science of food copy

Food Processing

Value added product development Ensure nutrition & safety Shelf life extension

Benefits of food processing

* *High-quality foods - healthy, safe, convenient and enjoyable*
* *Societal benefits - optimize food retention, reducing food waste, add nutritional value to the food supply*
* *employment to workers; aids in local, national economy*

Negatives of food processing

* Nutrient losses, high use of water, energy, fuel, transportation
* Control of food processing by large food corporations
* Consumer concerns- chemicals, additives, added fats, sugars, salt and the ways foods are marketed to children

Important innovation in Food Processing

Processing of Single Ingredient (isolating a single product and using it in everything to add value to product)

Effects of "value added" processing

opened up new markets & expanded the food industry

Shelf-stable foods

Processes allow us to store the product at room temperature

Processed foods take ____ energy to produce but usually take ____ energy to store than fresh foods

More; less

Today's consumers are concerned about

food product safety and quality than they were a year ago

FACT about "meat glue"

It is an enzyme sold for almost two decades that is used mostly in food service to bind pieces of meat together, such as a beef tenderloin or a strip of bacon to a filet.

Heat in food preservation:

* Kills most pathogens
* Eliminates or reduces spoilage organisms
* Destroys most enzymes
* Extends the shelf life of foods
* Improves palatability of foods

What do we modestly lose in heat processing?

Some Heat sensitive nutrients

Methods of heat transfer

conduction, convection, radiation

Radiation (method of heat transfer)

* direct heat; from sun, broiling, grilling, electric range
* Fastest method of heat transfer

Degrees of Preservation

* Mild Heat Treatments: Blanching and Pasteurization
* Severe Heat Treatments: Sterilization and Commercial Sterility

Blanching

* Mild heat treatment


* Used mainly for vegetables, prior to freezing


* Primary objective: to inactivate enzymes, that would deteriorate food during storage


* Freezing does not completely stop enzyme action, so blanching necessary

Not all bacteria are ___ during blanching

Destroyed

Blanching does not produce a ____ product

Sterile

Blanched foods need further preservation treatment, like ___ to increase shelf life

Freezing

HOW DO BACTERIA GET KILLED BY HEAT?

Wet heat, like steam, kills microorganisms by denaturing nucleic acids, proteins and enzymes

Concepts of killing bacteria

* Concept 1: Bacteria die exponentially/faster, by a factor of 10.
* Concept 2: It is theoretically impossible to kill all of them. It never reaches 0 survivors.

Pasteurization is a ____ process

Thermal

Main objectives of pasteurization (2)

* Destroy pathogenic microorganisms


* Extend shelf life by decreasing the number of spoilage organisms present

How to take care of post pasteurized products

Contamination is possible, therefore pasteurization foods must be refrigerated

3 methods of pasteurization process

1. High-Temperature-Short-Time Treatment (HTST)
2. Low-Temperature-Long-Time Treatment (LTLT)
3. Ultra-high temperature pasteurization (must be refrigerated; The shelf life of milk is extended 60 to 90 days.)

Organic milk lasts longer because of what process of pasteurization to preserve it?

Ultra pasteurization

Organic products often have to travel farther to reach store shelves because..?

It is not produced throughout the country

After opening, spoilage times for Ultra pasteurized and UHT products similar to those of___?

conventionally pasteurized products

Ultra-High-Temperature (UHT) Pasteurization with aseptic packaging

typically involves heating milk or cream to 280° to 302°F (138° to 150°C) for 1 or 2 seconds. The milk is then packaged in sterile, hermetically-sealed (airtight) containers and can be stored without refrigeration for up to 90 days.

UHT pasteurization for milk products

destroys some of the milk's vitamin content—not a significant amount—and affects some proteins, making it unusable for cheese

How is pasteurization proven?

Determined by the heat resistance of the most heat-resistant enzyme or microorganism in the food

Steam Pasteurization

* This technology uses heat to control or reduce harmful microorganisms in beef

\
* Steam pasteurization is used on nearly 50% of US beef

Examples of foods that are commonly pasteurized

* Whole Eggs Removed from Shells and Sold As a Liquid
* Dried Eggs
* Whole Eggs Pasteurized in the Shell
* Ice cream

What is sterilization?

Sterilization is a controlled heating process used to completely eliminate all living micro-organisms, including thermoresistant spores in milk or other food.

commercial sterility canning

* Food is heated after packaging in canning
* product may contain viable spores

Main purpose of canning

* commercial sterility of food products
* extended shelf life ( increased minimum 6 months)

Clostridium botulinum spores, may be present in ____ foods; but, they do not germinate and grow; so, no hazard

High-acid

home canned tomatoes

Are okay

Home canned beans

Not as safe; no

Retort packaging

food is filled into a pouch or flexible metal/plastic foils, and, sealed

REPFEDs

\-REFRIGERATED PROCESSED FOODS OF EXTENDED DURABILITY

* Spores may be present

Freezing is one of the ____ and ____ used methods of food preservation

Oldest and most widely

Freezing allows preservation of...

Taste, texture, and nutritional value in foods better than any other method

Freezing is generally regarded as superior to... (for fruits and vegetables)

Canning and dehydration

Refrigeration slows down.... And extends...

