Food Science Nutrition 08/19/2013
Dr. Clark Facts
PhD in Animal Science with emphasis in Meat Science
Colorado State University.
REVIEW THE BONUS QUESTIONS BEFORE EACH EXAM!!! Food Science Nutrition 08/19/2013
Chapter 1: Food Safety
Food Science is the scientific study of raw food materials and their behavior during formulation, processing,
packing, storage and evaluation as consumer food products.
Nutrition is the science of food the nutrients and other substances therein.
Areas of food science:
Spewing, Cramps, Raw Cookie Dough
Brian & Carlos
Food bar, 3 hours, vomiting
Coma Kidney failure, sprouts
Food Poisoning Statistics
Illness – 76 Million people
Hospitalizations – 325,000
Deaths – 5,000 Food Science Nutrition 08/19/2013
The Numbers to Change from year to year.
Food in the News
The American food supply is the safest in the world
Media Covers outbreaks all the time
Peanut butter, hamburger, spinach
Why does this contradiction exist?
Bacteria don’t read laws and regulations
It is not good enough yet
Any Food that makes us sick when we eat it
Presence of Harmful Microbes
Presence of Natural toxicants
Presence of environmental contaminants
Presence of harmful additives
Presence of allergens.
Fresh Foods contain more harmful microbes than processed products.
Feces (insect, rodent and bird droppings plus organic fertilizers) Food Science Nutrition 08/19/2013
Rank The Dangers
Canned tuna fish
Unpasteurized orange juice
Microbes Associated with food Disease and Death
Methods to limit Microbes
Spoiled Food is not pleasant to eat, but it is not necessarily unsafe.
Not all food that is unsafe may show signs of spoilage Food Science Nutrition 08/19/2013
The common factor between spoiled and unsafe foods is usually microbes
Control of handling and storage is needed.
The expiration date represents the best guess on how long the food will last before it spoils
Expiration dates are set based on quality factors (not safety) and are useless if products are not properly
handled and stored.
Food Poisoning is a sickness caused by consuming a contaminated food
Nausea, vomiting, diarrhea, cramps
Dizziness, dehydration, coma, death
The last meal consumed is not the usual vector in food poisoning.
Infection vs Intoxication*
Infections require the consumption of viable microbes that grow and produce symptoms typical for an
Intoxications occur after consumption of foods in which microbes have produced a toxin.
Tracking Down the Culprits
Epidemiologists are scientists who track the cause of an outbreak
An outbreak occurs when more than one unrelated individual contracts a foodborne illness
Samples of patient’s feces are tested along with residual food samples to find matches and trace to the
source. Food Science Nutrition 08/19/2013
Fresh foods are more likely to contain harmful microbes than commercially processed products
Food preservation involves reducing the chances that food will spoil or become unsafe.
Methods of Food Preservation
Preservatives are food ingredients that slow spoilage and prevent food borne illness
Salt and sugar are common examples
Food additives serve a useful purpose and must be effective for the intended use
They are required by law to be safe.
Safety of the American Food Supply
The public is becoming aware of dangers associated with foods
Causes of illnesses
Recent Changes Noted in the Food Industry Food Science Nutrition 08/19/2013
New and newly identified microbes
Greater reliance on imported foods
Less knowledge by food prepares
Centralization of food processing
Improved sanitation may reduce immunity.
Safety in the Home
Responsibility for food safety starts with production and ends with the consumer
The least controlled step is whenever consumers handle and prepare food.
Would the Health Department shut you down?
Frequent Factors in Food Poisoning*
Improper storage temperature
Poor personal hygiene
Food from unsafe sources.
Simple rules for food handling
Keep hot food hot and cold food cold.
DANGER ZONE: 40 to 140 degrees F
Rule 2 Food Science Nutrition 08/19/2013
When in doubt, throw it out.
Transfer hot leftovers to a clean, shallow container and refrigerate immediately.
Pesticides and Other Contaminants
Pesticides are chemicals applied to crops to kill pest.
They are designed to break down to less harmful levels and residue levels are monitored in raw processed
Organic Food Production
Organic production avoids the use of fossil fuels and synthetic chemicals.
Proper composting of animal waste (for natural fertilizer) should kill harmful microbes
Contaminated irrigation water is a leading source of microbial problems.
Organic Product Characteristics
Desired by many consumers
Often cost more
Have a shorter shelf life
May not look as attractive
May be less safe than products grown with pesticides.
