Food Drying and Fermentation Review

Flashcards covering essential concepts related to food drying, fermentation, and microbial growth.

why do we dry?

Preservation, Volume, desired flavor/texture & Cost

Water activity

Measures the availability of free water in a substance that can affect microbial growth and chemical reactions.

Wet basis measurement

Mass of Water/ Total Product

What is the major factor in which effects microbial growth?

Time and temperature

Case hardening

A condition in dried food where the outside is hard but the inside retains moisture.

What is the third temperature threshold?

Minimum growth temperature for a microorganisms

Optimal pH range for bacteria

3-8

Thermophiles

Microorganisms that thrive at temperatures between 20 and 45ºC.

Mesophiles

Microorganisms that thrive at temperatures above 45ºC.

Psychrophiles

Microorganisms that thrive at temperatures below 20ºC.

Purpose of blanching

To deactivate undesirable enzymes in food.

Porous nature of material

Affects the drying speed; more porous materials dry faster.

Starter culture for wine processing

Saccharomyces cerevisiae (S. cerevisiae) is the primary starter culture.

Factors in food drying

Humidity and temperature of the drying environment are crucial.

Which of the following is not a requirement for fermentation cultures? a. pH b. culture media c. temperature d. dissolved oxygen e. enzymes

temperature

what is the stationary phase in microbial growth

The phase where maximum temperature is reached and growth ceases.

Difference between drying and dehydration

Drying is a natural process; dehydration occurs under artificial controlled conditions.

Hygroscopic materials

Materials that readily absorb moisture from the air.

main source of starter culture media

Carbohydrates are the main source used in starter culture media.

Physical stability

Related to the moisture content of food rather than water activity.

Blanching requires what types of heat treatment to deactivate enzymes? a. Low heat b. Medium heat c. High heat d. Low heat

high heat

Which of the following food do not require fermentation? a. Cheese b. Milk c. Yogurt d. Sourdough bread

milk

What is the formula for dry basis?

Water Weight/ Dry Weight * 100%

21. This dryer is a mobile batch drier made with metal or wooden boxes and is set for drying semi dried products a. Freeze dryer b. Cabinet dryer c. Bin dryer d. Drum dryer

bin dryer

Which of the following is not a physical separation process? a. Pneumatic b. Centrifugal c. Solvent extraction d. Hydraulic press

solvent extraction

What factors influence drying?

Air temperature, Relative humidity, Air velocity, Size, shape, thickness of product, Load of wet material per unit are

At what phase is microbial growth the fastest? a. Lag b. Log c. Stationary d. Death

log

Components of physical separation of food?

a. Filtration, centrifugation, pneumatic, separation, and mechanical expression

Are Sourdough and Summer sausage fermented products?

yes