Food Science - Exam #3/Final Flashcards
1
Q
What is food processing from field/farm to consumers?
A
All of the operations that make raw foodstuffs suitable for consumption and storage.
2
Q
What are all raw foods?
A
- Perishable;
- Related to the amount of biologically active water available (Aw = water activity)
- Preservation techniques rely on the manipulation of the food’s environment to minimize the activity of these modes of deterioration.
3
Q
What are Unit Operations?
A
- The systematic approach to processing foods involves the application of many different operations;
- Broad categories of common food processing operations in practice in the food industry;
1. Materials handling
2. Separating
3. Cleaning
4
Q
What is Materials handling?
A
-Getting the raw materials from the field to the processing facilities
5
Q
What is Separating?
A
-Isolation of a desirable part of a food raw material from another part
6
Q
What is Cleaning?
A
- Removal of dirt, bacteria, etc. from the food with the use of water/detergent.;
- Cleaning compounds are AMPHIPHILIC (both polar and nonpolar), allowing them to interact with water and dirt/debris by suspending them in solution
7
Q
What are the methods cleaning foods?
A
- Pre-rinse
- Detergent cleaning
- Post-rinse
8
Q
What are the method of cleaning equipment?
A
- Pre-rinse
- Detergent cleaning
- Post-rinse
- Sanitizing
9
Q
What is Sanitizing?
A
- Using sanitizers to kill microorganisms on the surface of food handling equipment;
- Sanitizers = chemical compounds that are bacteriostatic (preventing) /bactericidal (killing) agents
10
Q
What is Disintegrating?
A
Refers to particle size reduction of foods
11
Q
What is Pumping?
A
Moving liquid or semi-liquid foods from one point to another during processing.
12
Q
What is Mixing?
A
Blending of food ingredients to make a food product
13
Q
What is Heat Exchange?
A
The application or removal of heat from a food.
14
Q
What is Evaporation?
A
The removal of moisture from a food to concentrate its solids content;
-EX: Evaporated milk
15
Q
What is Drying?
A
more complete removal of moisture than with evaporation.
16
Q
What is Forming?
A
Putting food products into specific shapes
17
Q
What is Packaging?
A
Protects foods from the environment and provides convenience for retailers/consumers
18
Q
What are the six basic principles of food processing to achieve preservation?
A
- Moisture removal
- Heat
- Cold
- Acid (reduce the pH)
- Nonthermal processing
- Innovative nonthermal methods
19
Q
What is Moisture Removal?
A
Removal of biologically active water to stop the growth of microbes and reduce rate of chemical/enzymatic reactions: oSun drying – dried fruit/nuts oDrum drying – instant mashed potatoes oSpray drying – powdered milk, eggs oFreeze drying – instant coffee
20
Q
What is Water Activity?
A
water that is AVAILABLE to microorganisms:
- Molds = 0.6 AW
- Yeast = 0.7 AW
- Bacteria = 0.9 AW
- **On average lower to about 0.85 to ensure most won’t grow
21
Q
What is Heat Treatment?
A
Heat preservation through:
- Blanching;
- Pasteurizing;
- Sterilization
22
Q
What is Sterilization?
A
- Most severe form of heat preservation, is usually accomplished with a RETORT (commercial pressure cooker);
- Refers to the COMPLETE destruction of microorganisms.
23
Q
What is Commercial Sterilization?
A
Kills all pathogens and all but the most heat resistant bacteria.
24
Q
What is Pasteurization?
A
A milder form of preservation aimed at killing all pathogens. → Does NOT kill all SPOILAGE bacteria
25
What is Flash Pasteurization?
A high-temperature, short-time heat treatment applied to drink boxes and pouches.
•High Temp, Short time
•Ultra High Temp
26
What is Blanching?
tThe mildest form of heat preservation, aimed primarily at INACTIVATING ENZYMES.
27
What is LOW-Temp Treatment?
- Refrigeration or Freezing;
- Aimed at reducing microbial growth and chemical reactions
1. **Individual Quick Frozen (IQF) – has become the standard in freezing foods for high quality = Uses CO2 to quickly freeze foods in only 10 minutes;
2. Liquid Nitrogen (N2) – -320F
3. Blast freezing – -40F
28
What is Acidity Control?