Natural chemicals and products are not necessarily superior to artificial or processed products
Artificial chemicals are indistinguishable from natural compounds
Natural extracts are less pure synthetics and some impurities may be toxic. Food Science Nutrition 08/19/2013
Natural Toxin Examples
Mushrooms – hydrazine
Cabbage – thiocyanate
Nutmeg – myrsticin
Sassafras – saffrole
Cassava – glucoside
Allergies and Food Sensitivities
Food Allergens induce an abnormal immune response in susceptible individuals.
Gastroenteritis, anaphylactic shock.
Sensitivities (aka atopic responses are not true allergies but symptoms are similar and unpleasant)
Sulfites, MSG, Lactose
Allergens of Major Concerns
All of these allergens (if present) must be declared on processes foods that are FDAregulated. Food Science Nutrition 08/19/2013
A number of rules and regulations will be covered in this semester
Key agencies with responsibility for the safety of the food supply are:
US Food and Drug Administration (FDA)
Center for Food Safety and Nutrition (CFSAN)
US Department of Agriculture
Food Safety and Inspection Service (FSIS)
Inspects food processing facilities
Prohibits distribution adulterated or misbranded foods
Approves processing methods.
Establishes Good Manufacturing Practices (GMP)
Approves food additives
Regulates label content.
Regulates all meat and poultry plants that distribute products interstate or internationally
Inspects every carcass
Requires a Hazard Analysis and Critical Control Point system (HACCP) for food safety hazards
Environmental Protection Agency (EPA) regulates pesticides applied to foods
State (and local) health departments inspect restaurants, institutions and retailers according to the food
Centers for Disease Control and prevention (CDC) investigates foodborne illness outbreaks. Food Pathogens 08/19/2013
Foodborne Disease by Microorganisms Food Pathogens 08/19/2013
By products, or the whole organism, once ingested, cause human illness.
Two principal types
Intoxication – a toxin is formed by the microorganism prior to ingestion
Infection – the live microorganism must be ingested to cause disease
Note – These pathogens do not necessarily cause the food to look or smell spoiled.
40140 degrees F
Chronically ill – AIDS
Pregnant and neonatal
Shingella Food Pathogens 08/19/2013
Commonly called “foodhandlers” disease
Associated with skin and nose of humans
Produces a heat stable toxin
Problem with improperly cooled and reheated leftovers
Fairly Intense GI effects
Cause of botulism (ptomaine poisoning)
Central nervous system effects
Most toxic protein known
Easily inactivated by heat
Requires anaerobic environment for toxin production
Vacuum packaged fish
Garlic in oil.
Associated with soil
Caouses “wound botulism”
With honey – infant botulism
Wrinkle remover – BoTox treatments
Controlling C. bot.
pH <4.6 Food Pathogens 08/19/2013
Temperature <10 degrees C for most foods, <5C for fish
Salt >15% alone, combined with other factors may be as low as 5%
Report processing – required for commercial sterility of low acid canned foods.
Major cause of diarrhea in the world
20% of cases become lifethreatening
Gerally associated with poultry
Wimpy bug – easily controlled with sanitation and cooking.
Also an intestinal microorganism, thousands of species
Usually transmitted by crosscontamination of the ‘fecaloral’ route
Major reported cause of food borne illness in the US
A cold tolerant group of bugs, usually associated with water and marine environments
Part of the ‘coliform’ group of bacteria
Associated with the lower intestine of warm blooded animals and some insects
Normally intestinal flora for most humans
Used and an indicator organism Food Pathogens 08/19/2013
Now many subspecies known to cause gastrointestinal symptoms.
E. coli 0157:H7
Normal components of the intestinal flora of ruminant animals, wild animals?
0157:H7 – a particular subspecies that causes infections in humans (there are at least three others) “new”
in 1988 from Canada
Causes bloody diarrhea and kidney failure (HUS)
Cold and acid resistant
Very low dose required
Heat to >160 degrees F to kill.
Shigella ToxinProducing E. coli
Aka verocytotoxin – producing E. coli (VTEC)
Causes flulike symptoms, miscarriages and postnasal sepsis
Associated with many foods.
Very cold and processing tolerant – grows at refrigeration temperatures
Very low infection dose.
Mycotoxins – general term
Most are acutely toxic, but may also have chronic effects
Aflatoxin – peanuts and other sored commodities Food Pathogens 08/19/2013
Ergot alkaloids – central nervous systems
Mushrooms – GI symptoms and neurological distress
Cigutera – GI
Puffer fish – paralysis leading to death
Scombroid – a giant allergic reaction
Other seafood toxins – GI and CNS symptoms
Toxoplasma – kitty litter, causes birth defects
Trchinella – garbage eating animals
Cryptosporidium – contaminated water
Cyclospora – raspberries (water)
Giardia – water.