\-The chemical and biological processes in foods

\-The shelf life of the products

Most foods freeze over a ___ of temperatures instead of a single temperature

Range

Refrigeration of foods only involves...

Cooling

The freezing of foods involved three stages:

(Initial) Cooling, freezing, and further cooling

What is the optimum storage temperature of most fruits and vegetables?

About 0.5 to 1 degree Celsius, above their freezing point

Freezing may stop the growth of ____, but it may not necessarily kill them

Microorganisms

Low rates of freezing cause:

growth of large ice crystals in the food and allow plenty of time for the flavors of different foods to mix. This hurts the quality of the product, and thus this simple method of freezing is usually avoided.

air blast freezing

high-velocity air at about- 300C is blown over the food products

contact freezing

packaged or unpackaged food is placed on or between cold metal plates and cooled by conduction

Immersion freezing

food is immersed in low temperature brine

Cryogenic freezing

food is placed in a medium cooled by a cryogenic fluid such as liquid nitrogen or carbon dioxide

The air blast freezer is for the purpose of small freezing capacity, especially for ...

pieces of meats, pork, poultry, beef, mutton

Straight-belt freezer is for...

fruits, vegetables, and uniform-sized products- French fries, peas and diced carrots

Plate freezing can be used for what food?

Fish can be frozen in this method

Cryogenic freezing immerses or sprays foods with ___

Liquid nitrogen

Why use liquid nitrogen?

* Freezing in seconds
* Smaller ice crystals
* Less dehydration and moisture loss
* lower captial costs

Practically every vegetable (except herbs and green peppers) is___; promptly cooled prior to freezing

Blanched

What happens in blanching?

* slows or stops enzyme action
* some bacteria is destroyed
* vegetables are wilted or softened
* surface dirt is removed

Problems with refrigeration & freezing

* Chilling injury characterized by internal discoloration, soft scald, skin blemishes, soggy breakdown, and failure to ripen.
* The severity of the chilling injury depends on both the temperature and the length of storage at that temperature.
* The lower the temperature, the greater the damage in a given time.
* Therefore, products susceptible to chilling injury must be stored at higher temperatures

Dehydration, or moisture loss from fresh fruits and vegetables is also called?

Transpiration

Cooling at the field before the product is shipped to the market or storage warehouse is referred to as..?

Precooling

package icing

products are cooled by placing crushed ice into the containers (fruits)

vacuum cooling

products are cooled by vaporizing some of the water content of the products under low pressure conditions (lettuce, spinach)

Poultry processing plants are completely ____?

automated

the preservation of _____ is an important consideration in the refrigeration and freezing of meats

Tenderness

genetic engineering

the artificial manipulation, modification, and recombination of DNA in order to modify an organism or population of organisms.

some almond trees developed a mutation so that they lacked the ___?

cyanide-producing chemicals

Broccoli is a result of the selective breeding of?

wild cabbage plants

Bt insecticides are popular with organic farmers because they are considered

"natural insecticides" (gene put in to make insecticides)

GM corn is not considered

organic

GE FOODS

genetic engineered foods

GMO

genetically modified organism

Seedless watermelons are NOT

GMOs

Almost every fruit, vegetable, or crop grown today has been in some way___

genetically modified

Genetically modified foods

farmers have improved their crops by crossbreeding plants that have good traits.

Older techniques of GMO

conventional crossbreeding- require several generations to achieve particular trait

Current form of genetically modified

shortcut- Scientists can take a gene from one living thing and put it directly into another plant or animal.

Ingredients derived from genetically modified corn, soy, sugar beets and canola are used in a wide ____ of foods including cereal, corn chips, veggie burgers and more.

Variety

Scientists say the new techniques of GMOs have created crops that are

pest-proof, disease resistant and more nutritious.

Genetically modified AquAdvantage Salmon is as safe to eat and as nutritious as food from___

other non-GE Atlantic salmon

Myth: GMOs contribute to the cause of certain...

life-threatening illnesses and food allergies.

Myth: GMOs are not thoroughly ___ before being commercially available.

Tested

Myth: GMOs are nutritionally ____ to their non-GMO counterparts

inferior

"Arctic" apples are genetically modified to have less of the enzyme that causes

Browning

Innate potato are Genetically engineered to

- reduce the amounts of a potentially harmful ingredient* in French fries and potato chips

Acrylamide

chemical suspected of causing cancer in people

Innate potato does not contain

genes from other species like bacteria, and instead contains fragments of potato DNA to silence their OWN genes.

What do organic producers/farmers rely on to the fullest extent?

Natural substances and physical, mechanical, or biologically based farming methods

How can produce be considered organic?

If it's certified to have grown on soil that has had no prohibited substances applied for three years prior to harvest.

Organic foods DO contain...

Pesticides!

Pesticides approved for organic farming are __ toxic to humans

Toxic

What makes organic farming different?

not the use of pesticides, but the origin of the pesticides used

Prohibited substances in organic farming include...

most synthetic fertilizers and pesticides

When people are buying organic food, they often make the incorrect assumption that there are no

Pesticides

It's true that organic production often uses fewer dangerous chemicals, but

certain pesticides are allowed.

There are no synthetic feeds, hormones, pesticides, other substances in organic products, unless...

On the list!

Renin function in organic cheese

coagulates milk during cheesemaking; liquid whey removed from the curds that are later pressed into cheese