- Reducing pH along with other types of preservation methods such as heat treatment, can more efficiently preserve foods;
- PICKLING foods (adding acidulants), or FERMENTING foods (natural production of acids) are pH reduction.
29
What are HIGH acid foods?
- Foods with naturally low pH, such as fruits and some vegetables are referred to as HIGH ACID foods;
- pH of ~4.6 prevents bacterial growth
30
How do foods rank by acidity?
- Acid foods – naturally 4.6 pH;
- Acidified foods – acid is ADDED to reduce the pH to 4.6;
- Fermented foods – undergo natural fermentation that reduces the pH to 4.6;
- Low aid foods – pH is greater than 4.6
31
What are the forms of NONTHERMAL preservation?
- Antimicrobial chemical preservatives;
| - Packaging
32
What are Antimicrobial Chemical preservatives?
-ACIDULANTS such as the organic acids, including short-chain fatty acids such as propionic acid, salt, sugar, spice extracts, etc. that can help prevent microbial spoilage;
-Also antioxidants such as BHT (synthetic) and ascorbic acid (natural).
•BHT – butylhydroxytoluene
•Ascorbic acid – vitamin C
33
What is Packaging?
Offers protection from biological, chemical and physical factors that could influence quality;
- Considerations for packaging material (glass or plastic);
- Package environment (modified atmosphere);
- Smart packaging (incorporation of antioxidants or antimicrobials)
1. MAP – modified atmosphere packaging
2. CAP – controlled atmosphere packaging
34
What are some NONthermal Processing Innovations?
-Irradiation;
-High pressure;
-Pulsed electricity or light
....all represent areas where modern food processors are looking for newer ways to preserve food and its quality.
35
What is Heat Transfer?
The manner in which heat energy is transferred from an heat source to food particles in a container.
36
What is Conduction?
Heat is transferred directly between objects. → Moving through a solid
37
What is Convection?
Heat moves through material due to MOLECULAR motion
38
What is Radiant Heating?
Due to the movement of heated fluid from hot regions to cold. → NO medium, directly to the product
39
What type of heat transfer takes place in a Retort Canner?
- Retort is the principal approach to commercial sterilization of foods;
- Heat transfer is by BOTH convection and conduction;
- Take all the air out and inject steam → Removing air pockets of cold air;
- Trying to reach a really high temp ;
- Can destroy most pathogenic and heat resistant bacteria
40
What CONDUCTION takes place within a Can?
–Transfer of heat between food molecules inside the can by molecular collisions;
-Solid foods
EX: Veggies, pumpkin, sweet potatoes
41
What CONVECTION takes place within a Can?
-Transfer of heat through a liquid according to density difference;
EX:Soup or broth occurs in the can
42
What is the COLD POINT of a can?
-the LAST part to be heated;
-The cold point of a can heated by conduction alone would be at the CENTER of the can. ;
-When convection occurs, the cold point shifts to below the center (or above). ;
-Determines overall process time/temperature for a product.
•Tach commercial sterilization of a product;
**Need to achieve a COLD POINT of -250F for at least 15 minutes!!
43
What does the Cold Point need to reach?
- Time and temp needed to reach commercial sterilization of a product;
* *Need to achieve a COLD POINT of -250F for at least 15 minutes!!
44
What is Vacuum?
- Canned foods are packed under VACCUUM;
- Prevents cans from swelling and bursting open if they are stored at lower pressure;
- Removes OXYGEN which can produces off flavors and colors in foods;
- Allows packages to be shipped to different atmospheric pressures
45
What is Food Spoilage?
any factor that reduces the quality of food during storage
46
What are Biological Factors that cause food spoilage?
- Include all microorganisms that can potentially contaminate food during its handling/processing;
- SPOILAGE is generally considered the LOSS of aesthetic quality, rather than loss of food safety. → Color, aroma, etc.;
* *Most spoilage microorganisms are NOT pathogenic
47
What are Chemical Changes that cause food spoilage?
- Occur due to enzymatic and nonenzymatic degradation of chemical constituents of food;
- Sometimes these changes are desirable (cheese manufacture) and sometimes they are not (rancid meat).
48
What are Physical Changes that cause food spoilage?
