food preservation methods and food processing

Food and Microbes

Test 6 Notes

CANNING

is the process of heating the product at a specified temperature for a specific length of time (pasteurizing)

vacuum sealing the pasteurized food in special glass jars

fruits, vegetables, meats, seafood, and some prepared foods.

Home Methods VS Industrial Methods

FREEZING

is the process of chilling foods to at least 0°F.

It can be used with all foods

True freezing is not possible in the freezer compartment of your refrigerator where the temperature is typically much warmer, between 10°F to 32°F.

Easy method

DRYING

is the process of dehydrating foods until there is not enough moisture to support microbial activity.

It can be used with most foods

Several different techniques, relatively easy to do and require no special equipment.

Meals-Ready-to-Eat (MRE)

FERMENTING

is the process of encouraging the growth of “good bugs” to inhibit the “bad bugs” that can spoil food.

It can be used with many types of foods

Produce a wide range of products such as wine (from grapes), sauerkraut (cabbage), cured sausage (meat), and yogurt (milk).

produced without any special equipment.

PICKLING

is the process of soaking food in a solution containing salt, acid, or alcohol.

It can be used with most foods

Most methods require no special equipment.

However, pickled foods can be unsafe if prepared carelessly or stored at room temperature.

Pickling is often combined with another method, such as fermenting, canning, or just refrigerating

CURING

is similar to pickling, and uses salt, acid, and/or nitrites.

It is used for meat and fish.

Simple, modern curing methods often reduce the amount of salt and nitrites, which may require that you refrigerate or freeze the final product.

Some curing methods also employ a secondary process such as fermenting, smoking, or sealing.

SMOKING

is a complementary process to curing that improves flavor and appearance, and can also act as a drying agent.

Smoked meats are less likely to turn rancid or grow mold than unsmoked meats.

SEALING

is a process of covering food to keep out air, which delays (but does not stop) the activity of spoilage organisms.

It is used primarily as a complementary process to other methods such as drying or freezing.

Both fat sealing and vacuum sealing methods are relatively easy.

Importance of Bacteria

It would be impossible to make cheese without a starter culture. As the culture grows in the milk, it converts the sugar lactose into lactic acid, which ensures the correct level of acidity and gives the cheese it

In yogurt and other fermented milk products, the culture is responsible for the taste and texture of the final product.

Probiotic cultures have become popular in dairy products because of their health benefits

Meat starter cultures are used to make dried, fermented products such as salami, pepperoni, chorizo and dried ham

Yeasts are responsible for the fermentation process which produces alcohol in wine.

Animal Slaughter

Many countries have poor sanitation and animal processing methods

What do we know about the growth of bacteria?

How would the “normal microbiota” help in the breakdown of tissue? How would the “normal microbiota” influence the growth of “bad bacteria.”

How do these processes compare? Sanitary wise? Microbial growth?

African Cow

Australian Sheep

What’s Next?

Tuesday: Local Culture

Wednesday: Brief Review of

Methods and Articles

Thursday: In Computer Lab

Friday: Quiz/Mini Test over Methods & Computer lab if needed

Monday: Start Microbial diseases of Skin and Eyes