Podcast
Questions and Answers
What does food texture assessment primarily involve?
What does food texture assessment primarily involve?
What is a key factor in material transfer during food processing?
What is a key factor in material transfer during food processing?
Which of the following statements about mass transfer is incorrect?
Which of the following statements about mass transfer is incorrect?
Which factor does not influence the rate of mass transfer?
Which factor does not influence the rate of mass transfer?
Signup and view all the answers
What sensory method is used for texture profiling of food?
What sensory method is used for texture profiling of food?
Signup and view all the answers
What aspect of food is influenced by the material transfer process during frying?
What aspect of food is influenced by the material transfer process during frying?
Signup and view all the answers
Which type of processing operation relies heavily on mass transfer?
Which type of processing operation relies heavily on mass transfer?
Signup and view all the answers
How does chewing food relate to material transfer?
How does chewing food relate to material transfer?
Signup and view all the answers
What is the main reason heat processing is effective at preserving food?
What is the main reason heat processing is effective at preserving food?
Signup and view all the answers
What does the D value represent in food processing?
What does the D value represent in food processing?
Signup and view all the answers
Which of the following is NOT listed as a source of energy in food processing?
Which of the following is NOT listed as a source of energy in food processing?
Signup and view all the answers
What characterizes the death of micro-organisms when heated?
What characterizes the death of micro-organisms when heated?
Signup and view all the answers
What happens to enzyme activity when food is heat processed?
What happens to enzyme activity when food is heat processed?
Signup and view all the answers
When heating food, what proportion of micro-organisms die in a given time interval?
When heating food, what proportion of micro-organisms die in a given time interval?
Signup and view all the answers
Which factor is consistent in the process of micro-organism destruction during heat treatment?
Which factor is consistent in the process of micro-organism destruction during heat treatment?
Signup and view all the answers
What type of reaction describes the destruction of micro-organisms during heating?
What type of reaction describes the destruction of micro-organisms during heating?
Signup and view all the answers
What is the implication of a higher number of microorganisms in a raw material?
What is the implication of a higher number of microorganisms in a raw material?
Signup and view all the answers
What does the z value represent in the context of the TDT curve?
What does the z value represent in the context of the TDT curve?
Signup and view all the answers
Which statement is true regarding the destruction of microorganisms?
Which statement is true regarding the destruction of microorganisms?
Signup and view all the answers
How does temperature affect the rate of microbial destruction?
How does temperature affect the rate of microbial destruction?
Signup and view all the answers
What is the purpose of processing in food safety?
What is the purpose of processing in food safety?
Signup and view all the answers
What is the minimum time-temperature condition needed to destroy Clostridium Botulinum?
What is the minimum time-temperature condition needed to destroy Clostridium Botulinum?
Signup and view all the answers
What does the D value characterize?
What does the D value characterize?
Signup and view all the answers
Which of the following is NOT a factor affecting the decimal reduction time?
Which of the following is NOT a factor affecting the decimal reduction time?
Signup and view all the answers
How do growth media and incubation conditions influence heat resistance studies?
How do growth media and incubation conditions influence heat resistance studies?
Signup and view all the answers
What is the relationship between heat processing and the retention of nutritional properties?
What is the relationship between heat processing and the retention of nutritional properties?
Signup and view all the answers
What is the water activity level below which almost all microbial activities are inhibited?
What is the water activity level below which almost all microbial activities are inhibited?
Signup and view all the answers
Which method operates on the concept of high-temperature short-time processing?
Which method operates on the concept of high-temperature short-time processing?
Signup and view all the answers
Which method does NOT effectively reduce the availability of water in foods?
Which method does NOT effectively reduce the availability of water in foods?
Signup and view all the answers
What determines the shelf life of a food product?
What determines the shelf life of a food product?
Signup and view all the answers
At what water activity level does most fungi begin to be inhibited?
At what water activity level does most fungi begin to be inhibited?
Signup and view all the answers
What is a consequence of high water activity in foods?