-Influence quality, such as dehydration (freezer burn) and separation (oily peanut butter).
49
What are Thermal Processes?
- Designed to kill the most heat resistant pathogen, which is C. botulinum.→ Causes botulism and is mainly associated with canned foods;
- Thermal process of specific time/temperature combination must be established for all thermally processed foods.;
- Avoid overheating because of the effect on other quality factors
50
What are D-values?
-Time required to produce a one log (90%) reduction in the microbial population;
-Determined by heating a bacterial population at a specific temperature for a period of time;
-
51
What is the reference microorganism for D-values?
- Bacillus stearothermphilus;
- MORE heat resistant than C. bot so can be sure that the pathogenic C. bot would for sure be killed;
- NOTPATHOGENIC, so using it was a reference is safe;
- Used to check the autoclave in the lab to ensure it is adequately sterilizing
52
What is the 12D Concept?
- Generally accepted thermal process is one in which a 12 log has occurred in the reference microorganism (C. botulinum);
- Food processors will heat their product so that it reaches 121C and remains at that temperature for 7 minutes;
- Actually more than a 12 D process.
53
What is TDT-Thermal Death Time?
- Takes both TIME and TEMP into account;
- Establishes the heating times necessary at different. temperature to achieve a similar log reduction in microbial populations.
54
What is Ohmic Heating?
-Relatively new approach to heating foods for the purpose of PRESERVATION because it is believed to cause less damage to other quality factors
55
What is TRADITIONAL Non-Thermal Food Preservation?
- TRADITIONAL Non-thermal Processing for Food Preservation ;
- Refers to the methods of food preservation WITHOUT the use of heat.;
- These include chemical preservatives and packaging that have been discussed previously.
- EX: Sugar, salt
56
What is INNOVATIVE Non-Thermal Food Preservation?
- Hurdle Technology;
- PEF - Pulse Electric Fields;
- OM - Oscillating Magnetic Fields;
- HPP - High Pressure Processing;
- PLT - Pulse Light Technology
57
What is PEF – Pulse Electric Fields?
-Similar to ohmic heating, except that the electricity is higher voltage and pulsed;
-Microorganisms are destroyed but the product is not heated appreciably, thus persevering quality.
EX: Milk, liquid eggs
58
What is OMF – Oscillating Magnetic Fields?
-Magnetic fields kill microorganisms and inactivate enzymes, thus this process is more adaptable to solid foods;
-Treatment of SOLID AND LIQUID foods in flexible pouches.
EX: Tuna
59
What is HPP – High-Pressure Processing?
- Microorganisms, but not spores, are killed by putting the food product at extremely HIGH PRESSURE;
- Textural properties can also be improved or changed in this process;
- EX: Oyster processing
60
Why is HPP good for oyster processing?
- Helps to prevent V. vulnificus and Noro Virus and makes them easier to shuck WITHOUT heat and therefore doesn’t cook the oyster;
- Makes them safer (less bacteria) and preserves much of the flavor typically lost during shucking by loss of the “juices or liquor”;
- Noro virus – caused more food borne outbreaks in the US in the last few years; Similar to Hep. A
61
What is PLT - Pulse Light Technology?
- Utilizes brief bursts of extremely high intensity light including energy in the UV and IR range. ;
- Light energy affects proteins and DNA of microorganisms, which kills them;
- Used primarily to STERILIZE SURFACES (i.e. no penetrating power) such as PACKAGING material and the surface of foods such as fruits and vegetables.
62
What are the steps in Milk Processing?
1. Clarification
2. Fat adjustment
3. Fortification
4. Pasteurization
5. Homogenization
6. Cooling (35F)
7. Fill containers
63
What is Clarifying milk?
Clarified cold by CENTRIFUGE at slow speed to separate out the dirt and sediment but not the cream
64
What is Fat Adjustment of milk?
Pumped into a storage tank and sampled for fat content, adjusted to meet regulatory standards by adding butter fat or skim milk.
65
How is milk fortified?
Fortified with vitamins= Centrifuge to separate the fat out, then regulate the amount of fat in the mil, and then fortify with vitamins:
- 400 IU Vitamin D per quart;
- 2000 IU Vitamin A per quaert
66
What is Pasteurization of milk?
