FSC 325 Exam Questions and Verified Answers/Accurate Solutions| New Update
Already Graded A+
respiration metabolism of CHO and organic acids in the presence of atmospheric oxygen
- produces CO2, water, heat
- heat of respiration is sufficient to influence refrigeration requirement
- rate of quality loss is associated with the rate of R
Respiration rates - not all produce at same rate
- may be induced by ezposure to wthylene
- slowing of RR delays senescence
- lower temperatur reduces RR
How to measure
- amount of CO2 evolved by fruit
- amount of O2 consumed by fruit
climacteric fruits - tomatos bananas apples
- show a sharp inc in respiration rate
- sharp inc in ethylene production
non climacteric fruits - grapes, oranges, cherries
- continuous decrease in respiration rate
Chilling to Control RR - dec temp slows RR
- chill injury in produce
- rigor mortis (glycogen to lactic acid)
- cold shortening = chilling before rigor mortis, electrical stimulation
, chill injury in produce - time/temp dependent
- deteriorative effects to quality
- browning
controlled atmosphere storage (CAS) - useful for crops that ripen after harvest or
deteriorate quickly
- atmosphere continulaly monitored
2 types
- O2 dec and CO2 inc to 21%
- total concentration of O2 and CO2 are red to 1-5%
limitations to CAS - low O2 and high CO2 is toxic to many foods
- may inc ethylene
- may produce off odors and flavors
CONTROL is key
Modified atmosphere storage (MAS) - air tight conditions
- vents exhaust excess CO2
- grains and apples
- very expensive
Modified atmosphere packaging - air removed
- gas flush to desired gas mixture
- external humidity
- SA of pkg in relation to quantity of food
- passive
Already Graded A+
respiration metabolism of CHO and organic acids in the presence of atmospheric oxygen
- produces CO2, water, heat
- heat of respiration is sufficient to influence refrigeration requirement
- rate of quality loss is associated with the rate of R
Respiration rates - not all produce at same rate
- may be induced by ezposure to wthylene
- slowing of RR delays senescence
- lower temperatur reduces RR
How to measure
- amount of CO2 evolved by fruit
- amount of O2 consumed by fruit
climacteric fruits - tomatos bananas apples
- show a sharp inc in respiration rate
- sharp inc in ethylene production
non climacteric fruits - grapes, oranges, cherries
- continuous decrease in respiration rate
Chilling to Control RR - dec temp slows RR
- chill injury in produce
- rigor mortis (glycogen to lactic acid)
- cold shortening = chilling before rigor mortis, electrical stimulation
, chill injury in produce - time/temp dependent
- deteriorative effects to quality
- browning
controlled atmosphere storage (CAS) - useful for crops that ripen after harvest or
deteriorate quickly
- atmosphere continulaly monitored
2 types
- O2 dec and CO2 inc to 21%
- total concentration of O2 and CO2 are red to 1-5%
limitations to CAS - low O2 and high CO2 is toxic to many foods
- may inc ethylene
- may produce off odors and flavors
CONTROL is key
Modified atmosphere storage (MAS) - air tight conditions
- vents exhaust excess CO2
- grains and apples
- very expensive
Modified atmosphere packaging - air removed
- gas flush to desired gas mixture
- external humidity
- SA of pkg in relation to quantity of food
- passive
