Food Processing Flashcards
In thermoprocessing, what is the difference between ““sterility” and “commercial sterility”?
“Commerical sterility” means the probability of spores and cells surviving is low but not absolute
Name 3 methods of food preservation
Drying, salt addition, heat, freezing
The most commonly used surfactants in the food industry are?
Monoglycerides and Diglycerides
What is IQF?
Individually Quick Frozen
Which test would you use to determine whether Coke is sweeter?
Increasing foam stability but decreasing foam value
Of the 4 components of a refrigeration system, which one involves constant entropy?
Compressor
Basic Principles of Food Processing
1) moisture removal
2) heat treatment
3) low-heat treatment
4) thermal processing
5) nonthermal processing (traditional & nontraditional)
6) acidity control
What is the purpose of processing Food?
To preserve food and create a specific desirable food product
What is Food Spoilage?
Perishability of raw foods through microbial growth, enzymatic reactions, and chemical changes (mainly through factors of water, temp, and pH)
What are Unit Operations?
the processing step of a product, like in a factory (i.e. heat exchange, evaporation, drying, and material handling)
What is Heat Treatment?
Process of inactivating pathogens and spoilage microorganisms and enzymes, i.e. blanching and pasteurizing
What is D-value?
The specific time at a specific temperature for a specific food to destroy 90% of the population (one log) of a specific MO.
What is the 12D Concept?
The D-value to destroy 90% of C. Botulinum at a 12 log reduction: ensures safety of low acid foods
What is the purpose of thermal death time studies?
to determine an organism’s heat resistance (D-value) in a specific product to develop a process for that product
What is the purpose of Low-Temperature Treatment?
a) slows spoilage reactions
b) freezes the water in food to reduce aW
Define Acidity Control
The more acid present in a food, the lower the pH becomes, lowering the potential of microbial spoilage, and requires less heat treatment
What is Traditional Nonthermal Processing?
Chemicals added to food for preservation to control aW and extend shelf-life through packaing
Name the Types of Traditional Nonthermal Processing
1) modified atmosphere packaging (MAP)
2) controlled atmosphere storage (CAS)
3) nitrogen flush packaging
4) vacuum packaging
What is Innovative Nonthermal Processing?
Refers to new technologies that preserve the food supply without raising the temperature; to eliminate thermal degradation of food quality
What is blanching?
Process used to inactivate enzymes and set color
What is Pasteurization?
Process used to inactivate pathogens (e. coli) and vegetative (alive) pathogens
What makes a product commercially sterile?
free of all pathogens and other microorganisms that could potentially grow in the product
Why is commercial sterilization important?
To achieve long-term shelf stability for canned foods and other products: majority after being placed in container
What are the factors that affect thermal processing?
- Product pH or acidity
- Heating and cooling characteristics
- Size of container
- Heating and cooling medium
- Time/temperature relationship
- Product composition
What are the 3 pH parameters of food?
Low acid over 4.5
Medium acid and acid 3.7 to 4.5
High acid below 3.7
What is conduction heating?
Uniform heating of the product from all directions with the slowest or coldest location at or near the center of the container
What is Convection heating?
(canned liquid) the first heated portion of the liquid becomes lighter in density and rises thereby setting up circulation within the can. coldest location at bottom of container
What is the purpose of refrigeration storage?
To extend shelf-life by slowing down derogatory reactions and limiting microbial growth
What is the refridgeration temperature range?
Temperature range - approximately -1 to 8 C
What are the changes caused by refrigeration?
Retard microbial growth Limit lipid oxidation Limit non-enzymatic browning and enzymatic browning Slow down sugar conversion Reduce respiration reactions
What are the 4 phases of refrigerated storage?
Commercial storage
Transport storage
Retail storage
Home storage
What are some reasons for refrigeration combining methods
Combined refrigeration with other preservatives techniques to enhance shelf life.
MAS (Modified Atmosphere Storage)
What are some ways of deterioration of product quality?
