Card Set Information
Protein efficiency ratio.
Gives an index of the nutritional value of a food.- determined by accounting for the % of the most limiting aa relative to a reference protein.
Used as a source of energy.
Nutrient CHO- sugars such as glucose and sucrose Glucose and fructose) and lactose (Galactose and glucose)
Starches, including dextrins (complex CHO)
Glycogen, the end product of CHO digestion. Glucose in the body
Glucose + oxygen--> energy + CO2 + water
Fiber, (bran- cellulose, hemicellulose, lignin)
Pectin- a structural CHO in fruits. Partly digestible. Holds water together. When fruit ripens, pectin breaks down.
Fats or Lipids
One gram of fat yields 9 kCal.
One gram of CHO yields 4 Kcal
CHOs and fats are interchangeable as fuel foods.
Saturated- no double bonds.
Solids at room temp or oils at rooms temp
Some fatty acids are essential - linoleic and linolenic acids
Often found in the form of triglycerides
glycerin + 3 fatty acids
Vitamins and minerals essential to the body.
There are water-soluble and fat-soluble (DEAK)
Micronutrients are used for enzymatic processes
(Calcium in blood clotting)
for aiding in tissue and organ maintenance
(Vitamin E for anti-oxidant protection)
and for proper functioning of organs and glands
(Iodine for the thyroid gland)
What are some of the diseases brought on by nutritional deficiency?
Scurvey- vitamin C- loss of teeth hemorrhagic skin
Rickets- vitamin D and calcium- weak bones distorted ribs
Pellagra- Niacin, B5- Skin rash, bloody diarrhea, mental disorder
Anemia- Iron- paleness of skin, short of breath, low hemoglobin
1 micrometer is size
Reproduce by binary fission- 1-->2-->4-->16
Rapid reproduction, dividing every 20 min
Some have ability to form spores (dormant form of organism, that have a coating similar to a seed) that are resistant to environmental stress
: freezing, radiation, acid
Spores will not grow in high acid or low water activity (Aw) conditions.
Some species are motile, while others are not.
Some species are considered beneficial- living on our body. We get ill when an imbalance occurs.
Some are pathogenic.
Acetobacter makes vinegar (not beneficial for wine makers though)
Salmonella makes you sick
Average size is 10X bigger than bacteria. from 1-10 micrometers.
Reproduce mostly by budding, fission or by spore formation
Some species produce spores, some do not. This can be sexual or asexual reproduction
Single celled or multicellular and Eukaryotic
Generally not heat resistant
More resistant to highly acidic or low water activity (Aw) conditions (Compared to bacteria and yeast)
Reproduce by sporulation, can be asexual or sexual
Strict Aerobes- require oxygen. Grow on surface of foods
Intrinsic Growth Parameters
Most microbes grow best at pH values around 7.0 which is neutral
Most fruit has lower pH than veggies thus molds tends to spoil fruit and bacteria spoil veggies
Some foods tend to resist changes in pH and are said to have buffering capacity
Adjustments in pH can help preserve food
Olives are basic, but we process them
Most food is acidic
Drying is one of the oldest preservation techniques where moisture as a nutrient is removed from food
Water requirements of MOs should be expressed in terms of water activity (Aw) in the food environment
The Aw of most fresh foods is above .99
Several preservation methods also change the Aw of the food:
Salting, adding sugar to fruit to make preserves, using additives or ingredients as humectants
Intermediate Moisture Foods (IMF)
Foods that are intermediate moisture range but have prolonged shelf-life because they contain water-binding agents, or humectants
Humectants- chemical compounds that bind to and absorb water consequently lowering the Aw. Ex
: Glycerol, sorbitol, other sugars, propylene glycol
Energy Source- sugars alcohols or amino acids
Nitrogen source- primary is amino acids (proteins)
Vitamins and related growth factors
Lactenin in fresh milk designated an anticoliform factor
Lactoperoxidase in raw milk effective against some streptococci
Lysozyme in egg white and tears
Benzoic acid in cranberries
Lipids and essential oils
Skin on fruit- prevents moisture loss and insect entry
Shell on nuts
Hides of animal
Outer shell and membranes of eggs
Extrinsic Growth Parameters
-Temperature of storage
Thermophilic range- 110-160 F optimum 131-151
Mesophilic range- 70-110 F optimum 95-98
Psychrophilic (Refridge) range- 45-86 F optimum 68- 77 F
- Relative Humidity of environment (High humidity= foods pick up moisture)
- Presence and concentration of gases (Packaging)
Occupational Safety and Health Administration
Microorganism Spoilage in Foods
MOs are interested in reproducing themselves.
