Podcast
Questions and Answers
Other microorganisms such as __________ are sensitive to acids and prefer alkaline conditions.
Other microorganisms such as __________ are sensitive to acids and prefer alkaline conditions.
Vibrio cholerae
Most bacteria are killed in strong ______ or strong alkaline environment except Mycobacteria.
Most bacteria are killed in strong ______ or strong alkaline environment except Mycobacteria.
acid
Salting and drying reduces the ______ of a food product.
Salting and drying reduces the ______ of a food product.
water activity
The water activity of ______ is equal to 1.0.
The water activity of ______ is equal to 1.0.
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Microorganisms require ______, carbohydrates, lipids, water, energy, nitrogen, sulphur, phosphorus, vitamins, and minerals for growth.
Microorganisms require ______, carbohydrates, lipids, water, energy, nitrogen, sulphur, phosphorus, vitamins, and minerals for growth.
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Meat has ______, skin and other membranes that prevent microbial entry.
Meat has ______, skin and other membranes that prevent microbial entry.
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Fascia is a thin casing of ______ tissue that surrounds and holds every organ, blood vessel, bone, nerve fiber and muscle in place.
Fascia is a thin casing of ______ tissue that surrounds and holds every organ, blood vessel, bone, nerve fiber and muscle in place.
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Eggs have ______ and inner membranes that prevent yolk and egg white from infection.
Eggs have ______ and inner membranes that prevent yolk and egg white from infection.
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The growth of microorganisms is affected by the environmental ______.
The growth of microorganisms is affected by the environmental ______.
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Various microorganisms require for growth, either high oxygen tension (aerobic), low oxygen tension (microaerobic) or ______ of oxygen (anaerobic).
Various microorganisms require for growth, either high oxygen tension (aerobic), low oxygen tension (microaerobic) or ______ of oxygen (anaerobic).
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Foods with low water activity placed at high ______ environment take up water, increase their water activity and get spoiled easily.
Foods with low water activity placed at high ______ environment take up water, increase their water activity and get spoiled easily.
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For example, dry grains stored in a ______ environment with high humidity will take up water and undergo mold spoilage.
For example, dry grains stored in a ______ environment with high humidity will take up water and undergo mold spoilage.
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Microbial growth is an ______ process.
Microbial growth is an ______ process.
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The factors that affect microbial growth in foods are ______ and extrinsic factors.
The factors that affect microbial growth in foods are ______ and extrinsic factors.
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Most bacteria grow best at ______ or weakly alkaline pH.
Most bacteria grow best at ______ or weakly alkaline pH.
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Yeasts and molds grow within a wide pH range of ______ to ______.
Yeasts and molds grow within a wide pH range of ______ to ______.
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Microorganisms that are able to grow in acid environment are called ______ microorganisms.
Microorganisms that are able to grow in acid environment are called ______ microorganisms.
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Yeasts and molds grow under ______ conditions.
Yeasts and molds grow under ______ conditions.
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Study Notes
Microorganism Sensitivity and Growth Requirements
- Microorganisms such as Mold are sensitive to acids and prefer alkaline conditions
- Most bacteria are killed in strong acid or strong alkaline environments, except Mycobacteria
Food Preservation Methods
- Salting and drying reduces the water activity of a food product
Microorganism Growth Requirements
- Microorganisms require proteins, carbohydrates, lipids, water, energy, nitrogen, sulphur, phosphorus, vitamins, and minerals for growth
Natural Barriers to Microbial Entry
- Meat has skin and other membranes that prevent microbial entry
- Fascia is a thin casing of connective tissue that surrounds and holds every organ, blood vessel, bone, nerve fiber, and muscle in place
- Eggs have outer and inner membranes that prevent yolk and egg white from infection
Environmental Factors Affecting Microbial Growth
- The growth of microorganisms is affected by the environmental temperature
- Various microorganisms require either high oxygen tension (aerobic), low oxygen tension (microaerobic), or absence of oxygen (anaerobic) for growth
Effects of Water Activity on Food Spoilage
- Foods with low water activity placed at high humidity environment take up water, increase their water activity, and get spoiled easily
- Dry grains stored in a humid environment with high humidity will take up water and undergo mold spoilage
Microbial Growth Process
- Microbial growth is an ongoing process
- The factors that affect microbial growth in foods are intrinsic and extrinsic factors
pH Tolerance of Microorganisms
- Most bacteria grow best at neutral or weakly alkaline pH
- Yeasts and molds grow within a wide pH range of 2 to 9
- Microorganisms that are able to grow in acid environment are called acidophilic microorganisms
- Yeasts and molds grow under aerobic conditions
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Description
Explore the factors influencing the kinds and numbers of microorganisms in food, focusing on how microbial growth is an autocatalytic process and requires the presence of viable cells to occur. Learn about the relationship between viable biomass and growth rate.