Chemical, Biochemical, Physio-chemical, and Nutritional
Name the 4 Biochemical reactions of product quality
Enzymatic browning, glycolysis, proteolysis, lipolysis
What is the Freezing/Frozen temperature range?
Freezing below the temp. at which ice crystals begin to form within the food -10 to -20º C
Name 2 food freezing systems
Indirect contact and direct contact
Define Heat capacity
the amount of heat necessary for a unit mass of substance to change its temperature by one degree. Heat capacity is really a measure of how fast we can heat or cool a material.
Define specific heat
the ratio of the heat capacity of a substance to that of water.
Define Sensible Heat
the amount of heat added to or removed from a substance that results only in a change in temperature, it takes into consideration the mass of the material and heat capacity.
Define Latent heat or hidden heat
the amount of heat energy transferred to or from a material and results in phase change only without changing its temperature
What is thermal conductivity?
how heat penetrates the food when freezing the food. It takes into consideration Mw, solids, fat, general composition of the food product
What can be used to define changes in quality?
Degradation of pigments
Loss of vitamins
Enzyme activity
Oxidation of lipids
What is HTST full name?
High temperature short time
A substance that has a high affinity for water?
Humectant
What is the stabilization factor for colloidal suspension?
Particle size, viscosity, electrostatic interaction.
What are the three modes of heat transfer?
Conductive, convective, radiation
Which category of food materials can be heated by microwave?
Dielectric material
What are the two common polymerization methods?
Addition polymerization and condensation polymerization
In extrusion, which surface is rough and which one is smooth? Inside surface of barrel or outside surface of screw?
The inside surface of barrel is rough and outside surface of screw is smooth.
What does commercial sterilization refer to?
The use of a thermal process to achieve a shelf stable food product.
What concept motivates the use of multiple preservative factors to prevent growth of pathogens in processed foods?
The hurdle concept
What are SOP and SSOP?
Standard operating procedure, sanitation standard operating procedure
Which enzyme is commercially used to produce maltose by hydrolyzing starch?
𝛽-amylase
In sugar refining process, what is the function of earth and charcoal?
Decolorize
microwave heating is accomplished by _______
molecular friction
which of the procedures listed is designed to kill most microorganisms: A.radappertization, B.radicitation, or C.radurization?
A. radappertization
Milk is sometimes concentrated using RO and UF equipment; what do these abbreviations stand for?
RO=reverse osmosis ; UF=ultra filtration
list 2 approved application of gamma irradiation in foods
inhibit sprouting in tubers and bulbs,reduce microbial population in spices,destruction of salmonella in poultry,destruction of spoilage microorganisms
name 2 non-thermal food processing technologies.
UV light, ultrasound, high pressure, pulsed light, pulsed electric field, irradiation
what does the acronym NFPA stand for?
National Food Processors Association
what is the term for an ingredient that is added during processing that is later, during shipping, handling, and storage is altered, removed, or diminished?
a processing aid
what kinds of acids are the most effective acid-based antimicrobial preservatives in foods?
weak organic acids, because only undissociated acids can cross the cell membrane
describe the flow direction of water across a cell membrane in an isotonic, hypotonic, and hypertonic solution
Isotonic=no net flow (equilibrium);Hypotonic= water flows into the cell;Hypertonic= water flows out of the cell
classify the following as either endothermic or exothermic: melting, condensation, evaporation, boiling, freezing, crystallization
melting=endo; condensation=exo; evaporation= endo; boiling= endo; freezing= exo; crystallization= exo
fruits can be classified according to their respiratory patterns. List 2 climacteric fruits
apple, apricot, avocado, banana, mango, papaya, passion fruit, papaw, peach, pear, plum, tomato, watermelon
fruits can be classified according to their respiratory patterns. List 2 non-climacteric fruits
blueberry, cacao, cherry, cucumber, fig, grapefruit, lemon, grapes, melon, orange, pineapple, strawberry, tamarillo