- Mild heat treatment to kill bacteria that may be harmful to human health;
- Louis Pasteur = To reduce tuberculosis being passed from cows to humans
67
What is Homogenization of milk?
- Decreases size of fat globules in milk to prevent them from clustering and forming a cream separation;
- Then immediately cooled and packaged
68
What is Cheese?
- A fresh or matured dairy product made by draining the whey after coagulation of casein;
- Very high concentrated source of nutrients → Calcium , protein, viamins, fats, etc.
69
What is cheese Ripening?
The physical and chemical changes that take place between the time of curd precipitation and the development of desired characteristics.
70
How is Ice Cream made?
- Ice cream mix is blended, pasteurized, homogenized, aged, frozen, packaged and hardened.;
- Blend of protein, sugar, fat, water and air
71
What determines the quality of the ice cream?
- Milk fat and the blending of air (over-run) determine the TEXTURE:.
- Initial freezing transforms about HALF of the water to frozen state;
- Packaged ice cream is then hardened at LOWER temperatures in order to facilitate marketing;
- Prevention of GRITTINESS due to ice crystals or sugar crystallization is critical to ice cream quality
72
What is the role of SUGAR in frozen desserts?
- No sugar added – hard and icy;
- 1 cup added – somewhat softer;
- 2 cups added – smooth and creamy and easy to scoop
73
What is Yogurt?
- Fermented, coagulated milk product, manufactured using bacterial STARTER cultures;
- Its characteristic sour flavor and texture are due to Lactobacillus and Streptococcus cultures.
- Final pH is ~ 3.7-4.3 = preservative effects, flavor and texture.
74
How are Eggs prepared?
- Mostly for in-shell consumption (shell eggs);
- Or further processing
* *Packaged products must be kept at REFRIGERATED or FROZEN temperatures.
75
What happens to further processed eggs?
- Categorized as whole egg, whites and yolk products;
- After eggs are graded and inspected, they are broken out of their shells and separated;
- This process is all automated and includes separation of shell pieces and yolk membranes.
76
What is Pasteurization of eggs?
- The pasteurization process is critical because it must be done in such a way as to minimize protein denaturation;
- Pasteurization temp must be highly controlled to not denature protein!
1. Whole eggs and yolks = 149- 153 degrees
2. Just white = 131 degrees
77
How can liquid eggs be DRIED?
- Often used in the baking industry;
- SPRAY drying is used for whole egg and egg yolk= Need to remove the GLUCOSE so Maillard rxn won’t occur;
- PLATE drying is used to dry egg whites which produces highly functional egg white crystals with high foaming capacity.
78
What are Egg Substitutes?
- Egg substitutes are about 99% egg white, with vegetable gums for texture and beta-carotene for color, along with small amounts of flavorings and other nutrients;
- They have NO cholesterol and very little fat.;
- They must be pasteurized and refrigerated, much like milk products.
79
What is Meat?
- Meat is the edible flesh of animals, including all further processed products;
- All red meat animals, poultry, seafood, and game (venison, rabbit, nutria), as well as exotic species such as alligator and ostrich.;
- Further processed meat products include cured meats such as bacon and ham, deli meats and sausages, fish sticks, etc.
80
What determines Meat Quality?
- Sensory meat quality is determined by its flavor, juiciness, and texture with TEXTURE tending to be of prime importance;
- Texture refers to the degree of TENDERNESS of a meat product, which is highly dependent on the amount of connective tissue (collagen and elastin);
- Muscles that do a lot of work, or are from older animals, tend to have higher connective tissue content and are therefore tougher.
81
What is Rigor Mortis?
- Also called Rigor (stiffness of death) occurs because the actin and myosin proteins irreversibly cross-link after the circulatory system is lost during the slaughter process;
* *Before rigor = Muscle; After rigor = Meat
82
How long does Rigor take?
- Rigor is resolved when enzymes (proteases) break down the protein structure.
- Beef – ~ 2.5 hours after slaughter → takes about 24hrs to complete;
- Poultry, lamb and chicken – ~ 1hr.
* *Don’t want to cook the meat before this time, or during rigor;
83
What is Cold Shortening?
- Occurs when meat is chilled too rapidly after slaughter, especially in carcasses with little external fat;
- Results in a tougher meat product;
- Can be alleviated to a certain extent by electrical stimulation of the carcass prior to chilling, which is practiced in some packing plants.
