Flashcards in Food Engineering Deck (319)
Give two foods that are pasteurized using high pressure.
Guacamole; deli meats
What are QUATs & what is their purpose?
Quaternary ammonium compounds; used as sanitizers
What is Biot's Number and what are it's units?
Ratio of heat transfer resistance inside of and at the surface of a body; dimensionless
In expressing units for vacuum in the English system, how many inches of mercury is the atmospheric pressure?
During the manufacture of ice cream, you discover that 1 liter of mix makes 2.0 liters of frozen ice cream. What’s your overrun percentage?
What pH value is used to determine when a food is acid or low acid?
What is pH cutoff for high acid and low acid foods?
A retort temperature of 250 F is achieved with how many pounds of pressure per square inch?
What is the cutoff Reynold’s number for laminar flow in pipes?
What are two factors critical for potato chis color and texture?
Free reducing sugars; Specific gravity (for absorption of oil, moisture loss during frying)
The ratio of two extensive properties of a homogeneous system is (a) an extensive property, (b) an intensive property, (c) a dimensionless quantity, or (d) none of the above?
(b) an intensive property
What is the average density of globular proteins?
~1400 kg/m3 or 1.4 g/cm3
What is the Reynolds number in a laminar flow?
What is the freezing point for most natural foods?
0 to -2 C
What is the temperature of triple point for water?
What are the units for humidity?
1 lb water/ 1 lb air
1 Candela per square meter is equal to what?
In brines, salt is measured with a salometer; what is 1° Salometer equal to?
1% of saturated NaCl solution (OR 0.265% salt = 1 degree salometer)
When convection predominates, where is the coldest spot in a can?
1/3 into can? (It can vary)
High-pressure processing of foods is often conducted in what pressure range?
What is the saturation pressure of water at 100 °C
101.325 kPa or 1 atm.
The z-value you have calculated for your process is 18 degrees F. What is the z-value in degrees Celsius.
What is the mean surface area of a Delicious apple?
How many BTU’s must be taken from a pound of water to change it from a pound of liquid water at 32°F to a pound of solid ice at 32°F?
What is the mean surface area of a Bartlett pear?
What is the minimum time and temperature required for batch or vat pasteurized milk?
145F (63 C) and 30 minutes
What are LTLT (low temp/long time) conditions in milk pasteurization?
145F for 30 minutes
What is an Intermediate Moisture Food?
20 - 40% moisture, Shelf stable, No rehydration needed, Combination of Low aw and additives
Given the gauge pressure in a retort is 100 kPa, what is the absolute pressure?