Long incubation period (15 to 30 days)
Norwalk and other viruses
24 hour “flu”
No evidence of foodborne transmission
The Take Home Message
Wash your hands
Keep Hot food Hot and Cold food Cold.
Keep foods and food handling areas clean
Take special care with special people. Healthiness of Foods 08/19/2013
Scenarios Healthiness of Foods 08/19/2013
Weight gain, latest diet
Working out, powders and supplements
High caloric intake, no activity
Strict vegetarian, weight loss
Healthy and Unhealthy Foods
Carrot, whole wheat bread, yogurt
Colas, pizza, hamburgers, fries.
Good nutrition involves getting proper nutrients without too many calories
Dieticians and food scientists may differ on getting consumers to eat a healthy diet.
Macronutients are needed in the largest amounts and include carbohydrates, lipids and proteins
Micronutrients are needed in lesser amounts and include vitamins and minerals
Malutrition implies an imbalance results in poor nutrition and health.
Weight loss Without Pain
Freshman fifteen and weight control Healthiness of Foods 08/19/2013
Ads and marketing often push weight loss with empty promises
Counting calories is effective for monitoring food intake and requires knowledge of food composition.
See the chart on the slideshow
Low Carbohydrate and High Protein Diet
The Atkins Diet is an example where the body uses proteins and fats for energy
Low carb diets can lead to imbalances
High Protein leads to excess urea in urine and possible kidney failure
Ketosis is a result of low blood sugar and may result in brain damage.
Reducing fat intake is a way to reduce calories
Eliminating fats is unhealthy
Selecting lower fat versions is possible
Substituting carbs or protein may work
Scientists have developed some fake fats
Challenges faced by replacement are taste, texture and digestive problems.
The MyPyramid is educational material to help consumers desdign a healthy diet.
Natural, Organic, & Whole Foods Healthiness of Foods 08/19/2013
Commercially packaged foods are not necessarily less safe or less nutritious than simpler alternatives
Safety and nutritive value is a function of production, handling, storage and preparation
Processing may change some products but offer other advantages.
Natural foods may refer to items that can be found in nature
Fresh vegetables, spices, venison
There is an implication that manmade foods are not nutritious (but they may have good nutritive value)
Canned corn, bread, juices
Snack cakes, nutritional bars, frozen pizza.
Organic Food Production aims to minimize the use of fossil fuels and synthetic chemicals
Organic meats come from animals that meet certain production requirements
No synthetic growth hormones
No pesticidetreated feed
Whole foods are readily identifiable by their original components
Milk, fresh vegetables, processed fruits, ground meats
Lowfat, diet foods, or fortified items are not considered whole foods but may be both nutritious and safe.
Cancer is not linked to a specific deficiency or single carcinogen Healthiness of Foods 08/19/2013
Diet may increase or decrease risk
High fat food smoked foods, alcohol
Dietary fibers, antioxidant vitamins
The cause, treatment, and prevention of cancer is not as clear as malnutriotion
Other Chronic Diseases
Over consumption of fatty foods and sugars may increase the risks
Linkage between the cause treatment and prevention is not clear
Heart disease, diabetes, and obesity significant problems for a portion of the population
Dietary supplements are substances to supply a need or reinforce one’s diet
Typical vitamin or mineral pills
Special circumstances like pregnancy may require supplementation
Nutraceuticals are foods designed to like drugs
Green Tea extracts
Conjugated linoleic acid
Functional Foods Healthiness of Foods 08/19/2013
Functional foods are those which contain ingredients marketed to perform a specific function
Fortified cereals, beverages, juices
Ketchup, wine, snack bars
Enhancing Athletic Performance
Athletes require additional calories or risk losing weight and strength
Without exertion and exercise, calorie, reduction is necessary to prevent weight gain
Ideal diets for athletes contain 6070% of calories from carbs
2530% from fats and 1015% from protein
Fasting is the voluntary avoidance of solid food intake for personal or religious reasons
Extended fasting or involuntary starvation can lead to health problems
Low blood glucose
Serious eating disorders may occur when peer pressure clashes with biological needs
A diverse and balanced diet is ideal for most people
Some individuals have special dietary needs but food fads may result in malnutrition Healthiness of Foods 08/19/2013
Brightly colored foods
Supplements for intelligence or alertness
Water us a major component in may foods
Caffeine and alcohol are diuretics so beverages with these components are not useful for daily needs
Water Content of some foods and Beverages
Flour 1020 %
Whole Milk 87%