84
What is Thaw Rigor?
-Occurs when meat is frozen prior to the resolution of rigor and also results in tougher meat products.
85
What is PSE?
Pale, Soft, Exudative =
- Primarily in PORK;
- Due to a rapid decline in post-mortem pH, which results in a deterioration in the protein causing it to bind less water.
- Thought to be due to stress susceptible animals, said to have Porcine Stress Syndrome (PSS).
86
What is Meat Processing?
- Refers to any alteration in the meat from its original form, including reduction of carcasses into retail cuts;
- May involve mechanical, chemical or enzymatic manipulations (including fermentation by microorganisms)
87
What is Canning for Meats?
- Preserving meat (shelf-stable) by placing it in a hermetically sealed can and heating it sufficiently to kill all but the most heat resistant microorganisms;
- Canned ham, spam, etc. → Can last up to 2 years.
88
What Chemical Additives can be used in Meat Processing?
1. Antioxidants (ascorbic acid) - reduce oxidation
2. Curing salts (nitrate and nitrite) - kill microorganisms and produce characteristic flavor and color.
3. SALT is common in a variety of meat products for flavor and texture.
4. Plant proteases (e.g. papain from papaya) can be used to tenderize tougher cuts of meat.
89
What is Cold Storage of meat?
-Refers to BOTH refrigeration and frozen storage, both of which REDUCE the growth of microorganisms and slow chemical reactions.
90
What is Refrigeration?
* 0-4C;
| - Provides a shelf-life of about 5 days and prevents most pathogenic microbial growth (except Listeria).
91
What is Frozen Storage?
* *-18C;
- Provides from 3 to 12 month shelf-life depending on the product;
- Ground meat and sausage for the shorter periods, whole muscle products for longer;
- More rapid freezing improves quality b/c smaller ice crystals formed;
- When products thaw, the liquid lost is called PURGE;
- Reduced and ultimate quality is retained through SLOW thawing.
92
What are the frozen storage times?
- Beef – 12 months;
- Pork – 6 months;
- Sausage and ground beef – 2 months
93
What is Comminution?
- Meat particle size reduction.;
- Involves finely chopping the meat and fat to allow emulsion formation;
- Other comminuted products include hamburger, surimi (deboned and washed fish protein paste), etc;
- MSM = mechanically separeated meat
94
What is MSM?
- Mechanically separated meat → mechanically separated paste-like substance;
- Used especially in mass-produced chicken nuggets
95
What is Curing of Meat?
- Addition of salt, sugar, nitrites, etc. for flavor, texture, and food safety enhancement;
- Dry curing or Brining
96
What is Dry Curing?
- Dry curing agents are rubbed onto the surface of the meat;
| - The natural juices solublize and allows for its distribution into the meat.
97
What is Brining?
- More typical approach in commercial curing is to use BRINE;
- Curing agents solubilized in liquid, which is injected into the meat.
98
What is Drying of Meat?
-Perhaps the OLDEST form of processed meat in the form of sun-dried meats (jerky), done to preserve meat, but also for characteristic quality attributes.
99
What is Freeze Drying of Meat?
- Modern development in meat drying;
- Involves the sublimation of water vapor from frozen products under a vacuum and low heat;
- Reduces the quality changes due to drying and upon rehydration the original quality of the meat is obtained.
100
What is Fermentation of Meat?
-Introduction of BACTERIA to obtain characteristic flavor and texture and preservation due to REDUCED moisture levels and pH caused by microbial growth;
EX: Dry sausages such as pepperoni and summer sausage.
101
What is Irradiation of Meat?
- Also called cold pasteurization;
- Exposure of meat packaged with a HERMETIC SEAL to ionizing radiation.;
- Produces extremely long shelf-stable products with very little deterioration of quality;
- Controversial because of issues related to the use of ionizing irradiation.
102
What is Restructuring of Meat?
- Turning comminuted meat products into products that resemble whole muscle products;
- Achieved by addition of additives (salt, phosphate, binders), mixing and cooking. → Add butter, bread, shape and fry;
- The best examples are canned ham and Chicken McNuggets™
103
What is Smoking of Meat?