What is a consequence of high water activity in foods?
Signup and view all the answers
Which of the following factors interacts with water activity to affect microbial growth inhibition?
Which of the following factors interacts with water activity to affect microbial growth inhibition?
Signup and view all the answers
What is the first-order reaction associated with heat processing?
What is the first-order reaction associated with heat processing?
Signup and view all the answers
What is a common method for immobilizing water in intermediate-moisture foods?
What is a common method for immobilizing water in intermediate-moisture foods?
Signup and view all the answers
How do enzymic and chemical reactions differ during food storage?
How do enzymic and chemical reactions differ during food storage?
Signup and view all the answers
Which statement about bacterial inhibition is true?
Which statement about bacterial inhibition is true?
Signup and view all the answers
What does the Relative Vapor Pressure (RVP) measure in food?
What does the Relative Vapor Pressure (RVP) measure in food?
Signup and view all the answers
What is the key effect of water activity on food?
What is the key effect of water activity on food?
Signup and view all the answers
Which of the following unit operations does NOT remove water physically?
Which of the following unit operations does NOT remove water physically?
Signup and view all the answers
Study Notes
Food Properties and Processing Theory
- Food texture can be assessed using sensory methods, including taste panels and quantitative descriptive analysis.
- Numerical texture profiling can involve quantifying the force required to shear, penetrate, extrude, compress or cut a food.
- Mass transfer is crucial in food processing, influencing operations like solvent extraction, distillation, membrane processing, and blanching.
- Mass transfer of gases and vapors is key during evaporation, dehydration, baking, roasting, frying, freeze drying, freezing, and maintaining quality in chilled, MAP, and packaged foods.
- The rate of mass transfer is influenced by the driving force and the resistance to the flow of materials.
- Common sources of energy in food processing include electricity, natural gas, liquid petroleum gas, and liquid fuel oil.
- Heat processing is a preservation method that denatures proteins, thereby destroying enzyme activity and enzyme-controlled metabolism in microorganisms.
- Microbial destruction follows a first-order reaction, meaning the same percentage of microorganisms die within a given time interval regardless of their initial number. This is known as the logarithmic order of death.
- The decimal reduction time (D value) is the time required to reduce the number of microorganisms by a factor of 10 (90% reduction).
- The D value is dependent on the type of microorganism and the temperature.
- The thermal death time (TDT) curve represents the relationship between temperature and D value.
- The z value is the temperature change required to achieve a tenfold change in the D value, reflecting the temperature dependence of microbial destruction.
- The recovery of microorganisms in heat resistance studies is influenced by the growth media and incubation conditions.
- The concept of commercial sterility aims to reduce the number of surviving microorganisms to an acceptable level, not necessarily eliminating all microorganisms.
- Heat treatment can affect both nutritional and sensory characteristics of foods, often following a first-order reaction.
- The impact of heat on nutritional and sensory properties can be minimized by using higher temperatures and shorter processing times.
- The concept of high-temperature short-time (HTST) processing is based on minimizing the impact of heat on food quality.
- Water activity (aw) is a measure of the availability of water for microbial, enzymatic, or chemical activity in a food.
- Low aw inhibits microbial activity, with specific thresholds for different microorganisms (e.g., most bacteria below 0.9, most yeasts below 0.8, most fungi below 0.7, and almost all microbial activity inhibited below 0.6).
- Factors such as temperature, pH, oxygen, carbon dioxide, and chemical preservatives can influence the effectiveness of aw in inhibiting microbial growth.
- Unit operations that reduce water availability in foods include dehydration, evaporation, freeze drying, freeze concentration, and the use of humectants.
- The interaction between aw and other factors (temperature, pH, oxygen, etc.) plays a major role in controlling microbial growth and food spoilage.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers essential concepts in food properties and processing, focusing on texture assessment, mass transfer, and heat processing methods. You'll learn how different processing techniques affect food quality and preservation. Test your knowledge on key operations like extraction, evaporation, and baking.