Energy from Foods
Energy sources in foods include carbs, proteins, and fats
Vitamins and minerals are also important micronutrients
Dietary fibers should not be overlooked for adding bulk to diet
One calorie equals the amount of energy required to raise one
One kilcalories Healthiness of Foods 08/19/2013
Carbs 4 kcal/g
Proteins 4 kcal/g
Fats 9 kcal/g
Alcohol 7 kcal/g
Food Labels and Nutrition
The Nutrition Labeling and Education Act of 1990 revised the layout and content to focus on calories and
micronutrients contributing to chronic diseases
Key Label Components
Principal display panel
Brand name of product, net weight
Handling or preparation instructions
Required on all processed foods unless exempt
Not required on whole foods but information Choosing the Food We Eat 08/19/2013
Food Choice Reasons Choosing the Food We Eat 08/19/2013
Spoiled foods are not always unsafe and unspoiled foods are not always safe
Proper cooking rinsing storage and sanitary practices related to foods decrease the chances of becoming ill
The fundamental function of foods is provide energy and nutrients for maintaining good health
Fasting, counting calories, avoiding, certain foods, taking appetite suppressants or supplements excersing
A sensible exercise program with a sound diet is the most effective and healthiest way to lose weight
Approximately 3,500 calories corresponds to a pound of body weight
Kosher Laws specify the types of animals that are permissible and forbidden, forbid the consumption of
blood, and forbid the consumption of meat and diary products in the same meal
Halal Laws also refer to permitted foods and are similar to Kosher laws
Locusts, shrimps, and lobster are halal and there is no requirement to separate meat from dairy products
Ethnicity Choosing the Food We Eat 08/19/2013
Food is an integral part of cultural heritage
Staples and specialty foods represent availability of local items
Advertising is directed at communicating to first advisors or influential individuals like Isaac
Endorsement by these key individuals like issac
Time and Trends
Diets have changed in generation
Tech has changed the food supply
People are generally sedentary
More meals are consumed away from home
Variety is much greater today
While food consumes about 12% of the average US household income, budgeting is still important
Splurging early in the month may result in only noodles at the end
Bulk Purchases may be less expensive per unit but only if there is no waste.
Diets are influenced by personal beliefs
Kyle may eat organic foods or those with less packaging and processing for many reasons
Color, flavor and texture are properties of foods that affect what we eat
Purchases decisions are often based on appearance of the product
Flavor is a combination of taste and smell
Texture problems lead to rejection of many foods. Choosing the Food We Eat 08/19/2013
Sound (E.g. crunch) is also a property.
People’s lives often revolve around finding, preparing and consuming good.
The availability of food in the US is vastly different from the “huntergatherer” days.
Forms of Convenience ***
Packaged foods in portions or single servings are often microwavable
Speedscratch refers to packaged items (e.g.) cake mix) that combine the essential ingredients but allow
the consumer to prepare the food.
Quick meals are readily available at ubiquitous fastfood restaurants
Speed is attained by various methods
Drivethru, multiple cashiers
Foods are Kept hot (safe) by
Made to order
Limited holding time
The antithesis to fastfood, slow foods are for those that reject convenience foods
The emphasis is placed on quality with the experience covering all stages from shopping, preparing and
enjoy the food.
Bad habits can affect health
An obsession with healthful eating is termed orthorexia nervosa and leads to the elimination of “bad” foods
and limiting the choices for “good” foods.
Selecting Healthy Foods
Most religious, ethnic and family traditions have healthy and unhealthy aspects
Economic, personal and political considerations may affect food choices
Moderation is an important value
Convenient foods aren’t all bad Processed Foods 08/19/2013
What are Processed Food? Processed Foods 08/19/2013
Processed foods are products that have been preserved so they will not spoil as quickly, whole foods.
Most raw materials are perishable and require processing to prevent loss.
Shelf Stable products are foods that may be kept at room temperature.
Why are they processed?
The primary reason is to reduce or eliminate harmful microbes
Another reason is to stop the loss of nutrients due to enzyme action
Benefits of Processing
Processed foods are more likely to be eaten
Shelf stable foods are ready when we are.
Loss of nutrients and quality is slower
Processed foods have less waste
Processed foods take more energy to produce, but use less energy to store.
Unit operations are distinct steps for converting raw materials into processed foods.
