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FoodPreservation
Chapter 13
Heat Treatments
1. Blanching – Heat to deactivate enzymes
2. Pasteurization – Heat to kill pathogenic bacteria
3. Sterilization – Heat to kill all bacteria and other organisms
Low Temperature
1. Refrigeration - < 40° F
2. Freezing - 0° F
Lowering Water Activity
1. Dehydration
2. Concentration
3. Salt
4. Addition of Sugar
Chemical Preservation
Food Additives
Food additives are any substitute that becomes
part of a food product
either directly or indirectly during processing, storing
or packaging.
Regulations on Food Additives
1. The Food and Drug Administration
2. 1938 Food Drug and Cosmetic Act
3. 1958 and 1960 Amendments
1. Delaney Clause
GRAS
Generally Recognized As Safe First established 700 placed on the
list without going through testing Now those substances are being
reevaluated Foods have been removed
What It Takes to Become A Food Additive
1. Prove additive is effective
2. Prove additive can be detected and measured in final products
3. Study the effects of the substance on animals (in large doses)
4. Submit results to validate the findings
5. Schedule a public hearing
6. FDA approves or rejects
Functions of Food Additives
1. Preservatives – Keep food fresh and reduce spoilage. Control bacteria, mold, fungi, and yeast.
Benzoates
BHT, BHA (antioxidants)
Calcium Propionate (inhibits molds)
Sodium Bisulfate
Sodium Nitrate
Functions of Food Additives
2. Processing Aids – Improve consistency, add stability, aid oil and water mixtures, and retain moisture
Gums (Algin, Carrageenan, Xanthan)
Aluminum Calcium Silicate
Benzoyol Peroxide
Functions of Food Additives
3. Nutrients – Maintain or improve the nutritional quality of food.
Alpha- tocopherol
Ascorbic Acid
Biotin
Beta Carotene
Calcium Pantothenate
Folic Acid
Functions of Food Additives
4. Flavors – Complement, magnify or modify the taste of aroma of a food
Aspartame
Corn Syrup
Ethyl Vanillin
Mannitol
Monosodium Glutamate
Functions of Food Additives
5. Colors –Give foods a desired, appetizing or characteristic color.
Carmel
Beta-apo-8-Carotenal (Orange)
Citrus Red
FD&C Blue No 1
FD&C Red No 3
FD&C Yellow No 5
Other Methods of Preservation
Controlled or Modified Atmosphere Storage and
Packaging 1. Modified Atmosphere (MA)
1. Nitrogen
2. CO2
2. Controlled Atmosphere (CA)
1. Vacuum Packaging
2. Shrink Wrapping
Irradiation
1. Pasteurization
2. Sterilization
Irradiation
kGy Food approved in the US
Pork Chicken Beef Fruits and Vegetables Grain
Many other foods approved in other countries
Irradiation Source
-
Irradiated Beef Patties
Purpose
To evaluate ordor, flavor, texture, and overall
acceptability of irradiated ground beef patties stored
over a six-week period
300-2.8 oz patties were blast frozenPacked 20 patties per Cryovac bagVacuum sealed Placed in a corrugated box and packed in dry ice Irradiated in Florida Dosimeter placed inside boxesStored at –18°C Sampled weekly for 6 weeks
Overall acceptability of irradiated ground beef patties
0 1 3 5 7 Dose (kGy)
Weeks
0 6.3 5.9 6.5 6.8 6.0
1 6.6 6.7 6.3 6.2 6.2
2 6.0 6.3 6.0 6.3 6.6
3 6.4 6.3 6.2 6.1 6.2
4 6.6 6.3 5.7 6.2 5.8
5 6.4 5.9 5.5 5.9 5.3
6 5.7 6.2 5.4 6.0 5.1 1 (=dislike
9 (=like)
Irradiated Strawberries
Materials and Methods
Fruit were irradiated at doses of
0, 0.25, 0.5, 0.75 and 1 Stored for periods of 0, 1, 3, 5, and 7
days at 2oC
ResultsAscorbic Acid
Ascorbic Acid
Day
0 2 4 6
m /
g f
resh
wei
gh
t
24
26
28
30
32
34
36
380kGy1 kGy
ResultsDHA
Dehydroascorbic acid
Day
0 2 4 6
m/g
fre
sh w
eig
ht
0
2
4
6
8
10
12
14
0 kGy 1kGy
Irradiated Strawberries