Geometric progression is unlike enzymatic or oxidative spoliage which is linear because the reagents are fixed.
By-products are excreted from the MO cells where they can cause spoilage or perhaps a desired change
These by-products can accumulate rapidly bc of rapid growth
The growth requirements of MOs both intrinsic and extrinsic, determine what foods they are going to spoil
MOs can be beneficial by the by products they produce
Vitamins K and B produced by intestinal bacteria
Flavor compounds like diacetyl produced by lactic acid bacteria
Pigments like orange pigment produced by yeasts
Food fermentations can be processes that use MO to produce a desirable effect in foods.
is the metabolic process in which the CHOs and related compounds are oxidized with the release of energy in the absence of any external electron acceptors (O2) (anaerobically)
Growth of undesirable MOs
Phage (virus) Growth
Antibiotic or antimicrobic production
All can result in inhibition of the desired culture
Fermentations must be carried out under strict QC. Good sanitation is desired
Produces acid (lactic) or R-OH and gas (CO2)
EX bakery products, alcoholic beverages
produces only acid
EX yogurt, buttermilk
Several species of bacteria
other biological agents (Mad Cow)
Food Borne Illness
MO's cause food-borne illness
is a common term used to describe two types of food-caused sickness
occurs when MO's in the infected food grow and produce the toxin
onset of symptoms are usually quick 2-8 hours after ingestion
it is the toxin that gets you ill
: Staphylococcus, Clostridium botulinum, C. perfringens, bacillus cereus, Aflatoxin, shellfish poisoning.
Caused by the ingestion of sufficiently high numbers of a pathogenic MO. The MO invades cells.
The pathogen grows in the human body rather than in the food.
Onset of symptoms is usually longer than for food intoxication- 24 hours or more after ingestion
: Salmonella, Shigella, Escherichia, Yersinia, Campylobacter, Vibrio
Non spore forming, rod shaped, motile, facultative anaerobes
Not heat resistant
Optimum growth temp= 37 C, body temp
Growth range- 4-47 C
Usually ingestion of contaminated shellfish, eggs, milk, raw and cooked meats
Shigella - Shigellosis
Non-spore forming, rod shaped, non motile, facultative anaerobe, requires very few MOs for infection.
4 to 7 day on set
Associated with meats, shellfish, salads
Symptoms are similar to bad salmonella
Opportunistic pathogen = given the opportunity it can cause illness. most bacteria fall into this category.
Onset usually 24 hours after ingestion
Fatalities are rare
Mesophile with optimum temp= 37 C
Rare food infection
Cousin of the causative agent or etiological agent of bubonic plague- yersinia pestis
Organism is a psychrotroph and found in beef, oyster, mussels and river water
Associated with seafood or water, esp raw seafood. The sea animals are always filtering water and they pick up MOs and they build up.
Cholera comes mainly from contaminated water supplies and is endemic in mainland Asia and pacific rim
Mildly halophilic (loves salt), mesophilic, facultative anaerobe. Rod shaped, non spore forming
Usually infects children or elders
Affects the central nervous system- meningitis. May cause "flu-like" symptoms, spontaneous abortions, or infectious mononucleosis.
Very hardy; cold and salt tolerant.
50% of water samples (rivers, lakes, and estuaries in UK) tested have this MO.
Today, thought to be more predominant than salmonellosis or shigellosis.
Associated with raw clams, poultry, pork, beef, and raw milk.
Heat sensative, mesophilic and microaerophilic.
Sanitation in the Home
Meat, eggs, poultry, and fish should be held at safe temperatures avoiding the danger zone - 40-140 F
Use 50 ppm chlorine (hypochlorite) for sanitizing.
100ppm for critical areas
Center for Disease Control and Prevention
Center for Food Safety and Applied Nutrition
Morbidity and Mortality Weekly Report
Free of Pathogens
Hazard Analysis and Critical Control Point System
A system developed to ensure the safety of foods.
