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Questions and Answers
What factors influence the spoilage of food items?
What factors influence the spoilage of food items?
Which component has the least impact on energy production in foods?
Which component has the least impact on energy production in foods?
What characteristic of healthy food tissues contributes to their shelf life?
What characteristic of healthy food tissues contributes to their shelf life?
What chemical process is primarily responsible for rancidity in fats?
What chemical process is primarily responsible for rancidity in fats?
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Which nutrient is highlighted as having specific requirements for spoilage prevention?
Which nutrient is highlighted as having specific requirements for spoilage prevention?
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Which of the following processes can lead to discolouration of food products?
Which of the following processes can lead to discolouration of food products?
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In terms of energy production, which nutrient is noted to be used least by food items?
In terms of energy production, which nutrient is noted to be used least by food items?
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What is the term used to describe the degradation of fats into undesirable flavors and odors?
What is the term used to describe the degradation of fats into undesirable flavors and odors?
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In food preservation, which of the following is used to inhibit enzymatic browning?
In food preservation, which of the following is used to inhibit enzymatic browning?
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Which factor is most likely to accelerate the rancidification process in fats?
Which factor is most likely to accelerate the rancidification process in fats?
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What is the primary reason that saccharomyces yeast is deemed unsuitable for specific fermentation processes?
What is the primary reason that saccharomyces yeast is deemed unsuitable for specific fermentation processes?
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What effect do undesirable yeast types have on high-quality food products?
What effect do undesirable yeast types have on high-quality food products?
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Which of the following best describes the main purposes of the e-smoking method in food processing?
Which of the following best describes the main purposes of the e-smoking method in food processing?
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What characteristic of food does the fermentation process involving saccharomyces yeast notably affect?
What characteristic of food does the fermentation process involving saccharomyces yeast notably affect?
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In what way does e-smoking differ from traditional cooking methods?
In what way does e-smoking differ from traditional cooking methods?
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What is a primary advantage of food production focused on ease of storage and distribution?
What is a primary advantage of food production focused on ease of storage and distribution?
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Which scenario emphasizes the importance of food production that can be stored and transported easily?
Which scenario emphasizes the importance of food production that can be stored and transported easily?
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What is a significant consideration in food production that affects its availability everywhere?
What is a significant consideration in food production that affects its availability everywhere?
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What impact does efficient food storage and distribution have in the context of food accessibility?
What impact does efficient food storage and distribution have in the context of food accessibility?
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How does food production tailored for difficult and secluded areas contribute to overall food security?
How does food production tailored for difficult and secluded areas contribute to overall food security?
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What does the sell by date indicate for food products?
What does the sell by date indicate for food products?
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How should consumers interpret the sell by date for home storage?
How should consumers interpret the sell by date for home storage?
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What is the primary purpose of the sell by date on food products?
What is the primary purpose of the sell by date on food products?
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What happens if a product is past its sell by date?
What happens if a product is past its sell by date?
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Which statement about the sell by date is incorrect?
Which statement about the sell by date is incorrect?
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Which of the following foods is NOT typically preserved by concentration?
Which of the following foods is NOT typically preserved by concentration?
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What is a critical factor to control during the concentration process?
What is a critical factor to control during the concentration process?
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Which of the following is an example of food typically preserved by concentration?
Which of the following is an example of food typically preserved by concentration?
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What happens to a food product during the latter stages of boiling in the concentration process?
What happens to a food product during the latter stages of boiling in the concentration process?
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Which of the following is an effect of localized burning during food concentration?
Which of the following is an effect of localized burning during food concentration?
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Study Notes
Food Technology 2
- Food Technology 2 is taught by Dr. Yanl AlLbawarshi
- This course covers food technology concepts.
Spoilage due to Enzymatic Activity
- Enzymes are complex chemical substances found in all living organisms.
- They control metabolic processes in food and plant tissues.
- These biochemical reactions are catalyzed by enzymes.
- Enzymatic spoilage is the leading cause of food deterioration.
- Endogenous enzymes cause desirable and undesirable changes in fruits, vegetables, and other foods.
