学模型,按三层结构组织:一级模型描述固定条件下数量随时间的变化(如 Gompertz、Baranyi、logistic 拟合,给出 µ 和迟滞期);二级模型描述这些参数如何随温度、pH、a_w 变化(如平方根/Ratkowsky 模型);三级模型则是把前两者整合的软件包(如 ComBase)。用于预测货架期与致病菌风险、支撑 HACCP——但仅在建模所用条件范围内有效,不可外推。
Microorganisms of importance for the food industry食品工业中重要的微生物
Beneficial microbes used in fermentation and food production (e.g. lactic acid bacteria, yeasts) and the modern, rapid methods used to detect and identify them.
用于发酵和食品生产的有益微生物(如乳酸菌、酵母),以及检测和鉴定它们的现代快速方法。
Microorganisms of potential food-safety concern潜在食品安全隐患微生物
Foodborne pathogens and spoilage organisms, their sources and control, including spore-formers and toxin producers. A recurring exam scenario is a swollen, foul-smelling, gassy can of low-acid processed meat — a signature of anaerobic spore-forming Clostridium (including C. botulinum), which is why low-acid canned foods need the '12-D botulinum cook' (commercial sterility at 121 °C). Control links to the D/z/F thermal-death framework and to HACCP critical limits (e.g. pH ≤ 4.6, a_w ≤ 0.85).
食源性致病菌与腐败菌,其来源与控制,包括产芽孢菌和产毒素菌。一个反复出现的考题情境是低酸加工肉罐头胀罐、发臭并放出气体——这是厌氧产芽孢梭菌(含肉毒梭菌 C. botulinum)的典型特征,因此低酸罐头需采用「12-D 肉毒杀菌」(121 °C 达到商业无菌)。其控制与 D/z/F 热致死框架及 HACCP 关键限值(如 pH ≤ 4.6、a_w ≤ 0.85)相关联。
Genetically modified microorganisms转基因微生物
The role and implications of genetically modified microorganisms in food production and food microbiology.
转基因微生物在食品生产与食品微生物学中的作用及其影响。
Practical laboratory program实验室操作课程
Hands-on training in modern and instrumental microbiological techniques, including the examination and identification of spoilage and disease-causing microorganisms. Assessed via a practical report.
现代及仪器化微生物学技术的实操训练,包括腐败菌与致病菌的检验与鉴定;以实验报告形式评分。
How FOOD90023 is assessedFOOD90023 怎么考核
Final exam: Yes期末考试:有| Component考核项 | Weight占比 | Note说明 |
|---|---|---|
| Six 10-minute quizzes throughout the semester学期内六次 10 分钟小测 | 10% | One quiz every fortnight.每两周一次。 |
| Practical report实验报告 | 20% | 1000 words, due Week 11.1000 词,第 11 周提交。 |
| Mid-semester exam期中考试 | 20% | 1 hour, held mid-semester.1 小时,学期中举行。 |
| Written exam期末笔试 | 50% | 2 hours, during the examination period.2 小时,于考试周举行。 |
Final written exam 50% (2 hours) + mid-semester exam 20% (1 hour) + practical report 20% + six fortnightly quizzes 10%.
