Transcript Chapter 1: Animal Agriculture

Chapter 3: Animal Products
• Chapter overview:
– Chapter 3 reviews the history, availability, and
processing of animal products, including:
•
•
•
•
composition and contribution to the diet
trends in consumption of animal products
preservation and safety of food products
grading of animal products
Primary Nutritional Reason for
Consuming Animal Products: Protein
• Relatively high amounts of protein as
compared to grains and vegetables
• High biological value (quality) of animal
protein
– Good to excellent ratios of dietary essential
amino acids, such as lysine
Composition of Selected Products:
Product:
Protein, %
Fat, %
CHO, %
Beef round
20.2
12.3
0.5
Chicken
light meat
Whole milk
23.4
1.9
0.5
3.3
3.6
4.7
Eggs
12.1
11.2
1.2
Cod fish
17.6
0.3
0.5
Nutritional Concerns Expressed about
Animal Products:
• Amount of fat (caloric density) of animal
products
• Level of saturated fat in certain animal
products
• Concentration of cholesterol in animal
products
• Incidence of protein allergy and lactose
intolerance
FDA Required Labeling:
• Serving size and servings per container
• Per serving: total calories, calories from fat, and
grams of fat, protein, carbohydrate, fiber and
sugars
• Percentage of the RDA per serving for each of the
nutrients listed above plus: vitamins A, C, thiamin,
riboflavin, niacin, and minerals calcium and
phosphorus
Typical Methods of Food
Preservation:
• High temperature
– Pasteurization kills spoilage and pathogenic
organisms (1864 – Pasteur)
– Longer temperatures and times can sterilize
foods
• Low temperature
– Refrigeration or freezing inhibits microbial
growth
Typical Methods of Food
Preservation:
• Dehydration
– Air drying
• Chemical preservatives
– Inhibitors of organism growth such as salt,
sodium nitrite, and propionates
• Bactofugation
– Removing bacteria from liquids by
centrifugation
Typical Methods of Food
Preservation:
• Environmental preservation
– Sealed or evacuated containers, generally
linked to one of the treatment methods listed
• Low pH
– Fermentation or acid addition inhibits microbial
growth
• Irradiation (or cold sterilization)
– Use of low-level ionizing radiation doses to
pasteurize or sterilize
Food Safety Regulation:
• Who: Food Safety and Inspection Service
(FSIS) of the USDA maintains
responsibility for food labeling and safety
• How: Hazard Analysis and Critical Control
Points (HACCP) procedures and
performance standards
FSIS - Essential Elements of Control:
• All state and federally inspected food plants
must have an HACCP program
• Plants must have written sanitation standard
operating procedures (SSOP)
• FSIS uses Salmonella detection on raw red
meat and poultry as a control standard
• FSIS uses E. coli tests on carcasses as
verification of process control (fecal)
Steps in Developing an HACCP Plan:
• Identify potential hazards likely to cause illness or
injury
• Locate steps in the process where there is an
opportunity to prevent food contamination
• Set limits on the process that will ensure safety
• Monitor and measure the process and keep records
• Pre-establish corrective actions in case of a failure
Specific Meat Preservation
Techniques:
• Curing - coating, immersing, or injecting
meat with agents that preserve meat,
generally done now to impart desired
flavors; example agent: salt
• Smoking - combining smoke and heat to
destroy bacteria and dehydrate the product
surface
• Canning - thermal processing followed by
packaging in sealed containers (Appert)
Pasteurization of Eggs and Milk:
• Eggs for liquid sale (for example: to be used
in food service) are generally treated at 140
degrees F for 3.5 minutes
• Milk is generally pasteurized in an
automated flow system through a grid
maintained at 161 degrees F with a 15
second transit time
Grading Animal Products:
• Grades of animal products are based on
chemical, physical, and sensory
characteristics
• Grades are generally a quality guide to the
customer and not a direct indication of
safety
– For example: a quality grade of beef is derived
primarily based upon intramuscular fat content
Egg Grades and Grading:
• Grades are determined by evaluation of
internal and external quality of the egg
– Internal quality determined by “candling”
includes consideration of size of air cell, shape
of yolk, and absence of foreign bodies such as
meat or blood spots
– External quality includes shape, cleanliness,
and integrity of the shell
Egg Grades and Size:
• Grades are: AA, A, B, C
• Grade is independent of size
– Size categories are based upon weight per
dozen
– “Large” size eggs are are the most common in
the grocery store and weigh 24 ounces per
dozen
Grading Milk Products:
• Milk grading reflects a different evaluation
than meat, egg, or wool grading
• Milk grades do reflect the sanitary care
taken in on-farm production of the product
• Unlike other animal products, milk
producing farms are inspected regularly and
must comply with very specific UDSA code
Grading Milk Products:
• Farms in most US states produce milk for
either Grade A or B sale
• But, products manufactured from milk may
fall under a grading system that is separate
from the farm grade
– Fluid milk is graded A only
– Butter may be graded AA, A, or B
– Cheese may be graded AA, A, B, or C
Grading Meat Products:
• Carcass grades for red meat fall under two
differing grading systems:
– Yield or cutability grading: evaluating amount
of external and internal fat versus amount of
lean muscle; higher grades are generally leaner
– Quality grading: evaluating the intramuscular
fat quantity; higher grades are generally fatter
Meat “Safety” versus “Quality”:
• Inspection of meat products for
wholesomeness is mandatory
• Grading of meat products is
optional