- Examples of endogenous enzymes include polyphenol oxidases (PPO), phenolases, peroxidase, catalase, lipoxygenase, pectic enzyme, lipase, and amylase.
What is Food Science and Food Technology?
- Food Science is the study of food's nature, the causes of deterioration, and the underlying principles of food processing.
- It uses biology, physical sciences, and engineering.
- Food Technology applies food science to selecting, preserving, processing, packaging, distributing, and using safe, nutritious, and wholesome food.
Factors Affecting Postharvest Quality of Fruits and Vegetables
- Postharvest quality is affected by biological/internal factors and environmental/external factors.
- Biological factors include Respiration rate
- Even after harvest, fruits and vegetables respire as living entities. The chemical reaction for respiration is : C6H12O6 + 6O2 → 6CO2 + 6H2O + 673 Kcal
Quality
- Quality is the degree of excellence of a food, which includes characteristics like taste, appearance, and nutritional content.
- Quality and price are not necessarily correlated.
Classification of Fruits
- Fruits are classified as either climacteric or non-climacteric based on their ripening pattern.
- Non-climacteric fruits cannot continue ripening after harvest, unlike climacteric fruits. Examples of non-climacteric fruits include dates, grapes, pineapple, lemon, lime, and pomegranate.
Food Quality Detection
- Food quality is detected and evaluated through sight, touch, smell, taste, and hearing. These include textural, appearance, and flavor factors.
Respiration Pattern in Climacteric and Non-Climacteric Fruits
- The image displays the respiration pattern of climacteric (tomato) and non-climacteric (orange) fruits.
Additional Quality Factors
- Important factors affecting food quality, aside from sensory observations, include nutritional quality, sanitary quality, and keeping quality.
- Nutritional quality is often determined through chemical or instrumental analyses of specific nutrients.
- Sanitary quality is typically measured by monitoring bacteria, yeast, mold, and insect fragments in addition to sediment levels.
- Keeping quality assesses a food’s stability during storage and handling.
Keeping Quality
- Keeping quality or storage stability is the ability of a food to maintain its stability during storage and handling, in line with expected environmental conditions during distribution and use.
Temperature
- Temperature is a crucial environmental factor influencing the rate of deterioration of harvested fruits and vegetables.
- For each 10° Celsius rise above the optimal temperature, the deterioration rate roughly doubles or triples.
Food Preservation and Storage
- Food preservation and storage are vital for a healthy life.
- Most food comes from agricultural and livestock sources.
- Unless preserved, food undergoes deterioration and spoilage from harvest, capture, slaughter, or production.
- Deterioration can create toxic substances or reduce nutritional value and quality.
Pectic Substances Nomenclature
- Protopectin (insoluble): immature plant material
- Pectinic acid (colloidal and soluble): mature plant material
- Pectin: mature plant material
- Pectic acid: overmature plant material
Food Preservation Knowledge
- Understanding processing and preservation techniques is essential for preserving foods for long periods with minimal loss in nutritional value.
Oxidoreductases
- 1 - Peroxidase (POD): An iron-containing enzyme with a prosthetic heme group. It's thermoresistant, so its presence indicates adequate blanching of vegetables.
- 2 - Catalase: When coupled with glucose oxidase, it results in the uptake of ½ O₂ per molecule of glucose.
- 3- Lipoxygenase: Catalyzes the peroxidation of fatty acids. It converts cis, cis groups into conjugated cis-trans hydro-peroxides leading to rancidity, and affects the flavor and bleaching of flour.
Additional Factors Affecting Quality
- Other factors that impact food quality include nutritional, sanitary, and keeping quality. These can be assessed chemically or instrumentally from a sensory perspective.
Quality Factors and Sensory Observations
- Some quality factors may not be apparent by sensory observations alone and may be assessed chemically or instrumentally, including nutritional value, hygiene, and keeping quality.
Preservation Methods
- Crucial methods to preserve foods entail elimination of oxygen, lowering enzyme activity, introducing preservation agents, and controlling external factors like insects, dust, odour, fumes, and physical damage.
Food Spoilage
- Spoilage is the undesirable changes in food, such as physical changes due to freezing, burning, drying, and bruising; chemical changes due to factors like osmosis and enzymatic reactions; and biological changes due to microbial growth.
