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