- Originally intended as a preservative method;
- Today it is used more to obtain the smoky flavor and appearance;
- Can be done using natural wood generated smoke, or more commonly with liquid smoke formulation that are spayed onto the product.
104
What is Vacuum Packaging of Meat?
- Eliminating the air in packages shelf-life can be extended;
- REDUCING aerobic microbial growth;
- REDUCING oxidation reactions;
- Removes all oxygen and prevents bacterial growth
- EX: deli meats either come in MAP or vacuum packing
105
How is FISH different than Red Meat?
- Fish muscles are similar to red meat, except that they tend to be lower in connective tissue and higher in polyunsaturated lipid;
- Fish tend to be MORE susceptible to bacterial spoilage because their typical pH is higher than red meat species.
* *Trimethylamine
106
What is the most important factor to Fish Processing?
- RAPID CHILLING immediately upon harvest;
- Most fish (>40%) is marketed FRESH, but it can also be processed in most of the ways described for red meats.;
- Cured fish, such as salted fish (kippers) and smoked salmon are popular specialty fish products.
107
What are the modern methods of fish processing?
Modern processing of fish includes the production of various styles of fish sticks, and surimi (imitation crab meat);
* *SURIMI = minced, washed fish protein that can be formed;
- Meat is removed from the bone, heat treated, made into a paste and then shaped
- Cyroprotectants such as sorbitol must be added to surimi to stabilize its texture during frozen storage
108
What is the difference between poultry and red meat processing?
- Primary difference b/w poultry and red meat is a higher content of WHITE muscle, due to LOWER levels of myoglobin;
- Less saturated fat → Will last longer in the freezer than red meat;
- Most poultry is marketed as fresh product, either as whole birds, or cut-up pieces;
- Has increased in the market in the recent years due to the belief it is healthier than red meat
109
What is Processing for fats/oils?
-Extraction of lipid from food materials.
110
What is Refining for fats/oils?
- Removal of impurities from extracted lipid → Makes more stable and protects from oxidation;
- Crude oil is the INITIAL extract;
- RBD oil - oil that has been refined, bleached and deodorized.
111
What is involved in a SOLVENT EXTRACTION of oilseeds?
Cleaning, grinding, steaming, flaking;
- Extraction with solvent, separating meal from oil-solvent solution (miscella);
- Removal of solvent from meal and miscella;
- Refining oil;
- Roasting/grinding/pelletizing the meal for other food or feed applications.
112
What is Rendering of fats?
melting lipids from animal fat
113
What is Pressing of fats?
squeezing oil from oil seeds
114
What is Solvent Extraction of fats?
use of organic solvents (e.g. hexane) to SOLUBLIZE lipid
115
What is Deodorization of fats?
- Use of STEAM to strip away LMW (low molecular weight) volatile odor compounds;
- LMW – give aromas to things
116
What is Degumming of fats?
removal of phospholipids with HOT WATER
117
What is Neutralization of fats?
removes free fatty acids with ALKALI solution
118
What is Bleaching of fats?
removes COLORED substances (carotenoids, chlorophyll) using diatomaceous earth
119
What is Hydrogenation of fats?
- SATURATION of double bonds;
- Stabilizes unsaturated fats;
- Creates TRANS FATS
120
What is Winterization of fats?
removal of high melting point lipid with cold tempering/centrifugation
121
What is Plasticizing of fats?
tempering hard fats to produce more pliable fats through crystal rearrangement
122
What is Mono/Diglyceride production of fats?
- Controlled hydrolysis of triglycerides to produce EMULSIFIERS;
- TAGS → DAGs → MAGs;
- Breakdown catalyzed by heat, NaOH catalyst
123
What is Fractionation of fats?
-Used to prepare butterfat fractions of differing melting points with greater spreadability direct from the refrigerator.
124
What is Interesterification of fats?
- Controlled REARRANGEMENT of fatty acids on triglycerides in order to improve the crystalline structure of fats;
- Produces smoother, creamier solid fats (e.g. lard).
125
What are the TESTS for fats?
1. Iodine value
2. Peroxide value
3. Acid value
4. Saponification value
5. Smoke point
126
What is Iodine Value of fats?