期末笔试 50%(2 小时)+ 期中考试 20%(1 小时)+ 实验报告 20% + 六次双周小测 10%。
When each FOOD90023 task is dueFOOD90023 各项考核时间
Test yourself: FOOD90023 practice questions自测一下:FOOD90023 练习题
- Still grow slowly at refrigeration temperature, so chilling alone is not a kill step
- Survive only above 60 °C, so reheating spreads it
- Grow only at water activity below 0.85
- Form endospores that germinate during freezing
- 在冷藏温度下仍能缓慢生长,故仅靠冷藏并不能杀灭它
- 只在 60 °C 以上存活,故再加热反而会扩散它
- 只在水分活度低于 0.85 时生长
- 形成内生孢子并在冷冻时萌发
Show answer查看答案
- Staphylococcus (cocci in clusters)
- Vibrio (curved rods)
- Streptobacillus (rods in chains)
- Sarcina arranged as single rods
- 葡萄球菌 Staphylococcus(成簇排列的球菌)
- 弧菌 Vibrio(弯曲杆菌)
- 链杆菌 Streptobacillus(成链排列的杆菌)
- 呈单个杆状排列的八叠球菌 Sarcina
Show answer查看答案
- Secondary model
- Primary model
- Tertiary model (software such as ComBase)
- A thermal-death (D-value) model
- 二级模型
- 一级模型
- 三级模型(如 ComBase 软件)
- 热致死(D 值)模型
Show answer查看答案
High-value exam questions in FOOD90023FOOD90023 高频考点 · 考试风格题
A worked FOOD90023 problemFOOD90023 例题
Why time and growth rate beat the starting count (exponential growth)为何时间与生长速率比起始菌数更关键(指数增长)
It is often said the final number of microorganisms N is directly proportional to the initial number N0. Yet the final count is far more affected by the specific growth rate µ and the time t. Explain why, using N = N0·e^(µt), and give a numerical example.
常说微生物的最终数量 N 与初始数量 N0 成正比,但最终菌数其实更受比生长速率 µ 与时间 t 的影响。请用 N = N0·e^(µt) 解释原因,并给出一个数值示例。
In N = N0·e^(µt), N0 appears as a linear multiplier, so doubling the initial load only doubles the result. But µ and t sit in the exponent, so changing them scales N by orders of magnitude. Worked numbers: with a generation time g = 20 min, the count doubles every 20 min, so n = t/g generations means N = N0·2^n. Starting at N0 = 100 CFU, after t = 5 h there are n = 15 generations, giving N = 100 × 2^15 ≈ 3.3 × 10^6 CFU. Doubling N0 to 200 only reaches ~6.6 × 10^6 (a 2× change), whereas extending the time or raising µ a little multiplies N enormously. This is exactly why food safety relies on time–temperature control (limiting t and µ via chilling and hurdles) rather than just starting with a low contamination level.
在 N = N0·e^(µt) 中,N0 是线性乘子,所以把初始菌数翻倍,结果也只翻倍。但 µ 与 t 位于指数项,因此略微改变它们就能让 N 以数量级变化。数值演算:世代时间 g = 20 min,则每 20 分钟翻一倍,n = t/g 代世代意味着 N = N0·2^n。设 N0 = 100 CFU,经 t = 5 h 即 n = 15 代,N = 100 × 2^15 ≈ 3.3 × 10^6 CFU。把 N0 翻倍到 200 也只到约 6.6 × 10^6(仅 2 倍变化),而稍微延长时间或提高 µ 就能让 N 成倍数量级增长。这正是食品安全依赖时间—温度控制(通过冷藏与栅栏技术限制 t 和 µ),而非仅靠起始污染低的原因。
FOOD90023 glossaryFOOD90023 术语表
- Predictive microbiology预测微生物学
- Use of mathematical models to forecast microbial growth or death in food from conditions like temperature, pH and water activity.
- 用数学模型,根据温度、pH、水分活度等条件预测食品中微生物的生长或死亡。
- Water activity (a_w)水分活度(a_w)
- Measure of unbound water available to microbes; a key intrinsic factor controlling microbial growth in food.
- 衡量食品中可供微生物利用的自由水的指标,是控制微生物生长的关键内在因素。
- Foodborne pathogen食源性致病菌
- A microorganism (e.g. Salmonella, Listeria, E. coli, Campylobacter) that causes illness when ingested via contaminated food.
- 经受污染食品摄入后会致病的微生物(如沙门氏菌、李斯特菌、大肠杆菌、弯曲杆菌)。
- Spoilage organism腐败菌
- A microbe whose growth degrades food quality (odour, texture, appearance) without necessarily causing disease.
- 其生长会降低食品品质(气味、质地、外观)但不一定致病的微生物。
- Microbial growth curve微生物生长曲线
- The lag, exponential (log), stationary and death phases describing a microbial population over time.
- 描述微生物种群随时间变化的迟滞期、对数(指数)期、稳定期和衰亡期。
- Fermentation发酵
- Controlled use of beneficial microbes to transform food components, producing products such as yoghurt, cheese and fermented vegetables.