HACCP is widely accepted and recommend for all aspects of the food industry.
Currently HACCP is mandated as necessary for the seafood, meat, poultry and juice industries.
HACCP Seven Steps
-Asses the potential hazards
-Determine the CCPs where controls are necessary to eliminate or reduce hazards
- Establish requirements and parameters to be met at each CCP
- Establish procedures to monitor each CCP
- Establish corrective actions if a deviation occur at a CCP
- Establish procedures for verification that the HACCP plan is working effectively
- Establish record-keeping procedures
Estimated that there are 40-80 million cases of foodborne illness in the US each year.
$74,000 in expenses per case to recover from a foodborne illness.
Protein rich foods are the most common cause.
Salmonella (infection) and stapylococcal food poisoning are the most common.
People may be carriers of Staph on or in the nose throat and hands.
25% of the cases are caused by poor personal hygiene Heat leftovers and poultry to 165 F
Most Commonly Used FDA Approved Chemical Sanitizers
Hypochlorite- Chlorine 50 ppm, 10 seconds for sanitizing, corrosive to steel, aluminum, silver plate utensils.
Iodophor- Iodine 12.5 ppm, 30 seconds for sanitizing, noncorrosive, looses amber color as it weakens
Quarternary Ammonium, 200ppm, 30 seconds for sanitizing, noncorrosive
Food Regulation and Regulatory Agencies
It is a proper function of our govt to determine the wholesomeness and purity of a food protecting the consumer from economic fraud and health hazards.
Laws require a basic need for implementation and public support.
3 Regulatory agencies have enforcement authority:
- Food and Drug Administration (FDA)
- Meat Inspection Division*
- Meat Inspection Service *
* apart of the food safety inspection service (FSIS) and US Department of Agriculture (USDA)
United States Department of Agriculture
Food Safety Inspection Service
Hemolytic- Uremic Syndrome
Found in Ecoli Patients 0157
Food Drug and Cosmetic Act, 1938
Established the FDA as an agency
Covered most things except food additives
The Food Additives Amendment to the Food, Drug and Cosmetic Act
Includes the "Delany Clause" for carcinogenic materials.
Introduced "GRAS" status
Nutrition Labeling Education Act, 1990
Went into full effect in 1994
Food Allergen Consumer Protection Act
2004, but goes into effect in 2006
Said items such as soy, wheat, egg, peanuts, treenuts, shellfish, and dairy had to be on the labels
The Food Allergy and Anaphylaxis Network
A well recognized consumer education organization
International Food Information Council Foundation
Mission to communicate science-based information on food and safety and nutrition to health and nutrition professionals and others
A food is adultered if
It is filthy, putrid or decomposed
It is produced under unsanitary conditions
It contains any substance deleterious to health
Chemical- lead, pesticides
Biological- MOs, ecoli
Physical- wood, bone, fragments
A food is misbranded if
It has a standard of identity and fails to meet the standard
It is wrongly labeled
It fails to meet the standard for fill of container
Environmental Protection Agency
Authorizes and regulated the use of pesticides. Monitors compliance and provides technical assistance to states
All labels must bear:
-The name of the product
- Net contents (in both common and metric units) or net weight, including liquid
- Name and address of manufacturer, packer, or distributor
Many foods are covered by standards of identiy
- ice cream must have > 10% butterfat
All ingredients must be listed- in order from most predominant by weight to least.
Any additive, colorant, allergen, or protein hydrolysates must be listed
Foods containing juice require percentage of total juice.
a genetic recessive disorder where babies cant break down an amino acid called phenylalanine.
They grow out of it by adolescenc.
Enzymes catalyze chemical reactions
An enzyme reacts with a substrate but does not become part of the final product.
Enzymes are critical for life and cellular functions
All life depends on enzymes to convert food nutrients into a utilizable form
Enzymes are proteins.
Cofactors help the substrate reach the product
Has temp and pH optimum
-some enzymes are active at freezing temps
An enzyme may require a coenzyme or cofactor to function- this is the role of many micro nutrients
Enzymes are classified in several ways, one of which is by substrate. Proteases act on proteins ect....