- Indication of UNSATURATION;
- High Iodine value = High unsaturation;
- Expressed as grams I2/100g of fat;
- Uses K1 Potassium Iodine
127
What is Peroxide Value of fats?
- Indication of LIPID OXIDATION;
| - High Peroxide Value = More Oxidation
128
What is Acid Value of fats?
-Indication of FREE fatty acids
129
What is Saponification Value of fats?
-Indication of the AVERAGE LENGTH of fatty acid carbon chains
130
What is Smoke Point of fats?
- Temperature at which heated oil begins to smoke;
| - An indication of frying oil stability
131
Where can Sugar be be harvested from?
- Two plants contain high concentrations:
1. Sugar BEETS from temperate climates
2. Sugar CANE from tropical climates.
132
What is Sucrose?
- Sucrose in sugar CANE deteriorates rapidly after harvest;
| - Sucrose in the sugar BEET is stable after harvest is processed in one step to refined sugar → Most stable!
133
What is the EXTRACTION process of Sugar?
- Harvest cane, clean, chop, extract by milling (pressing), clarify, evaporate to syrup, crystallize sugar, separate and dry crystals;
- Blackstrap molasses is a byproduct of the process (syrup from which no more sugar can be removed economically).
134
What is Neutralization and Clarification of Sugar?
- Use of LIME to neutralize the cane juice;
- Used to use egg whites or blood;
- Necessary to PREVENT the hydrolysis of sucrose (to invert sugar), which reduces yield;
- CLARIFICATION occurs in heated clarification vessel to yield clear juice.
135
What is Concentration and Crystallization of Sugar?
- Water is driven off in evaporators;
| - Cause supersaturated sugar solution (mother liquor) which is seeded with sugar crystals to produce crystallization
136
What is Separation and Drying of Sugar?
- Crystals and mother liquor are SEPARATED using centrifuges;
- Can be done several time until clean as possible;
- Sugar crystals are washed with water to help remove residual syrup;
- Washed sugar is dried to obtain RAW sugar.
137
What is Refining of Sugar?
- Raw sugar is typically further refined in the consuming country to produce white granular sugar, along with other sugar products such as confection sugar, brown sugar, etc;
- Brown sugar is made by the removal of molasses to refine and then add it back
138
What is Potable water?
* Drinking;
- water bottled with no other ingredients (except antimicrobial agents such as chlorine).;
- Bottled water – generally refers to natural mineral waters, carbonated or flavored water that is bottled;
- Purposes of bottled water processing are:
1. To ensure safety
2. To preserve properties of the water (flavor, mineral content).
139
What is used to bottle water?
-Ozone (O3) is used to reduce microbial contamination because it is a potent germicide and does not leave a residual taste;
-Ozone lyses the bacteria, it turns into oxygen so it won’t affect the food or change the flavor;
-Bottled water is generally sanitized and packaged in glass or plastic bottles.;
Flavored or carbonated water would be mixed with sanitized water, and then further pasteurized.
140
What are Carbonated Beverages?
- Originally an attempt to simulate naturally effervescent waters common in European spas;
- Eventually included sweetening and flavoring to obtain soda pop;
- Early versions included mind altering substances such as codeine, cocaine heroin, and still often contains caffeine.;
- Coca-Cola (cocaine from coca leaf and caffeine from Kola nut) was originally marketed as a cure-all tonic.
141
How does water quality affect cokes?
- Critical to the production of carbonated beverages;
| - Cleaned up using filtrations systems and superchlorination to remove all microorganisms.
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What is Carbonation?
- Supersaturation of CO2 gas in water using solid or liquid forms of CO2 in chilled carbonators.;
- Soda water is then mixed with mixtures of flavoring agents (syrups) to produce the soda pop.
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What are the special beverage categories?
1. Noncarbonated beverages:
- Many of the same ingredients.
- PASTEURIZED because they lack the bactericidal effect of the carbonation.
2. Powdered Soft Drinks = Dried with or without sweetener for reconstitution with water prior to consumption.
3. Neutraceutical beverages = special functional ingredients to promote health
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What are Cereal Grains?
Any grain used for foods
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What is Milling?