Food Preservation
- It involves processes to prevent or slow down decay and spoilage in foods.
- The process involves preventing microbial growth, enzymatic action, chemical reactions, and physical damage.
Shelf Life
- Shelf life is the period when the food remains safe and fit for consumption.
- The food must not cause food poisoning, must not be degraded or spoil, and must remain in quality terms, which meets the consumer's standards, and has not lost significant nutrients.
Factors Affecting Microbial Growth
- Intrinsic factors: inherent in food, including pH, moisture content, nutrient content, antimicrobial substances, biological structures, and redox potential:
- Extrinsic factors: external to food, including temperature of storage, presence/concentration of gases, and relative humidity. All of these factors affect the growth of various microorganisms in food.
Methods of Blanching
- It's a mild heat treatment used to inactivate enzymes in food, mainly plants, before freezing, drying, or canning.
- It also cleans the product, removes gases, shrinks it for correct fill weight, and preheats it, helping with vacuum formation in cans.
- Different methods exist, including hot water blanching (below 100°C) and steam blanching (above 100°C).
Methods of Pasteurization
- Pasteurization involves mild heat treatment to partially destroy pathogenic and spoilage microorganisms and deactivate enzymes.
- It's commonly used in low-acid foods and sometimes combined with refrigeration or freezing to enhance safety.
- The common methods include LTLT (low-temperature long time) and HTST (high temperature short time).
Methods of Preservation
- Asepsis: Keeping microorganisms out of food. This is done with proper packaging to separate the food from surrounding environments and maintaining clean conditions during handling processes.
- Removal of microorganisms: Includes physical methods like washing, trimming, discarding dirt, filtering, centrifugation, and sedimentation to reduce microbial count.
- Preventing degradation: Methods include managing temperature, controlling oxygen, using chemical agents (inhibitors), and irradiation to slow down the microbial decomposition, enzymatic or chemical reactions and damage (mechanical, insects & rodents).
- Killing microorganisms: Methods involve heat treatment (through pasteurization or sterilization), ionizing or electromagnetic radiation (e.g., gamma rays, cobalt-60 radioactive particles), and gases (e.g., ethylene oxide or ozone).
Food Preservation Methods
- Canning involves heating and sealing foods at high temperatures to destroy microorganisms and enzymes and create an anaerobic environment.
- Aseptic canning is an advanced process where food is sterilized, filled in pre-sterilized containers, and sealed to avoid in-can processing steps and cooling.
- Hot pack is another canning method, where pre-pasteurized containers are filled with hot food before sealing.
- Use of water activity: Reducing moisture content by drying, curing, and pickling slows microorganism growth.
- Use of organic acids: Increasing acidity by adding acids, like acetic, lactic, citric, and malic acids, inhibits microbial growth.
- Use of high sugar or salt: High sugar or salt solutions effectively draw water from microorganisms, limiting their growth.
Preservation by Use of Heat
- Heat application is an effective preservation method, broadly applicable to various preservation techniques.
- Heat treatment can be used to destroy toxins and microorganisms or reduce their growth, and deactivate enzymes.
- Forms of heat treatment include blanching, pasteurization, sterilization, canning, and ultra-high temperature (UHT) treatments.
Factors Affecting Heat Treatments
- Factors influencing the choice and effectiveness of food preservation methods include; The type of food (e.g., high acid, low acid), Level of contaminants, Presence of oxygen, Heat resistance of spoilage organisms or enzymes, Heat penetration, Packaging material, Size of container and desired sensory qualities.
Factors Affecting Food Spoilage (in Detail)
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Food spoilage is attributed to extrinsic or intrinsic factors
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Extrinsic factors are external to the food (e.g., temperature, humidity, oxygen).
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Intrinsic factors originate within the food. These include the food's composition (e.g., water activity, pH), its biological structures, and the presence of enzymes.
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Description
Test your knowledge on the factors influencing food spoilage and preservation methods. This quiz covers topics including rancidity, enzymatic browning, and the role of various nutrients in food quality. Delve into the essential chemistry behind food storage and shelf life.