Examples of unit operations
Pumping Processed Foods 08/19/2013
Types of Processed Foods
Processed whole foods
Canned peas, corn oil, orange juice
Bread, jam, chocolates
Ice Cream, deli meats, margarine
Pizza, potato salad, food service
Cooking kills spoilage and pathogenic microbes but does not sterilize food
Blanching is a unit operation to inactivate enzymes
Pasteurization kills pathogens bt not all spoilage microbes
Canning sterilizes product in a container
Aseptic processing sterilized product prior to packaging.
Types of Microbes
Clostridium botulinum, Bacillus stearothermophilus
Cold Point Processed Foods 08/19/2013
Acidity of product
Conduction involves heat transfer through a material due to molecular movement
Convection involves heat transfer through movement of heated fluid from hot regions to cold
Conducted in a retort or pressure cooker.
The acidity or pH of a product affects the amount of heat treatment needed
Low acid foods are those with a pH greater than 4.6 and aw of .85 or more
Acid foods are those that have a natural pH of 4.6 or less
Acidified foods are low acid foods to which acids are added so the pH is 4.6 or less and aw of .85 or more.
Freezing is a mild treatment that results in less loss of nutrients and quality than heat treatment
Freezing slows the growth of microbes but does not kill them so there may be safety and spoilage problems
Forced (blast) air
Individual Quick Freeze (IQF)
Removing moisture reduces the ability for microbial growth
Even dry foods (flour) contain moisture
(1015%) Processed Foods 08/19/2013
Water Activity (aw) refers to water that is available for microbial growth
Moisture content is not the same as water activity
Sun or air
Removal of water from a liquid food without changing it into a solid is Concentration
Common example are juice concentrates and maple syrup.
Curing is another way to decrease availability of water by adding preservatives
Salt and sugar are the most common choices
Sodium nitrite and sodium nitrate are additional curing agents applied to cured meat products.
Cereal grains are milled into flour to improve digestibility
Dry milling separates the seed into fractions based on anatomical structure (bran, germ, endosperm)
Wet milling separates components on anatomical and solubility differences (protein, oil and starch)
Extracting involves the removal of a portion from the raw material
Coffee and tea are common examples
Other examples include juices oils and flavors. Processed Foods 08/19/2013
Oil Extraction and Processing steps
Pressing is the mechanical squeezing of oil from oilseeds
Deoderization is the application of steam in a vacuum to strip odorcausing low molecular weight
compounds from oils.
Bleaching is the removal of colored substances from the oil using diatomaceous earth clays at 194 degrees
Degumming is the removal of phospholipids by water at 122140 Degrees F
Hydrogenation is the process of saturating double bonds to increase the melting temperature of the oil
Interesterification is the rearrangement of fatty acids on the oil to affect its melting temperature
Oils and Fats
Fats are usually solid at room temperature
Oils are usually liquid at room pemerature
All food lipids are a mixture of triglycerides
Mixtures result in melting temperatures that are a range
The is one process that depends on the growth or microorganisms
A starter culture is added to a perishable raw material to change it into a more stable food product Processed Foods 08/19/2013
Lactic acid and ethanol are the main preservatives.
Beer and Wine
Irradiation is a potent killer of microbes and can be used for foods it induces little or no heat.
Radiation can be applied at high doses to sterilize a product or may be used at low doses (radurization) to
be the equivalent of pasteurization.
Gamma radiation from cobalt has great penetration capability but requires elaborate safety measures
Electronbeam radiation has less penetration capability but fewer health risks.
A forming technique whereby a material is forced by compression through a shaped opening in a die to
produce a continuous profile
A versatile energy efficient and economical means to produce a wide variety of products. Processed Foods 08/19/2013
Cereals are mostly extruded to produce snacks or pellets for feed.
Consequences of Processing
Shelf Life is the length of time that a product may be kept before is should be discarded
It is related to safety but it is most closely related to spoilage
Many processes are intended to increase shelf life by reducing or eliminating microbes.
Extension of shelf life may accompany a decrease in nutritional values of food.
Washing, drying, heating, exposure to light or oxygen are contributors to the loss of vitamins and mineral
Fresh (breakfast links)
Cooked and smoked (bologna)
The most basic steps include
Meat Processing Processed Foods 08/19/2013
Meat is edible animal flesh and includes red meat, poultry and seafood
Further processed products include many familiar items
Unit Operations for Hot Dogs
Chemical additives used for meat products are
Meat Curing ***
The combination of salt, sugar and nitrite added to meat is aka curing. Processed Foods 08/19/2013
Curing affects color, flavor, preservation and safety (clostridium botulinum)