- Primary process of converting the grain into food products or ingredients;
- Can be done in a variety of ways depending on the grain and desired products =
- _____________ is typically dry milled by grinding into a flour;
- CORN can be wet or dry milled;
- _____________ is not ground but its outer layers (husk and bran) are removed by a abrasion leaving the starchy endosperm.
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How is WHEAT classified?
By PROTEIN content of the grain (hard or soft).;
- HARD wheat has a higher protein content, which results in more strong, elastic gluten formation during processing (e.g. baking).
- SOFT has a lower protein content and are ideal for cakes/biscuits.;
- Pasta is made from Durum wheat (_____________) that is very hard and produces tough inelastic dough.
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What is involved in the Milling of Wheat
- a series of grinding and sifting steps that break the grain into ever more finely ground fractions;
- Resulting flour is usually bleached and aged to obtain maximum functionality.
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How is BREAD made?
- Flour and water is mixed with salt, yeast, and other ingredients, a dough is formed that can be baked into bread.
- High quality dough is both EXTENSIBLE (will stretch when pulled) and ELASTIC in order to hold the gas that is produced during the yeast fermentation.
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What is the QUALITY of the dough dependent upon?
The quality of the dough is dependent on the formation of GLUTEN .
= Protein complex made up of the proteins GLIADIN and GLUTENIN;
-Gliadin is important for _____________, while glutenin for _____________.
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What is Yeast fermentation?
- Alcohol and CO2 produced;
- CO2 bubbles form around yeast cells;
- Expand during baking;
- 115F – yeast DIE;
- 140F – Starch granules begin to SWELL;
- 167F – Enzymes denature, sugars begin to brown
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What is critical to good crumb production in bread?
Proper mixing (KNEADING) is critical to proper dough formation, followed by FERMENTING (rising), proofing, molding or sheeting, and baking, which sets the protein structure that produces the crumb (texture).
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What are the challenges with making WHOLE WHEAT bread?
- Presence of bran = problems with gluten development;
- Imparts bitter flavor
* How do we fix this?
- Soak the whole wheat flour (8 – 24 hours);
- Dulls bran’s hard edges;
- Activates enzymes that convert starches to sugars
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What are Breakfast Cereals?
- Today, breakfast cereals represent a wide range of products that are made from a variety of cereal grains;
- Either ready to eat or require cooking;
- Types of RTE cereal: muesli, flakes, granola, puffed rice or corn, puffed wheat, baked, extruded.
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What are Alimnetary Pastes?
- Cooked and dried alimentary pastes (pasta products) that include macaroni, egg noodles, etc.;
- Often produced from SEMOLINA FLOUR, which produces a strong inelastic dough;
- Ingredients are mixed, dough is kneaded and allowed to rest.;
- Extruded into appropriate shapes and dried for marketing purposes.
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What are the steps in Pasta Processing?
1. Semolina flour and water;
2. Vacuum mixing;
3. Alimentary pastes (pasta dough);
4. Extruding;
5. Long noodle strands;
6. Cutting into foot-long strips;
7. Drying;
8. Cooling;
9. Packaging;
10. Dried spaghetti
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What are the types of Potato Chips?
Potato chip were probably the first commercially produced savory snack.
- Regular potato chips – HIGH Temp → Want high temp-cooks so fast so starches in potatoes do not gelatinized ;
- Kettle cooked potato chips – LOWER temps, cooked in batches → With kettle there is gelatin formation
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How are Snack Foods made?
generally produced from cereal flour dough that are extruded, puffed, fried, and seasoned to obtain the desired sensory properties
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How does ripening of fruits determine harvesting?
1. CLIMATERIC fruits and vegetables will continue to ripen after harvest → can be harvested while mature and will ripen over time even when not on plant
Ex: Apple, banana
2. NON-CLIMACTERIC fruits and vegetables DO NOT ripe after harvest, so it is best to harvest these plants at MAX ripeness. → DO NOT store sugars as starches
-Not getting sweeter and enzymes start to soften cell structure and cause more aromas which makes it seem like it taste better
Ex: Strawberries, grapes
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What continues after harvest for fruit and veggies?
-Fruits and vegetables continue to respire after they are harvested;
-Transpiration (moisture loss through pores in tissue) also occurs;
Life Cycle=
1. Growth - inedible.
2. Ripening - highly edible
3. Senescence - over-ripe, and essentially inedible again