- 有控制地利用有益微生物转化食品成分,制成酸奶、奶酪、发酵蔬菜等产品。
- Microbial metabolism微生物代谢
- The biochemical processes by which microbes obtain energy and act on food substrates.
- 微生物获取能量并作用于食品底物的生化过程。
- Rapid detection methods快速检测方法
- Modern instrumental techniques that identify microbes faster than conventional culture-based methods.
- 比传统培养法更快鉴定微生物的现代仪器化技术。
- Genetically modified microorganism (GMM)转基因微生物(GMM)
- A microorganism whose genome has been deliberately altered, considered for its role in food production.
- 基因组经人为改造的微生物,本课程探讨其在食品生产中的作用。
- Shelf life货架期
- The period a food remains safe and of acceptable quality; predictive microbiology helps estimate it.
- 食品保持安全且品质可接受的时间段,可借助预测微生物学估算。
- Specific growth rate (µ) / generation time比生长速率(µ)/ 世代时间
- µ is the rate of exponential increase in N = N0·e^(µt); the generation (doubling) time g = ln2/µ, defined in the log phase. Both dominate the final count over the initial load N0.
- µ 是 N = N0·e^(µt) 中指数增长的速率;世代(倍增)时间 g = ln2/µ,在对数期定义。两者对最终菌数的影响都大于初始菌数 N0。
- D-value (decimal reduction time)D 值(十进制递减时间)
- The time at a given temperature needed to kill 90% of a population (a 1-log reduction); paired with z-value (°C for a 10× change in D) and F-value (total equivalent process lethality, e.g. F0 at 121.1 °C).
- 在给定温度下杀灭 90% 菌群(降低 1 个对数级)所需的时间;与 z 值(使 D 变化 10 倍所需的温度差)和 F 值(总等效杀菌效力,如 121.1 °C 下的 F0)配套使用。
- Primary / secondary / tertiary models一级 / 二级 / 三级模型
- The hierarchy of predictive microbiology: primary = number vs time (Gompertz/Baranyi); secondary = how µ and lag vary with temperature, pH, a_w (e.g. square-root model); tertiary = software combining both (e.g. ComBase).
- 预测微生物学的层级结构:一级 = 数量随时间变化(Gompertz/Baranyi);二级 = µ 与迟滞期如何随温度、pH、a_w 变化(如平方根模型);三级 = 整合前两者的软件(如 ComBase)。
- Malolactic fermentation (MLF)苹果酸-乳酸发酵(MLF)
- Secondary conversion of harsh L-malic acid into softer L-lactic acid + CO2 by lactic acid bacteria (e.g. Oenococcus oeni) in wine; de-acidifies and stabilises wine. Inhibited by low pH, high SO2, low temperature and high ethanol.
- 葡萄酒中由乳酸菌(如酒类酒球菌 Oenococcus oeni)将较尖锐的 L-苹果酸转化为较柔和的 L-乳酸 + CO2 的二次发酵;可降酸并稳定葡萄酒。受低 pH、高 SO2、低温和高乙醇抑制。
FOOD90023 — common questionsFOOD90023 常见问题
How is FOOD90023 assessed?FOOD90023 怎么评分?
What are the prerequisites for FOOD90023?FOOD90023 有先修课要求吗?
How many credit points is FOOD90023 and what level is it?FOOD90023 是多少学分、什么层次?
Is there a lab component in FOOD90023?FOOD90023 有实验课吗?
Is using AskSia allowed under the University of Melbourne academic integrity policy?墨尔本大学的学术诚信政策允许用 AskSia 吗?
Other UniMelb course guides墨大 其他课程指南
AskSia is an independent study aid and is not affiliated with, endorsed by, or sponsored by The University of Melbourne. Course details may change — always confirm against the official handbook. Read about how this guide is built. AskSia 是独立的学习辅助工具,与墨尔本大学没有任何隶属、背书或赞助关系。课程信息可能变动,请始终以官方 handbook 为准。了解本指南的编写方法。